Static when recording more that one track from a mixer.

[Duo Jet]

I have a new Behringer XENYX 1204usb mixer, it’s connected to my laptop using a usb line.When using Audacity 1.3.13Beta the first track sounds good, but when I try to record a second track the sound is full of static. I’m trying to record electric guitar through a powered speaker and using a sm57 mic to record through the 1204. Can anyone help me in trying to figure out what I’m doing wrong?

[steve]

There can be many reasons for this problem - basically your computer is unable to keep up with the required amount of data being shifted through the system.
A common cause is if a USB hub is being used (don't use a USB hub, connect directly to the computer USB port - on fill size computers the USB ports on the back of the machine may be better than the USB ports on the front of the machine). If that is not the problem, see here for other troubleshooting tips: http://wiki.audacityteam.org/wiki/Manag ... nd_Drivers

[Duo Jet]

Thanks for the info! I'm using a Mac and using usb out of the mixer directly the Mac. (no hub) I was getting the same second track problems with a laptop and was told to try the Mac, but getting the same results.

[steve]

I think we need to be a bit more precise with the descriptions.
You say you're using a Mac but you posted in the Windows forum.
Are you actually getting "static" or is it just the the sound of your recording has a "crunchy" type of distortion?
We can only work with what you tell us.

[Duo Jet]

Ok, we want to use the windows laptop when recording with audacity, sorry for the confusion on the operating system. Just wanted you to know that we get the same results with the Mac.
You are more correct in calling it a crunchy distortion, you can actually see it in the recorded bar line of the track.
Before we started using the mixer we recorded using Audacity with a CO1U USB studio condenser connected directly into a windows laptop. We didn’t have any problems recording multiple tracks. We want to use the mixer to improve the sound.

[steve]

Just wanted you to know that we get the same results with the Mac.

Thanks, that's useful information.

I think what may be happening is that although the recording levels of individual tracks are OK, the combined level when you have more than one track is going too high.

Could you try a couple of tests - this may help to pinpoint the problem:

1) Record a track. The blue wiggly waveform should have a peak level of about half of the track height.
2) Record a second track. Again the waveform should have a peak level of about half of the track height.
3) Click on the "Solo" button of the second track. Press "Play" and you should hear the second track only - the sounds recorded on the first track should not be heard. The second track should not sound distorted.
4) Click the solo button again to un-solo the track.
4) Repeat for a third track. (ensure that solo button on the third track only is pressed when testing the third track.

OK so far?

5) If you un-solo all tracks, you may see that the playback meter gets a red vertical line at the 0 dB level and the sound is distorted. This is normal behaviour because the combined (mixed) level of the three tracks may be exceeding 0 dB. There are two options for how to deal with this:
a) Use the Gain (level) sliders on the left end of each track to reduce the playback level of each track.
b) Select all of the tracks (Ctrl+A) then apply the Amplify effect and enter a negative number in the "Amplification (dB)" box - say about -6 (minus 6).

Tip:
As a guide to keeping the playback level below 0 dB, look at the Playback meter.
To make the meter easier to read, click on the end of the meter toolbar and drag it with the mouse - the toolbar can be stretched to the full width of the screen which makes it a lot easier to see.