How it Works
Genelec
Loading...
DSP system
Owners manual
156 pgs8.56 Mb0
Owners manual
1 pgs153.02 Kb0
Table of contents
Loading...

Genelec DSP system Owners manual

GLM
dsp
AutoCa
l
TM
System Operating Manual
3
GENELEC DSP LOUDSPEAKER SYSTEM OPERATING MANUAL
Genelec Document D0066R001a. Copyright Genelec Oy 3.2006. All data subject to change
4
Table Of Contents
INTRODUCTION .................................................................................................................. 8
GLOSSARY ......................................................................................................................... 9
SYSTEM PARTS .................................................................................................................. 13
Loudspeaker Delivery Content ..............................................................................................13
Subwoofer Delivery Content .................................................................................................13
Contents of the delivery box .................................................................................................13
GLM DSP Loudspeaker Manager Package Delivery Content ..............................................14
GLM DSP Multiroom Expansion Package Delivery Content .................................................14
LOUDSPEAKERS ................................................................................................................ 15
Two-Way Loudspeakers (8200 Series) .............................................................................. 15
Subwoofers (7200 Series) .................................................................................................. 16
GETTING STARTED ............................................................................................................ 18
Quick course to system basics .............................................................................................18
Step-by-step system setup for GLM Control Network use ....................................................21
Step-by-step system setup for Stand-Alone use ...................................................................22
PLACING LOUDSPEAKERS IN THE MONITORING ROOM ............................................. 23
Full-bandwidth loudspeaker placement .................................................................................23
Subwoofer placement ...........................................................................................................25
Multi-channel System Layout ................................................................................................26
GENELEC LOUDSPEAKER MANAGER GLM ................................................................... 28
Overview ............................................................................................................................... 28
GLM Control Network ...........................................................................................................29
GLM Control Network Size ...................................................................................................32
Buying Cables for the GLM Control Network ........................................................................ 32
Installing the GLM Software ..................................................................................................32
Running the System Setup Wizard ....................................................................................... 32
Running the Acoustical Setup Wizard ...................................................................................35
5
BASIC USE OF THE GLM ................................................................................................... 36
GLM Main Page .................................................................................................................... 36
Mute All and Bypass BM .......................................................................................................37
Volume Control .....................................................................................................................37
Level Presets ........................................................................................................................39
Access to the GLM System Setup Editors ............................................................................ 39
Information Data Banner .......................................................................................................40
Audio Channel Group Functions ...........................................................................................40
Menu Items ...........................................................................................................................41
RAPID CABLING WIZARD ................................................................................................. 43
How to Use Rapid Cabling ...................................................................................................43
Stereo Pair Analog ................................................................................................................45
5.0 Surround System Analog ................................................................................................ 46
Stereo Pair (AES/EBU Single-Wire) ......................................................................................47
Stereo Pair with Subwoofer (AES/EBU Single-Wire) ............................................................ 48
5.0 Surround System (AES/EBU Single-Wire) ......................................................................49
5.1 Surround System with Subwoofer (AES/EBU Single-Wire) ............................................ 50
6.1 Surround System with Subwoofer (AES/EBU Single-Wire) ............................................ 51
7.1 Surround System with Subwoofer (AES/EBU Single-Wire) ............................................ 53
Stereo Pair (AES/EBU Dual-Wire) ........................................................................................54
Stereo Pair with Subwoofer (AES/EBU Dual-Wire) ...............................................................55
5.0 Surround System (AES/EBU Dual-Wire) ........................................................................56
5.1 Surround System with Subwoofer (AES/EBU Dual-Wire) ...............................................57
MANUAL CABLING WIZARD ............................................................................................. 59
Planning Audio Cabling .........................................................................................................59
Running the Manual Cabling Wizard ....................................................................................64
Saving the Setup ...................................................................................................................72
MANAGING SYSTEM SETUPS .......................................................................................... 73
Saving and Recalling Setups ................................................................................................ 73
Opening the System Setup Editor .........................................................................................74
Editing Audio Cabling Definitions ..........................................................................................74
Editing Group Definitions ......................................................................................................75
Replacing and Removing Loudspeakers in a System Setup File .........................................78
6
ACOUSTICAL SETUP WIZARD .......................................................................................... 81
Loudspeaker Placement and Distance .................................................................................82
Aligning Loudspeaker Levels ................................................................................................ 83
Setting Up Subwoofers .........................................................................................................85
AUTOCAL – FULLY AUTOMATED SYSTEM CALIBRATION ............................................ 89
Theory of Operation .............................................................................................................. 89
Setting up for AutoCal ...........................................................................................................90
Running AutoCal ...................................................................................................................92
Subwoofer Phase Aligment using the AutoPhase ................................................................94
Editing AutoCal settings manually ........................................................................................97
Storing settings permanently into loudspeakers ...................................................................97
EDITING ACOUSTIC CALIBRATIONS ............................................................................... 99
Opening the Acoustical Settings Editor .................................................................................99
Two-Way Loudspeakers ........................................................................................................100
Saving and Loading Acoustic Settings ..................................................................................106
Subwoofers ........................................................................................................................... 107
Using the Interactive Response Editor ..................................................................................116
STAND-ALONE OPERATION ............................................................................................. 117
Two-Way Loudspeakers ........................................................................................................117
Front panel warning light .......................................................................................................118
Back Panel Controls .............................................................................................................118
Subwoofers ........................................................................................................................... 120
Connector Panel Details .......................................................................................................122
Storing settings in loudspeakers and subwoofers ................................................................128
Selecting the stored settings ................................................................................................128
FUNCTION REFERENCE .................................................................................................... 129
Desktop Compensation .........................................................................................................129
Genelec AutoCal ...................................................................................................................129
Loudspeakers Online ............................................................................................................ 130
Load Setup ............................................................................................................................130
Wizard Introduction ............................................................................................................... 131
Rapid Cabling Preset Selection ............................................................................................132
Loudspeaker Marking ...........................................................................................................133
System Audio Connections ...................................................................................................134
7
Signal Format ........................................................................................................................136
Audio Cabling Summary .......................................................................................................140
Loudspeaker Connection ...................................................................................................... 141
Floating Level Fader .............................................................................................................144
Reference Level Calibration ..................................................................................................144
Vertical Axis Trim ...................................................................................................................146
Index .... 148
8

