Re: [linux-audio-user] Radio Interference problems when recording

jmacdermott@email-addr-hidden wrote:
> This is a bit OT, but since I do all my recording on Linux machines, I thought
> I'd see if anyone on the list can help...
>
> I used to do all my recording in a basement, but since we've moved I got a new
> computer setup in our finished attic. 64studio is loaded on it (and works
> GREAT out of the box on my HP Athlon 64), and everything was working
> tickety-boo, audio running in and out of my M-Audio 1010LT via an old, beat-up,
> road-weary 16-channel mixing panel.
>
> This basic setup (different computer and distro, same sound card, cables, mics,
> etc.) was working fine at the old place in the basement. But now when I plug
> my mics (ie: Shure SM58) via XLR into the panel, I hear a LOT of radio
> interference. I never used to get any of this.
>
> My first thought is that the location (way up in the air) is what is causing it.
> I already tried the cheapest/quickest/easiest fix, new cables. That made no
> change.

Double check all of your connecting cables to make sure that each of
them is OK. My band has found new cables that had sloppy soldering jobs
that generated neat, mysterious hums.

> I will try plugging the unit into another outlet and see if that helps. I have
> the following questions for the more experienced readers on the list:
>
> 1) Could it be my beat-up old board? Does a newer, better board (ie: modern
> Mackie, etc.) have fewer problems with RF? (I know it would be quieter!)

Possibly. I'd try some RF filters first - cheaper (see below).

> 2) I'm afraid that the RF might be coming through the power lines. Any tips on
> eliminating this?

Check your local electronics places for RF filters. A number of power
strips or surge protectors include them.

> 3) Is the location of my equipment (3rd storey attic) an issue?

Possibly, if there are any radio broadcast antenna around the area. I
used to work for a company that occupied the 15th floor of one building.
Several blocks to the east of it was a broadcast tower with several
radio station antennae on it. Any computer monitor on that side of the
building suffered from what we called "televators" - a narrow horizontal
ripple that slowly ascended from bottom to top. The same monitor on the
other side of the building wouldn't have the problem. The monitors were
shielded, it was just that we were so close to the tower.

If you're in that situation, you might have to see about shielding your
attic.

-- 
David
gnome@email-addr-hidden
authenticity, honesty, community