Corrupted audio files recorded with firewire interface

arion · Post by **arion** » Mon Feb 27, 2012 2:28 am

It happened the second time that during recording of 24bit 48 khz files ( two stereo, one mono ) with a a white Macbook 1,8, DP 5.13, Focusrite pro 40 - the recorded files turned to be corrupted. Their length was different by the end of the recording - by 1-2 seconds on a 15 minutes long track and during playback there was only a digital noise audiable.
The build up behaviour of the waveforms was already during the recording strange. The three waveforms were building up asynchron,visible different as usual.
The recorded waveform looked interresting too, it depends on the zoom factor how they looke. At great zooms there was only a black strip, on smaller zooms I could see the normal expected waveform. I have no idea what to suspect. The Macbook, the system (10.6.

, the firewire connection, Pro 40, focusrite driver or DP 5.13 ?
Any idea, that could help me ?

MIDI Life Crisis · Post by **MIDI Life Crisis** » Mon Feb 27, 2012 5:29 am

Update to the latest DP but it sounds like perhaps a HD or system failure. Have you checked the health of the drive? Also, you should nor be recording audio to your internal drive.

arion · Post by **arion** » Mon Feb 27, 2012 5:53 am

Thanks. I know that my setup is not top pro, but it has been working for three years. I must have changed something, so I am curious if somebody had similar problems.

MIDI Life Crisis · Post by **MIDI Life Crisis** » Mon Feb 27, 2012 6:07 am

MIDI Life Crisis wrote:Have you checked the health of the drive?

<sigh>

arion · Post by **arion** » Mon Feb 27, 2012 6:44 am

Yes! And the volume was found corrupt and needed repair.

Excuse me for not answering your question for the first time, I check my disk every week and the SMART status was always verified. This is a nice example for what routine does with an otherwise open mind.
Thanks!

bayswater · Post by **bayswater** » Mon Feb 27, 2012 7:18 am

You were seeing the black bars when you zoomed in because at that point in the recording process there is no detailed waveform image available. And it is probably not a good idea to be zooming the display and otherwise using up the resources on a Macbook that old while recording.

arion · Post by **arion** » Mon Feb 27, 2012 7:26 am

It was not black bars, it was a black stripe on one side of the stereo soundbite - the other side looked normal - and it was of course not during recording, but afterwards. I had the impression of an sampling rate mismatch - all soundbites had a different sampling rate than 48 k.
I hope that the disk repair helped, but am not completly shure.

stubbsonic · Post by **stubbsonic** » Mon Feb 27, 2012 4:02 pm

MIDI Life Crisis wrote:Also, you should not be recording audio to your internal drive.

On my G5, I have 2 internal drives, and record to the non-startup drive (which is internal). On my MBP (and the MB before it) I exclusively recorded audio to my internal/startup drive. Granted, I didn't record tons of tracks simultaneously.

Playback was never an issue. The only time I've had glitched audio was with a presonus firebox-- not sure what caused it, but I don't think it was the internal drive.

It is a safe piece of advice to give, but perhaps a bit superstitious?

Setting an appropriate buffer size can help the drive keep up.

It's nice that DP lets us know when there's a problem (at least sometimes).

kgdrum · Post by **kgdrum** » Mon Feb 27, 2012 4:40 pm

stubbsonic wrote:
MIDI Life Crisis wrote:Also, you should not be recording audio to your internal drive.
On my G5, I have 2 internal drives, and record to the non-startup drive (which is internal). On my MBP (and the MB before it) I exclusively recorded audio to my internal/startup drive. Granted, I didn't record tons of tracks simultaneously.

Playback was never an issue. The only time I've had glitched audio was with a presonus firebox-- not sure what caused it, but I don't think it was the internal drive.

It is a safe piece of advice to give, but perhaps a bit superstitious?

Setting an appropriate buffer size can help the drive keep up.

It's nice that DP lets us know when there's a problem (at least sometimes).

I have to agree w/ MLC:
Recording to the boot drive should be avoided,the internal drive should be for OS & apps.Doing this for 3 years is a heavy load for a drive.

arion · Post by **arion** » Tue Feb 28, 2012 1:00 am

I agree with the advice not to record on the boot drive, but in my case I'm not shure about the risks of overloading the firewire bus if I connect an external FW disk two the second FW port of my Focusrite Pro 40.
( We use three macbooks at home with my musician sons and record always on the internal bus untill now without problems.)

bayswater · Post by **bayswater** » Tue Feb 28, 2012 6:52 am

For a few tracks, you will not get any significant contention between an audio converter and audio drive on the same FW bus. There are a few exceptions for some devices, like a FW iSight, but in those cases it is not a bandwidth issue, but more the way the device deals with FW.

MOTUnation.com