Telex ISP-100 User Manual

ISP-100

INTEGRATED SIGNAL

PROCESSOR

Users Manual

THIS PAGE LEFT BLANK

INTENTIONALLY

PROPRIETARY NOTICE

The Merlin product information and design disclosed herein were originated by and are the property of Telex
Communications, Inc. Telex reserves all patent, proprietary design, manufacturing, reproduction, use and
sales rights thereto, and to any article disclosed therein, except to the extent rights are expressly granted to
others.

PATENT NOTICE

This equipment contains and uses a design for which patent applications have been made. Patents Pending.

COPYRIGHT NOTICE

Copyright 1997-98 by Telex communications, Inc. all rights reserved. Reproduction in whole or in part without
prior written permission from Telex is prohibited.

NOTICE TO USER

This manual should not be construed as any representation or warranty with respect to the software named
herein. Occasionally changes or variations exist in the software that are not reflected in the manual.
Generally, if such changes or variations are known to exist and to affect the product significantly, a release
note or README file accompanies the manual and the distribution disks. In that event, be sure to read the
release note or README file before using the product.

This publication could include technical inaccuracies or typographical errors. Changes are periodically made
to the information herein; these changes will be incorporated in new editions of the publication. TELEX
Communications may make improvements and/or changes in the product(s) and/or program(s) described in
this publication at any time.

i

TRADEMARKS

VUE-IT™ and Virtual User Environmental for InterActive Technology™ are trademarks of TELEX
Communications. Windows®, Windows 3.1®, Windows 3.11®, Windows 95®, and MS-DOS® are all
trademarks of Microsoft Corporation. Names of other products mentioned herein are used for identification
purposes only and may be trademarks and/or registered trademarks of their respective companies.

UNPACKING AND INSPECTION

Immediately upon receipt of the equipment, inspect the shipping container and the contents carefully for any
discrepancies or damage. Should there be any, notify the freight company and the dealer at once.

WARRANTY INFORMATION

Merlin products are warranted by Telex Communications, Inc. to be free from defects in materials and
workmanship for a period of three years from the date of sale.

The sole obligation of Telex during the warranty period is to provide, without charge, parts and labor
necessary to remedy covered defects appearing in products returned prepaid to Telex. This warranty does
not cover any defect, malfunction or failure caused beyond the control of Telex, including unreasonable or
negligent operation, abuse, accident, failure to follow instructions in the manual, defective or improper
associated equipment, attempts at modification and repair not authorized by Telex, and shipping damage.
Products with their serial numbers removed or effaced are not covered by this warranty.

To obtain warranty service, follow the procedures entitled “Procedure for Returns” and “ Shipping to
Manufacturer for Repair or Adjustment”.

This warranty is the sole and exclusive express warranty given with respect to Merlin products. It is the
responsibility of the user to determine before purchase that this product is suitable for the user’s intended
purpose.

General Information

ii

ANY AND ALL IMPLIED WARRANTIES, INCLUDING THE IMPLIED WARRANTY OF MERCHANTABILITY
ARE LIMITED TO THE DURATION OF THIS EXPRESS LIMITED WARRANTY.

NEITHER TELEX NOR THE DEALER WHO SELLS MERLIN PRODUCTS IS LIABLE FOR INCIDENTAL
OR CONSEQUENTIAL DAMAGES OF ANY KIND.

CUSTOMER SUPPORT

Technical questions should be directed to:

Customer Service Department
Merlin/Telex
9600 Aldrich Avenue South
Minneapolis, MN 55420 U.S.A.
Telephone: [phone]
Fax: [phone]

RETURN SHIPPING INSTRUCTIONS

Procedure for Returns

If a repair is necessary, contact the dealer where this unit was purchased.
If repair through the dealer is not possible, obtain a RETURN AUTHORIZATION from:

Customer Service Department
Telex Communications, Inc.
Telephone: [phone] or [phone] extension 425 or 420
Fax: [phone] or [phone]

DO NOT RETURN ANY EQUIPMENT DIRECTLY TO THE FACTORY WITHOUT FIRST OBTAINING A
RETURN AUTHORIZATION.

Be prepared to provide the company name, address, phone number, a person to contact regarding the repair,
the type and quantity of equipment, a description of the problem and the serial number(s).

Shipping to Manufacturer for Repair or Adjustment

All shipments of Merlin products should be made via United Parcel Service or the best available shipper
prepaid. The equipment should be shipped in the original packing carton; if that is not available, use any
suitable container that is rigid and of adequate size. If a substitute container is used, the equipment should be
wrapped in paper and surrounded with at least four inches of excelsior or similar shock-absorbing material. All
shipments must be sent to the following address and must include the Return Authorization.

Factory Service department
Telex Communications, Inc.
West 1st Street
Blue Earth, MN 56013 U.S.A.

Upon completion of any repair the equipment will be returned via United Parcel Service or specified shipper
collect.

10 July 1998

End-User License Agreement for Telex® Software

IMPORTANT – Please read this document carefully before using this product.
THIS DOCUMENT STATES THE TERMS AND CONDITIONS UPON WHICH TELEX COMMUNICATIONS,

INC. (the “COMPANY”) OFFERS TO LICENSE THE INSTALLED SOFTWARE OR PROGRAM (the
“SOFTWARE”) FOR USE WITH THE PRODUCT IN WHICH IT WAS INSTALLED. YOU ARE AGREEING
TO BECOME BOUND BY THE TERMS OF THIS AGREEMENT. IF YOU DO NOT AGREE TO THE TERMS
OF THIS AGREEMENT, DO NOT USE THIS PRODUCT. PROMPTLY RETURN THE PRODUCT TO THE
PLACE WHERE YOU OBTAINED IT FOR A FULL REFUND.

The installed Software as supplied by the Company is licensed, not sold, to you for use only under the terms
of this license, and the Company reserves all rights not expressly granted to you. You own the product or
other media on or in which the Software was originally or subsequently recorded or fixed, but the Company
retains ownership of all copies of the Software itself.

1. License: This license allows you to use the Software for internal purposes only on a single product in which
it was installed.

2. Restrictions:
(a) You may not market, distribute or transfer copies of the Software to others or electronically
transfer or duplicate the Software. YOU MAY NOT REVERSE ENGINEER, DECOMPILE,
DISASSEMBLE, MODIFY, ADAPT, TRANSLATE, RENT, LEASE OR LOAN THE SOFTWARE OR
CREATE DERIVATIVE WORKS BASED ON THE SOFTWARE OR ANY ACCOMPANYING
WRITTEN MATERIALS.

iii

(b) The Software and the accompanying written materials are copyrighted. Unauthorized copying of
the Software, including portions thereof or the written materials, is expressly forbidden.

(c) You understand that the Company may update or revise the Software and in so doing incurs not
obligation to furnish such updates to you.

3. Limited Warranty: The Company does not warranty that the operation of the Software will meet your

requirements or operate free from error. THE COMPANY DISCLAIMS ALL OTHER WARRANTIES AND
CONDITIONS EITHER EXPRESSED OR IMPLIED, INCLUDING THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT OF THIRD
PARTY RIGHTS.

4. Limited Liability: The liability of the Company for any claims arising out of this License based upon the

Software, regardless of the form of action, shall not exceed the greater of the license fee for the Software or
$50.

General Information

iv

Table of Contents

INTRODUCTION .................................................................... 1-1

An Overview of the ISP-100 ................................................................................................ 1-1

About this Manual................................................................................................................ 1-2

Customer Support ............................................................................................................... 1-2

Conventions Used in this Manual........................................................................................ 1-2

SETUP & INSTALLATION ...................................................... 2-1

Introduction.......................................................................................................................... 2-1

Unpacking ...................................................................................................................... ..... 2-1

Front Panel Features........................................................................................................... 2-1

Rear Panel Features ........................................................................................................... 2-2

Power Requirements........................................................................................................... 2-2

Operating Environment ....................................................................................................... 2-2

Rack Mounting .................................................................................................................... 2-2

Card Installation Procedure................................................................................................. 2-3

Cable Diagrams................................................................................................................... 2-4

Analog Audio ................................................................................................................. 2-4

Digital Audio .................................................................................................................. 2-5

Serial Communications ................................................................................................. 2-6

General Purpose Inputs (GPI)....................................................................................... 2-9

Master Sync Input ......................................................................................................... 2-9

TROUBLESHOOTING ............................................................ 3-1

User Modifications............................................................................................................... 3-1

In Case of Problems............................................................................................................ 3-1

Diagnostics.......................................................................................................................... 3-2

Factory Default Mode .......................................................................................................... 3-2

Retrieving Version Numbers ............................................................................................... 3-3

Retrieving Serial Numbers .................................................................................................. 3-3

Changing the Fuse .............................................................................................................. 3-4

Changing the Battery........................................................................................................... 3-4

Technical Support ............................................................................................................... 3-6

Procedure for Returns......................................................................................................... 3-6

Shipping to Manufacturer for Repair or Adjustment ............................................................ 3-7

SPECIFICATIONS .................................................................. 4-1

Components........................................................................................................................ 4-1

Compressor................................................................................................................... 4-1

Crossover ...................................................................................................................... 4-1

Delay ............................................................................................................................. 4-1

Dither............................................................................................................................. 4-1

Gain............................................................................................................................... 4-1

Gate............................................................................................................................... 4-1

Limiter............................................................................................................................ 4-2

Filters............................................................................................................................. 4-2

10 July 1998

Table of Contents

LowPass Filter........................................................................................................... 4-2

HighPass Filter .......................................................................................................... 4-2

AllPass Filter.............................................................................................................. 4-2

LowShelf Filter........................................................................................................... 4-2

HighShelf Filter .......................................................................................................... 4-2

Notch Filter ................................................................................................................ 4-2

PEQ........................................................................................................................... 4-3

Combine ........................................................................................................................ 4-3

Input .............................................................................................................................. 4-3

Output............................................................................................................................ 4-3

ISP-100 Component Plots................................................................................................... 4-3

Compressor................................................................................................................... 4-3

Limiter............................................................................................................................ 4-3

Gate............................................................................................................................... 4-4

Linkwitz-Riley 3-way Crossover .................................................................................... 4-4

Notch Filter .................................................................................................................... 4-4

Parametric Equalizer Filter ............................................................................................ 4-4

Peaked HighPass Filter................................................................................................. 4-4

Shelving Filter................................................................................................................ 4-4

System Measurements........................................................................................................ 4-5

System Frequency Response ....................................................................................... 4-5

System Noise Floor ....................................................................................................... 4-5

System THD+N ............................................................................................................. 4-5

MIM-1 & MIM-2 Analog Input Modules................................................................................ 4-6

Power ............................................................................................................................ 4-6

Performance.................................................................................................................. 4-6

Miscellaneous................................................................................................................ 4-6

Notes ............................................................................................................................. 4-6

MOM-1 Analog Output Module............................................................................................ 4-7

Power ............................................................................................................................ 4-7

Performance.................................................................................................................. 4-7

Miscellaneous................................................................................................................ 4-7

Notes ............................................................................................................................. 4-7

MDM-1 AES/EBU Digital I/O Module................................................................................... 4-8

Power ............................................................................................................................ 4-8

Performance (Sample Rate Converter Engaged) ......................................................... 4-8

Performance (Sample Rate Converter Bypassed) ........................................................ 4-9

Miscellaneous................................................................................................................ 4-9

Notes ........................................................................................................................... 4-10

Physical............................................................................................................................. 4-10

Height .......................................................................................................................... 4-10

Width ........................................................................................................................... 4-10

Depth........................................................................................................................... 4-10

Weight ......................................................................................................................... 4-10

Included Accessories .................................................................................................. 4-10

Power ................................................................................................................................ 4-10

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General Information

vi

Table of Contents

INSTALLING VUE-IT........................................................... 5-1

Minimum System Requirements ......................................................................................... 5-1

Identifying a Serial Port ....................................................................................................... 5-1

Loading the Software .......................................................................................................... 5-1

Updating the ISP-100’s Operating System.......................................................................... 5-2

Configuring the Software..................................................................................................... 5-4

GETTING STARTED............................................................... 6-1

Starting VUE-IT ................................................................................................................... 6-1

Starting a New Project......................................................................................................... 6-2

VUE-IT File System............................................................................................................. 6-3

Archiving Projects.......................................................................................................... 6-4

Mounting Projects.......................................................................................................... 6-4

QuickMAP Template Files ............................................................................................. 6-4

Component Directory .................................................................................................... 6-4

Operating System (OS) Files ........................................................................................ 6-4

USING VUE-IT ....................................................................... 7-1

File ........................................................................................................................... ........... 7-1

New Project ................................................................................................................... 7-1

Open Project ................................................................................................................. 7-1

Save .............................................................................................................................. 7-1

Save As ......................................................................................................................... 7-1

Activate Project Manager .............................................................................................. 7-1

Activate QuickSET Manager ......................................................................................... 7-1

Exit ................................................................................................................................ 7-1

Most Recently Used Files.............................................................................................. 7-1

Edit ...................................................................................................................................... 7-2

Cut................................................................................................................................. 7-2

Copy .............................................................................................................................. 7-2

Paste ............................................................................................................................. 7-2

Tools ................................................................................................................................... 7-2

Refresh Directories........................................................................................................ 7-2

Scan .............................................................................................................................. 7-2

Options................................................................................................................................ 7-2

Preferences ................................................................................................................... 7-2

System Configurations .................................................................................................. 7-2

Window ............................................................................................................................... 7-3

Cascade ........................................................................................................................ 7-3

Tile................................................................................................................................. 7-3

Arrange Icons ................................................................................................................ 7-3

Help..................................................................................................................................... 7-3

About ............................................................................................................................. 7-3

Preferences......................................................................................................................... 7-3

Soft Mute Ramp in ms ................................................................................................... 7-3

Display Recently Opened Files in the File Menu........................................................... 7-4

10 July 1998

Table of Contents

OpenDevice Status Panel on Error ............................................................................... 7-4

Display QuickMAP Pop-Up names................................................................................ 7-4

Display Filter Bandwidth in “Q”...................................................................................... 7-4

System Configurations ........................................................................................................ 7-4

New Projects ................................................................................................................. 7-4

Component Library........................................................................................................ 7-4

QuickMAP Library ......................................................................................................... 7-5

Company Name ............................................................................................................ 7-5

Designer’s Name........................................................................................................... 7-5

Communications............................................................................................................ 7-5

Default Preference ........................................................................................................ 7-5

Project Manager.................................................................................................................. 7-5

Properties for the ISP-100............................................................................................. 7-6

Project Properties.......................................................................................................... 7-7

QuickMAP Selection...................................................................................................... 7-7

QuickMAP Properties .................................................................................................... 7-8

Component Properties .................................................................................................. 7-8

Component Export ........................................................................................................ 7-9

Component Import....................................................................................................... 7-10

QuickSET Manager........................................................................................................... 7-10

Creating New QuickSETs............................................................................................ 7-11

Deleating QuickSETs .................................................................................................. 7-11

Selecting the Active QuickSET.................................................................................... 7-11

Updating a QuickSET.................................................................................................. 7-11

Discarding Changes .................................................................................................... 7-11

GPI .................................................................................................................................... 7-11

Configuring Input Pins ................................................................................................. 7-11

Testing the GPI Assignments ...................................................................................... 7-12

QuickMAP ......................................................................................................................... 7-13

QuickMAP Component Bypassing .............................................................................. 7-13

I/O Properties .................................................................................................................... 7-14

Input ............................................................................................................................ 7-14

Output.......................................................................................................................... 7-15

Digital I/O..................................................................................................................... 7-15

Status Information ................................................................................................... 7-16

Device Status Panel .......................................................................................................... 7-17

Clock Sync .................................................................................................................. 7-17

Digital Data.................................................................................................................. 7-17

Low Battery ................................................................................................................. 7-17

Input Clip ..................................................................................................................... 7-17

Process Clip ................................................................................................................ 7-17

Output Meters.................................................................................................................... 7-18

vii

PROCESSING COMPONENTS ............................................... 8-1

Combine.............................................................................................................................. 8-2

Input Attenuators ........................................................................................................... 8-2

Fine (F) or Coarse (C) Control ...................................................................................... 8-3

General Information

viii

Table of Contents

Polarity Control (+/-) ...................................................................................................... 8-3

Mute Control (M) ........................................................................................................... 8-3

Bypass Control (master)................................................................................................ 8-3

Compressor......................................................................................................................... 8-4

Familliar Controls .......................................................................................................... 8-4

Unfamiliar Controls........................................................................................................ 8-6

Metering ........................................................................................................................ 8-8

Notes on Operation of the Compressor......................................................................... 8-8

Meter ............................................................................................................................. 8-9

Threshold ...................................................................................................................... 8-9

Attack, Window, Release, and Crest Factor Controls ................................................... 8-9

Fine (F) or Coarse (C) Control .................................................................................... 8-10

Knee Control ............................................................................................................... 8-10

Ratio Control ............................................................................................................... 8-10

Sidechain..................................................................................................................... 8-10

Bypass Control (master).............................................................................................. 8-10

Crossover.......................................................................................................................... 8-11

Two-Way Crossovers .................................................................................................. 8-11

Three-Way Crossovers ............................................................................................... 8-13

Four-Way Crossovers ................................................................................................. 8-17

Sum-to-Allpass Characteristics of Linkwitz-Riley Crossovers ..................................... 8-20

Low, Low-Mid, Mid, Mid-High, and High Controls ....................................................... 8-21