INTRODUCTION

Congratulations and thank-you for the purchase of this Genelec Active Digital Monitor System. These systems are designed to integrate easily into the digital production environment. There are several ways to configure and operate the DSP loudspeakers for a wide variety of high quality audio applications. The two-way loudspeakers have also analog inputs, making them versatile and intelligent replacements for analog loudspeakers.
This manual addresses the Genelec Loudspeaker Manager GLM™ and the proprietary Genelec loudspeaker control network, guiding step-by-step through the setup process. The DSP loudspeakers can also be used in stand-alone mode just like any other loudspeaker but enjoying the benefits of additional flexibility and versatility.
Genelec Loudspeaker Manager (GLM), Genelec AutoCal, AccuSmooth, SinglePoint, and MultiPoint are trademarks of Genelec Oy.
Parts of the Genelec Loudspeaker Manager are written using MATLAB®. © 1984 -2005 The MathWorks, Inc.
9

GLOSSARY

.eq1 file A subwoofer acoustical settings file.
.eq2 file A two-way loudspeaker acoustical settings file.
.gtd file
Genelec Time Data file containing the computed impulse responses of a loudspeaker or subwoofer.
3.5 mm Measurement Signal Cable
A 3.5 mm stereo jack-to-jack interconnection cable used to connect the MIC OUT socket on the GLM Network Interface to a computer’s soundcard input.
AccuSmooth
A proprietary smoothing algorithm that has a higher resolution (narrower smoothing bandwidth) at low frequencies than a standard 1/3 octave smoothing, and a similar resolution at high frequencies. This is used by AutoCal to ensure accurate placement of notch filters at critical bass frequencies.
Acoustical Settings Editor
A page in the GLM that provides access to the Acoustical Settings in the loudspeaker or subwoofer. The Interactive Response Editor can also be accessed here.
Acoustical Setup Wizard
A self-guided Wizard that allows for manual or automated (AutoCal) calibration of the Loudspeaker Acoustic parameters.
Analog Signal Cable
The GLM supports AES/EBU digital audio cables and analog audio cables. An analog audio cable carries one channel of audio. An AES/EBU cable can carry one or two channels of audio.
Audio channel
Although the definition of an audio channel is rather straightforward and clear, it should not be confused with loudspeakers or audio cables in the loudspeaker system. The AES/EBU digital audio cables may carry one or two audio chanels. There may be one or more loudspeakers reproducing one audio channel.
Bass Management
Bass Management is used to reproduce the low frequency content of audio channels over one or more subwoofers instead of loudspeakers. This can be the low frequency content from the full-bandwidth audio channels. Parts or the entire LFE audio channel can also be bass managed.
Digital Signal Cable
The digital signal cable carries an AES/EBU audio signal. The GLM supports AES/EBU digital audio cables and analog audio cables. An AES/EBU cable can carry one or two channels of audio.
10
Digital Thru
The connector on the back of a loudspeaker used to pass the AES/EBU digital audio signal presented to the digital input connector onto another loudspeaker.
Genelec 8200A Calibration Microphone
A factory calibrated acoustic measurement microphone used for AutoCal system alignment.
Genelec AutoCal
Genelec AutoCal is a property of the GLM software that utilizes built-in test signal generators inside all Genelec DSP loudspeakers to acoustically measure and align the loudspeaker system.
Genelec AutoPhase
Genelec AutoPhase is a part of Genelec AutoCal. It aligns the the phase of the subwoofer(s) in the system to the designated loudspeaker(s).
GLM Control Network
The GLM loudspeaker control network is a proprietary network allowing the setting, reading and monitoring of loudspeakers and subwoofers on the GLM network. System setup can be achieved very rapidly by simply opening a System Setup file, which causes all system and loudspeaker settings to be automatically communicated to all loudspeakers.
GLM DSP Loudspeaker Manager Package
The GLM control network delivery package containing all hardware and software to build a GLM Loudspeaker Manager environment. Loudspeakers and subwoofers are purchased separately.
GLM DSP Multiroom Expansion Package
An expansion package providing a license and hardware to install the GLM in multiple rooms within a single facility.
GLM Main Page
The face of the GLM. This page is used to access all other functions of Loudspeaker Manager.
GLM Network Interface
The GLM Network Interface is a USB device that connects the computer to the GLM loudspeaker control network. The GLM Network Interface translates communication between the computer and the control network, enabling a very large and physically long control network with multiple loudspeakers. The GLM Network Interface isolates the private and confidential messaging with loudspeakers from any public data networks and from the functioning of the computer running the GLM software.
GLM System Setup Editor
This page is used to access more detailed sections of the GLM including the Acoustical Settings Editor.
11
GLM Software
GLM is an abbreviation for the Genelec Loudspeaker Manager. This software enables setup and control of loudspeakers on the GLM control network through the use of system setup files, and supports fully automated loudspeaker system setup.
Group
Loudspeakers or audio channels designated to play simultaneously.
ID Tone
A built-in tone in the DSP loudspeakers and subwoofers used to identify which loudspeaker is being communicated to.
IEC Mains Cable
A standard detachable mains cable used to apply mains electrical power to the loudspeaker or subwoofer.
Interactive Response Editor
Located in the Acoustical Settings Editor, this Editor allows for the interactive adjustment of a measured response using the Room Response Controls.
Loudspeaker
This term is used for loudspeakers that are not subwoofers. A 8240A or 8250A two-way active DSP loudspeaker.
Manual Acoustic Wizard
A self-guided Wizard that allows for manual calibration of the loudspeaker acoustic parameters.
Manual Cabling Wizard
A self-guided Wizard that allows for more complicated and versatile System Setups not found in the Rapid Cabling Wizard.
Manual Controls
The user interface settings on a loudspeaker or subwoofer used when in stand-alone mode.
Microphone Holder
The rubber mounting hardware to attach the Genelec 8200A Calibration Microphone to a standard microphone stand.
MultiPoint
A method of spatial averaging used in AutoCal measurements, used when optimizing the Acoustical Settings.
Network Cable
A CAT5 cable with RJ45 connectors (type PC-to-HUB, straight not crossed wiring). This cable is also used as an Ethernet network cable. Network cables connects the GLM Network Interface to the loudspeakers and subwoofers to form a network of devices that may be controlled using the GLM software
Network Control Mode
The use of Genelec DSP loudspeakers with the GLM software and the control network.
Node
Every loudspeaker and the GLM Network Interface is a node on the GLM control network.
12
Rapid Cabling Wizard
The GLM contains pre-made system setups of the most typical loudspeaker arrangements. Rapid Cabling makes system setup simple and fast by allows the selection of one of these presets.
Room Response Controls
A collection of controls used to modify the loudspeaker or subwoofer response in order to improve the in-room sound quality at the listening position.
SinglePoint
A measurement taken in the main monitoring position used by AutoCal when optimizing the Acoustical Settings.
Software CD
The CD-ROM containing the install files for Genelec Loudspeaker Manager and AutoCal.
Stand-Alone Mode
The use of Genelec DSP loudspeakers as individual loudspeakers, without the GLM software and the control network.
Stored Settings
The settings stored inside a loudspeaker or subwoofer. These settings are used when the loudspeaker is operated in the stand alone mode
Subwoofer
A 7260A, 7270A or 7271A active DSP subwoofer with 8 channel bass management.
System Setup File
Files stored on the hard drive of a computer running the GLM. Loading a System Setup File in GLM automatically sets up all loudspeakers in the system with stored monitoring Group definitions, audio cable definitions, defaults for monitoring levels and all acoustical alignment settings.
System Setup Wizard
System Setup Wizard guides the user through the process of setting up the GLM.
Third-party Volume Controller
A peripheral device (e.g. Griffin PowerMate) used to control the system volume.
USB Cable
A type A-B USB cable used to connect the GLM Network Interface to a computer.
13

