Sound cracking after bounce!!

[thestrokes89]

AHHHH I keep bouncing my song to iTunes, but when I do it keeps making a cracking sound only in iTunes. So I went to logic and turned down the master track volume then bounced it again and it still does it! How can I get it to stop?

[Homina]

I don't understand what you mean by "bounce to iTunes." I assume the project sounds alright when played in Logic. Does the bounced file play OK in QuickTime Player or another audio app? If so, then iTunes is the likely source of trouble. If these "cracks" are audible in apps besides iTunes, then my suspicion would shift to your signal levels.

[Ricey]

could be a sample rate thing - hard to tell without knowing more. if your logic project is in 48kHz, say, and your built in audio (iTunes) is in 44.1

 

i assume this is an Offline bounce? which is actually a waste of time IMO because you still have to check the track in real time.

[thestrokes89]

Would bouncing it in real time help? Or would it not change anything?

[Homina]

Your computer attempts to process data as fast as possible in offline mode. If your track number, instruments, effects, etc... overwhelm your CPU, artifacts could be created in the output file. Real-time bouncing does not place the same processing demands on your machine and makes it less likely your system would choke.

 

You haven't answered any questions, though. Does a bounced file play OK in QT Player or another audio app?

[Noyan]

AHHHH I keep bouncing my song to iTunes, but when I do it keeps making a cracking sound only in iTunes. So I went to logic and turned down the master track volume then bounced it again and it still does it! How can I get it to stop?

 

Do you use external MIDI device?

[Jope]

Your computer attempts to process data as fast as possible in offline mode. If your track number, instruments, effects, etc... overwhelm your CPU, artifacts could be created in the output file. Real-time bouncing does not place the same processing demands on your machine and makes it less likely your system would choke.

 

Seems implausible to me. The opposite is more likely true: In Offline mode, the process of bouncing takes exactly the time that is needed to have all calculations done, while real-time bouncing means the computer has to calculate samples within fixed time-slices under any circumstances. That's why songs can be bounced offline even when the machine is too slow to play them back.

[michael.lee]

Logic can accommodate overloading of the main bus by a few dB, so even if you're blowing past the 0 line, you won't hear the digital distortion. You don't get that same advantage when you bounce, however. Check to make sure your main outputs aren't peaking into the red - slap a hard limited on the mains, set the output to -1 dB and see if you get the same problem.

[Jope]

Logic can accommodate overloading of the main bus by a few dB, so even if you're blowing past the 0 line, you won't hear the digital distortion. You don't get that same advantage when you bounce, however.

 

I don't like to play the know-it-all, but there is no difference whether you bounce to a fixed-format file or output to a fixed-format DAC. As long as the signal is a stream of numbers within logic, it is plainly impossible to overload anything but the meters since logic uses 32bit floating point arithmetics. But DACs and commonly used audio file formats have a fixed 16 or 24bit format.

 

Check to make sure your main outputs aren't peaking into the red - slap a hard limited on the mains, set the output to -1 dB and see if you get the same problem.

 

That's always a good idea. And, as was asked before: Do other players output the cracks, too? Did you try to picture the waveform to find out more about the cracks' nature?

[Jope]

One more thing... Are we talking about mp3 or any compressed format? This might cause trouble when the levels go to the limit even where the uncompressed bounce didn't crack.