speaker cable and heating ducts

Posted by: Justin on 11 June 2001

Ok, here's my situation:

Because of the configuration of my room, I must locate my equipment on the wall perpendicular to my new SBL's (they will be here soon--very excited). Unfortunately a large entryway to another room sits between my system and the speakers, thereby necessitating my need to run my naca5 either (i) over the doorway or (ii) under the floor and out again near the speakers. For many reasons, I have chosen number (ii), and in fact, the routing was somewhat easy as a conventional aluminum heating duct runs under the floor and exits right next the the speakers.

As such, I have gained access to the heating duct through the wall. As it stands now, my naca5 runs through approximately 7 feet of ductwork before it exits near the speakers.

But. . .I am concerned. Two issues. First, in the winter, may forced air gas furnace sends heated air through the ducts at temperatures topping out at near (i imagine) 130 F (sorry, I don't know the C conversion). Will this (a) melt my insulation or (b) heat the copper and cause a detrimental effect to either speakers or amp?

Second, I'm not sure, but I don't think it sounds quite as good since I routed the cable through the the ductwork. Could the huge amount of aluminum I'm routing the cable through be interfereing with the signal somehow?

Thanks.

Posted on: 11 June 2001 by Mike Hanson

I would worry about the heat only if the air coming out of your ducts burns your hand. Otherwise, I'm sure the insulation and copper in the NACA5 can take it.

As to the detrimental effect, perhaps your getting RFI due to the proximity of the duct work. Also, there are some who believe that cables should be isolated from the environment (i.e. suspended above the floor). I don't generally believe in this concept, but I suppose you should consider it as a possibility.

-=> Mike Hanson <=-

Posted on: 12 June 2001 by Stephen Bennett

..run a hard cased plastic tube through the duct and run the cable through that? It should give some protection from temperature though not any electrical problem. Can you get tubular faraday cages? I'd try an AB test with cable in & out and see if it's a real effect.

Regards

stephen