Insider, You are quite correct that copper is a better conductor by volume, however aluminium is a better conductor by weight.insider9 said:You mention aluminum cables and copper and Ohms law in above comments. I agree with your statement that
will sound the same.andyjm said:<p>
two similarly sized cables, decently constructed of approximately the same length
Knowing that copper is a far superior conductor than aluminium how can this apply to two cables one made from CCA and the other OFC. By what I gather considering same length to achieve similar impedance you'd need a 2.5mm2 CCA cable or 1.5mm2 OFC due to differences in impedance of materials used.
I'm just curious... Am I wrong to think that or did I misunderstand your point?
In the case of the Grid, the weight of the cable matters, as the cable has to support its own weight between pylons. The cables you see strung around the country are aluminium, with a steel core for strength. Volume clearly doesn't matter, they can just use thicker cable to achieve the same line resistance as copper, but weight is all important.
The same is true for speaker cables. I have yet to meet anyone who is so tight for space down the back of their amp that they couldn't use a slightly thicker speaker cable - so they could achieve the same resistance as copper by using aluminium, using a slightly thicker cable. There are other reasons why aluminium isn't such a great choice for speaker cables, primarily the problems of termination, but that is a mechanical issue, not electrical.
The reason I mentioned aluminium was to illustrate that the whole oxygen free copper thing was nonsense, not to suggest that aluminium would make a good speaker cable. Almost all speaker cables are copper, so my statement about 'the same construction....' implied that the cable was copper.