What Cable Gauge Do I Need for my Speakers?

[Zene]

Gene, so I guess my question is how low in relationship to speaker impedance should the cable be?
Rule of thumb has been 5% of the lowest impedance for the range the speaker will be operating in.
Zene

 

[Irvrobinson]

Gene, so I guess my question is how low in relationship to speaker impedance should the cable be?
Rule of thumb has been 5% of the lowest impedance for the range the speaker will be operating in.
Zene

I've heard that 5% "rule of thumb", and I think 5% is unacceptably high and completely unnecessary to tolerate. Considering a modern high-end speaker that is likely to have an impedance minimum of about 3 ohms, 3 x 0.05 = 0.15 ohm, which is 3x to 5x the output impedance of a typical well-designed amplifier. Really high-end amps often have an output impedance in the range of .01 to .03 ohms.

Secondly, most home listening is done at very low voltages, in the range of 0.5v to 2.0v, which means that the small increases in resistance from wires will have a greater impact, meaning higher insertion losses, than if the voltages were higher. This is why PA systems use 70v distribution strategies.

Worrying about speaker cables is unnecessary, because it is cheap to make the problem go away. The resistance of 12 gauge wire is about .0015 per foot, so even 20ft cables will have a resistance of only 0.03 ohms, or 1% of 3 ohms, and frankly in the case of speakers that dip to 3 ohms I'd use 10 gauge wire, which gets you to about .001 ohms per foot. This is why so many of us just run 10 gauge speaker cables and consider it done. 10 gauge zip cord is commonly available for less than $1/ft, if cost is a factor. For some connectors 10 gauge is too big, but just about anything can handle 12 gauge.

Considering all of this, what is your argument, Zene, for using anything other than 10ga or 12ga cable?

 

[Zene]

Slowly my eyes open, thanks Gene and Erv. I think I'm getting on track.
Zene

 

[Cpt.H.M.Murdock]

Hail Guru's of the speaker world. I am a rookie to the whole non-HTiB world of things so bare with my newb questions.

Ok so I have been reading some of the articles/posts around here and you guys really know your stuff. Some of the technical stuff no lie goes well over my head, and I am ok with that. I love that you guys use technical info to back up what you say. Even if i don't completely understand it.

Now to on subject I would say to me it seemed like a no brainer that having a longer run speaker cable or for that you need a bigger AWG wire. I get it and it is intuitive so it is easy to rap my head around. My questions are this, and this will be for my first build (which the rest of the build I will ask about in the appropriate threads). If all things being equal why would you go with 14awg for your say short run to front channel speakers and then go with 10awg or even say an 8awg cable to your rears. Why not just run 10awg all the way around? Did I miss something? I understand that thicker wire will be more stiff and also harder to hide, but as I haven't even started yet getting the path laid out to hide the cabling won't be that much a difference in effort.

Also, I didn't really consider the make-up of the core wire beyond the composition. Yes Gold has way better properties than copper. It is also way more expensive and I seriously doubt anyone could really afford to run their entire speaker system with 10awg solid gold cabling..if they even made such a thing. I am more average Joe and couldn't imagine spending more on cabling than I did for my car. That said I know your system will only be as good as its weakest link. You can have an A+ speaker with A+ components and C cabling and only get a modest sound quality. Sure it would still sound better than any HTiB but not as good as it could. So, all said an done I am going to be setting up my HT in a room approx 14x20. I have hardwood floors..well really laminate atm I plan on ripping them up soon and replacing with the real deal here in short order. Before I do that I want to get the speaker set up so I can determine their ideal locations and that way when I lay the new flooring I can make a channel to get the shortest run possible under the flooring. I know it will take a lot of time/effort, but in the end it will be worth it. Has anyone done this in their exp. I know wood expands and contracts is this expansion going to mess with my cabling, or should the expansion be relatively uniform thus negating any change in wire position between boards? Can anyone recommend a good cable that will be able to take being laid beneath the floor. I really don't want to have to run this through the walls/attic. I have 13' vault and attic space is pretty tight. I suppose I could also run the cabling in a channel made through the quarter round, but in any direction the cable would be forced through a doorway to get to the rear speakers. So would be challenging. Also, how does setting up wireless rear speakers sound to you guys? IE setting up a transmitter from the back of the source then placing a receiver at the rear of the room which carried the signal/power to rear speakers. Do they make anything like this which has little signal loss?? I know that anytime you go 'wireless' that you are going to experience signal loss. The question is how much, and is it noticeable? I would assume the amount of interference from competing frequencies would play into this, but lack the real world exp to say with certainty. I am thinking that I would be better served just sticking with direct wired connection, but don't want to offhand through out options.

