2. speakers
  3. 191342-171531

Speaker wire impedance? Speaker impedance?

I finally got into the owner’s manual for the speakers I bought last May (Revel M126Be) and under "SPEAKER CABLE" Revel is saying that, "High loop resistances that exceed 0.07 Ohms (for each wire run) will cause the loudspeaker’s filter network to be mis-terminated, resulting in considerable degradation of sound quality."

I ohmed out my (longer than I think is optimal) single run (the Revels are not bi-wireable) of (what I think I remember being) Kimber 8TC and I read 0.07. My B&Ws were shotgun bi-wired, so today I also doubled up my single runs with the other bi-wire cable (so two wires are terminating on one speaker post for + and - for both speakers) and rechecked the impedance and read 0.05 ohms which I assume is a variance going in the proper direction.

But I have a probably stupid and probably very basic question (as I make NO claims of having a tight grasp on this stuff). If a lower impedance run of speaker cable makes for an easier load for an amp to drive, why is it that a speaker with higher impedance is a easier load to drive? Can this be dumbed down for me?

I apologize because I am sure this has been asked before, but I cannot find the right combination of words for a search engine that is yielding an answer.

 

immatthewj

Showing 2 responses by carlsbad2

carlsbad2's avatar
carlsbad2
2,026 posts
 

You really need a micro-ohmeter to measure such small resistances. best bet is to calculate it. if it is too high, then you need larger wire. the manual only mentioned "resistence" which is a funcion of wire gauge and length only, so the inductive portion of impedance apparently isn’t a problem for these speakers, still it should be minimized. Avoid loops, for example.

https://www.engineeringtoolbox.com/copper-wire-d_1429.html

Also avoid alloy wires for speakers. Surprisingly, alloys are always higher resistance--add silver to copper and you get an alloy that is a worse conductor than either silver or copper alone.

As for your question, the impedence of the speaker is the load where power is turned into sound, the resistance (lets equiate it to impedence) of the cable is the circuit that transmits the signal to the speaker. You don’t want any of the power being disipated there.

Jerry

carlsbad2's avatar
carlsbad2
2,026 posts
 

Your 8TC cables are 9AWG equivalent which is heavy enough for any run inside a listening room.  You have nothing to worry about.

Jerry

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