SYSTEM PARTS

The Genelec DSP loudspeaker system consists of
• Two-way loudspeakers
• Subwoofers
• GLM Genelec DSP Loudspeaker Manager Package containing the user interface software with the GLM Control Network Interface and a factory calibrated acoustic measurement microphone for controlling DSP loudspeakers
• Multiroom Expansion Package
A basic working system requires only loudspeaker(s). See Getting Started.

Loudspeaker Delivery Content

Contents of the delivery box

• Loudspeaker
• IEC Mains Cable
• Network Cable
• Loudspeaker Operating Manual

Subwoofer Delivery Content

Contents of the delivery box
• Subwoofer Loudspeaker
• IEC Mains Cable
• Network Cable
• Subwoofer Operating Manual
14

GLM DSP Loudspeaker Manager Package Delivery Content

The GLM™ Genelec Loudspeaker Manager is a loudspeaker control networking system that offers capability to control all system parameters as well as the possibility for detailed acoustical alignment of every loudspeaker in the system. The use of the GLM is warmly recommended. Genelec AutoCal™ provides the GLM with a fully automated multi-loudspeaker system acoustical calibration capability and comes with a factory-calibrated measurement grade microphone, microphone amplifier and microphone holder.
Contents of the GLM delivery box
• Software CD
• Genelec DSP Loudspeaker System Operating Manual
• Quick Connection Guide
• GLM Network Interface with a built-in calibration microphone amplifier
• USB Cable
• Network Cable
• Genelec 8200A Measurement Microphone
• Microphone Holder
• Measurement Signal Cable with 3.5 mm stereo plugs

GLM DSP Multiroom Expansion Package Delivery Content

The GLM software is sold with a site-license permitting installation into multiple rooms. The GLM DSP Multiroom Expansion Package delivers a GLM Network Interface and cables for installation into one additional room. Each additional room needs a multiroom expansion pack.
• GLM Network Interface
• USB Cable
• Network Cable
15

LOUDSPEAKERS

This section provides a rapid overview of Genelec DSP loudspeakers. In-depth information about the DSP loudspeakers is available at www.genelec.com and in the Operating Manuals supplied with the DSP loudspeakers.

