Audacity Forum

Hi folks,

I've been using Bias Peak for a while now with a USBPre on my MacMini and 10.4.11. Recently (details deleted for now) I started to see problems in Peak after applying the DC Offset removal. The meters would stop working correctly in the playback. USBPre support suggested I use Audacity for recording.

I did an experiment, opening up a file in Audacity that was problematic in Peak. I removed the DC Offset and saved. Peak was happy with the change. Very strange. Now I'm thinking about recording with the stable version of Audacity instead of using Peak.

The USBPre only supports 24-bit, not 32. In Peak I can select 24-bit 44.1 AIFF, but when I try anything like that in Audacity, it crashes when I try to record. I notice that when I save a 24-bit file in Peak and open it in Cool Edit on Windows or Audacity on OX they are identified as 32-bit or 32-bit float. What's with that?

I wondered if I should go ahead an use 32-bit in Audacity, but I don't want a bunch of zero padding in the resulting file. If I record a 32-bit AIFF in Audacity and open it in Peak, Peak thinks it is a 32-bit raw AIFF. Doesn't seem right, given that 24 bit files are read as 32 in the other apps.

As far as DC Offset goes, maybe i can sill record in Peak and just do the DC Offset in another app (Audacity or Cool Edit - I use the latter for removing clicks anyway).

-gritingrooves

You may be stuck. Audacity hates 24-bit files for some unknown reason. Audacity will explode into little brightly colored fragments every time. It's perfectly happy with 32-bit floating tho.

Koz

Thanks for the feedback, Koz,

Interesting that Audacity on OSX is opening up my 24-bit Peak files and fixing the DC Offset. When I open the fixed files in Bias Peak it meters them correctly. Odd, isn't it?

According the the USBPre people Audacity in Windows handles 24-bit fine. I'm waiting for them to release documentation about known good settings in recording apps. I hope they do this with non-Windows versions of Audacity.

BTW, if I set Audacity to 32-bit and record via the 24-bit USBPre, I'm padding with zero's, right? Any major disadvantage, or advantage to this?

Thanks,
-gritingrooves

<<<BTW, if I set Audacity to 32-bit and record via the 24-bit USBPre, I'm padding with zero's, right? Any major disadvantage, or advantage to this?>>>

You may not get a good recording. Give it a shot. There are any number of people trying to cross audio formats and that only works if Audacity is crystal clear what the originating format was. If not, you get all the complaints of Audacity playing a 30 minute performance in fifteen seconds. Only entertaining if you're on Meth. Or Crank. Which is it? I can never keep them straight.

There was a complaint a while back about 24 bit and I tried setting one of my well-behaved machines up for it and it exploded. So that's a known instability.

<<<According the the USBPre people Audacity in Windows handles 24-bit fine>>>

They may be, let's say, misinformed.

Koz

OK, good info, thanks.

I just did a test with the same Bias Peak 24-bit file brought over from OS X to Windows. I opened it in Audacity and in Cool Edit. I first set Audacity to use 24-bit by default. I saved the file with each program and found that while Cool Edit saved the file to the same as as the original (keeping it at 24-bit I guess), Audacity saved it as a larger file (32-bit).

I may have to do some more preference checking but it seems like Audacity doesn't even like to process 24-bit. I don't understand why SoundDevices (USBPre) would recommend Audacity for a 24-bit device if it didn't work (in Windows).

-gritingrooves

Ah, just found the File Format preferences, and set to "Other",

AIFF (Apple/SGI)
Signed 24 bit PCM

The saved file is smaller than the original.

-gritingrooves

The 24-bit thing may only apply to the Mac version. I don't remember either of the two other platforms having trouble.

I have Cool Edit, too. Love it.

You are talking about cross platform production, right? You're posting on the Mac forum.

Koz

I've been recording on the mac with Peak, and processing in Cool Edit with ClickFix on Windows (since it's better than any click/noise remover I know of on the Mac). I bring the file back to Peak after that to adjust gain and separate in to AIFF tracks. Then I use MacFlac to archive.

I guess I'll just do the DC normalization in Cool Edit before doing the other operations there now that I'm comfortable with the way it does it.

-gritingrooves