Sound Performance Lab 9632 User Manual

Manual

Digital Dynamics Processor

Loudness Maximizer

Model 9632

Loudness Maximizer

Model 9632

Manual

by Hermann Gier

Version 3.1 – 9/1999

The information in this document has been
carefully verified and is assumed to be
correct. However Sound Performance Lab
(SPL) reserves the right to modify the product
described in this manual at any time.Changes
without notice.

This document is the property of SPL and
may not be copied or reproduced in any
manner, in part or full without the authoriza­tion of SPL.

Limitations of Liability:

In no event will SPL be liable for any
damages, including loss of data, lost profits,
cost of cover or other special, incidental,
consequential or indirect damages arising
from the use of the unit, however caused and
on any theory of liability. This limitation will
apply even if SPL or an authorized dealer has
been advised of the possibility of such damage.

SPL electronics GmbH

P. O . B ox 1 2 2 7

D- 41368 Niederkruechten, Germany

Tel. +49 - (0)21 63 / 98 34-0

Fax +49 - (0)21 63 / 98 34-20

E-Mail: [e-mail]

www.spl-electronics.com

© 1999 SPL electronics GmbH. All Rights Reserved.

3

Contents

Dear customer,

Thank you for the confidence you have shown towards Sound
Performance Lab by purchasing the SPL Loudness Maximizer.You
have decided to use a tool of high performance which sets you in
the position to have faster success and a better sound quality in
your music productions and pre-masterings.

As a typical SPL unit the Loudness Maximizer combines exem­plary specifications and high manufacturing standard with excel­lent sound quality to provide you a precious component for
studio and mastering purposes.

Please read this manual carefully to ensure you have all the
information you need to use the Loudness Maximizer. We wish
you every success with your new Loudness Maximizer.

Your Sound Performance Lab-Team

I would like to start with my thanks to all our staff, who created
what is to be described here. Special thanks go to Jörg Houpert,
Jörg Mayer, Andreas Skäbe and Klaus-Peter Webersinke from
Spectral Design, as well as Harald Obenland from Octum electro­nics.

Our products are often tested and compared in many publica­tions and by our customers themselfs and constantly valued with
best results. I would like to pass on this broad appreciation to
those,who deserve it – my excellent colleagues.

Hermann Gier

Foreword

Thanks

Foreword................................................................................................... 3

Thanks........................................................................................................ 3

Introduction ............................................................................................. 4

Operation Safety..................................................................................... 5

Connections............................................................................................. 6

Flow Chart ................................................................................................ 7

Control Elements.................................................................................. 8

ACTIVE.........................................................................................................8

DESIRED GAIN.......................................................................................... 8

SOFT-HARD .............................................................................................. 9

MORE DENSITY ........................................................................................ 9

BOOST .......................................................................................................10

LCD DISPLAY ............................................................................................10

LED CHAINS .............................................................................................10

PRESETS ....................................................................................................11

INFO............................................................................................................12

Specifications ..........................................................................................17

Warranty ...................................................................................................18

Loudness Maximizer

Loudness Maximizer

4

SPL’s digital audio processors are designed in cooperation

with Spectral Design of Bremen, Germany,who are responsible for
the DSP programming.

Concept: The Loudness Maximizer is the first digital 19-inch
dynamics processor to utilize new psycho-acoustic algorithms
which are designed to maximize subjective loudness and to
exploit effectively up to 99.9% of the available headroom with
guaranteed clip-free performance. Even a normalized sound file
can be made subjectively louder without changing the essential
character of the sound, yet if the user wants even more loudness,
the Loudness Maximizer can be coaxed into producing audible
changes in the sound, which are optimized to be useful in a crea­tive sound design context.

The DSP-algorithm constantly analyzes the input signal and com­putes the data for the most unobtrusive dynamics processing
using an algorithm developed from extensive psycho-acoustic
and audiometric research. The dynamics processing is not simply
limited to Peak-Limiting nor Compression, but is an intelligent
combination of both, where the characteristics of the input signal
determine the processing, interactively and automatically. The
Compressor used within the Loudness Maximizer treats the audio
as an entity and utilizes a static (no-knee) compression characte­ristic that operates without steps.The use of a multi-band design
was specifically avoided, because splitting up audio into several
bands, then remixing them after processing usually affects the
coherence of the signal and causes intermodulation, resulting in
sound coloration.

The Limiter works after the Compressor and is designed to cut
peak levels effectively by creating a minimum number of invalid
samples.This is achieved by re-calculating the original peak-curve
on a lower level, but maintaining its shape, where the Soft/Hard
control provides access to the sound of the Limiter. Using the Soft
position creates a rounded bell with virtually no invalid samples.
You can gain more loudness by turning the control to Hard.

Operation: The handling of the Loudness Maximizer is very
easy. Only three control parameters and one switch function are
necessary to adjust the loudness maximization process.Most of
the parameters are set automatically by the programme material
itself.The algorithms are optimized so that the process is as trans­parent as possible.