Link/Unlink Control ...................................................................................................... 8-21

Slope ........................................................................................................................... 8-21

Class ........................................................................................................................... 8-22

Cutoff Frequency......................................................................................................... 8-22

Passband Gain............................................................................................................ 8-22

Fine (F) or Coarse (C) Control .................................................................................... 8-23

Polarity Control (+/-) .................................................................................................... 8-23

Mute Control (M) ......................................................................................................... 8-23

Cut..................................................................................................................................... 8-24

Attenuation and Polarity .............................................................................................. 8-24

Bypass......................................................................................................................... 8-24

Attenuator.................................................................................................................... 8-24

Fine (F) or Coarse (C) Control .................................................................................... 8-25

Polarity Control (+/-) .................................................................................................... 8-25

Mute Control (M) ......................................................................................................... 8-25

Bypass Control (master).............................................................................................. 8-25

Delay ................................................................................................................................. 8-26

Setting Delay ............................................................................................................... 8-26

Fine (F) or Coarse (C) Control .................................................................................... 8-26

Bypass Control (master).............................................................................................. 8-26

Dither................................................................................................................................. 8-27

Bit Level....................................................................................................................... 8-27

Dither Signal Characteristics ....................................................................................... 8-32

Bypass......................................................................................................................... 8-28

Dither Bit Level ............................................................................................................ 8-28

10 July 1998

Table of Contents

Bypass Control (master).............................................................................................. 8-28

Filter .................................................................................................................................. 8-29

Filter Bands ................................................................................................................. 8-29

LowPass Filters ........................................................................................................... 8-30

HighPass Filters .......................................................................................................... 8-30

LowShelf Filters........................................................................................................... 8-31

HighShelf Filters .......................................................................................................... 8-31

Notch Filters ................................................................................................................ 8-32

Parametric EQ Filters .................................................................................................. 8-32

Peaked HighPass Filters ............................................................................................. 8-34

AllPass Filters.............................................................................................................. 8-35

Filter Type ................................................................................................................... 8-35

Active Band ................................................................................................................. 8-35

Bypass......................................................................................................................... 8-35

Bypass Control (master).............................................................................................. 8-35

Frequency in Hz .......................................................................................................... 8-35

Boost/Cut..................................................................................................................... 8-36

Bandwidth.................................................................................................................... 8-36

Using the Magnitude (Mag.) or Phase Control ............................................................ 8-37

Using the Logarithmic (Log.) or Linear Control............................................................ 8-37

Using the 24 dB, 40 dB, 120 dB Controls.................................................................... 8-37

Gain Trim..................................................................................................................... 8-37

Fine (F) or Coarse (C) Control .................................................................................... 8-38

Isolate (Iso) Control ..................................................................................................... 8-38

Polarity Control (+/-) .................................................................................................... 8-38

Gain................................................................................................................................... 8-39

Metering ...................................................................................................................... 8-39

Gain and Polarity......................................................................................................... 8-39

Bypass......................................................................................................................... 8-39

Metering ...................................................................................................................... 8-40

Master Attenuator........................................................................................................ 8-40

Fine (F) or Coarse (C) Control .................................................................................... 8-40

Polarity Control (+/-) .................................................................................................... 8-40

Mute Control................................................................................................................ 8-40

Pre-Fader Metering (PFM) .......................................................................................... 8-40

Gate .................................................................................................................................. 8-42

Familiar Controls ......................................................................................................... 8-42

Unfamiliar Controls...................................................................................................... 8-43

Metering ...................................................................................................................... 8-44

Notes on Operation of the Gate................................................................................... 8-44

Metering ...................................................................................................................... 8-44

Attenuation and Threshold Controls............................................................................ 8-44

Open, Window, and Close Controls ............................................................................ 8-45

Key Channel................................................................................................................ 8-45

Fine (F) or Coarse (C) Control .................................................................................... 8-45

Bypass Control (master).............................................................................................. 8-45

Limiter................................................................................................................................ 8-46

ix

General Information

x

Table of Contents

Familiar Controls ......................................................................................................... 8-46

Unfamiliar Controls...................................................................................................... 8-48

Notes on Operation of the Limiter................................................................................ 8-49

Meter ........................................................................................................................... 8-50

Threshold .................................................................................................................... 8-50

Attack, Window, Release, and Crest Factor Controls ................................................. 8-51

Fine (F) or Coarse (C) Control .................................................................................... 8-51

Knee Control ............................................................................................................... 8-51

Bypass Control (master).............................................................................................. 8-51

Select ................................................................................................................................ 8-52

Selecting the Input....................................................................................................... 8-52

GLOSSARY ............................................................................A-1

STANDARD QUICKMAP LIBRARY ......................................B-1

10 July 1998

INTRODUCTION

An Overview of the ISP-100

Thank you for choosing the ISP-100™ for your signal processing needs.
The ISP-100 is the first in a line of high quality signal processing
products from TELEX Communications, Inc.’s Merlin division. The
ISP-100 represents a continued commitment to understanding and
meeting our customers needs through the development of innovative and
intuitive solutions.

The ISP-100 is designed with flexibility in mind, which results in a
powerful tool that allows you to adapt to ever-changing markets and
applications. The utmost in quality is also a prime directive in the design
and manufacture of this product.

A series of predefined signal path topologies called QuickMAPs™ are
offered which enable the designer to quickly define the system’s
processing structure. This approach allows for a continuation of new
processing solutions and/or variations that provide “market specific”
templates to help minimize your design time and increase your profit.

This single rack space unit can replace a multitude of traditional analog
components. Time and money savings are realized in reduced labor
costs for wire harnessing, rack size, assembly, and minimized failure due
to reduced interconnection. As a result of this consolidation of
processing, overall system performance and audio integrity is greatly
increased.

1-1

The four in eight out
configuration is only
possible when the
second card slot
contains a digital
I/O card.

An ergonomically designed software interface called VUE-IT™ provides
graphic control panels with the conventional look of signal processors, as
well as an advanced and easy to use filter tool panel which graphically
displays the configuration of your filter block settings.

One of the most impressive and unique features of the ISP-100 is the
configurable input/output (I/O). This feature allows the designer or
installer to select between analog input or output modules, and/or a
digital input/output combination module. These modules are two channel
units and can be intermixed between analog and digital, thus providing a
variety of I/O combinations. The ISP-100 supports a maximum of four
inputs and eight outputs. The inputs and outputs can be either analog,
digital, or a combination of both.

Because of our commitment to providing the utmost in audio quality the
dynamic range of the ISP-100 rivals anything currently on the market.

The ISP-100 has a typical noise floor of –110 dBu and a typical THD+N
of <0.004%. Propagation time is minimized in the ISP-100. No more than
two milliseconds of delay is introduced from any analog input to analog
output with full processing and delay set to zero.

The ISP-100 is flexible. A General Purpose Interface (GPI) allows
multiple system configurations to be selected without the need of a PC to
control the unit. This is accomplished through user-supplied contact

Introduction

1-2

closures. This interface allows users to change system settings directly
and/or scroll through various settings.

About this Manual

This manual is covers the installation and operation of the ISP-100’s
hardware and software.

The ISP-100 has been designed to be as user-friendly as possible.
However, this manual should be read before attempting to install or
operate the ISP-100.

Customer Support

Be sure to fill out the customer support registration card included in the
software envelope. This will register you in our database of users.

Conventions Used in this Manual

The margins in this manual include space for icons that provide
additional information to the user. The icons and their uses are given in
Table 1-1.

10 July 1998

Table 1-1

Information icons.

Save the shipping
carton in case the
ISP-100 needs to be
returned for service.

2-1

SETUP & INSTALLATION

Introduction

This section details the setup and installation of the MERLIN ISP-100.
Information is provided on the following: front and rear panel features,
physical requirements, installation of expansion cards, signal
connections for audio, data, and control.

Unpacking

The shipping carton is specially designed to protect the ISP-100 while
transporting under normal conditions. It is still possible for damage to
occur. Therefore, carefully inspect the outside carton for signs of abuse.
If for any reason the ISP-100 should need to be returned, use the
shipping carton that it came in. TELEX Communications, Inc. cannot
warranty against damage that occurs as a result of improper packaging.

The shipping box should contain the following items:

ISP-100
User’s Manual
VUE-IT Software Package
Spare Fuses (2)
Label Paper
IEC Power Cord

Front Panel Features (see Figure 2-1)

Figure 2-1

1. Label Holder—Provides a space to indicate the assignments of the
input and output modules.

2. Status LEDs—Provides power on/off, low battery, module presence,
signal clipping, and host communication status.

3. RS-232 Port—Links the PC to the unit via a DB-9 female connector.

4. RS-232 Selector—Selects between the front panel DB-9 port and the
rear panel RJ-45 port. Placing the switch in the down position
selects the DB-9 port located on the front of the unit. Placing the
switch in the up position selects the RJ-45 port located on the
rear of the unit.

5. Battery—Provides memory backup power. The expected life is
approximately four years.

6. Default Switch—Used to place unit in OS download request mode.

7. Fuse—Protects the power supply.

8. Power—Turns the unit on and off. Placing the switch in the down
position turns the unit on. Placing the switch in the up position
turns the unit off.

ISP-100 front panel features.

Setup & Installation

2-2

Rear Panel Features (see Figure 2-2)

Figure 2-2

1. AC Power—Connects to mains via an IEC type AC power cord.

2. RS-232 Port—Links the PC to the unit via a RJ-45 connector.

3. External Sync—Precision frequency reference input to the unit.

4. GPI—Provides a General Purpose Interface for the user. The user
provides inputs to the system via dry or electronic contact
closure inputs. These inputs can be used to change system
settings directly and/or scroll through various settings.

5. Output Slot 5—Accepts either an analog output module or digital
module.

6. Output Slot 4—Accepts either an analog output module or digital
module.

7. Output Slot 3—Accepts either an analog output module or digital
module.

8. Input/Output Slot 2—Accepts an analog input module, analog output
module, or digital module.

9. Input Slot 1—Accepts either an analog input module or digital module.

ISP-100 rear panel features.

Power Requirements

The ISP-100 uses a universal switching power supply that accepts input
voltages in the range of 90 VAC to 264 VAC, 50/60 Hz. All countries
using 220/240 VAC except Australia use a ½ amp slow-blow fuse. All
countries using 100/120 VAC and Australia use a 1 amp slow-blow fuse.

Operating Environment

Internal temperature: 50°F to 95°F (10°C to 35°C)
Humidity: 20% to 80%

Rack Mounting

The ISP-100 may be installed in a standard 19-inch (483-mm) equipment
rack with one rack unit (1.75 inches or 44.5 mm) of vertical rack space
per unit.

10 July 1998

Card Installation Procedure

2-3

CAUTION:
Failure to observe
anti-static handling
procedures could
result in damage to
equipment.

Figure 2-3

Battery/module tool.

Figure 2-4

Card being inserted.

1. Ground yourself using a wrist strap and anti-static mat.

2. Turn off the ISP-100.

3. Remove the screws securing the module slot cover.

4. If you are not replacing an existing card please proceed to step 6.

5. Use the battery/module removal tool to remove the existing module.
The battery/module removal tool is attached to the inside of the
front security cover. Place the hook end of the tool into the slot at
the bottom of the module and pull. Place the old module in an
anti-static bag. See Figure 2-3 for more information.

6. Being careful to avoid scraping the underside of the board, slide the
new module into the bottom slots on the card guides located
inside the opening. Push the module into the unit until you feel
resistance. See Figures 2-4 and 2-5.

7. Firmly push on the module’s faceplate to seat the module.

8. Replace the screws that were removed in step 3.

9. Turn on the ISP-100 and verify that the slot indicator for the module is
either solid green or blinking green. If the slot indicator is not
solid green or blinking green, then there is a problem with the
current hardware and/or software. Please refer to the
Troubleshooting section to identify the problem.

Figure 2-5

Card insert detail.

Setup & Installation

2-4

Cable Diagrams

Analog Audio (MIM-1, MIM-2, MOM-1)

Using low-cost
connectors can save
money in the short
term, but failures
could cost more.

Figure 2-6

Balanced Input from Balanced Output

Connect the positive (+) side of the line to pin 2 of the male 3-pin
XLR connector and the negative (-) side of the line to pin 3 of the
connector. In keeping with standard wiring practices, the shield
should not be connected at this end; it should only be connected
to pin 1 of the 3-pin female XLR connector or ground of the
source end. See Figure 2-6 for more information.

Balanced Input from Unbalanced Output

Connect the “hot” wire to pin 2 of the 3-pin male XLR connector
and the shield wire to pin 1 of the connector. To avoid a 6 dB
drop in level, connect pin 3 to pin 1 of the connector. See Figure
2-6 for more information.

Analog inputs.

Confused about
what type of cable
to use? Try Belden
8451 or 8723. Both
are good quality and
inexpensive.

10 July 1998

Figure 2-7

Balanced Output to Balanced Input

Connect the positive (+) side of the line to pin 2 of the 3-pin
female XLR connector and the negative (-) side of the line to pin
3 of the connector. In keeping with standard wiring practices, the
shield should be connected at this end; it should not be
connected to pin 1 of the male 3-pin XLR connector or ground of
the load end. See Figure 2-7 for more information.

Analog outputs.

Use the white block
on the I/O module
panels to write a
reference number or
other designator on
by using a permanent
marker. Then make
identical labels for
the cables that plug
into the module.

Balanced Output to Unbalanced Input

Connect the “hot” wire to pin 2 of the 3-pin female XLR
connector and the shield wire to pin 1 of the connector. To avoid
a 6 dB drop in level, connect pin 3 to pin 1 of the connector. See
Figure 2-7 for more information.

Digital Audio (MDM-1 Cards)

Figure 2-8

AES/EBU inputs.

AES/EBU Input

Connect the positive (+) side of the line to pin 2 of the male 3-pin
XLR connector and the negative (-) side of the line to pin 3 of the
connector. In keeping with standard wiring practices, the shield
should not be connected at this end; it should only be connected
to pin 1 of the 3-pin female XLR connector or ground of the
source end. The cable used should be 110Ω AES/EBU
compliant cable such as MOGAMI 3080. See Figure 2-8 for
more information.

2-5

Long unbalanced
cable runs (analog
or digital) are not
recommended.

SPDIF Input

Figure 2-9

SPDIF inputs.

Connect the positive (+) side of the line to pin 2 of the male 3-pin
XLR connector and the shield of the cable to pins 1 and 3.
Connect a ¼ watt 237Ω 1% resistor between pins 1 and 2 of the
3-pin male XLR connector. Connect the positive (+) side of the
line to the center pin of the RCA connector on the opposite end
of the cable. Connect the shield to the shield of the RCA
connector on the opposite end of the cable. The cable used
should be RG-59 or other similar 75Ω cable. See Figure 2-9 or
the application note MDM-1 SPDIF COMPATABILITY
P/N 42-02-053086 for more information.

Setup & Installation

2-6

AES/EBU Output

Figure 2-10

AES/EBU output.

Connect the positive (+) side of the line to pin 2 of the 3-pin
female XLR connector and the negative (-) side of the line to pin
3 of the connector. In keeping with standard wiring practices, the
shield should be connected at this end; it should not be
connected to pin 1 of the male 3-pin XLR connector or ground of
the receiving end. The cable used should be 110Ω AES/EBU
compliant cable such as MOGAMI 3080. See Figure 2-10 for
more information.

SPDIF Output

The ISP-100 is not capable of providing SPDIF outputs.

Serial Communications

Serial communications with the ISP-100 can be accomplished either
through the DB-9 connector located under the front panel security
cover or through the RJ-45 connector located on the rear panel. The
computer connected to the ISP-100 must have a free COM port
(1-4). Communications with the ISP-100 will not work properly if the
COM port is shared with another device such as a TEF™ analyzer. It
is important to set the serial port selection switch located under the
front panel security cover to the serial port used. The cable used
should be of low capacitance and suited to data communications.

Front Panel RS-232

When tuning the
system with a
computer controled
analyzer use a
separate computer
for the analyzer.
Using two PCs will
save time.

10 July 1998

Figure 2-11

DB-9 to DB-25.

Figure 2-12

DB-9 to DB-9.

The serial port selector switch should be set in the down
position. If the PC’s COM port is a DB-25 connector, wire the
cable according to Figure 2-11. If the PC’s COM port is a DB-9
connector, wire the cable according to Figure 2-12. A snap-on

2-7

Not using an RFI
choke while using the
front panel serial port
could cause increased
interference with other
devices and void the
FCC compliance.

Figure 2-13

RFI choke data.

RFI choke such as Steward PN: 28B2025-0A0 should be used
at the ISP-100 end of the cable. See Figures 2-13 and 2-16, and
Table 2-1 for more information.

Rear Panel RS-232

Figure 2-14

RJ-45 to DB-25.

Figure 2-15

RJ-45 to DB-9.

The serial port selector switch should be set in the up position. If
the PC’s COM port is a DB-25 connector, wire the cable
according to Figure 2-14. If the PC’s COM port is a DB-9
connector, wire the cable according to Figure 2-15. No RFI
choke is needed. See Figure 2-16 and Table 2-1 for more
information.

RS-232 cable runs
over 50 feet could
cause unreliable
communications. It is
better to use RS-485
converters for
connections over 50
feet. Be sure to read
the application note on
this topic before
buying converters.

Connections Over 50 Feet

The EIA specifications for RS-232 communications allow for
connections up to 50 feet. For longer connections, the RS-232
signals must be converted to a standard, such as RS-485, that is
tolerant of long distances. The converter on the PC end of the
connection can be PC powered, but the converter at the ISP-100
end of the connection must have its own power supply. Before
buying converters please contact TELEX Communications, Inc.
for an application note on this topic.

Setup & Installation

2-8

Table 2-1

RS-232 signal pinouts for RJ-45, DB-9, and DB-25 connectors.

The RS-232
standard is very
common to
computer controlled
devices. Table 2-1
and Figure 2-16 can
help you decipher
the RS-232
interfaces of many
devices.

10 July 1998

Figure 2-16

Connector pinouts.

If a permanent
contact closure is
used, the ISP-100
will remember the
QuickSET selected
even if the AC power
fails.

General Purpose Inputs (GPI)

Figure 2-17

GPI connector pinout.

Dry (i.e. switch) or electronic (i.e. open collector) contact closure
should be sufficient. The closure can be either momentary (10 ms
minimum duration) or continuous. Connect the desired input (1-8)
through the contact closure to common (9). See Figure 2-17 for more
information.

Master Sync Input

2-9

Figure 2-18

BNC cable example.

Synchronizing to an external clock source requires RG-58 or other
suitable 50Ω cable terminated with a BNC connector. A precision
(±5 ppm) clock source of 12.288 MHz, 6.144MHz, or 3.072 MHz is
supported. The Master Clock Input must be set to external from the
Properties for Merlin ISP-100 panel in the VUE-IT software. See
Figure 2-18 and page 7-6 of this manual for more information.

Setup & Installation

2-10

THIS PAGE LEFT BLANK

INTENTIONALLY

10 July 1998

User modifications
void the warranty.

WARNING:
Make sure the power
is disconnected from
the unit before
checking the fuse.

3-1

TROUBLESHOOTING

> > > CAUTION < < <

NO USER SERVICEABLE PARTS INSIDE. HAZARDOUS
VOLTAGES AND CURRENTS MAY BE ENCOUNTERED WITHIN
THE CHASSIS. TO AVOID ELECTRICAL SHOCK DO NOT
PERFORM ANY SERVICING OTHER THAN THAT CONTAINED
IN THESE OPERATING INSTRUCTIONS.

User Modifications

Modifications to Merlin products are not recommended. Such
modifications shall be at the sole expense of the person(s) or company
responsible, and any damage resulting from said modifications shall not
be covered under warranty or otherwise.

In Case of Problems

Check the following items:

Verify that the unit is properly connected to an AC power source
and the source is active.
Check the fuse.
Verify that the input connections are properly made.
Verify that the output connections are properly made.
Make sure the output relay indicators are green.
Check the input and output cables for proper wiring and
continuity.
Check the signal source(s).
Check the connection between the computer and the ISP-100 if
a computer is being used.
Check the GPI connections if the GPI is being used.

Troubleshooting

3-2

Diagnostics

Table 3-1

The ISP-100 was designed with built-in diagnostics that activate when
power is applied to the unit. During the power-up cycle, the ISP-100
performs several self-checks. The ISP-100 also will report problems, as
they happen, while the unit is running. The diagnostic messages are
communicated through the front panel LEDs. Refer to Table 3-1 for a list
of common LED conditions and corresponding diagnostic messages.

LED diagnostic messages.

Factory Default Mode

A yellow host LED indicates factory default mode. This mode usually
results from either an OS update or memory erasure. When in this
mode a default QuickMAP and QuickSET are loaded that prevents the
unit from passing damaging signals. The QuickMAP configures the
ISP-100 as a straight through processor with high pass filters on the
outputs. The corner frequencies of the high pass filters are set to
20 kHz.

To enter factory default mode, hold in the default switch (see Figure
2-1, item 6) while turning on the power. Continue to hold in the switch
until the front panel LEDs turn red and begin to rotate.

Note that when the
factory default
QuickMAP is loaded
one or more slot
LEDs may blink
yellow. This is normal
operation and not
an error.

10 July 1998

Retrieving Version Numbers

3-3

Figure 3-1

Application, OS, and DSP version numbers can be obtained by clicking
on the Help menu and then selecting the About entry. See Figure 3-1. If
an ISP-100 is not online, only the application version number will be
reported.

About VUE-IT dialog

Retrieving Serial Numbers

Figure 3-2

Clicking on the star icon in the Project Manager and then clicking on the
Properties button will reveal the ISP-100’s serial number. See Figure
3-2.

Properties dialog.

Troubleshooting

3-4

Changing the Fuse

The universal switching power supply in the ISP-100 adapts to input
voltages from 90 to 264 VAC, 50/60 Hz. To reduce risk of fire, replace
only with same type fuse. The fuse holder is located under the security
cover on the front panel.

The fuse is a standard 20mm X 5mm European type. The values used
are as follows:

All countries using 220/240 VAC, except Australia, use a ½ A slow-blow
fuse.

Schurter P/N: 0001.2501
Telex P/N: 51-04-052488

All countries using 100/120 VAC and Australia use a 1 A slow-blow fuse.

Schurter P/N: 0001.2504
Telex P/N: 51-04-051487

Changing the Battery

WARNING:

Disconnect AC power
before changing the
fuse. Failure to do so
could result in a shock
hazard.

WARNING:
Failure to install the
proper fuse could
result in damage to the
unit, property, and loss
of life.

Figure 3-3

The memory backup battery located under the security cover on the front
panel has an expected life of four years. If the Host LED is blinking the
battery needs to be changed.

CAUTION: The battery used in this device may present a risk of fire or
chemical burn if mistreated. Do not recharge, disassemble, heat above
212°F (100°C) or incinerate. Replace battery with Renata CR2450N or
MERLIN 40-02-052055 only. Use of another battery may present a risk of
fire or explosion.

Be sure to change the battery with the unit on. If the unit is turned off, all
of the setup information stored in the ISP-100 will be lost (i.e. the unit will
return to factory default mode).

10 July 1998

Battery/module removal tool.

Leave the AC power
connected and the
ISP-100 turned on
when changing a
failed battery.
Failure to do so will
result in loss of
data.

3-5

Saving the ISP-100
configuration data
to disk will guard
against the loss of
data in the event AC
power fails before a
failed battery has
been changed.

Caution: Use only the tool attached to the inside of the security cover to
change the battery. The tool is black anodized so it will not short out the
battery or anything else. DO NOT under any circumstance use pliers to
grip the battery. Doing so could cause damage. See Figure 3-3.

Replace the battery with a Renata CR2450N battery. Replacement
battery/module removal tools as well as replacement batteries are
available from Telex. Their part numbers are:

Battery/Module Removal Tool 40-04-052619
Replacement Battery 40-02-052055

Dispose of used battery promptly. Keep away from children. Do not
disassemble and do not dispose of in fire.

Denmark

Advarsel!

Lithiumbatteri. Eksplosionsfare ved feijlagtig handtering.
af samme fabrikat og type.
Lever det brugte batteri tilbage till leverandoren.

FINLAND

VAROITUS: Paristo voi rajahtaa, jos se on virheellisesti

asennettu. Vaihda paristo ainoastaan valmistajan
suosittelemaan tyyppun. Havita kaytetty paristo valmistajan
ohjeiden mukaisesti.

SWEDEN

VARNING: Explosionsfara vid felaktigt batteribyte. Anvand

samma batterityp eller en eller en ekvivalent typ som
rekommenderas av tillverkaren. Kassera anvant batteri enligt
fabrikantens instruktion.

VARNING:

Felaktigt batteribyte kan medfora fara for explosion. Anvand
darfor endast samma typ eller likvardig typ enligt
apparattillverkarens rekommendation.

Kassera forbrukade batterier enligt tillverkarens anvisning.

Troubleshooting

3-6

Technical Support

Technical questions should be directed to:

Customer Service Department - Merlin
Telex Communications, Inc.
9600 Aldrich Avenue South
Minneapolis, MN 55420 U.S.A.
Telephone: [phone]
Fax: [phone]

Helpful Information

Be prepared to provide the following information (if possible):

1. A detailed description of the problem.

2. QuickMAP being used.

3. Serial Number(s)

4. Version numbers for application, OS, and DSP software.

5. Front panel LED information.

6. PC operating system used.

7. COM port used.

8. PC type and amount of memory installed.

Procedure for Returns

If a repair is necessary, contact the dealer where this unit was
purchased.

If repair through the dealer is not possible, obtain a RETURN
AUTHORIZATION from:

Customer Service Department
Telex Communications, Inc.
Telephone: [phone] or [phone]
Fax: [phone] or [phone]

DO NOT RETURN ANY EQUIPMENT DIRECTLY TO THE FACTORY
WITHOUT FIRST OBTAINING A RETURN AUTHORIZATION.

Be prepared to provide the company name, address, phone number, a
person to contact regarding the repair, the type and quantity of
equipment, a description of the problem and the serial number(s).

10 July 1998

3-7

Save the box the
ISP-100 was
shipped in. It makes
a convenient way to
package a repair
unit.

Shipping to Manufacturer for Repair or Adjustment

All shipments of Merlin products should be made via United Parcel
Service or the best available shipper prepaid. The equipment should be
shipped in the original packing carton; if that is not available, use any
suitable container that is rigid and of adequate size. If a substitute
container is used, the equipment should be wrapped in paper and
surrounded with at least four inches of excelsior or similar shock­absorbing material. All shipments must be sent to the following address
and must include the Return Authorization.

Factory Service department
Telex Communications, Inc.
West 1st Street
Blue Earth, MN 56013 U.S.A.

Upon completion of any repair the equipment will be returned via United
Parcel Service or specified shipper collect.

Troubleshooting

3-8

THIS PAGE LEFT BLANK

INTENTIONALLY

10 July 1998

SPECIFICATIONS

Components

Compressor

Property Range Default Fine Coarse

Bypass in/out out n/a n/a

Threshold -60 dB to 0 dB 0 dB .5 dB 3 dB

Compression Ratio 1.2:1 to 24:1 1.2:1 n/a n/a

Attack Time 20 msec to 50 ms 20 msec .02 ms 1 ms

Release Time 20 msec to 5 sec 5000 ms 1 ms 100 ms

Detection Window 20 msec to 5 sec 50 ms 1 ms 100 ms

Crest Factor 0.00 to 1.00 .70 .01 .05

Knee hard/soft hard n/a n/a

Sidechain Channel self, max of both, or depends n/a n/a

Crossover

Property Range Default Fine Coarse

Slope 6,12,18,24 12 n/a n/a
Class Bessel, Butterworth, Butterworth n/a n/a

Cutoff Frequency 20 Hz to 20 kHz Depends 1/12 Oct. 1/3 Oct.

Gain +0 dB to -96 dB 0 dB 0.5 dB 1 dB

Absolute Polarity +/- + n/a n/a

4-1

sidechain

or Linkwitz-Riley

Delay*

Property Range Default Fine Coarse

Delay 0 ms to 2.7 s 0 ms .02 ms 1 ms

Dither

Property Range Default Fine Coarse

Bypass in/out out n/a n/a

Level 16 to 24 bits 20 bits 1 bit 1 bit

Gain**

Property Range Default Fine Coarse

Input Gain +18 dB to -96 dB 0 dB 0.5 dB 1 dB

Mute on/off off n/a n/a

Absolute Polarity +/- + n/a n/a

Gate

Property Range Default Fine Coarse

Bypass in/out out n/a n/a

Threshold -60 dB to 0 dB -60 dB .5 dB 3 dB

Attenuation 0d B to -100 dB 0 dB .5 dB 3 dB

Attack Time 20 msec to 50 ms .02 .02 ms 1 ms

Release Time 20 msec to 5 sec 5000 ms 1 ms 100 ms

Detection Window 20 msec to 5 sec 50 ms 1 ms 100 ms

Key Channel self, max of both, or depends n/a n/a

sidechain

* Depends on QuickMAP selected.
** In digital domain.

Specifications

4-2

Limiter

Property Range Default Fine Coarse

Bypass in/out out n/a n/a

Threshold -60 dB to 0 dB 0 dB .5 dB 3 dB

Attack Time 20 msec to 50 ms .02 ms .02 ms 1 ms

Release Time 20 msec to 5 sec 5000 ms 1 ms 100 ms

Detection Window 20 msec to 5 sec 50 ms 1 ms 100 ms

Crest Factor 0.00 to 1.00 .70 .01 .05

Knee hard/soft hard n/a n/a

Sidechain Channel self, max of both, or depends n/a n/a

sidechain

Filters

Property Range Default Fine Coarse

Bypass in/out out n/a n/a

Absolute Polarity +/- + n/a n/a

Gain Trim +12 dB to -12 dB 0 dB .1 dB 1 dB

LowPass Filter

Property Range Default Fine Coarse

Slope 6,12 12 n/a n/a

Cutoff Frequency 20 Hz to 20 kHz 20 1/12 Oct. 1/3 Oct.

Class Bessel, Butterworth, Butterworth n/a n/a

or Linkwitz-Riley

HighPass Filter

Property Range Default Fine Coarse

Slope 6,12 12 n/a n/a

Cutoff Frequency 20 Hz to 20 kHz 20 1/12 Oct. 1/3 Oct.

Class Bessel, Butterworth, Butterworth n/a n/a

or Linkwitz-Riley

AllPass Filter

Property Range Default Fine Coarse

Cutoff Frequency 20 Hz to 20 kHz 20 1/12 Oct. 1/3 Oct.

Filter Order 1,2 2 n/a n/a

LowShelf Filter

Property Range Default Fine Coarse

Slope 6,12 12 n/a n/a

Cutoff Frequency 20 Hz to 20k Hz 20 1/12 Oct. 1/3 Oct.

Boost/Cut +12 dB to -12 dB 0 dB .1 dB 1 dB

HighShelf Filter

Property Range Default Fine Coarse

Slope 6,12 12 n/a n/a

Cutoff Frequency 20 Hz to 20 kHz 20 1/12 Oct. 1/3 Oct.

Boost/Cut +12 dB to -12 dB 0 dB .1 dB 1 dB

Notch Filter

Property Range Default Fine Coarse

Center Frequency 20 Hz to 20 kHz 20 1/12 Oct. 1/3 Oct.

Cut 0 dB to -50dB 0 dB 1 dB 6 dB

Bandwidth .08 to 1.0 octaves 1. 0 .01 Oct. .1 Oct.

10 July 1998

PEQ

Property Range Default Fine Coarse

Center Frequency 20 Hz to 20 kHz 20 1/12 Oct. 1/3 Oct.

Boost/Cut +12 dB to -12 dB 0 dB .1 dB 1 dB

Bandwidth 0.08 to 3.0 octaves 1. 0 1/12 Oct. 1/3 Oct.

Combine

Property Range Default Fine Coarse

Channel “1” Entry Gain +0 dB to -96 dB 0 dB .5 dB 1 dB

Channel “1” Entry Polarity +/- + n/a n/a

Channel “2” Entry Gain +0 dB to -96 dB 0 dB .5 dB 1 dB

Channel “2” Entry Polarity +/- + n/a n/a

Input

Property Range Default Fine Coarse

Left Gain (A) 0,2,4,8 dB 0 dB n/a n/a

Right Gain (B) 0,2,4,8 dB 0 dB n/a n/a

Left Pad (A) -20 dB Off n/a n/a

Right Pad (B) -20 dB Off n/a n/a

Output

Property Range Default Fine Coarse

Left Gain (A) -8,-6,-4,0,8 dB 0 dB n/a n/a

Right Gain (B) -8,-6,-4,0,8 dB 0 dB n/a n/a

Left Mute (A) on/off off n/a n/a

Right Mute (B) on/off off n/a n/a

Relay Mute on/off

4-3

ISP-100 Component Plots

Compressor Limiter

AP is a trademark of AudioPrecision, Inc.

Specifications

4-4

Gate Linkwitz-Riley 3-way Crossover

Notch Filter Parametric Equalizer Filter

10 July 1998

Peaked HighPass Filter Shelving Filter

AP is a trademark of Audio Precision, Inc.

System Measurements

4-5

System Frequency Response

System Noise Floor

System THD+N

AP is a trademark of Audio Precision, Inc.

Specifications

4-6

MIM-1 & MIM-2* Analog Input Modules

Power

Symbol Description Minimum Typical Maximum Units

VA18P positive analog supply voltage 17.50 18.00 20.00 volts
VA18M negative analog supply voltage -17.50 -18.00 -20.00 volts
VD5P positive digital supply voltage 4.75 5.00 5.50 volts
IA18P positive analog supply current 77(43.7) 81(46.0) 85(48.3) milliamps
IA18M negative analog supply current 72(41.6) 76(43.75) 80(46.0) milliamps
ID5P positive digital supply current 113(114) 123(124) 133(134) milliamps

Performance

Symbol Description Minimum Typical Maximum Units

THD+N Total Harmonic Distortion + Noise 0.003(0.002) 0.007(0.006) %
IMD Intermodulation Distortion
DIM Dynamic Intermodulation Distortion

Noise Floor

3

Channel Crosstalk -100 -80 dB

N Resolution 20(24) bits

Frequency Response +0.01, - 0.1 +.02, -0.15 dB

4

Delay
MCLK+ Master Clock 12.283 12.288 12.292 MHz
WST+ Word Clock 47.98 48.000 48.02 kHz

Oversampling 64X(128X)

Stopband Attenuation 100(110) dB

Maximum Input Level

Interchannel Phase Deviation
CMRR Common Mode Rejection 52 40 dB

Gain Accuracy
Z

in

Input Impedance

Operating Temperature 50 75 100 °F

7

Operating Humidity 20 50 80 %

1

2

0.004 0.007 %

0.003 0.006 %
110 107 dBu

18 (38.7) WST

5

6

8

26 30 32 dBu

0.5 1.0 degrees

±0.05 ±0.25 dB

11000 12000 13500 ohms

Miscellaneous

Overall Size:

9

8.40 long by 2.55 wide by 1.50 high
Weight: 4.0 ounces
Synchronous Sampling: Multiple cards can be synchronized via DPD signal on connector
Input connector: 3 Pin standard female XLR
Mating connector: 3 Pin standard male XLR
Internal connector: 48 pin standard female F size per DIN 41 612
XLR pinout: Pin 1  shield, Pin 2  positive signal, Pin 3  negative signal
Serial Interface: Master or slave, selectable via SPI control I/F.
Clock Mode: 256 or 384 times sample rate, selectable via SPI control I/F.
Digital Power Down: Selectable via SPI control I/F.
Analog Gain: Selectable: 0, -20, -18, -16, -12, 2, 4, 8 dB.

