DIY speaker wire: does insulation matter?

what kind of voltage are speaker wires subject to?

You can calculate a reasonably good approximation of that based on the relation P = (E^2)/R. Power (in watts) = Voltage (in volts) squared divided by Resistance (in ohms).

So the maximum voltage would be the square root of the maximum power that would be fed to the speakers times their rated impedance.

That is an approximation because speaker impedance is not purely resistive, and is not constant with frequency, but it should be good enough for your purposes.

Also, however, power in this context is usually specified as rms rather than peak, so the calculated voltage would be rms also. If you want to know the worst case instantaneous voltage more precisely, to assess insulation requirements, multiply the worst case rms result by 1.414 (the square root of 2) to get the corresponding peak voltage.

Regards,
-- Al

Thanks Elizabeth.

How close together? Should I twist the pair? Anti-cables are suggested to be twisted at 3 to 4 twists per foot.

Thanks

Cotton is a terrible suggestion as a dielectric for a copper conductor. Untreated cotton will absorb moisture from the atmosphere and allow unabated access of the atmosphere to the conductor. In the form that you will be using it in it's dc is a min. 3.9 a bit higher then PVC (not good for this app.)BTW I believe anti-cables use a polyester varnish like magnet wire not PVC.

The only thing cotton has going for it is that it reduces vibrations that is why it is used as a filler not an insulation.

Try something with teflon...
http://www.takefiveaudio.com/mall/shopdisplaycategories.asp?id=8&cat=Cable%2FWire

I tried Anti-Cables twisted and not.... I untwisted them for a more open and effortless sound.