Emotiva UMC-1 Operation Manual page 39

SUBWOOFER LOCATION
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The UMC-1 has two subwoofer outputs, the unbalanced RCA output and the balanced sub output.
A subwoofer typically sounds best in a corner with at least 5 feet of wall to either side. Due to the short wavelengths of
high-frequency sounds, they don't interact strongly with the size and shape of a room. Lower frequencies long
wavelengths that can cause "standing wave" problems. Placing the subwoofer in a corner usually creates the best
possible situation for the sound to speak to the room, allowing even distribution of the bass frequencies. Often the
corner that offers nearby placement to the front speakers may yield the best results, but you should try several
locations before settling on just one.
The best location for a single subwoofer can be found by playing a couple of different low frequency test tones (or
some music with heavy sustained bass passages) and proceeding with the following easy 1-2-3 process:
1. Place the subwoofer right on the seat of your couch or listening chair.
2. You can then either run the calibration (noise) signal through it, or simply plug the analog outputs of a CD player
directly into your subwoofer's low-level inputs. Turn down the subwoofer's volume level before turning on the CD, then
play the test tones or some music with heavy sustained bass passages.
3. Walk around the room, standing in all the positions where you might be able to place the subwoofer. Again, this is
usually near the corners of the room. Try locations fairly close to the front speakers.
Notice where in the room the bass output from the subwoofer sounds the loudest. Shut things down and install the
subwoofer there. This is the best position for the subwoofer. The bass will sound the best when you are sitting in your
normal listening position.
If your subwoofer seems to sound best when it is near the front speakers (often the case), keep in mind that most older
CRT television sets may not react well to the subwoofer if it is not built specifically for use in a home theater
application. While most front Left/Center/Right speakers do have shielding when intended for use in a home theater
application, subwoofers are not always magnetically shielded and may damage the CRT television if placed too close. If
you want to check if this will be a problem, select an unused video input on the television to bring up a single color
screen. If you see any color distortion anywhere on the screen, an unshielded speaker is too close to the screen and
should be moved away from the television until the color distortion disappears. (LED, plasma and micro mirror displays
are not affected by magnetic fields)
Note - most powered home subwoofers feature a phase control with a range between 0-180 degrees. This is present so
that in situations where the optimum location is not particularly desirable, you can locate the subwoofer elsewhere
nearby and make a slight adjustment to the phase so that is sound arrives to the listener at the same time as the other
speakers. Ideally, sound arriving at the same time is what allows the subwoofer to create the illusion of the main
speakers producing the bass.
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