Homemade Shielding?

[Alanfc]

hello-

I have a small home "studio" space and have just put my cables in order, separating and grouping the power sources away from the audio cables.

I have one unavoidable problem though, is that even though none of these two types of cables are touching, they come near one another, sometimes as close as 1 inch. I've re-done this setup a few times and want to ask this before going through it again.

I'm clueless on 2 things:
a) for the power sources and audio cables to come within 1 inch , is that a problem? In some cases they're parallel for a few inches and in some cases they're not. If I can't hear any hum or noisy stuff, do I need to take addtional measures? I mean I can't hear any obvious noise, but someone told me that some inaudible noise can creep into everything (!?)

b) if I do indeed need to do something about this, whats the material thats used for shielding.? Don't know exactly if thats what I need, but at the points where these cables get close , can I wrap something around cables, or put up some kind of barrier that will serve as shielding? Like wood, cardboard, formica, ?? As it is now, I am using the old Radio Shack black flex tubing for routing cables and organizing things. Does that black ribbed plastic serve my purpose ?
I know I asked a related question on here somewhere about organizing my small space. this is the next step

thanks

[realdynamix]

Originally posted by Alanfc:


...for the power sources and audio cables to come within 1 inch , is that a problem? In some cases they're parallel for a few inches and in some cases they're not

Hi Alan! Are you using any kind of digtal audio meter that goes to at least (-90 db) or so? It can be in your DAW software, or stand alone workstation.

Watch that meter, you can trace where noise is much easier if you are having a problem. Sometimes it is hard to keep AC cords away from lines, if they run side by side, this is not good, it is better to have them cross over at right angles to each other at some point.

I have not experienced any real bad noise unless something is using a lot of current, like a big power amp, or high gain lines come too close to a computer monitor power supply. If you are having problems, and still have your lines apart, then it might be a ground loop of some kind. This is a little harder to track down.

--Rick

[Rod Gervais]

Originally posted by Alanfc:
a) for the power sources and audio cables to come within 1 inch , is that a problem? In some cases they're parallel for a few inches and in some cases they're not. If I can't hear any hum or noisy stuff, do I need to take addtional measures? I mean I can't hear any obvious noise, but someone told me that some inaudible noise can creep into everything (!?)

If you are not having a problem now you are probably safe - as far as something "creeping in"... motor noise is probably your biggest threat going into it.

Rick is right that parallel is bad - quick cross is better - but (as i always advise) total seperation is the best of the best. And even total seperation won't stop a problem with a ground loop. I had a GL issue once that took us almost 3 months to figure out and solve.

b) if I do indeed need to do something about this, whats the material thats used for shielding.? Don't know exactly if thats what I need, but at the points where these cables get close , can I wrap something around cables, or put up some kind of barrier that will serve as shielding? Like wood, cardboard, formica, ?? As it is now, I am using the old Radio Shack black flex tubing for routing cables and organizing things. Does that black ribbed plastic serve my purpose ?

And the answer is "none of the above".

What is required for EM or RF signals is typically a conductive shield........ so the cables would be run within a special "tray" with those properties......... copper makes a good EM shield, but there are also materials made with carbon fibers.... and a ton of other specialties products. However - all of the EM/RF shielding products are typically rather expensive.

Rod

[Alanfc]

Thanks guys-

I have no noise and no problems now,so any luckily additional work isn't needed on this. I'm glad I asked though.
thanks again