Notes

(Unless otherwise specified measurements are at unity gain with +16 dBu signal.

1

Unity gain, SMPTE 4:1, 60 Hz & 7 kHz sine waves.

2

Unity gain, DIM30 4:1, 3.15 kHz SQ wave & 15 kHz sine wave, 30 kHz LPF.

3

Power spectral density.

4

Group Delay inherent in conversion process. WST=1/

5

20 dB pad engaged.

6

Maximum levels are differential and balanced. Limit set by protection circuit.

7

Relative to unity gain, 1 kHz.

8

Electronically balanced, RF surpressed, differential impedance 20- 20kHz.

9

Maximum dimensions: dominated by panel size for height and width.

48 kHz

* MIM-2 differences parenthetically noted.

10 July 1998

MOM-1 Analog Output Module

Power

Symbol Description Minimum Typical Maximum Units

VA18P positive analog supply voltage 17.50 18.00 20.00 volts
VA18M negative analog supply voltage -17.50 -18.00 -20.00 volts
VD5P positive digital supply voltage 4.75 5.00 5.50 volts
IA18P positive analog supply current 92 96 100 milliamps
IA18M negative analog supply current 47 51 55 milliamps
ID5P positive digital supply current 114 124 134 milliamps

Performance

Symbol Description Minimum Typical Maximum Units

THD+N Total Harmonic Distortion + Noise 0.003 0.007 %
IMD Intermodulation Distortion
DIM Dynamic Intermodulation Distortion

Noise Floor 110 107 dBu
Channel Crosstalk -100 -80 dB

N Resolution 20 bits

Frequency Response +0.1, - 0.5 +.2, -1.0 dB

3

Delay
MCLK+ Master Clock 12.283 12.288 12.292 MHz
WST+ Word Clock 47.98 48.000 48.02 kHz

Oversampling 128X

Stopband Attenuation 75 dB

Maximum Output Level

Interchannel Phase Deviation 0.5 1.0 degrees

Output Balance 0.5 dB

Gain Accuracy
Z

out

Output Impedance

Operating Temperature 50 75 100 °F

5

Operating Humidity 20 50 80 %

1

2

0.004 0.007 %

0.003 0.006 %

25 WST

4

6

21 26 dBu

±0.05 ±0.25 dB

594 600 606 ohms

4-7

Miscellaneous

Overall Size: 8.40 long by 2.55 wide by 1.50 high
Weight: 4.3 ounces
Input connector: 3 Pin standard male XLR
Mating connector: 3 Pin standard female XLR
Internal connector: 48 pin standard female F size per DIN 41 612
XLR pinout: Pin 1  shield, Pin 2  positive signal, Pin 3  negative signal
De-emphasis: 48 kHz de-emphasis, selectable via SPI control I/F.
Relay mute: Left and right output relay mute, selectable via SPI control I/F.
DAC mute: Left and right individually or group selectable via SPI control I/F.
Serial Data Interface: 7 formats available, selectable via SPI control I/F.
Analog Gain: Selectable: 0, -8, -6, -4, 8 dB via SPI control I/F.

Notes

1

Unity gain, SMPTE 4:1, 60 Hz & 7 kHz sine waves.

2

Unity gain, DIM30 4:1, 3.15 kHz SQ wave & 15 kHz sine wave, 30 kHz LPF.

3

Group Delay inherent in conversion process. WST=1/

4

Minimum levels are single ended, maximum levels are differential and balanced. Bridging load.

5

Relative to unity gain, 1 kHz.

6

Electronically balanced, RF surpressed, differential impedance 20- 20kHz.

48 kHz

7

Specifications

4-8

MDM-1 AES/EBU Digital I/O Module

Power

Symbol Description Minimum Typical Maximum Units

VA18P Pos Analog Supply Voltage 17.50 18.00 20.00 Volts
VA18M Neg Analog Supply Voltage Not Used Volts
VD5P Pos Digital Supply Voltage 4.75 5.00 5.50 Volts
IA18P Pos Analog Supply Current 8 9 10 mA
IA18M Neg Analog Supply Current Not Used mA
ID5P Pos Digital Supply Current 122 155 168 mA

Performance
(Sample Rate Converter Engaged)

Symbol Description Minimum Typical Maximum Units

F

s

THD+N Total Harmonic Distortion 0.00002 0.00016 %

IMD Intermodulation Distortion

MCLK/2 Sample Rate Converter

MCLK+ Master Clock TBD 12.288 TBD MHz
WSR+ Receive Word Clock
WST+ Transmit Word Clock
SCKR+ Receive Bit Clock
SCKT+ Transmit Bit Clock

Sample Rate for Digital 32 48 >54 kHz

Input Data

plus Noise3 (RELATIVE)

(SMPTE 4:1)

Jitter in Output Clock

2

4

5

(700 Hz - 100KhZ)

Tolerable Jitter in Input 90 nS

Clock before Loss of Lock

Resolution (input)

Resolution (output)

Frequency Response

Dynamic Range

Noise Floor

10

11

Delay through transmitter

Interchannel Phase Deviation

Reference Clock Source

6

7

8

9

12

13

14

15

16

17

18

1

TBD %

415 pS

4 20 bits
24 24 24 bits

+/-0.01 dB

117 120 dB

-117 dBFS

43

/

64

WST+
periods

0 Degrees

4.333 6.144 6.667 MHz

(MCLK+)/256 Hz
(MCLK+)/256 Hz
(MCLK+)/4 Hz
(MCLK+)/4 Hz

10 July 1998

Performance
(Sample Rate Converter bypassed)

Symbol Description Minimum Typical Maximum Units

F

s

THD+N Total Harmonic Distortion 0.00002 %

IMD Intermodulation Distortion

Sample Rate for Digital TBD 48 96 kHz

Input Data

plus Noise

19

20

(RELATIVE)

21

0%
(SMPTE 4:1)
Jitter in Output Clock 415 pS
Tolerable Jitter in Input 35 nS
Clock before Loss of Lock

22

Resolution (input) 24 24 bits
Resolution (output) 24 24 24 bits
Frequency Response
Dynamic Range

Noise Floor

25

Delay through receiver
Delay through transmitter
Interchannel Phase Deviation

MCLK+ Master Clock
WSR+ Receive Word Clock
WST+ Transmit Word Clock
SCKR+ Receive Bit Clock
SCKT+ Transmit Bit Clock
Z

in

Z

out

Input Impedance 110 Ohms
Output Impedance 110 Ohms

23

24

Equal to Dynamic Range dB

+/-0 dB

of input signal
Equal to Noise Floor dB

26

27

28

29

30

31

32

33

of input signal

2 WSR+periods

43

/

64

WST+periods

0 Degrees

TBD 12.288 24.576 MHz

(MCLK+)/256 Hz
(MCLK+)/256 Hz
(MCLK+)/4 Hz
(MCLK+)/4 Hz

Miscellaneous

Overall Size: 8.40" long by 2.55" wide by 1.50" high
Weight: 3.8 Ounces
Input Connector: 3 Pin standard female XLR
Output Connector: 3 Pin standard male XLR
XLR pinout: Pin 1 shield, Pin 2 positive input, Pin3 negative input.
Input Data Format: AES/EBU (AES3) Professional and S/PDIF. (IEC958) Consumer data formats are automatically identified and

correctly decoded.
Output Data Format: AES/EBU Professional, regardless of input data format.
De-emphasis: Not implemented; emphasis information from Channel Status Bits is relayed to host via Serial Peripheral

Interface (SPI).
Mutes: Linked Left and Right input mute selectable via SPI control; linked Left and Right output mute selectable via

SPI control.
Serial Data Interface: TBD
Synchronous Sampling: Multiple outputs may be synchronized via DPDB signal on connector. MDM-1 transmitter is slaved to MCLK+,

WST+, and SCKT+ signals. MDM-1 receiver may be configured as Master, to generate MCLK+ (via AES_CLK),

WSR+, and SCKR+ signals derived from input data stream, or as Slave, to receive WSR+ and SCKR+ signals

from card-edge connector, either with or without the Sample Rate Converter. With sample rate converter

engaged, the MDM-1 cannot be configured as the master.
Unless otherwise noted:

Signal measurements are at unity gain, +16 dBu and 20 Hz to 20 kHz bandwidth.

Power measurements are quiescent.

Operating temperature with non condensing humidity

4-9

Specifications

4-10

Notes

1

Per Analog Devices AD1890 data sheet, where applicable.

2

With 6.144 MHz MCLK/2 input.

3

20 Hz to 20 kHz, full-scale input, through sample rate converter, to output via passthrough.

4

From input, through sample rate converter, to output via passthrough.

5

When installed in ISP-100.

6

When installed in ISP-100.

7

Input samples longer than 20 bits are truncated to 20 bits.

8

Least four significant bits are zero filled.

9

DC to 20 kHz input, through sample rate converter, to output via passthrough.

10

20 Hz to 20 kHz, -60 dB input, through sample rate converter, to output via passthrough.

11

From input, through sample rate converter, to output via passthrough.

12

From SDO0 pin on card connector, through transmitter, to output. The fractional-sample delay is inherent in the Crystal CS8404 transmitter.

13

From input, through sample rate converter, to output via passthrough.

14

Frequency is tripled by a PLL on the MDM-1 before being applied to the sample rate converter.

15

Must be derived from MCLK+.

16

Must be derived from MCLK+.

17

Must be derived from MCLK+.

18

Must be derived from MCLK+.

19

Must be nominally 48 kHz when installed in ISP-100.

20

From input to output via passthrough.

21

From input to output via passthrough.

22

When installed in ISP-100.

23

DC to Fs/2.

24

From input to output via passthrough.

25

From input to output via passthrough.

26

From input, through receiver, to SDI0 pin on card connector.

27

From SDO0 pin on card connector, through transmitter, to output. The fractional-sample delay is inherent in the Crystal CS8404 transmitter.

28

From input to output via passthrough.

29

Must be Fs x 256.

30

Must be derived from MCLK+.

31

Must be derived from MCLK+.

32

Must be derived from MCLK+.

33

Must be derived from MCLK+.

Physical

Height

1.75 inches (44.5 mm)

Width

19.0 inches (483 mm)

Depth

14.5 inches+0.5” (368 mm + 12.7 mm) for protrusions

Weight

Approx.12.9 lbs. (5.9 kg)

Included Accessories

IEC power cord, user’s manual, software, spare fuse

Power

Universal AC input voltage
90-264 VAC; 50-60 Hz; 35 W Maximum
Internal Power Supply Sync. Frequency - 153.6 kHz

10 July 1998

INSTALLING VUE-IT

Minimum System Requirements

CPU: Pentium® processor.

5-1

VUE-IT is currently
not available for
Windows NT.

OS: Microsoft® Windows 3.1x, Windows 95, or Windows 98
Memory: 8MB RAM
Hard Drive: 5MB of available space (beyond swap file needs)
Disk Drive: 3.5 inch high-density
Monitor: 640X480, 256 color
Pointing Device: mouse or other Windows compatible pointing device
Communications: free COM port (1-4) with 16550 UART

Identifying a Serial Port

The ISP-100 requires a serial port to communicate with the PC. You
must determine if you have a free 16550 serial port on the PC you intend
to use with the ISP-100. You can do this by looking at the back of the
computer for an empty 9-pin D-sub male (DB-9) or a 25-pin D-sub male
(DB-25) connector. If you are unable to find an available serial port, then
you must either disconnect a device from one of the ports that is
currently being used, or install an additional serial port.

If you are unfamiliar with this, please contact your local computer dealer
for assistance.

Leaving programs
running while trying
to install VUE-IT
could cause
problems.

NOTE:

ports in Windows 95. A good example of this would be a device driver
for an external modem. This will eliminate the possibility of a software
conflict between the VUE-IT software and other device drivers.

It may be necessary to remove device drivers attached to serial

Loading the Software

1. Close all programs before beginning installation.

2. Insert the disk labeled “VUE-IT FOR THE ISP-100” into your 3.5-inch
floppy drive.

3. Windows 95 users should click on the Start button and select Run.

4. Windows 3.1x users should click on File and select Run.

5. Type “A:\setup.exe” (Substitute the appropriate drive letter for your
system.)

6. Click on the OK button and follow the instructions as they appear on
the screen.

7. Reboot the computer.

Installing VUE-IT

5-2

Updating the ISP-100’s Operating System

Figure 5-1

Figure 5-2

The updating of the operating system contained in the ISP-100’s flash
memory is usually required after loading a new version of VUE-IT on the
computer. A dialog box such as those in Figures 5-1 and 5-2 usually
indicates this.

The procedure is as follows:

1. Make sure both the computer and the ISP-100 are both turned off.

2. Connect the computer to the ISP-100.

3. Hold in the default switch located to the left of the power switch and turn
on the ISP-100. Continue to hold in the default switch until the LEDs turn
red and begin rotating. See Figure 2-1 item 6.

OS mismatch dialog.

OS download request dialog.

4. Turn on the computer and start the VUE-IT software. Y ou should see a
dialog box similar to that in Figure 5-2.

10 July 1998

5-3

Figure 5-3

Open OS file dialog.

5. Download the OS software file you need via the application when
prompted. See Figure 5-3 for more information. The default location for OS
files is “c:\program files\vue-it\isp-100”.

Figure 5-4

Download progress dialog.

6. The lights will continue to rotate with only brief pauses. Y ou will also
see a progress indicator on the PC’s screen similar to the one in Figure
5-4.

7. When the download is complete, the ISP-100 will automatically restart.

Figure 5-5

ISP-100 detected dialog.

8. Wait for the HOST LED to light yellow and the rest of the LEDs to light
green. At this point a window similar to the one in Figure 5-5 will appear.
The ISP-100 is now ready for use.

Installing VUE-IT

5-4

Configuring the Software

Turn on the ISP-100. The power switch is located at the far right under the
front access panel. This is accomplished by placing the switch in the
down position. See Figure 2-1 for the location of the power switch.

Check to make sure that the LEDs light in a percentage complete fashion.
Launch the VUE-IT application on the PC.

Figure 5-6

A dialog box similar to the one in the Figure 5-6 should appear.
The System Configuration dialog box (see Figure 5-6) allows the user to

select the serial port used, modify directories used, and enter information
such as the company’s and designer’s names. It is recommended that
you do not change the directory names unless you are an experienced
user and know the implications of doing so. See the entry titled “VUE-IT
File System” in section 6 for more information. After the proper information
has been entered or selected, click on the OK button.

Figure 5-7

After clicking on the OK button a dialog box like the one in the Figure 5-7
should appear. Click on the OK button. The ISP-100 and the PC are now
ready for use together.

System configuration dialog.

ISP-100 detected dialog.

You will not be
prompted again for
this information. You
can change it at any
time by clicking on

OptionOption

the

Option menu

OptionOption
and selecting
ConfigureConfigure

Configure.

ConfigureConfigure

10 July 1998

5-5

Figure 5-8

ISP-100 not detected dialog.

If a dialog box like the one in Figure 5-8 appears in place of the one in
Figure 5-7, the cable connecting the computer to the ISP-100 should be
checked. If no problem is found there, try selecting a different serial port.

Figure 5-9

Communications error dialog.

If a dialog box similar to the one in the Figure 5-9 appears, then a serial
port that does not exist has been selected. Another serial port must be
selected.

Y ou can change the serial port selection at any time by clicking on the
Option menu and selecting Configure.

If you continue to have problems please contact T echnical Support. See
section 3 for contact information.

Installing VUE-IT

5-6

THIS PAGE LEFT BLANK

INTENTIONALLY

10 July 1998

GETTING STARTED

Starting VUE-IT

6-1

Figure 6-1

When VUE-IT is started, you will see a screen similar to the one in Figure
6-1. The window displayed in Figure 6-1 is the basic environment in which
all interactions with VUE-IT take place. There are six key features of this
window that users should be aware of:

1. Menu Bar - This is where the user will find features that are either
integral to VUE-IT or standard in windows. When you see a reference to a
command located under a menu, this is where you should look. Below the
menu names are short-cut buttons that provide access to common
commands via a single mouse click. The buttons are (from left to right):
New Project, Open Project, Save Project, Revert, Scan, Project Manager,
Help, and Exit.

2. Work Space - This is where the QuickMAP, Project Manager,
QuickSET Manager, and component boxes appear . This is the main work
area for the user.

