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Mike Rivers[_2_] Mike Rivers[_2_] is offline
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Default USB Midi vs audio interface MIDI

On 11/10/2016 7:04 PM, Neil wrote:
Very true...if the piano is used by itself. It may still be better to
use the interface if there is also audio feeding it, since that reduces
the load on the USB buss and may allow for better sync of the piano with
the audio.


I'm not going to study this very hard for you, so I haven't thought it
out fully, but I'm not sure that if there's anything to be gained, it
would be synchronization between the audio and MIDI. The interface acts
like a USB hub with one port fed by the audio output of the A/D
converter, and another port fed by the MIDI-to-USB converter. They both
go through the same "funnel" - the USB output port on the interface.

MIDI contains so little data that it its contribution to the USB stream
is negligible. However since it goes through the same port as the audio,
if the USB stream gets interrupted by another CPU process, the MIDI is
just as likely to glitch as the audio. As far as synchronization goes,
if the MIDI stream gets re-clocked to the same clock as the interface
uses for the audio, that, in theory, might lock them together better,
but I think that the difference would be to small to be heard.

I could make the argument that either approach (using the MIDI In on the
interface or another USB port direct from the keyboard) could be better.
If there's a difference at all, it would be dependent on the particular
computer, and maybe how the interface's driver handles MIDI.


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