Manual
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Digital Drive Series User’s Manual - 27
NOTE: Your goal in setting the low pass crossover is to make the crossover point (the point at which the
subwoofer meets the main speakers in terms of frequency) as smooth as possible. Another big factor in
smoothing this point in the curve is phase, discussed in step 17, below.
15. Now adjust the low pass crossover slope. This setting is shipped at 24 dB/octave – a fairly steep slope
to prevent the subwoofer from playing upper frequencies that might call attention to it during normal
operation. At this stage, set the crossover settings under the column entitled SETUP. Reduce the slope
if necessary and use the TEST button to return to the EQ setup screen and observe the “SYSTEM
RESPONSE” graph – it should be as at as possible at the crossover frequency and immediately to
the left and right of it. Too gradual a slope (e.g. 6 dB/octave) may produce a bump at the crossover
frequency, and too steep a slope may produce a dip.
16. You should normally not need to adjust the subsonic lter. Do so only if there are anomalies in the very
lowest frequencies that you cannot address using the normal EQ process as described below.
17. Next adjust the phase and polarity settings. Phase is in eect a short delay in the reproduction of the
audio signal. The polarity reverses the phase (i.e. 180o shift). Adjusting phase can change the dynamics
of standing waves and frequency cancellations in the room. Sometimes it may be useful to adjust the
phase if there is a particularly dicult peak or valley to eliminate, and/or your room placement options
are limited. Phase and polarity are also important tools to match your subwoofer to your main speakers.
You will often see a dip or peak in the crossover frequency between your subwoofer and main speakers.
Rather than correcting this dip with an EQ, try adjusting the phase and polarity settings. It is very
common for the main speakers to interact with the subwoofer to diminish or accent frequencies near the
crossover point (since this is the point where both the subwoofer and the speakers are playing the same
audio information). Don’t be afraid to experiment to nd the perfect match between your subwoofer and
main speakers!