Sorry I know it's a long ramble filled with grammar errors and some off topic questions. Thanks in advance for any/all advise.

 

[markw]

Yes Gold has way better properties than copper.

Really? Why do you say that?

Actually, from that statement alone I tend to question your motives here.

 

[Irvrobinson]

First of all, Captain Murdock, gold does not have better conductivity than copper, it's not as good. Silver is the best metal for conductivity, at about 5% better than copper, so copper is nearly as good as it gets.

There are flat speakers that can be laid under carpet, but I doubt under flooring.

Wireless still has power cable issues, unless that's easier for you to solve.

Personally I think surrounds are a big waste of effort, so I'd recommend staying with a great two-channel or 2.1 system, and avoiding the rear wiring hassle altogether, but that's just me.

 

[GSeifrit]

More A Question Than Reply

Klipsch Quintet Surround System.
Front speakers at most 10 feet cable- Rear speakers and woofer- about 35-45 feet of cable. Large room with cathedral ceiling.
Should I use different gauge for the job?
8 ohm impedance for the speakers.
Have bought 18 gauge wire- no special brand.
Thanks!

 

[Irvrobinson]

Klipsch Quintet Surround System.
Front speakers at most 10 feet cable- Rear speakers and woofer- about 35-45 feet of cable. Large room with cathedral ceiling.
Should I use different gauge for the job?
8 ohm impedance for the speakers.
Have bought 18 gauge wire- no special brand.
Thanks!

18 gauge wire is way too small for the longer run. Take it back for a refund, if you can. For the 35-45 feet run you need a minimum of 12 gauge. Any pure copper zip cord will do. For the fronts I'd also use 12 gauge, but you can get away with 14 gauge, if you insist on using a smaller diameter wire.

 

[Cpt.H.M.Murdock]

Really? Why do you say that?

Actually, from that statement alone I tend to question your motives here.

Sorry, I mis-typed. and was already corrected as above. Also, as I stated in the first line of my intial post I am new. I would tend to think that new people make more mistakes than the vets; do they not? Your statement tends to make me question your motives for being here. You here to bash the new guys or help people out??

The electrical resistivity of annealed copper is 1.7241 μΩ-cm, of hard-drawn, 1.771 μΩ-cm
The electrical resistivity of silver is 1.62 μΩ-cm
The electrical resistivity of gold is 2.44 μΩ-cm

Those are the figures I looked up w/ some research...again I was wrong. It has been a long time since I have had a chemistry class.

After looking up those figures I questioned why Gold would even be used at all...further digging leads to the aside from the obvious marketing ploy of Ooh it's shiny gold and it's more expensive it must be better. Is its corrosion resistance. As anyone w/ some old pennies can attest they do tend to oxidize. If you have ever polished some silver plate-ware again same deal.

Again I am new I am not stupid just not educated, and came here for education from those with the knowledge. If you are unwilling or unable to share knowledge and don't wish to teach the un-educated. Do as your mom taught you with the old adage if you don't have anything nice to say...don't say anything at all. If I wanted trolls I would get a twitter account.

 

[markw]

Cappy, when you jump into a forum with both barrels a-blazin', simultaneously spouting how much you know and total bullshit in a tome the length of one of the books of the old testament, you're gonna be looked suspiciously. ...particularly if you had bothered to read the thread before posting. For one of your supposeed education, you would have found more than enough information there to have answered your own question.

I'm still not too sure what I said was not the truth. Time will tell. And, I've helped many people out here. Which way did you come in?

