NHT X2 - Manual (Page 10)

Gain Switch (Rear Panel)
The Subwoofer Gain switch allows you to increase the gain of the X2 subwoofer output
by 10dB. Normally, the factory default "0" position will give you a wide range of volume
adjustment. However, if the sensitivity of your satellite speakers is greater than 93dB,
your range of volume adjustment on the X2 may be limited. In this case, set the Gain
Switch to 10dB.
Boundary EQ (Front Panel)
Reflective boundaries (such as walls) reinforce a speaker's
bass output (3dB for two walls, 6dB for a corner) if the sub-
woofer is placed near them. Conversely, placing a subwoofer
out in the room results in a relative decrease in bass output.
Boundary reinforcement may lead to low frequency response
that is uneven. Some frequencies will sound exaggerated rel-
ative to others, or the subwoofer will sound thin and lack
impact. The Boundary EQ control allows you to compensate
for the effects of room boundaries on the frequency response
of the subwoofer. Adjusting the control enables you to achieve
smooth low frequency output from the subwoofer regardless of
its location in your room.
The following diagrams show the correlation between sub-
woofer placement and Boundary EQ. These diagrams are
guidelines only. Your room acoustics and personal tastes will
ultimately dictate the final setting.