Two-Way Loudspeakers (8200 Series)

The two-way DSP loudspeakers accept both AES/EBU digital audio and analog audio.
Analog input
The analog input on Genelec loudspeakers has a fixed sensitivity. A 0 dBu (0.775 volts) signal produces a 94 dB SPL at 1 m. The maximum sound pressure level depends on the loudspeaker model. A larger loudspeaker will produce a higher maximum sound pressure level than a smaller one.
Digital audio input
The digital input has a fixed sensitivity. Digital signals are represented relative to their maximum value, or Full Scale (FS) value. For example, –10 dBFS means that the digital audio signal level is 10 dB below the full scale or the maximum representable digital signal.
In Genelec DSP loudspeakers, the maximum theoretical audio level for a 0 dBFS digital audio input signal translates to 130 dB SPL at 1 m sound pressure level. For example, a signal having -36 dBFS level produces a sound level of 94 dB SPL at 1 m. This is a technical specification of the loudspeaker, and the Genelec Loudspeaker Manager GLM can adjust the monitoring volume down from this level.
Digital audio sample rate can vary from 32 kHz to 192 kHz and word length from 16 to 24 bits. Single-Wire and Dual-Wire signals are automatically detected
Digital audio takes precedence over analog audio. If a valid AES/EBU signal is presented to the loudspeaker, that input will be selected and the analog audio will mute. Note that there may be a valid AES/EBU signal although the signal is silent.
16
Two-Way Loudspeaker Functional Blocks
All audio enters the DSP processor, where all signal processing and filtering takes place. The audio outputs go via digital-to-analog conversion to built-in power amplifiers and on to the tweeter and woofer drivers. The loudspeakers have built-in user interfaces with switches and a rotary level control in the rear of the loudspeaker, as well as a connection for the Genelec Loudspeaker Manager network enabling centralized management of up to 30 loudspeakers in one installation.

Subwoofers (7200 Series)

Digital audio input
The digital input has a fixed sensitivity. Digital signals are represented relative to their maximum or Full Scale value. For example, -10 dBFS means that the signal level is 10 dB below the full scale or the maximum representable digital signal.
In Genelec DSP subwoofers, the maximum audio level of 0 dBFS translates to the theoretical 130 dB SPL at 1 m sound pressure level. For example, a -36 dBFS signal produces a sound level of 94 dB SPL at 1 m. Genelec Loudspeaker Manager GLM adjusts the monitoring volume down from this level.
17
Digital audio sample rates can vary from 32 kHz to 192 kHz and word length from 16 to 24 bits. Single­Wire and Dual-Wire signals are automatically detected. Note that there may be a valid AES/EBU signal although the signal is silent.
Subwoofer functional blocks
The subwoofers have AES/EBU digital audio inputs only. There are no analog audio inputs. All audio enters the DSP processor, where all signal processing takes place. The output goes via digital-to-analog conversion to the built-in power amplifier and driver(s). The subwoofers have a built-in user interface with switches and rotary controls and a connection to the Genelec Loudspeaker Manager network enabling centralized management of up to 30 loudspeakers including subwoofers in one installation.
18

GETTING STARTED

Quick course to system basics

Control network and audio cabling are separate. The first observation to be made is that audio signals
and control information travel along different cables. This has the inherent advantage of allowing one to operate the system with the control network (known as the network control mode) or without the control network if so desired (known as the stand-alone mode).
When using the Genelec loudspeaker control network, full control to all features in a loudspeaker become available. Attaching the control network automatically puts the loudspeaker in the network-controlled mode.
Digital audio. All Genelec DSP loudspeakers and subwoofers have AES/EBU digital audio inputs. When applicable, run the AES/EBU audio cable(s) to the subwoofer first, then onto the main loudspeakers. If the AES/EBU cable carries two digital audio channels, run another cable from the “Thru” output of the loudspeaker to the input of the next loudspeaker.
19
If the audio source has a volume control for the AES/EBU digital audio, it can be used to control the monitoring level.
If the AES/EBU outputs are fixed level line-outs, various volume controls options are available in the GLM loudspeaker control software.
The GLM software provides several volume control faders on the computer display. These volume controls can be used in the same computer running audio processing or recording software.
Third-party volume control knobs (for example Griffin PowerMate2) that attach to a USB interface can also be used to control the monitoring level through the GLM software and the Genelec loudspeaker control network.
Analog audio. The two-way loudspeakers have an analog audio input and can be connected just like any other (analog) loudspeaker. They can be used with analog subwoofers and mixed with analog two-way loudspeakers to build a system. It is easy to achieve good system integration as the input sensitivity of the DSP loudspeakers is the same as that of the analog loudspeakers.
20
Cabling works just like any other analog loudspeaker setup. The analog audio cables are first connected to a Genelec subwoofer where bass management takes place, and then onwards to the two-way loudspeakers.
Stand-alone mode refers to using DSP loudspeakers without the GLM Control Network. Two-way DSP loudspeakers are equipped with both analog and digital inputs, and digital audio takes precedence over analog audio. In stand-alone mode the analog input works only if there is no AES/EBU digital audio input to the loudspeaker, for example when the digital cable is removed or the AES/EBU bit stream is halted at the source.
When using the GLM loudspeaker system control software, it is possible to select between analog and digital inputs. Analog and digital signals are never mixed.
When calibrating the DSP two-way loudspeakers one can select to use the same switch-based acoustic alignments that can be found on the analog loudspeakers, or to use a much more versatile set of room response controls available through the GLM loudspeaker control software and the Genelec loudspeaker control network link built into all DSP loudspeakers.
21
The GLM software runs on any Windows XP or Macintosh OSX computer. The GLM Network Interface connects the computer to the loudspeakers. Using the GLM software provides full access to all room response controls. After aligning the loudspeakers acoustically, it is possible to store these settings inside the loudspeaker’s memory.

