Balancing The System - Genelec Home Theater System Design And Installation Manual

so that listening is a pleasurable experience. Note that if the loudspeaker is placed behind a cloth or a
perforated projection screen, then the Treble Tilt or Treble Level control can probably be set to 0 dB to
compensate for the energy loss due to the sound absorption of the fabric in front of the treble driver.
Tables 7 and 8 can be used as a rough guide of how to set the dip switches. This is just a starting point
and the optimum settings will vary between different rooms.
Loudspeaker position
Free standing - damped room
Free standing - live room
In a corner
In a cabinet
Table 7. Recommended dip switch settings on bi-amplified models
Loudspeaker position
Free standing - damped room
Free standing - live room
In a corner
In a cabinet
Table 8. Recommended dip switch settings on tri-amplified models
If acoustic analysis tools such as RTA, TDS or MLS systems are available then this tuning can be
achieved quite quickly and effectively to give good loudspeaker sound quality and matching for each
channel. If such specialized equipment are not available, it is possible, with a little practice, patience and
objective listening, to do the tuning by ear. The tuning should not be done until the room is complete, as
the addition of seating and other absorbing materials may change the tonal balance of the system.
Take a very well recorded CD that contains a male vocal and a full band and/or orchestra (favour acoustic
instruments). Listen to a passage that contains the vocal and as little instrumentation as possible. Then
listen to a passage that has a substantial amount of bass. If the voice recedes or changes character,
then there is too much bass output. The bass energy is masking the midrange so set the Bass Tilt con-
trol, one switch at a time, until the vocal heard in the loud passage sounds the same it does in the quiet
passage.
To set the Bass Roll-off control, listen to the very lowest notes of a bass guitar or piano. If they are
reproduced substantially louder than the rest of the higher notes then progressively set the Bass Roll-off
control until a balance is achieved. Note that the Bass Roll-off control only operates around the lowest
frequencies of the loudspeaker enclosure so it will have little audible effect in a bass managed system.
Note: ONLY USE ONE DIP SWITCH AT A TIME in each group, as the switches are not cumulative (-2 dB
+ -4 dB does not equal -6 dB!). The exception to this rule is on the subwoofers' Bass Roll off and Phase
controls and on the 6020A and HT205 controls where two switches can be set to give a cumulative net
effect.
4.2.3

Balancing the System

Now that the subwoofer Phase control and the other Room Response Controls have been set correctly
(see previous two sections), the next stage is to balance the system so that each channel is reproduced
at the correct level. There is an important distinction here: this procedure is trying to balance the LFE
channel and main channels (electrical issue) and is not the same as balancing the subwoofer to the main
channels (an acoustic issue). Up to now the system should be balanced acoustically so now it is time to
balance the system electrically. This relatively simple process uses the pink noise generator in the sur-
round sound processor and any cheap sound pressure level (SPL) meter.
28
Treble Tilt Bass Tilt
-2 dB None
-4 dB -2 dB
-2 dB -4 dB
-2 dB -2 dB
Treble Midrange
Level Level
-2 dB None
-4 dB -2 dB
-2 dB None
-2 dB None
Bass Roll-off
None
-2 dB
-4 dB
-2 dB
Bass Bass
Level Tilt Roll-off
None -2 dB
None -2 dB
-2 dB -2 dB
-4 dB None
Bass
None
-2 dB
-2 dB
None