 

[Cpt.H.M.Murdock]

Opps..all those years writing book reports and forgot to cite my source... Copper, Silver and Gold

Also, thank you to Irvrobinson for correcting me and the tips.
If I may another query I do believe the power cable issue would be much easier to solve. I am just unsure if the loss of signal is less than the hassle it would be to run the cabling through the attic. The running the cabling under the floor was kind of a thought. I have no experience with actually doing this to say "Yes, it works great" or "No, its an abysmal failure." From your remark I am guessing the later is the case. Also, is signal degredation a problem over longer runs of cabling?? So all things equal say you had 1 speaker with 8awg wire on a 10' run and the same speaker with the same cabling on a say 20' run would the audio performance differ outside of the losses from the impedance gain from the longer cable? Is it a negligible amount? I guess the easy way to put the question without beating around the bush is to say that I am in 1 of 2 wiring scenerios in regards to rear speakers. 1. Run the wire through the attic, just ball parking based on height of the wall route I would need to take to run the cable and room dimensions I would guess at roughly 50' maybe more maybe less, but with it being the middle of summer climbing up in a 140 degree attic just to measure how long a potential cable run would be doesn't sound like fun. #2 Set up a wireless transmitter/receiver and then figure out a way to hide the cabling for power. There is an outlet on that way almost perfectly in the middle of where the 2 rears would go.

I would rather mount the rear speakers to the wall over head as placing them on stands would interrupt foot traffic in the room. IE going to the kitchen for more popcorn. I know I can be a bit wordy, but I would rather overload on info rather than leave details out and leave you to guess. Thanks again guys/girls

 

[Irvrobinson]

So all things equal say you had 1 speaker with 8awg wire on a 10' run and the same speaker with the same cabling on a say 20' run would the audio performance differ outside of the losses from the impedance gain from the longer cable?

Do you really mean 8 AWG, or was that a typo, and you mean 18 AWG?

If you really mean 8 AWG, length becomes rather irrelevant. Even 100 feet of cable would be fine.

If that was a typo and you intended to ask about 18 AWG, then the impedance will cause a loss of about 0.3db for a 20ft run, according to the chart in the article referenced by this thread. At 50ft you're at a 0.7db loss, which may not be all that audible in itself with surrounds, but there's a chance that with 4 ohm speakers you could affect the amplifier's frequency response due to the increased resistance. Even if the difference is the degradation is audible I think using 18 AWG wire for any speaker cables is just silly when even 14 gauge cable is so cheap and easy to use.

 

[Cpt.H.M.Murdock]

Sorry, I shouldn't come in with words like "I know" I should replace with "I think I know" .As you said there is "more than enough"; can be read as info overload. I haven't been doing this for 10+ years more like a few weeks here and there when I got the chance to read/study. So, a lot of what I am saying asking is Hey I read a bunch of ****...yes I did read, but it is the internet(full of snake-oil and misinformation). Not all of my info comes from here. I await you to point out the 'bullshit'. Maybe I misunderstood something I read, or I just read something wrong. Unless your calling out the bullshit correcting me and maybe putting up some supporting information you aren't adding to the conversation. As I have said before I am a newb be easy on me. I am but a puppy swimming in a sea of information. Help me sort through it, or toss bricks at me the choice is yours.

For a more succinct line of questions.
1. Zip cord, solid core, twisted strand? Is zip cord just solid core wire packaged together to have -/+ together with some shielding between?

I can't seem to locate the link to the article in my history, but was on here a round of different speaker cables. Which showed difference in cables. It doesn't show all cables and with the size of the market I know this to be impossible. Is there a difference yes, there was shown to be a difference. Could I perceive this I don't know. What are reputable brands for cabling? I don't know this and its hard to say where Audioholics may be promoting for advertising dollars or if just good cables? I am thinking in my price range $1/ft sounds reasonable.
2. I haven't seen but banana plugs vs spades?

I haven't come across any info on which is better or what situation would call for one versus the other. Seems just from looking at products that banana plugs are more prevalent. Again quality manufacture suggestions??




List of some(not all)things I read just relating to cabling not counting the endless sea off speakers and other A/V equipment...again some of the technical stuff goes over my head..could we have this in 'dumbass' ugh laymans terms?
Debunking the Myth of Speaker Cable Resonance | Audioholics
Speaker Cable Length Differences: Do They Matter? | Audioholics
Speaker Cable Reviews - Faceoff 2 | Audioholics

 

[Ampdog]

At 50ft you're at a 0.7db loss, which may not be all that audible in itself with surrounds, but there's a chance that with 4 ohm speakers you could affect the amplifier's frequency response due to the increased resistance.

