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Studiophile BX10s Deluxe Subwoofer
Phase Select (4)
As we mentioned before, this switch inverts the signal (the phase angle from 0° to 180°) that goes to
the subwoofer amplifier. The Phase Select function does not affect the signal going to your direct-field
monitors. You can select the appropriate position of this switch by listening to the way the sound from
the SBX10 subwoofer blends with the rest of your system. There is no "right" or "wrong" position,
per se–but logically you want the subwoofer to be "phase coherent" with your direct-field monitors at
the crossover frequency, and not have any audible energy cancellation. One way to determine this
phase coherence is by playing a sine wave signal at the crossover frequency you have selected and
put the phase switch in the position that gives you the strongest output.
Volume (12)
You should always send a line-level signal to the SBX10 inputs. When the volume control is all the
way up, 85mV of pink noise at the input will produce 100dBA output SPL at one meter from the front
baffle. The volume control affects the level going to the SBX10 amplifier and does not affect the level
of the SBX10 outputs that feed your direct-field monitors. Generally, we recommend that you try to get
the flattest, most even system response between your subwoofer and your direct-field monitors–so
depending on the acoustics of your environment and how you have set up your signal path and levels,
you should spend a few minutes calibrating the respective levels of the subwoofer and each of your
main monitors. If you have access to pink noise signals and/or swept sine waves (linear and logarith-
mic), they can be of great help for ensuring your system has the smoothest tonal balance from top to
bottom.
Subwoofer Bypass (11)
This is a 1/4" mono jack for connecting a non-latching footswitch like the M-Audio SP-1 (or any similar
sustain pedal for a keyboard controller). In 2-channel situations, toggling the footswitch triggers a relay
circuit that mutes the subwoofer output and reroutes the full-bandwidth audio signal directly to your
direct-field monitors. In essence, it takes the subwoofer (with its crossover) completely out of the
signal path so you can easily audition your mixes both with and without the presence of the SBX10
subwoofer's low frequency extension–all from your mixing position. This function can also be useful for
multichannel operation. Note that when SBX10 is in bypass mode, the LED Indicator on its front face
flashes red.
More information on using a subwoofer for multichannel applications may be found at www.dolby.com,
www.dts.com, or www.thx.com.
The web sites mentioned above are examples only and are in no way associated or affiliated with M-Audio or
Avid Technology, Inc. M-Audio does not guarantee the performance or availability of these services.
M-Audio SBX10 is not endorsed, sponsored, or approved by these companies
.