3. General Help - This box displays helpful messages about commands
and functions.

4. Component/Parameter T yp e - This box displays the name of the
component or parameter selected.

VUE-IT workspace.

5. Component/Parameter Input Range - This box displays the input
value range for a component or parameter.

6. Online/Offline Status - This box displays the status of the connection
between the ISP-100 and the PC running VUE-IT .

Getting Started

6-2

Starting a New Project

Figure 6-2

To start a new project select New Project from the File menu. A panel
similar to the one in Figure 6-2 will appear.

Y ou are allowed to select a name of up to eight characters for the project,
assign a path for the project to be stored, and create a new subdirectory if
needed. Y ou also will need to select the method by which the new project
will be created. T o select the method, click on the diamond to the left of
either the Build from Script or Upload from ISP-100 options. The Build
from Script option uses files stored on your hard drive to create the
QuickMAP. The Upload from ISP-100 option creates the QuickMAP
based on the information stored in an ISP-100 that is connected to the
PC. When you have given the project a name, assigned a path or
directory , and selected the creation method, click on the Create button to
start the project creation process.

Create new project dialog.

Figure 6-3

If the Build from Script option is selected a dialog similar to the one in
Figure 6-3 will appear. Here you will be able to select the script that will be

10 July 1998

QuickMAP selection dialog.

used to create the QuickMAP. The QuickMAPs can be sorted by Name,
I/O Configuration, Creation Time, and Modification Time. To sort the
QuickMAPs, click on the heading button of the property you wish to sort
by (i.e. Name, I/O Configuration, etc.). The first click of the mouse will
sort the QuickMAPs in ascending order and the second click will sort
them in descending order.

If you select the Upload from ISP-100 option there will be a pause while
the QuickMAP in the ISP-100 is loaded. Using the Upload from ISP-100
option is a good way to retrieve the settings of an ISP-100 when the
original project file does not exist. Please note that this feature is NOT
backward compatible. An ISP-100 with a project created using a previous
version of VUE-IT will NOT be able to upload the project to your computer.

6-3

CAUTION:
Trying to connect to an
ISP-100 with a VUE-IT
version different from
the one used to create
the project stored in it is
not allowed. Do not
update the OS.
Updating the OS will
erase the project stored
in the ISP-100. Use the
version of VUE-IT that
created the project to
Upload the project from
the ISP-100 to the PC
and save it. Then
update the OS and
restore the project..

Figure 6-4

New project created.

After the QuickMAP has been created three panels will appear on the
screen. They are: Project Manager, QuickSET Manager , and QuickMAP.
See Figure 6-4.

VUE-IT File System

When a new project is created a number of files and directories are
created. By default, the directory structure used by VUE-IT projects is as
follows:

C:\PROGRAM FILES\VUE-IT\ISP-100\PROJECTS\<Directory Name>\<File
Name>.<Extension>

The files created by a new project are stored in the project directory . The
file names are the same as the name given the project when it was
created. The file name formats are as follows:

Project File: <File Name>.VUE
Project QuickMAP File: <File Name>.QMS
Project QuickSET File: <File Name>.QM0
Project GPI Settings: <File Name>.GP0

Getting Started

6-4

Archiving Projects

T o save a project for archival purposes do the following:

1. Exit VUE-IT .

2. Save the project directory and the four files mentioned previously to
the archival media (i.e. floppy disk, zip™ disk, tape, CD, etc...). The
directory name will usually be the name you assigned the project.

Mounting Projects

T o install a project from an archive do the following:

1. Exit VUE-IT .

2. Create a directory under the C:\PROGRAMS\VUE-IT\ISP-100\PROJECTS\
directory .

3. Copy the four files mentioned previously above to the new project
directory created in step 2.

4. Restart VUE-IT .

QuickMAP Template Files

QuickMAP template files are, by default, located under the following
directory:

C:\PROGRAM FILES\VUE-IT\ISP-100\QMAPS\

The QuickMAP template file location is important to users who either
have access to QuickMAP creation software or have been sent a new
QuickMAP not contained in a standard VUE-IT installation.

Component Directory

Component files created by the Component Export command and
used by the Component Import command are, by default, located
under the following directory:

C:\PROGRAM FILES\VUE-IT\ISP-100\COMPLIB\

The files have the same name as the one assigned during export. The
format of the component file name is as follows:

<File Name>.CMP

Operating System (OS) Files

OS files are loaded into the ISP-100’s flash memory by VUE-IT . For
the procedure on updating the ISP-100' s OS, see section 5. The OS
files are, by default, located under the following directory:

C:\PROGRAM FILES\VUE-IT\ISP-100\

10 July 1998

The format of the OS file name is as follows:

<File Name>.OSI

Using VUE-IT

VUE-IT has a variety of commands available to the user. These commands
are accessible via the menu items along the top of the VUE-IT workspace
window.

File (see Figure 7-1)

7-1

Figure 7-1

New Project - Creates a new project file.
Open Project - Loads an existing project.
Save - Saves a project.
Save as... - Saves an existing project under another name.
Activate Project Manager - Opens the project manager window after it

has been closed.
Activate QuickSET Manager - Opens the QuickSET Manager window

after it has been closed. This function only works when one or more
components are open.

Exit - Shuts the program down.
The last eight projects used are listed at the bottom of the menu if the

Most Recently Used files (MRU) option is checked in the Preferences
panel under the Options Menu. If the project no longer exists you are
asked if you want to remove the item from the list.

File menu.

Using VUE-IT

7-2

Edit (see Figure 7-2)

Figure 7-2

Cut - Removes the selected item(s) and places them on the clipboard.
Copy - Places a copy of the selected item(s) on the clipboard.
Paste - Inserts item(s) from the clipboard.

Edit menu.

T ools (see Figure 7-3)

Figure 7-3 Tools menu.

Refresh Directories - Updates the directory list for QuickMAP and

component library files.

Scan - Looks to see if an ISP-100 is connected to the computer.

Options (see Figure 7-4)

Figure 7-4

Preferences - Allows the user to setup preferences available within

VUE-IT .
System Configurations - Allows the user to setup project directories,

company name, designer’s name, communications settings, etc.

10 July 1998

Options menu.

Window (see Figure 7-5)

7-3

Figure 7-5

Cascade - Arranges panels in overlapping layers.
Tile - Arranges panels side-by-side.
Arrange Icons - Arranges minimized panels side-by-side.

Windows menu.

Help (see Figure 7-6)

Figure 7-6

About - Lists the current application software version, OS version, and

DSP version if an ISP-100 is connected and online. If an ISP-100 is not
online, only the application software version will be reported.

Help menu.

Preferences (see Figure 7-7)

Figure 7-7

Soft Mute Ramp in Ms

This sets the amount (0 ms - 1000 ms) of ramp-up and ramp-down

VUE-IT preferences dialog.

Using VUE-IT

7-4

there is when changing between QuickSET s or using a GPI mute.
The total time for ramp-up and ramp-down is twice the time specified.
(i.e. If 50 ms of time is specified, the ramp-down will be 50 ms and the
ramp-up will be 50 ms. Thus, the total time between the start of the
ramp-down to the end of the ramp-up is 100 ms.)

Display recently opened files in the File Menu

The check box turns on and off the Most Recently Used files (MRU)
function. Removing the check mark will disable the function and clear
the list.

Open Device Status panel on error

When a device status message is received, the status panel is
automatically opened.

Display QuickMAP pop-up names

If selected the pop-up component nametags in the QuickMAP layout
display are shown.

Display Filter Bandwidth in “Q”

If the box is checked filter bandwidth to be displayed in terms of Q. If it
is unchecked bandwidth will be displayed in terms of octave fraction.

System Configurations (see Figure 7-8)

Figure 7-8

New Projects

This is the directory under which new projects are stored. T o modify
the path, click on the Modify ... button located to the right of the
directory path entry .

System configuration dialog.

10 July 1998

Component Library

This is the directory under which the component presets are stored.
T o modify the path, click on the Modify... button located to the right of
the directory path entry .

QuickMAP Library

This is the directory under which QuickMAP templates are stored. T o
modify the path, click on the Modify ... button located to the right of
the directory path entry .

Company Name

This entry is reserved for possible future use in documenting projects.
Y ou can enter the company name, but it currently will not be saved in
a project.

Designer’s Name

This entry is reserved for possible future use in documenting projects.
Y ou can enter your name here, but it currently will not be saved in a
project.

Communications

This list allows you to select which COM port (1-4 and offline) on the
PC will be used for communications with the ISP-100. Once a new
COM port is selected you may need to select Scan from the Tools
menu in order for the software to identify an ISP-100 connected to the
new COM port.

Default Preference

This list is reserved for future program expansion. Via this list you
would be able to change settings based on a designer’s preferences.
This would allow for multiple designers using the same program on the
same PC.

7-5

Project Manager

Figure 7-9

The Project Manager (see Figure 7-9) contains information related to the
project design. Via the manager , the user is able to define GPI inputs,
configure inputs and outputs, import and export component settings, and
adjust component settings. In addition to these functions, the user is also

Project manager dialog.

Using VUE-IT

7-6

able to access ISP-100 statistics such as free memory , number of
QuickSETs, etc.

Properties for the ISP-100

Figure 7-10

Properties for the ISP-100 (see Figure 7-10) reports statistics on the
ISP-100. It is accessed by double clicking on the entry next to the
star icon (see Figure 7-9), or by clicking on the entry next to the star
icon (see Figure 7-9) and then clicking on the Properties button in the
Project Manager.

Master Clock Selection

There are four location selections for master clock:

1. Main Board – no reference frequency . (default).

2. Slot #1 – 12.288 MHz reference frequency (AES/EBU only).

3. Slot #2 – 12.288 MHz reference frequency (AES/EBU only).

4. External Reference – 12.288, 6.144, or 3.072 MHz via

external input BNC.
An error will be returned if either slot 1 or slot 2 is selected as the

clock master while the slot contains a card configured to use the
sample rate converter (SRC).

The default clock master is the main board. If the user places an
AES/EBU card in an input slot the user can manually change the
clock master to select either the main, external sync, or input
card slot.

ISP-100 properties dialog.

10 July 1998

Input Slot Bit Level

The input slot bit level can be set to either 20-bit or 24-bit. 20-bit is
usually associated with consumer grade (SPDIF) digital audio.
24-bit is usually associated with professional grade (AES/EBU)
digital audio. However, it is possible to have consumer grade 24­bit digital audio. For optimal performance be sure to set the proper
bit level for the audio data stream.

Project Properties

7-7

A QuickMAP is a
signal processing
topology used with
an ISP-100. The
QuickMAP sets the
signal paths and
processing from
input to output. An
ISP-100 can hold one
QuickMAP at a time.

Figure 7-11

Project properties dialog.

Project properties (see Figure 7-1 1) provides the user with information
on the name of the project, project location, and notes related to the
project. It is accessed by double clicking on the project name entry , or
by clicking on the project name entry and then clicking on the

Properties button in the Project Manager.

QuickMAP Selection

Figure 7-12

QuickMAP selection dialog.

QuickMAP Selection (see Figure 7-12) is where a project’s
QuickMAP is chosen. It appears when the Build From Script option
is selected when setting up a new project. Here you will be able to
select the script that will be used to create the QuickMAP. The
QuickMAPs can be sorted by Name, I/O Configuration, Creation Time,
and Modification Time. To sort the QuickMAPs, click on the heading
button of the property you wish to sort by (i.e. Name, I/O

Using VUE-IT

7-8

Configuration, etc.). The first click of the mouse will sort the
QuickMAPs in ascending order and the second click will sort them in
descending order. See section 6 for the location of the QuickMAP
directory .

QuickMAP Properties

Figure 7-12

QuickMAP properties dialog.

QuickMAP Properties (see Figure 7-13) appear by clicking on the
QuickMAP entry in the Project Manager and then clicking on the
Properties button. From this dialog, you can change the QuickMAP
name. Y ou can also change the names of the input and output labels
by clicking on either the Inputs or Outputs buttons.

Component Properties

10 July 1998

Figure 7-14

Component properties dialog.

Clicking on a component (i.e. Cut, Compressor, Limiter, etc.) in the
Project Manager (see Figure 7-9) and then clicking on the Properties
button displays the properties for the selected component.
Component Properties allow the user to name the component and
enter notes related to that component. See Figure 7-14.

Component Export

7-9

Figure 7-15

T o export component settings from the Project Manager , click on the
desired component entry in the Project Manager (see figure 7-9) and
then click on the Export button. Y ou will then see a dialog box like
the one in Figure 7-15.

The Export Component dialog displays currently existing component
presets’ filenames in the lower left corner of the dialog. These files can
be sorted by clicking on the Name, T ype, and Group heading
buttons. The first mouse click on one of these buttons will sort the list
in ascending order and the second click will sort the list in descending
order.

The Export Component dialog requires you to supply a name for both
the component settings and the group to which it is assigned. In
addition to these entries, you are also allowed to provide a brief
description of the settings. Once the component name, group, and
description have been entered, click on the OK button. Clicking on the
OK button causes the program to create a file holding the component
settings and description in the COMPLIB directory . The full path to the
COMPLIB directory is assigned when you first installed VUE-IT . See
the System Configurations entry for information on changing the
COMPLIB directory’s path.

Component export dialog.

Using VUE-IT

7-10

Component Import

Figure 7-16

T o import component settings from the Project Manager , click on the
desired component entry in the project manager (see Figure 7-9) and
then click on the Import button. Y ou will then see a dialog box like
the one in Figure 7-16.

The Import Component dialog displays currently existing component
presets’ filenames in the upper half of the dialog box. These files can
be sorted by clicking on the Name, T ype, Group, and Mod Time
heading buttons. The first mouse click on one of these buttons will
sort the list in ascending order and the second click will sort the list in
descending order.

The lower half of the dialog box displays notes on the component
preset currently selected in the upper half of the dialog box.

Component import dialog.

QuickSET Manager

10 July 1998

Figure 7-17

QuickSET manager dialog.

The QuickSET Manager (see Figure 7-17) allows the user to develop and
manage multiple groups of component settings. The QuickSET Manager
is opened when a component is opened.

7-11

A QuickSET is made
up of the settings of
all of the
components in a
QuickMAP. Multiple
QuickSETs allow
users to change the
component settings
for a QuickMAP.
QuickSETs can be
changed without a
computer by assiging
a QuickSET to a GPI
input. When that
input receives a
contact closure, the
QuickMAP will change
its component
settings to those
contained in the
QuickSET assigned
to the GPI pin.

Creating New QuickSET s

The user can name a group of settings by clicking on the New button
and then entering the name in the pop-up window and clicking on the

OK button.

Deleting QuickSET s

If at least two QuickSET s exist, the user can delete an inactive one by
clicking on the Delete button, selecting the QuickSET from the list,
and then clicking on the OK button.

Selecting the Active QuickSET

The user can select a QuickSET from the list of available QuickSET s
by clicking on the arrow next to the Active QuickSET entry and
selecting the desired QuickSET from the list.

Updating a QuickSET

The user can use the Update button to save changes to a QuickSET
that has already been created. Using Update overwrites the
information previously saved in the selected QuickSET .

Discarding Changes

The Revert button allows the user to make changes to a QuickSET ,
and then go back to the original settings. This button only works when
changes have been made and the Update button has not been used.

GPI

Figure 7-18

Clicking on the GPI entry in the Project Manager and then clicking on the
Properties button will open the General Purpose Interface (see Figure

7-18). From this panel you can configure the GPI input pins.

Configuring Input Pins

Each input pin can be assigned a command by clicking on the button
to the right of the entry for that pin (see Figure 7-18). A pop-up menu

GPI properties dialog.

Using VUE-IT

7-12

will appear, and the proper command can be selected from the list by
clicking on it. The list displays the following options:

Empty - No command assigned to input pin.
Mute Combo - The initial contact closure causes the outputs to

mute. The subsequent contact closure causes the output to un-mute.

Mute Enable - Contact closure causes the outputs to mute.
Mute Disable - Contact closure causes the outputs to un-mute.
QuickSET Increment - Contact closure causes the next QuickSET

stored in memory to be loaded into the QuickMAP.
QuickSET Decrement - Contact closure causes the previous

QuickSET stored in memory to be loaded into the QuickMAP.
QuickSET Select - Contact closure causes the specified QuickSET

to be loaded into the QuickMAP.

T esting the GPI Assignments

10 July 1998

Figure 7-19

If you click on the GPI entry and then click on the Design button, you
will see a panel like the one in Figure 7-19. The panel in Figure 7-19
will allow you to simulate GPI contact closures without having to
hookup external contact closures to the GPI inputs of the ISP-100.

GPI panel.

A QuickMAP is a
signal processing
topology used with
an ISP-100. The
QuickMAP sets the
signal paths and
processing from
input to output. An
ISP-100 can hold one
QuickMAP at a time.

7-13

QuickMAP

Figure 7-20

Double clicking on the QuickMAP (name) entry or by clicking on the entry
and then clicking on the Design button can access a graphical
representation of the selected QuickMAP (see Figure 7-20).

Clicking on the green input triangles in the QuickMAP will open the I/O
Properties dialog (see Figure 7-21).

Clicking on the green output triangles will open the Output Meters (see
Figure 7-24).

Clicking on the component boxes will open the component. Placing the
pointer on a component, holding down the left mouse button, and dragging
the component onto a component of the same type and releasing the
mouse button will copy the component settings from the component being
dragged to the component it is dropped on.

QuickMAP panel.

