Hafler TRANSANA TRM10S - Manual (Page 21)

PHASE CONTROL
The Phase Control switches allow the TRM10s/TRM12s to be acoustically aligned with other speakers in your system.
0˚, -90˚, -180˚, or -270˚ degrees of phase shift at 80Hz can be selected using DIP switches 2, 3, and 4. For 0˚ degrees
of phase shift, leave all three switches in the OFF (up) position. –270˚ degrees of phase shift occurs when switch 2 is
selected in the ON (down) position. –180˚ degrees can be achieved by selecting both switches 2 and 3 in the ON
(down) position. Finally, selecting all switches 2, 3, and 4 in the ON (down) position produces –90˚ degrees of phase
shift.
Setup Procedure
1) Place all your speakers and any acoustically significant components in their working location in the
listening environment.
2) Insert a sine wave signal into the audio path. Be careful to turn down the level before turning on the amplifiers.
3) Choose a frequency that corresponds to the crossover frequency between the TRM10s/TRM12s and the full-range
speakers.
4) From the listening position, alternate between the TRM10s/TRM12s and the full range speakers and adjust the
levels until they have the same acoustic output. Use an SPL meter, a microphone on a VU meter, or your ears to
accomplish this.
5) With all speakers on, try the 0˚, -270˚, -180˚, and –90˚ degree phase settings. The setting with the highest SPL
reading from your listening position will produce the most effective acoustic alignment.
6) Set the TRM10s/TRM12s gain control according to your preference. This will not affect the acoustic alignment of
your system.
Here is a list of some items that can affect acoustic alignment: Relocating speakers, changing the TRM10s/TRM12s
Low Pass frequency, changing the acoustic environment (i.e., traps, diffusors, etc.), changing the listening position.
Although this procedure produces the maximum achievable acoustic gain for your system, listening tests may still lead
you to prefer another setup.
Input (2 cycles)
90 phase lead
90 phase lag
90 Phase Lead and Lag
Moved ahead 1/4 cycle
Moved back 1/4 cycle
12dB
High Pass
90
°
Lead
12dB
Low Pass
90
°
Lag
Sine
Wave
Phase Shift
180
°
(cancellation)
+
_
Example of how phase misalignment between high frequency speakers and a subwoofer can cause cancellation
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