![background image](/i/m-audio/158919/m-audio-sbx/h/m-audio-sbx-009.png)
Optimizing the Rear Panel Settings
There are four control knobs on the rear of the SBX: “Level,” “Phase,”
“Subwoofer” LPF cutoff frequency, and “Satellites” HPF cutoff frequency. These
combined controls make it possible to optimally match the low bass
frequencies from the subwoofer to your unique combination of satellite
speakers, room characteristics and subwoofer position. Because of these
variables, there is no single recipe for obtaining the best audio results. While
you can certainly apply sound meters and other analysis equipment in
establishing the right settings, most people use their ears and a few familiar
recordings to determine the best settings.
Setting the Level Control
Use the Level control (#2) to adjust the volume of the subwoofer to properly
match that of the satellite speakers. We suggest starting with this knob in the
12 o’clock position.
Note:
Placement has a great deal to do with how the Level knob is set. If
the SBX is placed on the floor against one wall in a normal room, for
example, the resulting sound pressure may be as much as 3dB greater
than if the subwoofer stands alone. Placement in a corner could add
another 3dB of sound pressure over placement against a wall alone.
Setting the Phase Control
The purpose of the Phase control (#3) is to match the phase of the Satellite
HPF cut off frequency to the phase of the Subwoofer LPF cutoff frequency.
Adjust the Phase in order to make sure that the Subwoofer and Satellites are
in phase at the selected crossover frequency. This will allow you to achieve
the maximum sound pressure and the most accurate sound quality from
the whole system. A little experimentation here may be in order. When signals
are out of phase, they tend to cancel each other. This is most likely to occur
when using bass management, in which case both the “Subwoofer” and
“Satellites” cutoff frequencies are set to the same frequency settings (see the
next two sections for more information). Rotate the Phase control knob until the
SBX sounds the most robust, or return it to the 0 degree position if that is the
optimum setting or if you hear no difference.
Level
Min
Max
Phase
0°
180°
Subwoofer
100Hz
140Hz
180Hz
50Hz
80Hz
Satellites
180Hz
50Hz
80Hz
100Hz
140Hz
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