Step-by-step system setup for GLM Control Network use

The Genelec DSP loudspeaker family uses a networking concept for controlling a system of loudspeakers. A control network cable is provided with all Genelec DSP loudspeaker products.
To setup quickly, follow the steps detailed below. For further information consult the sections of this manual mentioned in each step.
• Unpack and position the loudspeakers. See the “Loudspeaker Placement” section for details.
• Find the Genelec Control Network cables in each loudspeaker delivery box. Connect the control network. See the “Genelec control network cabling” section for details.
• Find the GLM Network Interface and follow cabling instructions. See the “GLM Network Interface Device” section for details.
• Launch GLM, then follow the on-screen instructions to complete a System Setup. Select either Rapid Cabling Mode or Manual Cabling Mode and follow the instructions.
• Select the appropriate Rapid Cabling preset in the GLM and launch the Rapid Cabling Wizard. See the “Rapid Audio Cabling” section for details.
• To acoustically align the system, run the Acoustic Setup Wizard in the GLM. See the “Acoustic Setup Wizard” section for details.
• Congratulations! Setup is now complete!
A more detailed system setup procedure can be found in the section describing the System Setup Wizard.
22

Step-by-step system setup for Stand-Alone use

Stand-alone use. Genelec DSP loudspeakers can be used like any other loudspeaker system, without
the GLM control network. This is known as stand-alone use.
• Note that when a two-way loudspeaker detects a valid AES/EBU word clock, the system will sync and run in the digital input mode.
• DSP subwoofers only have digital audio inputs and can be used in stand-alone mode running AES/EBU-digital audio.
• When DSP two-way loudspeakers are used as analog loudspeakers, analog subwoofers can be used.
• All Genelec DSP loudspeakers feature a user interface with switches and a rotary level control. These are used for stand-alone operation.
• For more information on setting up and using loudspeakers in stand-alone mode, see the section on stand-alone operation.
23

PLACING LOUDSPEAKERS IN THE MONITORING ROOM

Here is a quick introduction to monitoring loudspeaker placement.
• Place the loudspeakers in their expected positions before cabling anything.
• For most applications, the two-way loudspeakers (8240A and 8250A) should be located within 2-3 meters (7-10 ft.) of the primary listening position.
• Attempt to place all loudspeakers at ear height for the person in the primary listening position. If a loudspeaker is higher than ear height, tilt and turn the loudspeaker toward the listening position. Genelec two-way loudspeakers feature a vibration-isolating monitor stand, the IsoPod™, which enables the positioning of the loudspeaker towards to the primary listening position.
• Aim the acoustic axis of all loudspeakers towards the main listening position both horizontally (turn towards the listening position) and vertically (tilt towards the listening position).
• Position subwoofer(s) close to the wall(s).
• If a subwoofer is used, remember that all audio cables must go to the subwoofer first and then to the loudspeakers. Make sure that enough cable length is available to move the subwoofer around the room to find a location of optimal performance.
The following sections provide more detailed information about placing loudspeakers in a monitoring environment.

