M-AUDIO Delta RBUS - Manual (Page 58)

input distortion. Make sure you have the proper signal levels set on the
inputs to the Delta R-BUS. If you find that you are still clipping, you will
need to turn down the audio at the source.
Possible Cause 2: If you are recording from the S/PDIF input, but
you have the Delta R-BUS’s master clock set to something other than the
S/PDIF input, you are recording an out-of-sync S/PDIF stream. This can
result in lost or bogus samples being recorded.
Possible Cause 3: If you are recording from the R-BUS input, but
you have the Delta R-BUS’s master clock set to something other than the
R-BUS Clk, you are recording an out-of-sync R-BUS stream. This can
result in lost or bogus samples being recorded.
Possible Cause 4: Your application software may not have the proper
audio buffer sizes set. Each software application handles this differently, but
typically there is somewhere in the software’s setup to set the size of the
playback and recording buffers used by the application. Some applications
also require you to run a card calibration (sometimes called "profiling") the
first time you use the software with a new audio card.
Possible Cause 5: Some accelerated graphics cards use excessive
amounts of system bandwidth, preventing the recording buffer of an
audio card from keeping up with demand. This can cause clicks in the
recording. Reducing or turning off the graphics card’s graphics
acceleration feature often resolves this problem. In Windows, the level of
graphics acceleration is accessed from Start |Settings | Control Panel |
System | Performance | Graphics.
Problem: I’m getting some pops and clicks in my monitoring signal,
even when my system is idle.
Possible Cause: If the S/PDIF input is not muted in the monitor
mixer, and you have the Delta R-BUS’s master clock set to something
other than the S/PDIF input, you are monitoring an out-of-sync S/PDIF
stream. This can result in lost or bogus samples being recorded. This can
also occur when using the R-BUS input without “R-BUS Clk” selected as
you master clock.
Problem: The sound from the monitor mixer is muffled. It sounds as
if it were running through a mixer with the treble control turned all the
way down!
Possible Cause: The current Delta R-BUS sample rate is too low. The
monitor mixer is a digital device that runs at the current sample rate of the
Delta R-BUS board. The frequency response of the mixer is roughly one-half
of the sample rate. There is no way to prevent this lost frequency response
while playing back or recording at a low sample rate. However, it may be
prevented when the system is idle. See the "CODEC SAMPLE RATE"
paragraph of the section ‘Hardware Settings Page’ for more information.
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