Wiring Stereo Speakers

Thanks all, I am beginning to think that Maplin have sold me the wrong stuff. As I am keen to have all cores in a single cable, would a simple 4 core cable do the trick or are there any other considerations?

In short, 4 core would work - ideally 0.7mm2 or more per conductor.

2 core shielded cable will cause distortion and may damage your equipment.
 
Blimey. I just used a length of the ordinary 1.5mm^2 2-core flex I use for general 12v wiring on board :)

Well, it depends what you mean by "general", but I can't see a problem with that and it is what I do.

My long winded point is that the electrons which conduct current by exchanging charge in a speaker cable obey the same laws of physics as all other electrons in all other cable. Yes there is a skin and other effects, but if your audio system sound varies as a result then something much more basic is at fault. A lot of rules of thumb have been given, I am just trying to add a little calculation based on my own expertise and give a little back to a forum from which I gain a lot.
 
So have you ever listened to them? I'm guessing from your comments that you haven't so how can you be so sure?

Don't forget CAT6 cable is designed to carry signals up in the GHz range - it is much better at carrying high frequency detail than massive wads of copper.

In fact the "skin effect" means that the high frequency current is actually largely carried in the insulation rather than the copper itself, so the individually insulated strands in CAT6 cable are much better than a mass of uninsulated strands.

Listened to what? Why on earth would I want to listen to decent speakers attached to 0.5 mm2 wire? I'm sitting here listening to a couple of JBL speakers attached to a 3kW amplifier via 4mm2 cable (obviously set to a very low volume - most of the time!).

CAT6 cable is designed to operate in the GHz range by being an impedance matched twisted pair, terminated 100 Ohm each end - rather different to the >1 Ohm output impedance of an audio amplifier with an 8 Ohm (possibly 4 Ohm) speaker on the other end.

skin effect means the high frequency current is actually largely carried in the insulation
Yeah, right - I suggest you need to do a little more research!
 
2 core shielded cable will cause distortion and may damage your equipment.

No, it won't do either of those, but most 2-core shielded is too small copper area for the job.

As I've said, and others, just go for heavy gauge multi-stranded cable. No harm in using 4-core if you can get it, but I'd still aim for more than 1mm2 per core.
 
There is more rubbish spoken on audio forums about cables and there affect than any other topic i reckon. Anoraks aside... There are various theories about which is best. Your boat is probably never going to be an audiophile listening area, so i would just buy any car or home figure 8 speaker cable.

At home i use nordost valhalla... I am no way putting that in a boat... Stuff i wired in my boat was about 6 pound a meter and does the job...
 
Listened to what? Why on earth would I want to listen to decent speakers attached to 0.5 mm2 wire? I'm sitting here listening to a couple of JBL speakers attached to a 3kW amplifier via 4mm2 cable (obviously set to a very low volume - most of the time!).

CAT6 cable is designed to operate in the GHz range by being an impedance matched twisted pair, terminated 100 Ohm each end - rather different to the >1 Ohm output impedance of an audio amplifier with an 8 Ohm (possibly 4 Ohm) speaker on the other end.

Yeah, right - I suggest you need to do a little more research!

LOL So you are sitting there talking so knowledgeably about something you have never even tried :)

Talking about cable impedance matching at audio frequencies is nonsense - even at GHz frequencies it is totally irrelevant if you are talking about a few metres of cable.

Mind you if you think that 3kW is necessary to a domestic audio system then you probably would need somewhat thicker cable.

what gauge wire do you think your coils are wound with?

BTW I should say that I am not advocating a single core - my tweaters use 4 cores per each and the mid/bass 8 cores
 
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Each to their own, I guess :)

I'm not saying CAT6 cable won't work - I'm sure it does, at relatively low power levels. But the OP asked what was best, and CAT6 certainly isn't.

I can assure you that impedance matching is pretty important once you get into GHz range, but you're right, it isn't an issue at audio frequencies. I only mentioned it to indicate why CAT6 cable worked at GHz, but wasn't designed to be used as a loudspeaker cable. As it happens, I do use it for audio, as it's ideal for distributing low-level, balanced audio, as the designed twists in the cable make it pretty immune to interference. However, even loudspeaker cables for car stereo, or similar, need to carry peaks of several Amps, and it is important that the cable resistance is considerably lower than the speakers otherwise you just will not get the best results.