Full-bandwidth loudspeaker placement

Minimum distance from a wall behind a loudspeaker. Genelec two-way DSP loudspeakers (8240A
and 8250A) should be placed so that a minimum distance of 5 cm (2”) is left behind the loudspeaker for amplifier cooling and rear opening reflex port sound radiation.
Low frequency cancellations. In general, when a loudspeaker’s front baffle is more than 0,3 meters (1 foot) away from the wall behind the loudspeaker, a reflection from this wall can cause a cancellation of low frequencies and hence reduction of bass output. For two-way loudspeakers, low frequency cancellations in the 40 – 80 Hz frequency range should be avoided. Cancellations in the 80 - 200 Hz range should also be avoided if possible.
24
Recommended distances. Translating this into distance recommendations shows that loudspeakers can be placed close to a wall (see above) at a distance less than 1 meter (3 ft.). Distances between 1 and 2.2 meters (3-7 ft.) should be avoided.
Loudspeakers placed more than 2.2 meters (7 ft.) away from walls may suffer from cancellations around the low frequency cut-off of the loudspeaker limiting low frequency bandwidth. As a rule of thumb, the lower the low frequency cut-off the further away the loudspeaker must be placed from the wall in order to avoid this phenomenon.
Distances to the ceiling and other walls may be shorter than the distance to the wall behind a loudspeaker. Reflections from these surfaces may be important and should also be considered.
Recommended distances from a single wall to the front baffle of free-standing loudspeakers. Correct (green), acceptable (orange) and not recommended (red).
25

Subwoofer placement

Subwoofers can make life much easier in producing high quality low frequency reproduction. When a subwoofer is used, the loudspeakers can be placed more freely, thereby allowing more flexibility in finding a good location in the room for the reproduction of low frequencies.
A subwoofer should be placed close to a wall, preferably closer than 0.6 meters (2 ft.) from a wall. This placement eliminates most possible cancellation sources and the subwoofer response remains flat and well loaded.
Recommended distances from a single wall to the front baffle of loudspeakers combined with subwoofer(s). Correct (green), acceptable (orange) and not recommended (red).
Using a subwoofer provides an additional crossover frequency (typically at 85 Hz). This makes placing loudspeakers much easier. Acceptable distances extend to 1.1 m because of the low frequency cut-off of loudspeakers. Loudspeakers may be placed 1.1…2 m without serious compromises due to the wall behind the loudspeaker causing serious cancellation effects.
Although Genelec subwoofers provide accurate phase control at the crossover point, loudspeakers should not be placed further than 2 m (7 ft.) from a supporting subwoofer. Larger distance differences may cause tonal balance differences around the crossover frequencies due to loudspeakers and subwoofer(s) exciting different room modes.
26

Multi-channel System Layout

The positioning of tables, screens, racks, etc, is critical in order to maintain accurate imaging. Early reflections can smear the of the sound image and compromise localization. To avoid this, reflecting surfaces between loudspeakers and the listening position should be minimized. Symmetrical positioning of equipment is essential. Even with symmetry, reflecting surfaces should be removed from the vicinity of acoustic paths.
Front loudspeaker, multi-channel layout. For multi-channel audio the Left and Right loudspeakers should be placed 60 degrees apart, with the Center loudspeaker in the middle. All loudspeakers should be of the same type so there are no coloration changes when panning sounds across the front stage.
Left figure: Example of non-symmetrical layout producing reflections from computer screens and table surface totally different for different loudspeakers. This situation creates front-back and left-right localisation smearing. Right figure: Symmetrical layout minimizes reflection surfaces and maintains accurate localisation because reflections are similar due to symmetry.
27
Recommended loudspeaker positioning for 5.1 multi-channel audio reproduction.
Surround loudspeakers. Surround loudspeakers should be placed in a positional window between ±100 to ±120 degrees from the centerline. If more than two loudspeakers are used an equal number of loudspeakers should be placed symmetrically on both sides of the center line, on a circle between ±60 to ±150 degrees. Most recording engineers choose ±110…130-degree position for a surround stereo pair.
System location in room. It is important that the multi-channel installation is symmetrically located in the room. Reflections created by boundaries should be identical from left to right so that spatial information and panning of sources remains stable. It is also recommended that the listening position be located in the front half of the room so that the direct sound level is maximized relative to the reverberant energy in the room.
Aiming of acoustical axes. All loudspeakers should be aimed towards the engineer’s listening position.
28

