Velodyne SMS-1 - Manual (Page 32)

www.velodyne.com 26 - Digital Drive SMS-1 User’s Manual
16. You should normally not need to adjust the subsonic filter. 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 effect 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 difficult 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 find the perfect match between your subwoofer and
main speakers!
NOTE: The following step shows using the graphic equalizer (using fixed frequencies and Q) to equalize the
room.
18. next, return to the eQ setup screen and adjust the graphical eQs to eliminate peaks and valleys from the
room response. Use the right and left arrow keys to position the cursor over the eQ you wish to adjust.
If you see a peak in the response at, say, 25 Hz (this would be evident in the “SYSTEM RESPONSE”
graph), simply navigate the cursor to the EQ that corresponds to 25Hz and use the up or down arrow
keys to “slide” the eQ up or down. An example of this is shown below: