Slightly OT...Noise with Pro Tools LE

[SlyFoxx]

Our singer has a Pro Tools LE set-up. We plan to use it for mixing and doing overdubs. (We're recording live to an Alesis HD24)

As soon as you fire up Pro Tools a steady noise in the neighborhood of B5 comes out of the speakers. (Even with no file opened) I'd guess it's about 60dB when I have the monitors set to devliver about 87dB at the mix position. Suffice it to say it's very noticable and annoying. The audio interface to the computer is this little blue box that come with Pro Tools. It has two recording inputs and a monitor and headphone out...connects via USB and gets its power via USB as well.

I'm new to this computer/pro tools thing. Is there something we can do to get rid of this noise?

 

[ratherdashing]

Re: Slightly OT...Noise with Pro Tools LE

Humming/whining noises like that usually mean one of the following:

- the computer monitor is throwing out interference. This is esp. true with CRT monitors. Try turning the monitor off and see if the noise stops.

- the computer itself is throwing out interference. If you hear the noise change pitch or volume when the hard drive grinds, it's the computer. Put some distance (vertical is best) between the MBox (the blue thing) and the computer

You should also try and determine if the sound is present on the input signal, or if it's only coming through on the monitor signal (speakers/headphones). The best way to do this is record a few seconds of silence, mix it down to a wav file, close ProTools, and listen to the wav through the PC's sound card. If you hear the noise, it's on the inputs. If not, it's on the signal from the MBox to the speakers, which means either you have crap speakers, or crap cables connecting them.

In general, try to reduce noise by using balanced connections wherever possible, and make sure that power and audio cables are isolated from each other (the standard recommendation is to have them run perpendicular to each other).

Also, you may have something hooked up incorrectly.

 

[More-Gear-Than-Skill]

Re: Slightly OT...Noise with Pro Tools LE

If the above does not help, try connecting the MBox via another USB port, or even a firewire port (IF YOU HAVE ONE)

 

[SlyFoxx]

Re: Slightly OT...Noise with Pro Tools LE

Wasn't the video monitor or the computer and moving the Mbox and trying other USB ports yeilded no improvement.

I was using an insert cable on the headphone jack. Working the TRS end back and forth in the jack caused the noise to lessen so it seems either the jack is a bit faulty or I've got a case of creeping crud. Anyway I tried two 3' 1/4 TS cables in the monitor out and that helped a lot. Noise was reduced about 80%. So it seems the noise is being generated by the Mbox. I'm going to try a good cleaning of the cable ends and the Mbox jacks to see if I can chase away the rest. But at least I can live with it as is.

-Thanks-