Centralized bass management
The centralized bass management method
uses fixed 85 Hz crossover filters in the
analog output channels in the 7380A SAM
subwoofer for the signal feeds going to
monitors. All analog signal cables are first
routed to the subwoofer's IN connectors
and then from the OUT connectors to the
respective main monitors. The outgoing
signal has the low frequencies removed.
The fixed highpass filters inside the
subwoofer can be used when using the in-built
controls or with GLM software-based control.
However, we recommend the much more
flexible distributed bass management method.
Distributed bass management
In the distributed bass management method
the monitors and the subwoofer receive
full banwidth audio signal and the filtering
is done separately inside each monitor
and subwoofer. The lowpass and highpass
filters are set in synchrony by the GLM
management network. This method is only
available in systems where GLM computer
management is used and with monitors
supporting this method. The subwoofer
crossover frequency can be adjusted from
50 Hz to 100 Hz.
The distributed bass management
supports three different signal cabling
configurations:
•
All channels are routed through the
subwoofer's IN/OUT connectors to the
respective monitors.
•
Y-cables split each signal to the
subwoofer's IN connector and the
monitor's input.
•
Signal sources with dual outputs for each
channel, one going to the subwoofer, the
other going to the monitor.
Use With GLM Control
Network
The 7380A SAM subwoofer is fully
compatible with Genelec Loudspeaker
Manager GLM software, the proprietary
Genelec monitor management network, and
all Genelec SAM monitors.
Managing the 7380A SAM subwoofer
using GLM software control unleashes
the full power of room compensation in
the 7380A SAM subwoofer, enabling 20
parametric room compensation filters. This
powerful room compensation functionality
is only available when the GLM is used.
Detailed information on the use with the
GLM network is presented in the GLM
System Operating Manual.
System setup
The 7380A SAM subwoofer reaches its full
potential when set up and calibrated using
the GLM software. Genelec Loudspeaker
Manager GLM and the proprietary Genelec
monitor management network offer
•
automated acoustic equalization
individually for every monitor and
subwoofer
•
automated level alignment
• distance (acoustic time-of-flight)
calibration
•
aligning of the subwoofers for bass
management
for any reproduction system from stereo
to complex 3D immersive setups, including
one or more subwoofers. GLM setup is fast
and accurate. It can precisely address the
typical narrow-band low frequency modal
resonances and radiation loads of a room
and offers precise frequency response
compensations. The settings can be
controlled with a computer or the settings
can be permanently stored in the monitors
and subwoofers, to make the setup available
at all times even when the computer is not in
use. Genelec recommends setting up SAM
monitoring systems using the GLM. You
can find a detailed description of the setup
process and the use of GLM in the GLM
System Operating Manual.
The setup using GLM is fast and consists of
the following steps:
•
Connect a CAT5 (RJ45) cable between
each monitor (and subwoofer) and finally
to the control network input of the GLM
Adapter device (see Figure 1).
•
Connect the GLM Adapter device to
computer USB connector.
•
Using a microphone stand, place the
Genelec measurement microphone at the
listening location with the microphone
pointing upwards and the microphone
top at the height of the engineer’s ear.
The microphone is a part of the GLM
User Kit.
•
Connect the GLM Adapter device to the
computer USB port using cable included
in the GLM User Kit.
•
Download the GLM software at the
Genelec web site (www.genelec.com).
•
Install the GLM software and follow the
instructions in the software to measure
and set up your system.
•
If you plan to not use a computer for
controlling the subwoofer, use the GLM
software to write the setting into the
subwoofer (use menu item “Store | Store
the Current Group Settings…”).
After storing the acoustic settings using
the GLM software, when the GLM network is
disconnected, the settings are retrieved and
activated by setting the STORED switch to
the ON position.
With GLM software active and controlling
the 7380A SAM subwoofer, the use of analog
and digital inputs is controlled by the GLM
software entirely. In the software ‘Input Type’
in the ‘Group’ definition sets this. The GLM
software allows you to select and switch
between the analog and digital audio inputs.
When using the in-built settings (stand-
alone manual mode), an AES/EBU digital
audio signal will override analog signal.
This means, if a valid digital audio clock is
detected, the digital audio is selected over
the analog audio.
When the GLM acoustic settings have
been stored in the 7380A SAM subwoofer
and are active, the input is selected by the
‘Group’ settings in the GLM software when
the settings are stored.
Setup Without GLM
Cabling
This subwoofer offers a fixed 85 Hz analog
crossover filter. The fixed crossover filter
is pre-selected when the subwoofer is
delivered from the factory. All analog outputs
on the subwoofer are highpass filtered in this
mode of operation.
When using this method, run each signal
cable first to the subwoofer. Then, run a
cable from the respective output to a monitor.
When using the LFE signal, run the LFE
signal to the subwoofer LFE in connector.
No computer access to the subwoofer is
needed to use this crossover mode.
Stand-Alone Controls
Please note that there is a slight delay before
the controls listed below take effect. This is
normal.
The BASS ROLL-OFF controls
compensate for the very low frequency boost
caused by the boundary loading, reducing
the 20 Hz level in 4 dB steps. Individual
controls add together, applying both controls
adds to a total of 12 dB attenuation. Setting
both switches to the "OFF" position obtains
a flat response.
The PHASE switches adjust the subwoofer
phase. This enables the subwoofer to be
put in phase with a selected main monitor.
