Axiom Home Page
Posted By: sl925 Cables and heat - 09/22/03 10:07 PM
I recently just set up my HT in my tiny apartment in NYC. In order to keep the cables hidden I ran them behind one of my heaters. There were no warnings regarding heat with the the cables so I'm not sure if this is necessarily a bad thing. Does anyone know if this is a fire hazard or is bad for the cables in general?
Posted By: pmbuko Re: Cables and heat - 09/22/03 10:13 PM
It could be a problem, depending on how hot it gets where you have run the cables. As a general rule, if it's too hot for your fingers, it's probably too hot for the cable.
Posted By: MIKEY Re: Cables and heat - 09/23/03 01:14 AM
Speaker wire, or ? Really, either way, all you would probably need to do is shield it.. Run it through a short length of EMT.. (The metal tubing used by electricians).. Or, for that matter, crinkle wrap it with aluminum foil.. In other words, not a perfect smooth wrapping, but kind of wrinkled.. That way, it will leave a lot of voids in the wrap, which will act as insulation, dissipating the heat..
Even a simple flat sheet of metal (like a cookie sheet) will ward off low amounts of heat..
Auto stores sell all sorts of heat shielding for engine compartment needs..
Posted By: catfish Re: Cables and heat - 09/23/03 01:47 AM
Is this a baseboard electrical heat or a steam radiator? How much of the wire is exposed to the heat? The first concern is not to damage the cable or cause a fire.

Also be aware that if you are running these wires a long way the increased heat will raise electrical resistance. This increased resistance will diminish signal quality and in the extreme may diminish the sound quality.
Posted By: JohnK Re: Cables and heat - 09/23/03 03:58 AM
SL, assuming that you have some airspace between the heater and the cable it should be okay. As Jeff(catfish)points out, electrical resistance increases with temperature. However, the temperature coefficient of copper is only about 0.0039 per centigrade degree(i.e. 0.39%). This means that even if the temperature of the wire was raised 100 degrees centigrade above room temperature(highly unlikely)it would increase the typical speaker cable resistance of about 0.2 ohms by 39% to about 0.28 ohms, still quite acceptable. So,if the cable got much hotter than that and melted the insulation the problem would be burning down the building, not a degradation of sound quality.
Posted By: alan Re: Cables and heat - 09/23/03 01:54 PM
Hi all,

Conversely, you could get a tank of liquid nitrogen and cool the speaker cables to the point where they became Super Conductors, with 0-ohms resistance! Could this be a new product for Axiom? We'll sell the cables with the tank of liquid nitrogen and a special jacket to enclose the cables and recirculate the liquid nitrogen . Besides, it could be a boon to listening in Southern climates.
Posted By: sushi Re: Cables and heat - 09/23/03 04:12 PM
Alan,

I don't think the relatively affordable liquid nitrogen is not cold enough to induce superconductivity in copper. I believe you need a tank of liquid helium, which is quite expensive even on the devout audiophile scale of dollars.
Posted By: JohnK Re: Cables and heat - 09/23/03 08:52 PM
Alan and Masa, no expense is too much(at least if it's someone else's money) for a true audiophile.Think how "fast" the reproduction would become. I'd suggest that you contact Noel Lee about this.
© Axiom Message Boards