Question: I reread the whole thread, so perhaps a mite info-overloaded. Are we talking about a nominal 8 ohm system here? Assuming that (and too lazy to calculate the real cable impedance ), I get a cable resistance of 0,67 ohm from your 0,7dB loss. Then, for a 4 ohm speaker system, that would amount to a 4,67 ohm load on the amplifier.

You say that could cause problems with the amplifier's frequency response? An increase of 17% in load affecting any good amplifier's frequency response? Kindly broaden my horizons.

Even if the difference in the degradation is audible I think using 18 AWG wire for any speaker cables is just silly when even 14 gauge cable is so cheap and easy to use.

Sure - that is only logical - and why I respectfully find many of the cable arguments veering slightly towards the academical only.

General;
I would say by now it should be evident that in any normal domestic system inductance and capacitance in loudspeaker cable plays no audible role. I still, however, find some reference to deterioration in damping factor with loudspeaker cable with a resistance of 100s of milli-ohms.

??

This is where the misleading definition of 'damping factor' seems to come in (I have not noticed that being mentioned). Practical damping of the loudspeaker system is not defined by (loudspeaker impedance)/(amplifier + cable impedance). The 'braking' effect on the driver is defined by the total circuit resistance, thus also including the voice coil resistance. For an 8 ohm driver I have that as nominally some 6 ohms. Thus the total real damping factor in such a case will be 1,33, even with cable resistance and amplifier output impedance = 0. I find it just a little academic to then mention the effect of cable resistance of say 0,1 ohm on damping factor (the real one). Hopefully this misconception does not upset too many members.

 

[Irvrobinson]

Even if the difference is the degradation is audible I think using 18 AWG wire for any speaker cables is just silly when even 14 gauge cable is so cheap and easy to use.

My apologies for the poorly-formed sentence; it should read:

Even if the degradation is inaudible, I think using 18 AWG wire for any speaker cables is just silly...

I never mentioned a deterioration in damping factor, I was only speaking of insertion loss.

 

[Jor4President]

If you haven't found the answer yet:

1. Zip cord, solid core, twisted strand? Is zip cord just solid core wire packaged together to have -/+ together with some shielding between?

Zip cord is always stranded. Some have less and thicker strands than others. Solid core wire is called romex and will work fine but is a b... to work with. They have shielding not only between +/- but also around the cables.

What are reputable brands for cabling? I don't know this and its hard to say where Audioholics may be promoting for advertising dollars or if just good cables? I am thinking in my price range $1/ft sounds reasonable.

Since you want to hide the cables in the ceiling or the floor I'd go with whatever CL2 rated cable you can get at a good price. Monoprice has cheap 12AWG with CL2 rating. I personally would get the 12AWG from bluejeans cable since it's the same price over there as zip cord here in Europe. If you don't need the extra cash you can get the 10AWG from bluejeans for 1$/ft. If Audioholics is promoting cables for advertising dollars they aren't very good at it. I do suspect they may have had some UTP network cable for sale on craigslist when they posted the article on DIY speaker cable. That article made me a very happy broke student back then.

2. I haven't seen but banana plugs vs spades?

Both increase resistance. Technically spades are better but banana plugs make your life much easier. If you're going to do the work to connect a spade you might as well use unterminated wire.

 

[Ponzio]

How about cable length? I'm re-wiring my 3.1 setup with 12AWG copper/banana plugs. Do all the wires need to be the same length going to the LRC speakers, with the longest run being 10'?

Thanks in advance.

 

[markw]

How about cable length? I'm re-wiring my 3.1 setup with 12AWG copper/banana plugs. Do all the wires need to be the same length going to the LRC speakers, with the longest run being 10'?

Thanks in advance.

Differeing cable lengths will not be an issue here, or in most any home situtation I can think of.

 

[Rickster71]

Solid core wire is called romex ............ They have shielding not only between +/- but also around the cables.

NM Wire with shielding? That's a new one on me.... do you have a link?
Not to be pedantic; Romex is a brand name. To be clear solid core doesn't only come as NM wire, it's also comes in THHN, MC.

 

[Speedskater]

I think that 'shielding' was a typo. It's insulation or maybe dielectric or sheath.