DESIRED GAIN sets the maximum level change. Adjustable
values range from 0dB to +15dB. The Done LED-bar shows how
much of the desired gain change was achieved by the Loudness
Maximizer. The Soft/Hard control adjusts the sound character of
the Limiter.You can gain more loudness by turning the control to
the Hard position, which increases the risk of audible distortion.
The MORE DENSITY control allows to sweep from Peak-Limiter
performance to Compressor performance. The higher the value
the more compression is applied. The BOOST button increases
loudness by an additional 2dB.

Introduction

Maximizing the subjective
loudness without sound colo­ration

A „look ahead“-signal analysis
computes data for most
unobstrusive limiting and
compressing.

Easy and intuitive operation

Operation Safety

Indications and Metering: The Loudness Maximizer is equipped

with PPM meters for input and output that show the signal level
with maximum resolution (0.01dB) just before 0dB.

The Signal LED is the first LED in each PPM meter that lights up

when a digital source is present at the inputs

The Possible LED chain represents the first device to show how
much subjective loudness can be gained. Initial settings for the
DESIRED GAIN control are shown here.

The Done LED chain indicates the percentage of achieved gain
change. It shows how much of the Desired gain setting was
actually realized.

The philosophy behind the digital audio processors is that they
are designed to be operated like analogue units; there is only one
INFO menu but no multi-function controls. The LCD readout
simply shows the current encoder positions and the preset
number.The encoders are built without clicks or detents, so they
feel like analogue pots. Our DSP platform uses two Motorola
56002 DSPs running at 66 MHz. This enormous computational
power guarantees real-time operation where sophisticated DSP
algorithms will not be restricted by resource limitations. The
general concept is that each digital processor should fulfill only
one task, in the most effective way possible, and with a minimum
of controls and switches. As much as possible should be auto­mated to promote user-friendly operation – the external controls
access only the sonically relevant parameters. Additionally all
controls with a wide value range (e.g. 0 to 100) are programmed
with an 'alpha-dial' logic. Turning the encoder rapidly causes the
values to jump in steps of 10, whereas turning the encoder slowly
causes the values to proceed in single increment steps.

The housing of the Loudness Maximizer has the standard 19"­EIA format and occupies 1U (44 mm) in your rack.When installing
the unit in a 19"-rack, the rear side of the unit needs some
support, especially in a touring case. The Loudness Maximizer
should not be installed near units which produce strong
magnetic fields or extreme heat. Do not install the Loudness
Maximizer directly above or below power amplifiers.

Check that the voltage details quoted on the back panel are the
same as your local mains electricity supply. Use a minus (-)
screwdriver to set the voltage selector to the voltage for the area
in which the unit will be used.

Never cover up the ventilation slots on the top of the unit. If,
during operation, the sound is interrupted or indicators no longer
illuminate, or if abnormal odor or smoke is detected, or if liquids
are spilled on the unit, immediately disconnect the power cord
plug and contact your dealer.

Only clean your Loudness Maximizer with a soft, lint-free cloth.

Input and Output

PPM metering

POSSIBLE-LED-bar shows how

much subjective loudness can

be gained

„Analogue“ control feeling

The DSP Platform:

Enormous computational

power guaranteeing real-time

operation

User-friendly programmed

software

5

Loudness Maximizer

Loudness Maximizer

6

Before connecting the Loudness Maximizer switch the power

off at all connected units.

The rear panel provides AES/EBU- and S/P-DIF-inputs and
outputs. Any additional channel, status and user-bits are passed
through unaltered,and the outputs can be used at the same time
if required.

The Loudness Maximizer operates with 24 bit word width. It
accepts 16 bit and 20 bit inputs and will create output signals
according to the input resolution.

For synchronisation purposes Wordclock In and Wordclock
Through BNC connectors are fitted with a switchable 75 Ohm
termination.

MIDI In and MIDI Through connectors allow presets to be
selected via MIDI program change commands.

For easy upgrade of future software releases, the rear panel
offers RS-232 interface for PC and RS-422 interface for MAC.

Installing Updates:

Note: All presets will be lost after installing a new software
version!

1. Connect your computer with the Loudness Maximizer via a
serial port with a standard Z-modem cable. RS-232 for PC and RS­422 for MAC.

2. Open a terminal program like “Hyperterminal” on PC and
make the following adjustments:
Baud rate: 9600; Stop bit: 1; Parity: none; Data bit: 8; Handshake:
no;Transfer mode: ZMODEM

3. Switch on the Loudness Maximizer and depress both Preset
Up and Preset Down until the LC- display says “wait for Zmodem
download“.

4.Load the update file into your terminal program and send it to
the Loudness Maximizer.The LC-display shows the progress of the
download in kB.

5. After successfully installing the new software version the
LC-display says “download valid”.

6. Switch the Loudness Maximizer off and on. The new software
version number is displayed in the first INFO page (simulta­neously depress Store and Apply; also refer to Control Elements
No.9, INFO).

7.If an error occurred during download the LC-display says
“download failed”. The Loudness Maximizer now waits for a new
download. Please check all adjustments on your terminal
program and try again. If you are still unsuccessful contact your
local dealer.

Connections

Rear view Loudness Maximizer, Model 9632