Speaker Cable Different for 8ohm vs 4ohm

Thank you for excellent information. I am using Magnepan 3.6's at the moment with six foot runs of DH Labs Silver Sonic Q-10 Signature biwires. The Q-10's use one run of smaller wire for the tweeter/midrange and a heavier run(12gauge I think) for the woofer connection. I've used this cable for years with no complaints. I believe that it is solid copper with a very thin cover of silver.

I am looking at the new Magnepan 20.7's and if I go there I will have to change the speaker wire since they are not bi-wireable as a result of the new crossover design. Also, I will probably want to extend the speaker cable length to around eight feet. The six foot runs are a bit tight.

I may just go with DH Labs single runs but I am open to sugestions for a really top notch speaker wire that works well with the 20.7's.

I find that using shorter speaker cables lessons the ability of the cables to actually physically reach to the location of my speakers, resulting in a distortion-free, low noise, utter lack of any sound at all.

So that is what a dead short is! I always wondered.

Al, your voltage divider example does clear things up I think.

Let me just clarify one point, is the goal for Vin and Vout to be equal (ie in perfect world where the speaker cable would have no resistance or inductance) such that the voltage output by the amp (Vin) would be the same at driver (Vout)?

Thus in the real world as Z1 increases then for a given Vin the Z2/(Z1+Z2) ratio decreases and reduces the value of Vout.

Thanks

Hi Nick,

Yes to both questions. However, the most significant issue is not the voltage loss in itself, but the fact that the amount of the voltage loss will vary as a function of frequency, and thus it can affect tonal balance. While the Maggies that Stickman is asking about have a relatively flat impedance curve, as you no doubt realize the impedance of many speakers (Z2 in the equation) will vary widely over the audible frequency range. So even if Z1 is constant (i.e., a pure resistance), if Z1 is not small enough frequency response flatness may be affected to a perceptible degree. And Z1 can also vary as a function of frequency at least slightly, due to the effects of its inductive component at high frequencies. Also, excess resistance can degrade bass damping, especially for speakers having cone-type woofers.

That dependency of the effects of the cable on the impedance vs. frequency characteristics of the speaker is one example of why cable effects tend to be system dependent.

Regards,
-- Al