GENELEC LOUDSPEAKER MANAGER GLM

Overview

The Genelec Loudspeaker Manager GLM is the control software for Genelec DSP loudspeaker systems. The GLM runs on PC (Windows XP) and Macintosh (OSX) computer platforms.
The GLM knows which DSP loudspeakers are present on the control network and provides access to all loudspeaker settings and system level controls.
The GLM is capable of controlling up to 25 main loudspeakers and 5 subwoofers and offers control of everything within the loudspeaker system. This includes controls built into individual speakers as well as full system controls including monitoring volume, mute/solo for audio channels, audio channel Group selection and more.
All settings can be collectively stored into the computer as a System Setup File. Loading a System Setup File recalls all system level settings and all settings inside each loudspeaker, including acoustic calibration.
Using the GLM, all acoustic settings can also be stored into each loudspeaker for stand-alone use.
The basic structure of a GLM Control Network has the following components;
• Computer running the GLM software.
• One USB port of the computer connected to the GLM Network Interface.
• The GLM Network Interface.
• Network cable connected to all loudspeakers on the control network.
29

GLM Control Network

GLM Network Interface
The GLM Network Interface serves as the communicator between all loudspeakers on the control network and the computer. Attach the GLM Network Interface to a USB port. The device driver is installed automatically.
The USB cable runs from the computer to the GLM Network Interface. Once the GLM Network Interface is connected to the computer flashing lights on the interface indicate that the network is active. If no communication lights are flashing, check that the control network cable and the USB cable are securely attached and the GLM software is running.
The Genelec loudspeaker control network runs on CAT5 cables. These are the same cables that are used for Ethernet. Instead of using Ethernet for communication with loudspeakers, Genelec uses a proprietary protocol defining the method of communication, and the GLM Network Interface that connects to the USB port on the computer.
There are several important reasons why a USB interface is used instead of, for example, the Ethernet. This keeps the network running at all times, even if the computer crashes. The GLM Network Interface acts as the master controller on the network, and communicates to all loudspeakers even if the computer is rebooting.
The Genelec network uses a proprietary communication protocol to ensure integrity of communication to and from loudspeakers. The GLM Network Interface is used as a translator between the Genelec control network and any computer hardware using it. This ensures that loudspeaker control traffic remains insulated and secured from any public networks. This is necessary because of the possibility of congestion on public networks (loudspeaker control messages do not get through), and in order to limit the range of access (outsiders on a public network could possibly control the loudspeakers).
The USB interface is ubiquitous in the computer world. A USB cable run is normally limited to 5 m (15 ft.), but this is not a problem. The computer network cable from the GLM Network Interface can extend to any practical distance needed. If the GLM Network Interface cannot be placed close the computer the USB cable can be extended with actively buffered cables up to 25 meters (75 ft.) in length.
30
Note
If the GLM Network Interface is disconnected or the computer is powered down, the GLM will no longer control the loudspeakers. In that event, the loudspeakers maintain their current settings until the loudspeaker is powered down.
When the loudspeakers are re-powered and the GLM software is not controlling the network, the loud­speakers obtain acoustic settings based either on the user interface controls on the loudspeaker (manual controls) or from their internal memory (stored settings). This choice is determined by the position of switch marked “STORED/MANUAL CTRL”.
GLM Control Network Cabling
Control comes from the computer running the GLM software. The computer connects to the GLM Network Interface via the USB port (a 1.5-meter USB cable is provided). The GLM Network Interface connects onwards to all loudspeakers using network cable.
The GLM Control Network starts from the GLM Network Interface and connects to the first loudspeaker (any one, just take a pick) and then onwards until all loudspeakers have been connected.
Each loudspeaker has two control network connections. One is used as the input and the other as the output to the next loudspeaker. It does not matter in which order the loudspeakers are connected on the GLM Control Network. On the last loudspeaker of the control network chain, only one of the two Genelec control network connectors will be used.
Loading...
+ 126 hidden pages
Buy Points How it Works FAQ Contact Us Questions and Suggestions Privacy Policy Cookie Policy Terms of Use