Clipping/distorted recording

[pinkmoonfan]

hi all im having serious issues with a clipping/distorted sound on playback. im using an sm57 into a mixing desk with a usb interface then straight to audacity beta. my latop is windows vista. the sound isn't there all the time and is very random as it can affect a whole take or just two seconds of a take. ive gone through all the project rates (Hz) and all are the same at 44100. im very stuck and frustrated and would greatly appreciate any help whatsoever.
thanks

[DVDdoug]

...clipping/distorted sound on playback. im using an sm57 into a mixing desk...

What? Is this a recording problem or a playback problem? Can you play back other sounds OK?

If it's a recording problem it could be a driver (or a driver-settings issue). The recording application (Audacity) just sets-up the driver/format and routes the data to the hard drive and it shouldn't affect the quality or reliability of the recording.

Did the mixer come with a program that you can try? Is it possible that there is another audio application running at the same time? (and maybe messing with your settings?)

Does the mixer have "meters" or clipping indicators? Maybe your levels are too high? (Clipping is flat-topped waves due to overdriving something, or exceeding digital limits.)

Are you monitoring the mixer's analog output, and is it OK? That would help to determine if the problem is on the analog or digital side. If the analog is OK and if your computer has line-in, you can use your existing soundcard.

[pinkmoonfan]

Hey thanks for the reply.
I believe its a recording issue as I have never experienced this problem playing back any music (wav or mp3) before. However I can usually tell if the recording is bad before playback because i can see it in the wave form while im recording. The mixer came with audacity so I'm assuming thats the recommended recording software to use with it. i generally don't have any other applications running whilst recording. Its definitely not clipping as I balance out all the level before recording. I don't believe the issue is with the mixer itself as the analog output is perfect, and I never get the same distorted/clipping sound until after I've recorded and am listening to playback. It must be something on the digital side however I'm not the most technological person in the world and im very stumped. Thanks for your reply and I would greatly appreciate any help or suggestions you would have for me!

[steve]

Could you post a short sample of the problem (just a couple of seconds in WAV format).
To make a short WAV file from a recording, select the appropriate part of the audio track, then from the File menu select "Export Selection".
Short WAV files can be uploaded to the forum as an "attachment".

[pinkmoonfan]

there you go, just recorded that five minutes ago.
thanks for the help

[steve]

It's most probably a USB problem.
Data is being dropped because for some reason the system is not able to keep up with the required continuous data transfer.

Do you have any other USB devices connected?
Is the mixer connected directly to the computer (not through a USB hub)?
Try connecting to a different USB socket - if it's a full size PC, try the sockets on the back of the machine.

Which make/model mixing desk do you have?

If the problem persists, then as a test:
Try disconnecting from the Internet (if you use a wired connection, physically unplug the cable) and temporarily shut down your anti-virus program, and Windows update, and anything else that may want to check for updates.

[pinkmoonfan]

yeah thats what i was thinking. i dont have any other usb devices connected and ive already tried using different usb ports. my laptop is pretty crammed with stuff that i dont need and thats what could be slowing me down, i was contemplating a reset to factory setting and using the laptop for recording only, would this work? if not would a firewire interface fix the problem? the mixer is a behringer xenyx 1204.
thanks for all the help so far.

[steve]

The USB interface should be fine for recording a stereo mix. (I regularly use a similar set-up).

my laptop is pretty crammed with stuff that i dont need and thats what could be slowing me down,

Hmm yes, it could.
How much free disk space do you have?
Have you defragmented your hard drive lately (or ever)?

It would probably be worth doing a bit of a clean-up on the computer, get rid of some of that unwanted stuff and make some space - then defragment the hard drive.
Check in the Task Manager to see what's running and shut down anything that is non-essential, then try recording and see if there's any improvement.
(Task Manger help: http://support.microsoft.com/kb/323527 )

[pinkmoonfan]

I'm currently in the process of cleaning up my hard drive and i will defragment it when im done because ive never done that before. i currently have 123GB of 218GB on my C drive and 5.27GB of 14.6GB on my D drive. thanks very much for the help, its very much appreciated. I will do a bit of recording tomorrow evening after cleaning the computer up and will post with the results!

[pinkmoonfan]

okay lads, after a disk defragmentation and a clearout of all unnecessary programmes files on my computer i'm STILL getting this horrible sound when i try to record although its much less frequent than before. Any help??
Thanks