Logic Pro 9 Varispeed Problems

bayswater

Logician
Yesterday I tried to use Varispeed to record an impossible guitar solo written by a composer I work with. I used the Speed only option, and set the buffer to 512. There are four VI tracks existing in the song at this point, all frozen. Everything is working as expected with Varispeed off. With Varispeed on, anything below -15% causes playback to stutter severely and eventually cut out altogether. At -50%, absolutely nothing happens. Monitoring of the channel I'm recording from also cuts out. Recording works as expected, but without being able to hear the existing audio tracks, and with no input monitoring, it's pretty difficult.

Seems to me this project is pretty light. My Mac is not top of the line, but it's well within the requirements. CPU meters are showing very low usage. Can anyone suggest things I can try to get Varispeed working?
 
I still have monitoring at -50% with an I/O of 128 in a project with 8 software instruments and 16 audio and drums/percussion loop tracks. But the audio does sputter when Input Monitoring or Record are enabled.

Maybe others have something more specific to offer.
 
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As an update: I did a cold restart and tried again, and everything worked fine for a couple of hours but then Logic crashed, saving the project. I started it up again, and again, it worked for a couple of hours, and then started cutting out again, and so on.

I've had the experience of Logic simply going quiet on random channels since V8, and coming back after closing and reopening, so I guess it might be just more of the same. But Varispeed does seem to cause some pain for Logic on my system, even though the CPU meters don't show it.
 
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This is a wild guess but I have had problems with sample rate 512 and up. Note- I've had problems w/midi and audio synching by only changing the sample rate.(project goes out of time)
It doesn't make sense to me but it has happen enough times where I try to keep the sample rate at 128, or if higher leave it where it is.:hippy:
 
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I finally got the recording done. I was surprised that when I moved the Varispeed setting from -50% speed only, to 0% speed only, it actually put the pitch of the recording up an octave in addition to speeding it up. No other settings did anything different, an no method of getting the final result out of Logic into a sound file worked.

I was able to play it to another Mac to record it, import it back in, and use Varispeed with a +100% setting speed only, and then play the result to the other DAW again to get a finished recording at the correct speed and pitch.

This was nowhere near what I expected. Is anyone's experience with Varispeed trouble free?
 
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bayswater,

That is puzzling.

I only use Varispeed on occasion when recording a complex MIDI part when audio parts are already in place. Used in this manner, Vs works great.
 
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Thanks for your comments everyone. CSeye, yes, that much worked for me too. VS did eventually slow down the existing piece, and maintain the proper pitch so I could record audio at half speed. The problem arose when I put it back to normal speed. This would not be a problem with MIDI which would simply be triggered at a faster rate, but not a higher pitch. It also works speeding up newly imported audio without altering the pitch, so as you say, it's puzzling why it would not work with audio that had just been recorded. The only explanation I can see is that when I recorded the audio with VS running at half speed, it actually recorded it as if it was running at full speed. If that's true, it's a odd way to design the feature, making it a lot less useful.
 
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