Cleaning up signal path and reducing noisy hum....HELP>>> -Sound Forge - PC

Subject:Cleaning up signal path and reducing noisy hum....HELP>>> Posted by: munkittrick Date:10/16/2002 9:39:29 PM Hi again all. I finally got Sound Forge back up and running after uninstalling every DirectX plugin on the box and now I'm getting an electrical buzz in the signal line. I thought it might have been a 60Hz cycle hum, but it seems to be introducing itself around 8k. I've EQed the mess out of it, but it is apparent even higher in the band and there is a noticeable dip in the response if I do a parametric EQ. Does anyone have any suggestions of how to clean up my signal path or to track down the possible culprit? My system now consists of; a SB Extigy USB sound card (which is magnificent at 96k), a Behringer MX1604A mixer, a RODE N-1 and N-2 mic(s), and all XLR signal path until it must go phono to mee the needs of the computer input. Any ideas at all? Michael
Subject:RE: Cleaning up signal path and reducing noisy hum....HELP>>> Reply by: Jacose Date:10/16/2002 10:57:32 PM are there any power cables that are in close proximity to an audio cable?
Subject:RE: Cleaning up signal path and reducing noisy hum....HELP>>> Reply by: munkittrick Date:10/17/2002 12:33:45 PM Unfortunately, yes there are, but they are necessary to power the mixer and the computer system. The cables are insulated with a rubber sheath, but within about 4-5' of the audio patch line. Is this the problem? I've also go the mixer running on the same power outlet as the computer. Could that be introducing a hum or a cycle loop? Thanks. Michael
Subject:RE: Cleaning up signal path and reducing noisy hum....HELP>>> Reply by: Rednroll Date:10/17/2002 3:09:50 PM I believe your behringer board should have an unbalanced output along with the XLR outputs. I would expect a grounding issue with the chords you're using,due to the XLR balanced to the unbalanced input of your sound card. Instead of routing through the balanced outputs, try routing out an unbalaced output, like an aux send and use a 2 conductor chord with the proper ends to match each side. See if that fixes the problem and that should tell you if the XLR to unbalanced connection is the problem. Also, having everything on the same plug is a better solution, than seperating them. Actually seperating them like you questioned will cause more of a problem. Also, it doesn't matter if there are rubber insulators on the chords you're using, what matters is if the audio chords have an inner shield, which provides a path to ground, so when outside signals bleed into the cable it goes directly to ground instead of in your audio signal. You might have to cut the inner shield connection from 1 side of the chord, depending how you're studio is setup.
Subject:RE: Cleaning up signal path and reducing noisy hum....HELP>>> Reply by: Jacose Date:10/17/2002 3:29:10 PM good tip

Subject:Cleaning up signal path and reducing noisy hum....HELP>>>

Posted by: munkittrick

Date:10/16/2002 9:39:29 PM

Hi again all. I finally got Sound Forge back up and running after uninstalling every DirectX plugin on the box and now I'm getting an electrical buzz in the signal line. I thought it might have been a 60Hz cycle hum, but it seems to be introducing itself around 8k.

I've EQed the mess out of it, but it is apparent even higher in the band and there is a noticeable dip in the response if I do a parametric EQ.

Does anyone have any suggestions of how to clean up my signal path or to track down the possible culprit?

My system now consists of; a SB Extigy USB sound card (which is magnificent at 96k), a Behringer MX1604A mixer, a RODE N-1 and N-2 mic(s), and all XLR signal path until it must go phono to mee the needs of the computer input.

Any ideas at all?

Michael

Subject:RE: Cleaning up signal path and reducing noisy hum....HELP>>>

Reply by: Jacose

Date:10/16/2002 10:57:32 PM

are there any power cables that are in close proximity to an audio cable?

Subject:RE: Cleaning up signal path and reducing noisy hum....HELP>>>

Reply by: munkittrick

Date:10/17/2002 12:33:45 PM

Unfortunately, yes there are, but they are necessary to power the mixer and the computer system. The cables are insulated with a rubber sheath, but within about 4-5' of the audio patch line. Is this the problem? I've also go the mixer running on the same power outlet as the computer. Could that be introducing a hum or a cycle loop? Thanks.

Michael

Subject:RE: Cleaning up signal path and reducing noisy hum....HELP>>>

Reply by: Rednroll

Date:10/17/2002 3:09:50 PM

I believe your behringer board should have an unbalanced output along with the XLR outputs. I would expect a grounding issue with the chords you're using,due to the XLR balanced to the unbalanced input of your sound card. Instead of routing through the balanced outputs, try routing out an unbalaced output, like an aux send and use a 2 conductor chord with the proper ends to match each side. See if that fixes the problem and that should tell you if the XLR to unbalanced connection is the problem. Also, having everything on the same plug is a better solution, than seperating them. Actually seperating them like you questioned will cause more of a problem. Also, it doesn't matter if there are rubber insulators on the chords you're using, what matters is if the audio chords have an inner shield, which provides a path to ground, so when outside signals bleed into the cable it goes directly to ground instead of in your audio signal. You might have to cut the inner shield connection from 1 side of the chord, depending how you're studio is setup.

Subject:RE: Cleaning up signal path and reducing noisy hum....HELP>>>

Reply by: Jacose

Date:10/17/2002 3:29:10 PM

good tip