Newsgroups: rec.audio.tech
Subject: Re: Speaker wire problem
References: <[email protected]>
Joseph Oberlander  writes:

> My father is still putting together his audio system.  He's a newbie.
> THis is not a troll - just amazing.
> 
> Now, I don't want to get into a situation of which wire to use - the 
> difficulties are different that that hot topic.
> 
> These are extremely simple issues, but he is stubborn. 
> 
> Background - 
> He was an electrican and knows all about wiring, or so he thinks.
> Telling him won't work - he needs links to respected sources to
> tell him or he will think he is right.  Sigh.
> 
> Problems:
> 
> - Need a url for an article that states that unshielded speaker wires 
>   cannot be run with electrical wire.  

He is might be correct. Technically you can run speaker cable alongside
power cables, and telephone cables without interference (with most amps),
though a separate duct would be preferable to keep potential
noise minimum.

Then there are the electrical safety regulations (electrical wiring code).
In the country I live in (Finland), the general rule is that you
can't run mains power wires and low signal wires on the same
"electrical pipe" for safety reasons (maybe something to do
with the noise as well).

> He also wants to run it with
>   telephone wire in PVC pipe.  I can't imagine that it would not
>   pick up the telephone when it rings.
>   (run along the power cables 12 ft and then with the phone!)

Telephone cable and speaker cable on the same tube micht not be that
big problem. The speakers would not most propably pick up the
ring or other telephone signal noticably. In some cases it could
be possible that telephone line would pick up speaker signals
more easily.

> - Need a url for the same about wires run for long lengths and near
>   electrical equipment should be shielded.  He wants to use standard
>   unshielded 14-gauge electrical wire.  I maintain that while this
>   works fine for most people, his AV setup has a lot of EM nearby.
>   (computer, tv, halogen lights, etc)

Normal electrical wire works well as speaker wire. 
In some special application shielded cable is preferred,
but generally unshielded is the right cable type for speakers.

Here are some links on audiovideo wiring.
http://www.epanorama.net/audiopro.html#wiring
http://www.epanorama.net/wire_av.html

> - Need a url stating that all speaker wires should be the same length
>   for pairs.  He wants to run 8 ft to one speakers and 25 to the other.
>   The 25 ft is the first scenario.  The 8 ft is a clean path to the
>   speaker.  His reaction is "well, there is a balance knob...:

If the speaker cable is any decent thickeness, this kind of distance
difference should not do any harm. The attenuation caused
by cable is very small, propably smaller than the normal
difference of the sensitivity or other parameters of the speakers
and the balance error in most cheap hifi amplifiers.


-- 
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at 
http://www.epanorama.net/