Legacy Audio Xtreme XD - Manual (Page 17)

17
While seated at your listening position, have someone sweep the phase
control slowly from one extreme to the other.
Using pink noise or a 50-60 Hz test tone, listen for the strongest output.
Now take note of that setting. Next, play music program material and
optimize the level and phase settings further; adjusting for the smoothest
output.
NOTE: Because the LFE input bypasses the subwoofers internal
crossover in favor of the preamp/processors crossover, the Freq. control
will be inactive when using the LFE connection.
Fine Tuning