Subject:midi sync

Posted by: jocks

Date:11/13/2003 5:37:51 PM

hi there,
recorded audio tracks from a synced drum machine drift from Acid clock after a while. sound cards are my SB Live and an integrated sound card. however, my rme-audio card doesn't have this problem.

gear: p4 2.6GHz with 1Gb ddr400, Nvidia graphics, WinXP, AcidPro4.0e
drum machine is an alesis sr-16
any suggestions ?
/jocks

Subject:RE: midi sync

Reply by: pwppch

Date:11/13/2003 11:30:45 PM

The SB Live internally only works at 48 kHz. If your project is 44.1 kHz, the drifiting could becaused by this as Windows resamples everything on the fly from 44.1 to 48 kHz.

Since ACID relys on the audio hardware for MIDI i/o sync, this could be the cause of your problem.

Most on board audio is based upon a similar concept as the SB Live, so it may also be resampling the audio on the fly.

Peter

Subject:RE: midi sync

Reply by: jocks

Date:11/15/2003 3:22:05 PM

hi Peter, and thanks for your help !
since the midi to audio sync is dependant of the audio card clock, I ran the beatmapper wizzard on the recorded stereo track that fell out of sync to analyse it. the track was recorded at 140bpm in Acid, but beatmapper told me it had a 139.97 bpm... I let beatmapper set the project to that tempo, and the drum machine finally ran in sync with the recorded track all the way thru the song ! I suspect many integrated sound cards and other cheap cards has this problem, with long audio tracks. you can also reajuste the beat markers in beat mapper, but that takes time with 100bars after each recording...
I hope this info will help other musicians out there :-)
/jocks