Speaker Wire Length for 3% and 5% Signal Loss (5% is considered acceptable) -
Power Handling of Common Speaker Wire -
would break down like this -
Power = Current² x Resistance = 3.7² x 8 = 13.69 x 8 = 109.52 sustained watts of power
Power = Current² x Resistance = 12² x 8 = 144 x 8 = 1152 peak working watts
Power = Current² x Resistance = 22² x 8 = 484 x 8 = 3872 max peak watts of power
would look like this -
Power = Current² x Resistance = 5.9² x 8 = 34.81 x 8 = 279 sustained watts of power
Power = Current² x Resistance = 15² x 8 = 225 x 8 = 1800 peak working watts of power
Power = Current² x Resistance = 32² x 8 = 1024 x 8 = 8192 max peak watts of power
12ga wire would break down like this -
Power = Current² x Resistance = 9.3² x 8 = 86.49 x 8 = 692 sustained watts of power
Power = Current² x Resistance = 20² x 8 = 400 x 8 = 3200 peak working watts of power
Power = Current² x Resistance = 41² x 8 = 1600 x 8 = 12,800 max peak watts of power
As others have said, if you are under normal circumstances, that is not exceptionally long wire runs, then any Oxygen Free Copper (OFC) of 14ga will get the job done. Generally you are looking for purity above 99%, but you will find that 99.9% and 99.99% are common.
With 13ga (2.5²mm) wire, at 50 feet or more, Inductive losses start to add up. From memory at 50ft, the combined Inductive and Resistive losses are about 15% which translates to roughly 1.5dB. Keep in mind that Inductive loss is frequency dependent, so in this example, the losses at 3500hz are about 3% but the losses at 12khz are about 10%.
I think for front speakers, most people will have no problem keeping their losses due to the Resistive
aspect of speaker wire down in the area of 1%.
But longer runs come with a second problem I had never calculated before. Using the above analysis, I determined what frequencies would be effected by the Inductive Impedance of 50ft of very common 13ga/2.5mm² twin lead cable.
At 2.286% Inductive Impedance loss, the frequency was 3,614hz.
That is MUCH lower than I would have imagined.
At 10% Inductive Impedance loss, the frequency was 12,650hz.
Capacitive loses were still well outside the Audio Range. But, again, the Inductive
losses were much more significant than I imagined.
This thread focus on all the measurable parameters of Speaker Cable -
- Skin Effect
- Current and Power handling capacity.
We have also considered Power Handling
ability. With all these factors combined and all reaching the same conclusion, I'm not sure what else we need to know.
All the high claims made by high-end speakers are true - long grain copper, Litz Wire, etc....
- they are true, but they don't matter. Plus while fancy Jacket and Pants look cool and cost money, they too don't functionally matter.
You might want something prettier than this, but this is all you really need unless your circumstances are unusual -
KabelDirekt Speaker wire - 14ga, 99.9% Pure OFC Copper - $30.92/50ft -
Just passing it on.