BSS Audio FDS366T OMNIDRIVE User Manual page 61

Utilities - Alignment Assistant
5. Accuracy
It is difficult to predict accuracy but, under the correct conditions
the Alignment Assistant will be more than adequate for aligning
drivers to within a few degrees.
Very low frequency bands are often aligned less accurately in
terms of time, because of the poor stimulus bandwidth, but will
be more than adequate in terms of phase angle. Note also that
very low frequency bands can easily be phase shifted by DC
block filtering, both within the FDS-366T and in external
equipment, causing additional time shifts to be correctly aligned
out.
6. C input - care needed with feedback
When using input C in your system care should be taken when
Alignment Assistant finishes, since the routing of input C will
revert back to feeding outputs. Although the gain will be very
much lower (because the microphone amplifier is defeated), this
could under some circumstances cause feedback to the
microphone.
7. Exiting the Alignment Assistant
If at any time during the process you wish to escape back to
normal operation, press the RECALL button.
8. Maximum distance/delay
Alignment Assistant has an upper limit on the maximum delay
time that may be measured of approximately 75ms (23 metres or
75 feet). If the distance between the driver and the microphone
causes a delay any greater than this, erroneous readings will
result.
9. Microphone type
The choice of measurement microphone is not critical, although a
high quality capacitor microphone with a flat frequency/phase
response will give more accurate results.
If the microphone is phantom powered, it must be capable of
operating at a phantom voltage of at least 15V.
We recommend the BSS FPC900-MIC for this application.
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FDS-366T