Ask Dr. A! Does Speaker Cable Gauge Matter?

[admin]

It's been a while since Dr. A answered a reader question so we pulled him away from his 4 month karaoke binge and tossed a new question at him. Seems like Dr. A has an addictive personality so we'll need to keep him a bit more occupied in the future for his own good. This question, from philophobos via our forums, has to do with speaker cable gauge, but we expanded it a bit in our answer to address some other related situations.


Discuss "Ask Dr. A! Does Speaker Cable Gauge Matter?" here. Read the article.

[ibgarrett]

I'm in the process of finishing my basement and I'm putting in a home theater system as part of the process. I've decided to try using some mini-coax cable because of the size and easy of use with the connectors. (For the cable type just send me an email - I haven't posted enough yet, so I can't include the link) I also like it because it's shielded.

How does that compare to speaker wire?

Brian

[gene]

I'm in the process of finishing my basement and I'm putting in a home theater system as part of the process. I've decided to try using some mini-coax cable because of the size and easy of use with the connectors. (For the cable type just send me an email - I haven't posted enough yet, so I can't include the link) I also like it because it's shielded.

How does that compare to speaker wire?

You don't need shielding for speaker cables in 99% of installs. Don't forget a speaker is a low impedance device so you won't get much pickup at all from outside sources.

Find out the gauge on the mini COAX but I suspect it will be 18AWG or higher thus I'd recommend either cross connecting 2 COAXs, or using conventional 4/4 speaker wire paralled to yield an effective gauge of 11AWG.

[yettitheman]

Yes and no. I reference the article at hand, as longer distances benefit marginally from increased wire gauge.

I'll say this; inside your typical HTR, the wires connecting the speaker terminals from the amplifier circuit board are usually MUCH smaller than the cable you are using to run to the speakers from your HTR.

[gene]

I'll say this; inside your typical HTR, the wires connecting the speaker terminals from the amplifier circuit board are usually MUCH smaller than the cable you are using to run to the speakers from your HTR.

Yes and those are extremely short distances and anything with power connections still usually have 14AWG or soldered on to pcb board with very thick traces. The small wires are usually connection digital circuits and pass extremely low current signals.

[kelsci]

Hi; I conducted passive surround sound experiments during the 80s and 90s with four and five channel dynaquad ciruits. My use was with 18 gauge wire. One time, I wired up the circuit with 16 gauge wire. The soundfield collapsed into the middle of the room as one big monophonic muddle. So this circuit told me something of the importance of 18 gauge wire. Many perhaps tried passive surround decoding in the pre-discrete days. If they fooled with the lower gauge wire, they would have experienced failure in getting that circuit to operate.

I also tried 20 gauge wire. The tonality of the sound of the whole sound field was thin, much like turning down a treble control on a receiver counter clockwise.

When it comes to an active discrete surround sound receiver as we have today, I cannot really comment on the effects of lower gauge wires since I did not have the opportunity to try that. My brother does have 16 gauge wire on his home theater system and it appears to work well. I have 18 gauge wire on mine and I am comletely satisfied as to its toneality and soundfield balance.

[gene]

My brother does have 16 gauge wire on his home theater system and it appears to work well. I have 18 gauge wire on mine and I am comletely satisfied as to its toneality and soundfield balance.

You may wish to rethink that as 18AWG wire has nearly 4x the DC resistance of 12AWG. Thus running 20ft of 18AWG wire would yield the same resistance of nearly 80ft of 12AWG!

insertion loss of 20ft of 12AWG with 8 ohm speaker = .07dB
insertion loss of 20ft of 18AWG with 8 ohm speaker = .28dB

The minor additive AC resistance of 12AWG wire at 20kHz is completely washed out by the DC resistance of 18AWG wire so even at frequencies up to the capabilities of human hearing, 12AWG wire still has FAR lower AC resistance, about 2.3 times lower as a matter of fact!