QuickMAP Component Bypassing

Right clicking on the component boxes will produce a pop-up menu. The
user is able to modify component settings (this is the same as left clicking
on the component), access its properties, import or export settings, and in
selected cases bypass the component. A fully bypassed component will
appear red in the QuickMAP. Please note that this only occurs when the
main bypass is activated for that component.

Using VUE-IT

7-14

I/O Properties (see Figure 7-21)

Figure 7-21

Input

The Input Function controls the levels entering the unit. This function
can be accessed in any of the following three ways:

1. Clicking on the green input triangles.

2. Right clicking on either the green input or green output triangles and
selecting Properties from the pop-up list.

3. Clicking on the I/O Slots entry in the Project Manager and then
clicking on the Properties button.

Using the Stereo Control

This button controls the tracking of the Gain/Attenuator levels. If
the LED is gray , then the two channels do not track each other . If
the LED is blue, then the channels track each other. Clicking on
the button will toggle the setting.

Gain

T o change settings, click on the arrow next to the number in the
text box. A selection list will appear. The list may or may not be
scrollable. Click on the desired entry to make a selection.

I/O properties dialog.

10 July 1998

Using the Pad Control

This button controls the insertion of a -20dB pad in the signal
path. A gray LED on the button indicates the pad is not inserted.
A red LED on the button indicates that the pad is inserted.
Clicking on the button will toggle the setting.

Output

The Output function controls the output levels from the unit.

Using the Stereo Control

This button controls the tracking of the Gain/Attenuator levels. If
the LED is gray , then the two channels do not track each other . If
the LED is blue, then the channels will track each other. Clicking
on the button will toggle the setting.

Mute Control

This button determines if the output signal will be muted. A gray
LED indicates that the signal is not muted, while a red LED
indicates that the signal is muted. Clicking on the button will
toggle the setting.

Using the Relay Control

This button activates and deactivates the output relays. A gray
LED indicates that the audio path is not complete. A green LED
indicates that the audio path is complete. Clicking on the button
will toggle the setting.

Gain

To change settings, click on the arrow next to the number in the
text box. A selection list will appear. The list may or may not be
scrollable. Click on the desired entry to make a selection.

7-15

Digital I/O

In Mute (RX)

Mutes the AES receiver data stream.

Out Mute (TX)

Mutes the AES transmitter data stream

Pass Through

Routes the input from the receiver directly through the transmitter
to the card’s output (the output data from the DSP is bypassed).
Either the In-Mute or Out-Mute will mute the output when Pass
Through is on. Data may still be received when Pass Through is
on. Pass Through is only valid with a 48 kHz bit stream, or with a
non-48 kHz bit stream and Sample Rate conversion enabled. A
non-48 kHz sample rate with no sample rate conversion will result
in an error when the Pass Through option is selected.

SRC

Clicking on the SRC button turns on the Sample-Rate-Converter.
The SRC is used to convert non-48 kHz data streams into 48 kHz
data streams compatible with the ISP-100.

Note: Turning on the SRC will result in a 20-bit output data stream
except in the case of Pass Through.

Using VUE-IT

7-16

Status Information

Figure 7-22

Status information can be obtained for card slots 1 and 2 by
clicking on the Status button in the desired slot. See Figure
7-22.

Sample Rate Converter
On indicates that the sample rate conversion option is selected

on the card. The card cannot be selected as the clock master if
the SRC is turned on.

Off indicates that the sample rate conversion option is not
selected on the card.

Input Stream Format
Pro indicates that the digital receiver has detected an AES-EBU

formatted data stream.
Consumer indicates that the digital receiver has detected an

SPDIF formatted data stream.

Input Stream Emphasis
Emphasis indicates that the sending device has added emphasis

to the incoming data stream.

Digital I/O status panel.

10 July 1998

None indicates that the sending device has not emphasized the
incoming data stream.

Input Sample Rate

Indicates the sample rate of the data stream in kHz. There are
three possible frequencies 48.0 kHz, 44.1 kHz, and 32.0 kHz. All
other frequencies above and below these are listed as Out of

Range.

Note:

The emphasis information in the output data stream will be

set to no emphasis, regardless of the input emphasis status.

Device Status Panel

7-17

Figure 7-23

Clicking on the entry next to the star icon (see Figure 7-9) and then
clicking on the Design button in the Project Manager opens the Device
Status Panel. See Figure 7-23.

The device status panel has five simulated LEDs:

Clock Sync (red)

The main board cannot lock to specified location or frequency .

Digital Data (red)

1. Data validity error. Card position dependent.

2. A non-48 kHz Sample Rate is being used, and no Sample Rate
Converter is selected. Card position dependent.

3. Non-Audio Input Stream. Card position dependent.

4. Slot Cannot be chosen as master and have sample rate converter
present. Card position dependent.

5. An input slot must have an AES card to be master. Card position
dependent.

Device status panel.

Low Battery (yellow)

Please check battery .

Input Clip (red)

Input audio has clipped before the DSPs.

Process Clip (red)

Which slot and channel caused the clip.

The specifics of an error condition can be found by clicking on the ?
button. Y ou are also able to clear the error indication. If the error condition
still exists or reoccurs, the error LED will turn on again.

Using VUE-IT

7-18

Output Meters

Figure 7-24

The Output Meters (see Figure 7-24) provide monitoring of the outputs of
the DSPs before digital-to-analog conversion. T o activate the Meters, click
on the green output triangles in the QuickMAP, or click on the Meter Bank
entry in the Project Manager and then click on the Design button.

Output meter panel.

10 July 1998

PROCESSING COMPONENTS

The components used in the VUE-IT interface have a wide variety of
controls for adjusting settings.

Each component description begins with a full explanation of the
component including all of the parameters that can be adjusted. In some
areas the explanations may go into more depth than the average user
would need. This was done in order to satisfy the advanced user who
feels a need to understand the inner workings of the component.
References to specific journal articles and other supplementary sources
are provided for further reading.

An explanation of how to manipulate the various controls follows the
component explanation. In many instances a specific parameter may
have multiple means of adjustment. An example of this would be the
gain control in the Gain component. A user accustomed to traditional
hardware would probably prefer the virtual faders and knobs, whereas a
user accustomed to computers and exact entries would probably prefer
the text box where the amount of gain or attenuation can be directly
entered.

8-1

Processing Components

8-2

Combine

Figure 8-1

The Combine component (see Figure 8-1) adds multiple input signals
together and sends the sum to a single output. In QuickMAPs, 2-to-1,
3-to-1, and 4-to-1 combines may exist. The combine’s default attenuation
is set so that the combine’s output level is unity. In every case the
attenuation applied to each input channel may be independently adjusted
between -96 dB and 0 dB, or muted, and the polarity applied to each
input channel may be independently set to + or - (in-phase or out-of­phase). Attenuation and polarity are applied to the input signals before
they are added to the combination.

Bypassing a combine sets all attenuations to 0 dB and all polarities to +
(in-phase).

Input Attenuators

The input attenuators can be adjusted three ways:

Using the Knob

Click on the indicator on the knob and while continuing to hold
down the mouse button, move the mouse in an arc. The
numbers in the box below the knob will change. When the
desired level is reached, release the mouse button.

Using the Text Box

Click in the box. Using the Back Space and/or Delete keys
erases the current entry and enters the new level. Be sure to
press the Enter key after the entry is made. Clicking outside the
text box without pressing the Enter key will cause the setting to
return to the number that it was before a change was attempted.
Alternatively, click and drag across the number in the box to
highlight the number in it. Type the new setting and press the
Enter key when finished.

2-to-1 combine component.

10 July 1998

Using the UP/DOWN Arrows

To increase the level, click on the up arrow. To decrease the
level attenuation, click on the down arrow. The amount of
increase or decrease is controlled by the fine/coarse control.

Fine (F) or Coarse (C) Control

This button determines the increment/decrement associated with the
UP/DOWN arrows. Fine produces small steps in value, while Coarse
provides large steps in value. Clicking on the button will toggle the
setting.

Polarity Control (+/-)

This button determines the polarity of the signal. A + indicates that
the signal will not have it’s phase altered. A - indicates that the
signal’s phase will be changed 180°. Clicking on the button will
toggle the setting.

Mute Control (M)

This button determines if the input signal will be muted. A black M
indicates that the signal is not muted, while a red M indicates that the
signal is muted. Clicking on the button will toggle the setting.

Bypass Control (master)

This button determines if the component is in the processing chain. If
the LED on the button is gray, then the component is inserted into
the signal processing chain. If the LED is red, then the component is
bypassed in the signal processing chain. A bypassed component will
be colored red in the QuickMAP.

8-3

Processing Components - Combine

8-4

Compressor

Figure 8-2

Compressor component.

A compressor (see Figure 8-2) is used in situations where the input
signal has a greater dynamic range, or ratio of loudest to softest, than is
desired in the output signal. Compression is accomplished by preventing
the output signal from changing in level as much as the input signal, and
can be thought of as a form of automatic gain riding.

Familiar Controls

Most of the controls in the ISP-100 Compressor are common to
nearly all traditional dynamic range compressors. These controls
should be familiar to anyone with experience in the operation of any
compressor.

Compression Ratio

The Compression Ratio control adjusts the amount by which the
output signal level changes for a given change in input signal
level. When compressing, the output level change in dB will be
equal to the input level change in dB divided by the compression
ratio:

changeleveloutput =

changelevelinput

rationcompressio

For example, if the compression ratio is 2:1 and the input level
changes by +10 dB, then:

changeleveloutput +=

changelevelinput

rationcompressio

dB10

+

==

dB5

2

Any compressor is essentially a limiter once the compression
ratio is increased beyond approximately 6:1.

10 July 1998

Compression Ratio is selectable from {1.2:1, 1.5:1, 2:1, 3:1, 4:1,
6:1, 8:1, 12:1, 16:1, 24:1}, though any compressor is essentially
a limiter once the compression ratio is increased beyond
approximately 6:1.

Threshold

The Threshold control adjusts the input signal level above which
compression is used. When the input signal level is below the

threshold value, no compression takes place and the change in
level of the output signal exactly matches the change in level of
the input signal. When the input signal level is above the
threshold value, compression is used and the change in level of
the output signal is less than the change in level of the input
signal by the amount dictated by the selected compression ratio.

Threshold is adjustable in the range -60 dBFS to 0 dBFS.

Attack Time

A compressor monitors the level of the input signal and controls
the level of the output signal accordingly. When the input signal
level suddenly increases, a compressor allows the output signal
level to also increase, but only as much as is appropriate for the
selected compression ratio setting. Desirable sound effects can
sometimes be created if a compressor is forced to ramp the
output signal level to its new value gradually rather than
instantaneously. The Attack Time control adjusts the duration of
this ramp. Attack Time is adjustable in the range 20 µSec (one
sample) to 50 mSec.

Release Time

A compressor monitors the level of the input signal and controls
the level of the output signal accordingly. When the input signal
level suddenly decreases, a compressor allows the output signal
level to also decrease, but only as much as is appropriate for the
selected compression ratio setting. A compressor generally
sounds better if it is forced to ramp the output signal level to its
new value gradually rather than instantaneously. The Release
Time control adjusts the duration of this ramp. Release Time is
adjustable in the range 20 µSec (one sample) to 5 mSec.

8-5

Knee Selection

Below the threshold level, no compression is taking place and
any changes in input level are matched exactly by changes in
output level. Above the threshold level, compression is taking
place and changes in output level are less than the
corresponding changes in input level. The transition from no
compression to compression can be set to take place abruptly or
gradually.

Under hard knee conditions the output level tracks the input level
perfectly as it rises up to the threshold. Above the threshold the
output level continues to rise as dictated by the compression
ratio. There is an abrupt transition from no compression below
the threshold to compression above.

Under soft knee conditions, there is a smooth, gradual transition
from no compression below the threshold to compression above.

Under soft knee conditions the output level and the input level
track until approximately 12-18 dB below the threshold, beyond
which they slowly begin to diverge. Depending upon the
compression ratio selected, the output level may be as much as

Processing Components - Compressor

8-6

2.5 dB below the input level at the threshold. The divergence
continues to increase gradually until approximately 6 dB above
the threshold, beyond which the output level rise is dictated
solely by the selected compression ratio. There is a smooth,
gradual transition from no compression below the threshold to
compression above.

The sonic differences between the two knee types are often
subtle and are very much signal-dependent. Experimentation is
recommended.

Sidechain Source

There are situations in which compression is applied to one
channel based upon the level in another channel. This might be
used in a stereo signal pair to prevent image shift; one of the
channels would be considered to be the level reference and the
compressors in both channels would be set up identically.
Another example might be ducking, where the compression
applied to background music in one channel would be controlled
by the level of the announcer’s voice in another.

The Sidechain Source channel selection indicates the channel
whose level is to be used to control the compressor. If the input
channel is to control itself, then it should be selected as the
Sidechain Source. Otherwise the appropriate other channel
should be selected from the set of available Sidechain Sources
in the menu.

Unfamiliar Controls

There are two controls on the ISP-100 compressor that are not
available in traditional dynamic range compressors. These controls
provide much greater flexibility and utility to this compressor than
can be achieved with traditional compressors.

Detection Window

The detection window is the period of time over which the
compressor computes the average signal level. Every dynamic
range compressor that operates upon average signal level uses
a detection window. In traditional compressors this window is of
fixed length, and the operator may not even be aware of that
length.

Some traditional compressors provide switching between
average and peak detection. This is actually just a selection
between a relatively long detection window of generally a few
tens or hundreds of milliseconds, and a very short detection
window of generally a few tens or hundreds of microseconds.

The ISP-100 compressor provides for operator control of the
length of the detection window. Very dynamic signals and
signals containing a lot of high frequency energy require shorter
detection windows. Non-dynamic signals and signals containing
mostly low frequency energy require longer detection windows.
Detection Window is adjustable in the range 20 µSec (one
sample) to 5 Sec.

10 July 1998

Crest Factor Sensitivity

A signal’s crest factor is the ratio of a its peak level to its average
level. The signal having the lowest possible crest factor is the
square wave, whose peak and average levels are equal and
whose crest factor is therefore 1.0. The peak level of a pure
sinewave tone is 1.414 times its average level; a sinewave
therefore has a crest factor of 1.414. Most music and speech
signals contain peaks that are very much higher than their
average levels; therefore their crest factors are very much
greater than one. The important points to remember are that a
signal’s peak value is always greater than or equal to its average
value, and that the crest factor of any signal is therefore always
greater than or equal to 1.0.

The Crest Factor Sensitivity adjustment on the ISP-100
compressor function controls its sensitivity to the crest factor of
the input signal. It works like this:

The signal level detection algorithm used in the ISP-100
compressor consists of two separate detectors operating in
parallel. One of the detectors computes the average level over
the selected detection window; the other computes the peak
level of each input sample.

8-7

The peak level is multiplied by the setting of the Crest Factor
Sensitivity control, which is always a number between zero and
one. The two quantities are then compared and the larger is
returned as the signal level.

When the Crest Factor Sensitivity is set to 0.00 the ISP-100
compressor operates as a traditional compressor responding to
average signal levels; when the Crest Factor Sensitivity is set to

1.00 the ISP-100 compressor operates as a traditional
compressor responding to peak signal levels. Values in-between
represent various hybrids of the two. If the compressor is to
ignore peaks and respond only to average levels, then the Crest
Factor Sensitivity may be set near zero. If the compressor is to
respond only to peaks, then the Crest Factor Sensitivity may be
set near one.

Good results may be obtained by following these steps:

1. Set the Crest Factor Sensitivity to 0.00. This will cause the
ISP-100 compressor to behave like a traditional compressor
responding to average signal levels.

2. Set all of the other compressor controls as appropriate for the
signal being compressed, just as they would be set in a
traditional compressor.

3. Adjust the Crest Factor Sensitivity control so that the
compressor responds appropriately to short signal peaks. If it
were possible to know, in advance, what the crest factor of the

Processing Components - Compressor

8-8

input signal was going to be, then the Crest Factor Sensitivity
control would ideally be set to:

1

SignalInputofFactorCrest

Since this quantity is not generally known, it is best to
experiment until satisfactory results are obtained.

Metering

The compressor meter shows the attenuation applied to the signal
passing through the compressor at any given moment in time. When
the signal is being compressed the meter indicates negative values
(gain less than 1.0). When the signal is not being compressed the
meter indicates 0 dB (gain of 1.0). Meter values are raw, no
averaging or ballistics are applied.

Notes on Operation of the Compressor

Bypass

Bypassing a compressor causes the signal to pass through
unaltered.

Overshoot

The compressor algorithm used in the ISP-100 allows for a small
amount of overshoot on transients, regardless of the settings of
the Detection Window and Crest Factor Sensitivity controls. The
amount of overshoot is somewhat dependent upon the setting of
the Threshold control; the lower the threshold the greater the
overshoot. This represents normal operation for the compressor.

Computation of Average Level

There are two common methods of computing average signal
level; one is based upon RMS (Root Mean Square) calculations,
and the other is based upon Absolute Value calculations. Each
of these methods produces a slightly different value for signal
level, and the difference depends upon the characteristics of the
signal itself. The ISP-100 compressor uses Absolute Value for
its computation of signal level, so the level reported by the
compressor may differ slightly from the RMS value expected for
a given signal.

Crest Factor Sensitivity and Sinewaves

The peak level of a pure sinewave tone is 1.414 times its
average level. The ISP-100 compressor will therefore apply
approximately 3 dB more compression to a pure sinewave
signal when the Crest Factor Sensitivity is set to 1.00 (peak­responding) than when it is set to 0.00 (average-responding).
This represents normal operation for the compressor.

