Incorrect phase alignment can cause a drop
in the audio level at the crossover frequency.
Correct phase alignment eliminates this
level dip. See chapter "Setting the Phase
Switches."
The DIGITAL LFE switch selects the low
pass frequency for the LFE signal (see "LFE
CHANNEL" below). The possible frequencies
are 85 Hz for "OFF" position and 120 Hz for
"ON" position.
The LFE CHANNEL A/B selects which
subframe is carrying the LFE signal. The
position "ON" selects subframe A as the
LFE signal route, position "OFF" selects
subframe B. If subframe A is selected for
LFE, subframe B is assumed to carry the
main channel audio and vice versa.
The LFE +10 dB function increases the
LFE channel level by +10 dB. See chapter
"Using the LFE +10 dB function."
The LEVEL switches scale down the
subwoofer output level. The switch settings
are additive and they combine with the rotary
level adjustment control.
The TEST TONE switch turns on the
85 Hz test tone. This tone is intended for
manually calibrating the subwoofer phase.
See chapter "Manual Phase Adjustment
Method"
The ISS switch activates the signal
sensing automatic energy saving function.
This function puts the subwoofer in very low
power consumption state when there is no
input signal for a period of time.
The STORED switch selects the room
acoustic compensation settings stored
inside the memory of the subwoofer instead
of the settings in the built-in DIP switches in
the subwoofer. The stored settings can be
created using the GLM Loudspeaker Manager
Software and the GLM control network. The
stored settings can provide superior flexibility
and accuracy compared to the subwoofer's
local user interface controls.
The ROTARY LEVEL CONTROL In
addition to the LEVEL switches, the level of
the subwoofer relative to the loudspeakers
can be adjusted with this potentiometer.
Connector Panel Light
When used without a connection to the GLM
software, the light on the connector panel is
green, indicating normal operational mode.
A red colour indicates amplifier clipping and
yellow indicates thermal overload. If the red
or yellow warning light appears, turn down
the level.
Setting the Phase Switches
Incorrect phase alignment between main
monitors and subwoofer can cause a drop
in the audio level at the crossover frequency
(see Figure 3).
The phase alignment between the main
monitors and subwoofer depends on
the listening position, the position of the
subwoofer and the monitors in the room.
The phase adjustment should be done only
after the preferred positions are found and
the subwoofer and monitor levels have been
aligned.
The GLM software can adjust the phase
automatically.
If the GLM is not available, the following
manual phase matching can be applied.
Manual Phase Adjustment Method
The Genelec 7380A subwoofer is equipped
with a built-in 85 Hz frequency test tone
generator for phase alignment at the fixed
85 Hz crossover frequency. Connect the
monitor to the subwoofer's "TEST 1" output
with a cable. Set the TEST TONE switch
to "ON." Now, you hear an 85 Hz test tone
through the subwoofer and the main monitor.
•
Toggle the -180° phase switch on and
off. Set it to the position giving the lowest
sound level at the listening position.
• Toggle the -90° phase switch on and off.
Set it to the position giving the lowest
sound level at the listening position.
•
Finally, move the -180° phase switch to
the opposite setting. Deactivate the test
signal. The phase adjustment is now
complete.
Using the LFE +10 dB Function
The LFE channel is usually recorded 10 dB
lower than the main channels so that there
is 10 dB of extra level (headroom) available.
Most AV processors automatically add 10
dB to the LFE channel to restore the level in
the LFE channel but some medium format
mixing consoles and many smaller consoles
do not have the facility to apply the +10 dB
gain to the LFE. To overcome this limitation
Genelec subwoofers provide a +10 dB LFE
gain selectionchannels, this switch should
be set to “OFF”.
The “LFE +10 dB” function should not be
used in the following cases:
Figure 3. The effect of phase difference between the subwoofer and the main monitors
Phase Difference: 0°
85 Hz
Phase Difference: 180°
85 Hz
Phase Difference: 270°
85 Hz
Phase Difference: 90°
85 Hz
3
1
3
5
4
4
2
Figure 4. Examples of subwoofer
positioning. 1 and 2 are good starting
positions for a single subwoofer and
also work well with two linked subwoof-
ers. Position 3 causes a significant
bass boost and may cause asymmetric
spatial imaging if only one subwoofer
is used. Position 4 also works best with
two subwoofers. Flush mounting (pos.
5) generally works well.