10 July 1998

Sidechaining

When the sidechain input to an ISP-100 compressor is selected
to be a channel other than its input, the compressor controls
must still be set. The sidechain selects only the channel’s data,

not its compressor control settings. If multiple compressors
utilize the same channel as their sidechain sources, then all
controls on all compressors must still be configured.

Meter

The meter located at the left of the component indicates the amount
of attenuation taking place in dB.

Threshold

The Threshold can be adjusted three ways:

Using the Slider

Click on the indicator on the slider and while continuing to hold
down the mouse button, move the mouse up and down. The
numbers in the box below the slider will change. When the
desired level is reached, release the mouse button.

Using the Text Box

Click in the box. Using the Back Space and/or Delete keys
erases the current entry and enters the new level. Be sure to
press the Enter key after the entry is made. Clicking outside the
text box without pressing the Enter key will cause the setting to
return to the number that it was before a change was attempted.
Alternatively, click and drag across the number in the box to
highlight the number in it. Type the new setting and press the
Enter key when finished.

8-9

Using the UP/DOWN Arrows

To increase the level, click on the up arrow. To decrease the
level attenuation, click on the down arrow. The amount of
increase or decrease is controlled by the fine/coarse control.

Attack, Window, Release, and Crest factor controls.

All of these controls can be adjusted in three ways:

Using the Knob

Click on the indicator on the knob and while continuing to hold
down the mouse button, move the mouse in an arc. The
numbers in the box below the knob will change. When the
desired level is reached, release the mouse button.

Using the Text Box

Click in the box. Using the Back Space and/or Delete keys
erases the current entry and enters the new level. Be sure to
press the Enter key after the entry is made. Clicking outside the
text box without pressing the Enter key will cause the setting to
return to the number that it was before a change was attempted.
Alternatively, click and drag across the number in the box to
highlight the number in it. Type the new setting and press the
Enter key when finished.

Processing Components - Compressor

8-10

Using the UP/DOWN Arrows

To increase the level, click on the up arrow. To decrease the
level attenuation, click on the down arrow. The amount of
increase or decrease is controlled by the fine/coarse control.

Fine (F) or Coarse (C) Control

This button determines the increment/decrement associated with the
UP/DOWN arrows. Fine produces small steps in value, while Coarse
provides large steps in value. Clicking on the button will toggle the
setting.

Knee Control

This button determines the type of transition that occurs when the
component goes from inactive to active. A Hard knee causes the
response by the component to be abrupt, while a Soft knee causes a
gentle response. Clicking on the button will toggle the setting.

Ratio Control

To change settings, click on the arrow next to the number in the text
box. A selection list will appear. The list may or may not be
scrollable. To make a selection click on the desired entry.

Sidechain

To make a selection click on the desired entry.

Bypass Control (master)

This button determines if the component is in the processing chain. If
the LED on the button is gray, then the component is inserted into
the signal processing chain. If the LED is red, then the component is
bypassed in the signal processing chain. A bypassed component will
be colored red in the QuickMAP.

10 July 1998

Crossover

8-11

Custom crossovers
other than those
available from the
crossover
component can be
constructed by
using the filter
component.

Figure 8-3

Crossovers (see Figure 8-3) are used to divide the audio signal into
multiple bands appropriate for different types of loudspeakers or
loudspeaker elements. In QuickMAPs, 2-way, 3-way, and 4-way
crossovers may exist. Each of these crossovers may be implemented
using Bessel or Butterworth filters with 1st- through 4th-order slopes, or
Linkwitz-Riley filters with 2nd- or 4th-order slopes, or combinations
thereof.

Two-Way Crossovers

Figure 8-4

Two-way crossover component.

Two-way crossover implementation.

In the ISP-100, 2-way crossovers are implemented as shown in
Figure 8-4.

Processing Components - Crossover

8-12

The lowpass filter LP1 and the highpass filter HP1 may each be
independently configured as:

Bessel 6 dB/octave (1st-order)
Bessel 12 dB/octave (2nd-order)
Bessel 18 dB/octave (3rd-order)
Bessel 24 dB/octave (4th-order)

Butterworth 6 dB/octave (1st-order)
Butterworth 12 dB/octave (2nd-order)
Butterworth 18 dB/octave (3rd-order)
Butterworth 24 dB/octave (4th-order)

Linkwitz-Riley (Butterworth-Squared) 12 dB/octave (2nd-order)
Linkwitz-Riley (Butterworth-Squared) 24 dB/octave (4th-order)

In addition, the cutoff frequency, attenuation, and polarity in the low
band and the high band may be independently adjusted, and the
filters in either band may be bypassed entirely.

The cutoff frequency in each filter is continuously variable from 20
Hz to 20 kHz.

The attenuation in each band is continuously variable from -96 dB to
0 dB, plus mute.

The polarity in each band is selectable as + or - (in-phase or out-of­phase).

Each band may be bypassed, in which case all of the crossover
filters in that band will be bypassed while the crossover filters in the
other band will not be affected.

Two-Way Bessel and Butterworth Crossovers

Bessel crossovers utilize Bessel filters. Bessel filters are
designed for maximally-flat group delay, meaning that they have
nearly linear phase and excellent transient response. Their
amplitude response is not as flat and their cutoff is not as sharp
as those of Butterworth filters.

Butterworth crossovers utilize Butterworth filters. Butterworth
filters are designed for maximally-flat amplitude response,
meaning that the amplitude response in the passband is as flat
as possible without ripple. Their phase response is not nearly as
linear and their transient response is not as good as those of
Bessel filters.

The Bessel filters used in the ISP-100 crossovers are
automatically scaled so that their amplitude response is -3 dB at
the selected cutoff frequency, regardless of the filter order.

10 July 1998

The amplitude response of a Butterworth filter is naturally -3 dB
at the selected cutoff frequency, regardless of the filter order.

Two-way Linkwitz-Riley Crossovers

Linkwitz-Riley designs constitute a special, even-order in-phase
class of two-way sum-to-allpass response crossovers, and they
must be configured in accordance with very strict phase and
polarity requirements.

A properly implemented 2-way, 12 dB/octave Linkwitz-Riley
crossover is characterized by:

•2nd-order Linkwitz-Riley (Butterworth-Squared) lowpass filter, -6
dB magnitude response at crossover frequency

•2nd-order Linkwitz-Riley (Butterworth-Squared) highpass filter,

-6 dB magnitude response at crossover frequency

• polarity of highpass band opposite that of lowpass band

A properly implemented 2-way, 24 dB/octave Linkwitz-Riley
crossover is characterized by:

•4th-order Linkwitz-Riley (Butterworth-Squared) lowpass filter, -6
dB magnitude response at crossover frequency

•4th-order Linkwitz-Riley (Butterworth-Squared) highpass filter, ­6 dB magnitude response at crossover frequency

• polarity of highpass band the same as that of lowpass band

8-13

Summarizing: In a 2-way, 12 dB/octave Linkwitz-Riley crossover
the high band must be out-of-phase with the low band; in a 2­way, 24 dB/octave Linkwitz-Riley crossover the high band must
be in-phase with the low band.

Three-Way Crossovers

Figure 8-5

In the ISP-100, 3-way crossovers are implemented as shown in
Figure 8-5.

Three-way crossover implementation.

This parallel structure was selected over the more common binary­tree structure for its suitability to the distribution of filters among
multiple DSPs. The parallel structure is also capable of perfect

Processing Components - Crossover

8-14

implementation of Linkwitz-Riley crossovers, for which the ISP-100
has been optimized. The filters marked optional in Figure 8-5 will be
explained in the Linkwitz-Riley Crossover section, below.

The lowpass filters LPx (except for the optional LP2) and the
highpass filters HPx may each be independently configured as:

Bessel 6 dB/octave (1st-order)
Bessel 12 dB/octave (2nd-order)
Bessel 18 dB/octave (3rd-order)
Bessel 24 dB/octave (4th-order)

Butterworth 6 dB/octave (1st-order)
Butterworth 12 dB/octave (2nd-order)
Butterworth 18 dB/octave (3rd-order)
Butterworth 24 dB/octave (4th-order)

Linkwitz-Riley (Butterworth-Squared) 12 dB/octave (2nd-order)
Linkwitz-Riley (Butterworth-Squared) 24 dB/octave (4th-order)

In addition, the cutoff frequency, attenuation, and polarity in the low
band, the mid band, and the high band may be independently
adjusted, and all of the filters in any band may be bypassed entirely.

The cutoff frequency in each filter is continuously variable from 20
Hz to 20 kHz.

The attenuation in each band is continuously variable from -96 dB to
0 dB, plus mute.

The polarity in each band is selectable as + or - (in-phase or out-of­phase).

Each band may be bypassed, in which case all of the crossover
filters in that band will be bypassed while the crossover filters in the
other bands will not be affected.

Three-way Bessel and Butterworth Crossovers

10 July 1998

Figure 8-6

Three-way Bessel & butterworth crossover implementation.

In the ISP-100, 3-way Bessel and Butterworth crossovers are
implemented as shown in Figure 8-6.

Bessel crossovers utilize Bessel filters. Bessel filters are
designed for maximally-flat group delay, meaning that they have
nearly linear phase and excellent transient response. Their
amplitude response is not as flat and their cutoff is not as sharp
as those of Butterworth filters.

Butterworth crossovers utilize Butterworth filters. Butterworth
filters are designed for maximally-flat amplitude response,
meaning that the amplitude response in the passband is as flat
as possible without ripple. Their phase response is not nearly as
linear and their transient response is not as good as those of
Bessel filters.

The Bessel filters used in the ISP-100 crossovers are
automatically scaled so that their amplitude response is -3 dB at
the selected cutoff frequency, regardless of the filter order.

The amplitude response of a Butterworth filter is naturally -3 dB
at the selected cutoff frequency, regardless of the filter order.

8-15

Three-way Linkwitz-Riley Crossovers

Figure 8-7

In the ISP-100, 3-way Linkwitz-Riley crossovers are
implemented as shown in Figure 8-7.

Linkwitz-Riley designs constitute a special, even-order in-phase
class of two-way sum-to-allpass response crossovers, and they
must be configured in accordance with very strict phase and
polarity requirements. Because the basic Linkwitz-Riley
crossover is a 2-way design, extra steps must be taken in 3-way
Linkwitz-Riley crossovers to ensure that these phase and
polarity requirements are met.

Three-way Linkwitz-Riley crossover implementation.

Note the presence of the unexpected θ1 allpass filter in the high

Processing Components - Crossover

8-16

band and LP2 lowpass filter in the low band. The inclusion of
these filters is mandatory for proper implementation of the 3-way
Linkwitz-Riley crossover; they ensure that the phase shift and
magnitude response in each band match those of the other
bands to maintain the fundamental Linkwitz-Riley sum-to-allpass
quality. A detailed explanation of the use of compensation filters
such as these may be found in “Active Realization of Multiway
All-Pass Crossover Systems” by Joseph A. D’Appolito;

of the Audio Engineering Society

1987.
A 3-way Linkwitz-Riley crossover is essentially a combination of

two 2-way Linkwitz-Riley crossovers. This means that the
polarity requirements associated with a 2-way Linkwitz-Riley
crossover carry over to a 3-way crossover.

A properly implemented 2-way, 12 dB/octave Linkwitz-Riley
crossover is characterized by:

•2nd-order Linkwitz-Riley (Butterworth-Squared) lowpass filter, -6
dB magnitude response at crossover frequency

•2nd-order Linkwitz-Riley (Butterworth-Squared) highpass filter,

-6 dB magnitude response at crossover frequency

• polarity of highpass band opposite that of lowpass band

, Volume 35, Number 4, April

Journal

In a 3-way crossover the bands associate in non-obvious ways
(see Sum-to-Allpass Characteristics of Linkwitz-Riley
Crossovers), and the polarity reference for the high band is
unexpectedly the low band, rather than the adjacent mid band.
Thus, if a 12 dB/octave filter is used for LP1 and HP1, then the
mid band must be out-of-phase with the low band. If a 12 dB/
octave filter is used for LP2 and HP2, then the high band must be
out-of-phase with the low band, not the mid band.

A properly implemented 2-way 24 dB/octave Linkwitz-Riley
crossover is characterized by:

•4th-order Linkwitz-Riley (Butterworth-Squared) lowpass filter, -6
dB magnitude response at crossover frequency

•4th-order Linkwitz-Riley (Butterworth-Squared) highpass filter,

-6 dB magnitude response at crossover frequency

• polarity of high band the same as that of low band

In a 3-way crossover the bands associate in non-obvious ways
(see Sum-to-Allpass Characteristics of Linkwitz-riley
Crossovers), and the polarity reference for the high band is
unexpectedly the low band, rather than the adjacent mid band.
Thus, if a 24 dB/octave filter is used for LP1 and HP1, then the
mid band must be in-phase with the low band. If a 24 dB/octave
filter is used for LP2 and HP2, then the high band must be the in­phase with the low band, not the mid band.

10 July 1998

Four-Way Crossovers

8-17

Figure 8-8

In the ISP-100, 4-way crossovers are implemented as shown in
Figure 8-8.

This parallel structure was selected over the more common binary­tree structure for its suitability to the distribution of filters among
multiple DSPs. The parallel structure is also capable of perfect
implementation of Linkwitz-Riley crossovers, for which the ISP-100
has been optimized. The filters marked optional in Figure 8-8 will be
explained in the Linkwitz-Riley Crossover section.

The lowpass filters LPx (except for the optional LP2) and the
highpass filters HPx (except for the optional HP2) may each be
independently configured as:

Bessel 6 dB/octave (1st-order)
Bessel 12 dB/octave (2nd-order)
Bessel 18 dB/octave (3rd-order)
Bessel 24 dB/octave (4th-order)

Butterworth 6 dB/octave (1st-order)
Butterworth 12 dB/octave (2nd-order)
Butterworth 18 dB/octave (3rd-order)
Butterworth 24 dB/octave (4th-order)

Four-way crossover implementation.

Linkwitz-Riley (Butterworth-Squared) 12 dB/octave (2nd-order)
Linkwitz-Riley (Butterworth-Squared) 24 dB/octave (4th-order)

In addition, the cutoff frequency, attenuation, and polarity in the low
band, the low-mid band, the mid-high band, and the high band may
be independently adjusted, and all of the filters in any band may be
bypassed entirely.

The cutoff frequency in each filter is continuously variable from 20
Hz to 20 kHz.

Processing Components - Crossover

8-18

The attenuation in each band is continuously variable from -96 dB
and 0 dB, plus mute.

The polarity in each band is selectable as + or - (in-phase or out-of­phase).

Each band may be bypassed, in which case all of the crossover
filters in that band will be bypassed while the crossover filters in the
other bands will not be affected.

Four-way Bessel and Butterworth Crossovers

Figure 8-9

Four-way Bessel & Butterworth crossover implementation.

In the ISP-100, 4-way Bessel and Butterworth crossovers are
implemented as shown in Figure 8-9.

Bessel crossovers utilize Bessel filters. Bessel filters are
designed for maximally-flat group delay, meaning that they have
nearly linear phase and excellent transient response. Their
amplitude response is not as flat and their cutoff is not as sharp
as those of Butterworth filters.

Butterworth crossovers utilize Butterworth filters. Butterworth
filters are designed for maximally-flat amplitude response,
meaning that the amplitude response in the passband is as flat
as possible without ripple. Their phase response is not nearly as
linear and their transient response is not as good as those of
Bessel filters.

The Bessel filters used in the ISP-100 crossovers are
automatically scaled so that their amplitude response is -3 dB at
the selected cutoff frequency, regardless of the filter order.

The amplitude response of a Butterworth filter is naturally -3 dB
at the selected cutoff frequency, regardless of the filter order.

10 July 1998

Four-way Linkwitz-Riley Crossovers

8-19

Figure 8-10

Four-way Linkwitz-Riley crossover implementation.

In the ISP-100, 4-way Linkwitz-Riley crossovers are
implemented as shown in Figure 8-10.

Linkwitz-Riley designs constitute a special, even-order in-phase
class of 2-way sum-to-allpass response crossovers, and they
must be configured in accordance with very strict phase and
polarity requirements. Because the basic Linkwitz-Riley
crossover is a 2-way design, extra steps must be taken in 4-way
Linkwitz-Riley crossovers to ensure that these phase and
polarity requirements are met.

Note the presence of the unexpected θ1 allpass filter and HP
highpass filter in the high band, the θ1 allpass filter in the mid­high band, the θ3 allpass filter in the low-mid band, and the LP
lowpass filter and θ3 allpass filter in the low band. The inclusion
of these filters is mandatory for proper implementation of the 4­way Linkwitz-Riley crossover; they ensure that the phase shift
and magnitude response in each band match those of the other
bands to maintain the fundamental Linkwitz-Riley sum-to-allpass
quality. A detailed explanation of the use of compensation filters
such as these may be found in “Active Realization of Multiway
All-Pass Crossover Systems” by Joseph A. D’Appolito;

of the Audio Engineering Society

, Volume 35, Number 4, April

Journal

1987.

2

2

A 4-way Linkwitz-Riley crossover is essentially a combination of
three 2-way Linkwitz-Riley crossovers. This means that the
polarity requirements associated with a 2-way Linkwitz-Riley
crossover carry over to a 4-way crossover.

Processing Components - Crossover

8-20

A properly implemented 2-way, 12 dB/octave Linkwitz-Riley
crossover is characterized by:

•2nd-order Linkwitz-Riley (Butterworth-Squared) lowpass filter, -6
dB magnitude response at crossover frequency

•2nd-order Linkwitz-Riley (Butterworth-Squared) highpass filter,

-6 dB magnitude response at crossover frequency

• polarity of highpass band opposite that of lowpass band

In a 4-way crossover the bands associate in non-obvious ways
(see Sum-to-Allpass Characteristics of Linkwitz-Riley
Crossovers). As expected, the polarity reference for the low-mid
band is the low band, and the polarity reference for the high
band is the mid-high band. However, the polarity reference for
the mid-high band is unexpectedly the low band, rather than the
adjacent low-mid band. Thus, if a 12 dB/octave filter is used for
LP1 and HP1, then the low-mid band must be out-of-phase with
the low band. If a 12 dB/octave filter is used for LP3 and HP3,
then the high band must be out-of-phase with the mid-high band.
And if a 12 dB/octave filter is used for LP2 and HP2, then the mid­high band must be out-of-phase with the low band, not the low­mid band.

A properly implemented 2-way 24 dB/octave Linkwitz-Riley
crossover is characterized by:

•4th-order Linkwitz-Riley (Butterworth-Squared) lowpass filter, -6
dB magnitude response at crossover frequency

•4th-order Linkwitz-Riley (Butterworth-Squared) highpass filter,

-6 dB magnitude response at crossover frequency

• polarity of high band the same as that of low band

In a 4-way crossover the bands associate in non-obvious ways
(see Sum-to-Allpass Characteristics of Linkwitz-riley
Crossovers). As expected, the polarity reference for the low-mid
band is the low band, and the polarity reference for the high
band is the mid-high band. However, the polarity reference for
the mid-high band is unexpectedly the low band, rather than the
adjacent low-mid band. Thus, if a 24 dB/octave filter is used for
LP1 and HP1, then the low-mid band must be in-phase with the
low band. If a 24 dB/octave filter is used for LP3 and HP3, then
the high band must be the in-phase with the mid high band. And
if a 24 dB/octave filter is used for LP2 and HP2, then the mid high
band must be the in-phase with the low band, not the low-mid
band.

Sum-to-Allpass Characteristics of Linkwitz-Riley Crossovers

A characteristic of 2-way Linkwitz-Riley crossovers is that the output
bands sum to an allpass filter—the frequency response of the sum
has a constant magnitude of one and only phase shift occurs. From
Figure 8-4, this means that

10 July 1998

LPx - HPx = θ

or

LP

+ HPx = θ

x

x

x

depending upon whether 12 dB/octave or 24 dB/octave filters are
used, respectively.

The following sections will show this sum-to-allpass trait to hold true
for the ISP-100 Linkwitz-Riley 3-way and 4-way crossover
implementations.

Three-way

From Figure 8-6

8-21

Summed Response = LP1LP2 ± HP1LP2 ± θ1HP

= (LP1 ± HP1)LP2 ± θ1HP
= θ1LP2 ± θ 1HP
= θ1(LP2 ± HP2)
= θ

Q.E.D.

1θ2

2

2

2

There is an alternate configuration, not implemented in the ISP­100, that also has this property:

Summed Response = LP1θ2 ± HP1LP2 ± HP1HP

= LP1θ2 ± HP1(LP2 ± HP2)
= LP1θ2 ± HP1θ
= (LP1 ± HP1)θ

2

2

= θ1θ2 Q.E.D.

2

Four-way

From Figure 8-9

Summed Response = LP1LP2θ3 ± HP1LP2θ3 ± θ 1HP2LP3 ±θ1HP2HP

= (LP1 ± HP1)LP2θ3 ± θ1HP2(LP3 ± HP3)
= θ1LP2θ 3 ± θ 1HP2θ
= θ1(LP2 ± HP2)θ
= θ1θ2θ3 Q.E.D.

3

3

3

Low, Low-Mid, Mid, Mid-High and High Controls

The Low, Low-Mid, Mid, Mid-High and High buttons determine if
that section of the crossover is bypassed. If the word Low, Low-Mid,
Mid, Mid-High or High is displayed on the button, then that portion of
the crossover is not bypassed. If the word Bypassed is displayed on
the button’s face, then that portion of the crossover is bypassed.
Clicking on the buttons will toggle their settings.

Link/Unlink Control

The Link/Unlink button determines if the settings in the crossover
track their corresponding partners. A simple rule of thumb is that
when the sections are linked, the component on the right will track its
partner on the left. Clicking on the button(s) will toggle the settings.

Slope

To change settings, click on the arrow next to the number in the text
box. A selection list will appear. The list may or may not be
scrollable. To make a selection click on the desired entry.

Processing Components - Crossover

8-22

Class

To change settings, click on the arrow next to the number in the text
box. A selection list will appear. The list may or may not be
scrollable. To make a selection click on the desired entry.

Cutoff Frequency

The Cutoff Frequency can be adjusted three ways:

Using the Knob

Click on the indicator on the knob and while continuing to hold
down the mouse button, move the mouse in an arc. The
numbers in the box below the knob will change. When the
desired level is reached, release the mouse button.

Using the Text Box

Click in the box. Using the Back Space and/or Delete keys
erases the current entry and enters the new level. Be sure to
press the Enter key after the entry is made. Clicking outside the
text box without pressing the Enter key will cause the setting to
return to the number that it was before a change was attempted.
Alternatively, click and drag across the number in the box to
highlight the number in it. Type the new setting and press the

Enter key when finished.

Using the UP/DOWN Arrows

To increase the level, click on the up arrow. To decrease the
level attenuation, click on the down arrow. The amount of
increase or decrease is controlled by the fine/coarse control.

Passband Gain

The Passband Gain can be adjusted three ways:

Using the Knob

Click on the indicator on the knob and while continuing to hold
down the mouse button, move the mouse in an arc. The
numbers in the box below the knob will change. When the
desired level is reached, release the mouse button.

Using the Text Box

Click in the box. Using the Back Space and/or Delete keys
erases the current entry and enters the new level. Be sure to
press the Enter key after the entry is made. Clicking outside the
text box without pressing the Enter key will cause the setting to
return to the number that it was before a change was attempted.
Alternatively, click and drag across the number in the box to
highlight the number in it. Type the new setting and press the

Enter key when finished.

Using the UP/DOWN Arrows

To increase the level, click on the up arrow. To decrease the
level attenuation, click on the down arrow. The amount of
increase or decrease is controlled by the fine/coarse control.

10 July 1998

Fine (F) or Coarse (C) Control

This button determines the increment/decrement associated with the
UP/DOWN arrows. Fine produces small steps in value, while Coarse
provides large steps in value. Clicking on the button will toggle the
setting.

Polarity Control (+/-)

This button determines the polarity of the signal. A + indicates that
the signal will not have it’s phase altered. A - indicates that the
signal’s phase will be changed 180°. Clicking on the button will
toggle the setting.

Mute Control (M)

This button determines if the input signal will be muted. A black M
indicates that the signal is not muted, while a red M indicates that the
signal is muted. Clicking on the button will toggle the setting.

8-23

Processing Components - Crossover

8-24

Cut

Figure 8-11

The Cut (see Figure 8-11) can apply as much as 96 dB attenuation, or
mute completely, and invert polarity.

Attenuation and Polarity

Application of attenuation is accomplished by multiplying each data
sample by a number whose absolute value lies between 1.0 (0 dB)
and 0.000015625 (-96 dB). Muting is accomplished by multiplying
each sample by zero. Polarity inversion is accomplished by
multiplying by a negative number. All gain and polarity changes are
soft, meaning that they are gradually changed from the old setting to
the new in order to help prevent the occurrence of clicks or pops.

Bypass

Bypassing cut is equivalent to setting its attenuation to 0 dB and its
polarity to + (in-phase). Bypassing a muted attenuator un-mutes it.

Attenuator

The attenuator can be set three ways:

Using the Knob

Click on the indicator on the knob and while continuing to hold
down the mouse button, move the mouse in an arc. The
numbers in the box below the knob will change. When the
desired level is reached, release the mouse button.

Cut component.

10 July 1998

Using the Text Box

Click in the box. Using the Back Space and/or Delete keys
erases the current entry and enters the new level. Be sure to
press the Enter key after the entry is made. Clicking outside the
text box without pressing the Enter key will cause the setting to
return to the number that it was before a change was attempted.
Alternatively, click and drag across the number in the box to
highlight the number in it. Type the new setting and press the

Enter key when finished.

Using the UP/DOWN Arrows

To increase the level, click on the up arrow. To decrease the
level attenuation, click on the down arrow. The amount of
increase or decrease is controlled by the fine/coarse control.

Fine (F) or Coarse (C) Control

This button determines the increment/decrement associated with the
UP/DOWN arrows. Fine produces small steps in value, while Coarse
provides large steps in value. Clicking on the button will toggle the
setting.

Polarity Control (+/-)

This button determines the polarity of the signal. A + indicates that
the signal will not have it’s phase altered. A - indicates that the
signal’s phase will be changed 180. Clicking on the button will toggle
the setting.

Mute Control (M)

This button determines if the input signal will be muted. A black M
indicates that the signal is not muted, while a red M indicates that the
signal is muted. Clicking on the button will toggle the setting.

Bypass Control (master)

This button determines if the component is in the processing chain. If
the LED on the button is gray, then the component is inserted into
the signal processing chain. If the LED is red, then the component is
bypassed in the signal processing chain. A bypassed component will
be colored red in the QuickMAP.

8-25

Processing Components - Cut

8-26

Delay

Figure 8-12

Delay (see Figure 8-12) is used to compensate for differences in the
physical alignment of loudspeakers or loudspeaker drivers.

In the ISP-100, the delay in each output channel is adjustable in the
range 0 – 2,500 milliseconds (depending on QuickMAP used) in 20.833
microsecond (single sample) increments. This translates to
approximately (0 - 2750 feet) in 0.275 inch increments, assuming that the
speed of sound is approximately 1100 ft/sec.

Setting Delay

The Delay control can be adjusted two ways:

Using the Text Box

Click in the box. Using the Back Space and/or Delete keys
erases the current entry and enters the new level. Be sure to
press the Enter key after the entry is made. Clicking outside the
text box without pressing the Enter key will cause the setting to
return to the number that it was before a change was attempted.
Alternatively, click and drag across the number in the box to
highlight the number in it. Type the new setting and press the

Enter key when finished.

Using the UP/DOWN Arrows

To increase the level, click on the up arrow. To decrease the
level attenuation, click on the down arrow. The amount of
increase or decrease is controlled by the fine/coarse control.

Delay component.

10 July 1998

Fine (F) or Coarse (C) Control

This button determines the increment/decrement associated with the
UP/DOWN arrows. Fine produces small steps in value, while Coarse
provides large steps in value. Clicking on the button will toggle the
setting.

Bypass Control (master)

This button determines if the component is in the processing chain. If
the LED on the button is gray, then the component is inserted into
the signal processing chain. If the LED is red, then the component is
bypassed in the signal processing chain. A bypassed component will
be colored red in the QuickMAP.

Dither

8-27

Figure 8-13

Dithering (see Figure 8-13) is used when shortening high resolution
digital audio data words to a lower resolution; for example, when sending
24-bit ISP-100 audio data to 20-bit D/A converters, or directly to a 16-bit
Digital Audio Tape recorder through a digital interface. Simply truncating,
or discarding, the unused bits results in audible artifacts that are
generally objectionable. Dithering does not eliminate these artifacts, it
changes their characteristics so that they are less noticeable to the
human ear.

If, after reducing the number of bits in a signal, the original high­resolution (more bits) signal is subtracted from the final lower-resolution
(fewer bits) signal, the difference is called the error signal:

(Final Signal) - (Original Signal) = (Error Signal)

Some very simple algebra shows that the final signal can be thought of
as the sum of the error signal and the original signal:

(Final Signal) = (Error Signal) + (Original Signal)

When audio data words are shortened by simple truncation, it turns out
that the error signal is correlated with itself and with the original signal.
This simply means that the error signal is not pure white noise, and that
the frequency and amplitude of the error signal is in some way related to
the frequency and amplitude of the original signal.

Dither component.

If noise with some very specific amplitude and spectral characteristics is
added to the original signal before truncation, then the correlation is
destroyed and the error signal sounds like low level noise instead of
tones. Even though the added noise actually raises the noise floor in the
final low-resolution signal, it sounds better because human hearing finds
low level broadband noise to be much less objectionable than spurious
tones.

This addition of noise before truncation is called dithering. The noise that
is added is called the dither signal.

In summary, dithering is a way of making digital audio better by making it
worse.

Bit Level

In the ISP-100 the bit level of the dither signal is selectable as whole

Processing Components - Dither

8-28

numbers between 16 and 24 bits, inclusive. The bit level of the dither
signal should be set to the bit resolution of the destination for the
data. The resulting dither signal will have an amplitude equal to ±1.0
quantization level (peak-to-peak) at the selected Bit Level.

Using the examples, the bit level for the dither signal should be set to
20 bits when the data are destined for the 20-bit D/A converters, and
to 16 bits when the data are destined for the DAT recorder.

Dither Signal Characteristics

The dither signal used in the ISP-100 has a highpass spectral shape
for reduced audibility. It is characterized by approximately a +6 dB/
octave slope in the audio band.

The dither signal used in the ISP-100 has a triangular probability
density function (TPDF) for the minimization of noise modulation
effects.

Bypass

Bypassing dither results in no dither whatsoever being added to the
signal. This is different than setting the dither to the 24th bit level.

Dither Bit Level

To change settings, click on the arrow next to the number in the text
box. A selection list will appear. The list may or may not be
scrollable. To make a selection click on the desired entry.

Bypass Control (master)

This button determines if the component is in the processing chain. If
the LED on the button is gray, then the component is inserted into
the signal processing chain. If the LED is red, then the component is
bypassed in the signal processing chain. A bypassed component will
be colored red in the QuickMAP.

10 July 1998

Filter

8-29

The filter component
can be used to
implement custom
crossovers.

Figure 8-14

Filters (see Figure 8-14) are used to modify the spectral balance,
frequency content, or phase response of the signals upon which they
operate.

Filter Bands

The filters in the ISP-100 are arranged in bands, each of which
represent a single 2nd-order filter in the DSP code. Each band can
be configured as one of seventeen different filter types:

LowPass Filter, 6 dB/octave
LowPass Filter, 12 dB/octave*

HighPass Filter, 6 dB/octave
HighPass Filter, 12 dB/octave*

LowShelf Filter, 6 dB/octave
LowShelf Filter, 12 dB/octave

HighShelf Filter, 6 dB/octave
HighShelf Filter, 12 dB/octave

Notch Filter

Filter component.

Parametric EQ Filter
Peaked HighPass Filter
AllPass Filter, 1st-order

AllPass Filter, 2nd-order
* More filters available in the Crossover filters.

Processing Components - Filter

8-30

All filters in the ISP-100 are derived from analog prototypes. The
analog filters are approximated by the Bilinear Transform method,
prewarped to match response at the critical frequency appropriate for
the type of filter (cutoff frequency for LowPass/HighPass and Peaked
HighPass; hinge frequency for LowShelf/HighShelf; center frequency
for all others).

Each filter band may be bypassed; so as to pass the signal
unaltered.

LowPass Filters

LowPass Filters pass low frequencies and stop high frequencies.
Since it is not realistically possible to create a perfect filter that
passes low frequencies totally unaltered and stops high frequencies
completely, lowpass filter design involves compromises that allow
some rounding of the corner at the filter cutoff frequency and some
slope in the transition to the high frequency stopband. Different
compromise schemes are given different names; the ISP-100
incorporates Bessel, Butterworth, and Linkwitz-Riley lowpass filter
types.

The cutoff frequency is defined as the frequency at which the
magnitude of the filter response has fallen to -3 dB relative to the
unfiltered signal in the Bessel and Butterworth types, and to -6 dB in
the Linkwitz-Riley types. In the ISP-100 lowpass filters the cutoff
frequency is continuously variable from 20Hz to 20 kHz.

In the ISP-100 lowpass filters the passband slope is selectable from

-6 dB/octave to -12 dB/octave for the Bessel and Butterworth types.

NOTE

: Linkwitz-Riley filters are also known as Butterworth-Squared
filters because they are the product of two Butterworth filters. A -12
dB/octave Linkwitz-Riley lowpass filter may be constructed by
cascading two identical -6 dB/octave Butterworth lowpass filters; a ­24 dB/octave Linkwitz-Riley lowpass filter may be constructed by
cascading two identical -12 dB/octave Butterworth lowpass filters.

HighPass Filters

HighPass Filters pass high frequencies and stop low frequencies.
Since it is not realistically possible to create a perfect filter that
passes high frequencies totally unaltered and stops low frequencies
completely, highpass filter design involves compromises that allow
some rounding of the corner at the filter cutoff frequency and some
slope in the transition to the low frequency stopband. Different
compromise schemes are given different names; the ISP-100
incorporates Bessel, Butterworth, and Linkwitz-Riley lowpass filter
types.

The cutoff frequency is defined as the frequency at which the
magnitude of the filter response has fallen to -3 dB relative to the
unfiltered signal in the Bessel and Butterworth types, and to -6 dB in
the Linkwitz-Riley types. In the ISP-100 highpass filters the cutoff
frequency is continuously variable from 20Hz to 20 kHz.

10 July 1998