And, yes, of course, 3kW is a tad excessive for domestic audio, as it's sitting there doing nothing most of the time I decided I might as well listen to it. I have no idea what gauge the speaker coils are wound with. I do know what their rated power is and routinely throw that at them for several hours at a time (not at home!), and haven't managed to blow them up yet! But then, that's what they're designed for, with cunningly designed ventilation and heat dissipation features.
 
According to musical fidelity... You cant have too much power :D
Dont think they sell a 3kw amp though... Thats some beasty :)

Not exactly domestic - Behringer EPX3000, and I've got two of them for my PA hire business. Behringer don't have the best of reputations but I've had no trouble with mine. They're a little over-powered for the speakers at 1500W per channel into 4R, the speakers are JBL TR225, rated at 450W continuous 4R each. Peak rating is 900W+, so not too far off! I've got a couple of sub-woofers too, but that's a bit much for the office!

Oh yes, you can't have too much power! :D
 
I am planning on having an extra set of speakers on a wandering lead so I can get music where I want out on deck. I am using a specific speaker connector which has 4 terminals marked +1 -1 +2 -2 which I assume the + to be signal and - the return. I bought 15 M of 2 core speaker cable from Maplin's and was surprised that the screen on each core was touching and therefore shorting.

I have no knowledge of sound systems beyond normally having 2 separate 2 core cables, one for each speaker. Is it normal that the returns for stereo speakers are common??

Thanks in anticipation....

Is the 4 core connector carrying left and right or (getting technical) HF and LF for a bi amped system?

Assuming the former, are you intending to use one speaker or two? If two, you will probably need two cables coming out of the plug (Is it a speakon type plug?), If the cable runs are not excessively long say <10M I would suggest 1.0mm or 1.5mm twin flex from the amplifier to the socket and 0.75 or 1.00 mm white twin oval cable out of the plug to the speakers. Generally speaking the thicker the better but you have to be practical.

We use 2.5mm Twin flex, usually OFC (Oxygen free cable) for ship show lounge and theatre systems, 4mm would probably be better but I have not come across it being used although it probably is for very high power concert systems.
 
LOL So you are sitting there talking so knowledgeably about something you have never even tried :)
I guess that most people haven't tried it, because it is a stupid idea. Just like most people have not tried using bell wire to install a 1kW metal cased electric fire in their bathroom, but I have seen it done.

are you intending to use one speaker or two? ...

I have asked this question twice now, but I think the OP has been scared away by the BS. He said that he wanted all the cores in one cable, which to me implies that he is going to put the speakers side-by-side. If this is the case, then only one speaker is necessary, wired to the + of the left channel, and the - of the right (or the other way around).

If not, then there are plenty of other sensible options: none of which include Ethernet cable.
 
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Thanks once again, I am sure the answer is in here somewhere! To clarify, I am intending to separate the speakers close to the point of use so will split the cable for the last couple of metres. I think a relatively large cross section 4 core cable will do the trick and return the other stuff to Maplin. I am using the Speakon connector which will be connected to the front speaker output of the car radio. Hi Fi it ain't but 2 speakers will help.
 
Each to their own, I guess :)
As it happens, I do use it for audio, as it's ideal for distributing low-level, balanced audio, as the designed twists in the cable make it pretty immune to interference. However, even loudspeaker cables for car stereo, or similar, need to carry peaks of several Amps, and it is important that the cable resistance is considerably lower than the speakers otherwise you just will not get the best results.
That's an interesting change of position. I have efficient speakers so the power required to drive the tweeters is very low - the cables to the tweeters probably carry no more power than the interconnects, yet you seem to think that one is a good idea and the other is unthinkable
 
Thanks once again, I am sure the answer is in here somewhere! To clarify, I am intending to separate the speakers close to the point of use so will split the cable for the last couple of metres. I think a relatively large cross section 4 core cable will do the trick and return the other stuff to Maplin. I am using the Speakon connector which will be connected to the front speaker output of the car radio. Hi Fi it ain't but 2 speakers will help.

You can get 4-core mains cable that would be OK for the first part of the run, or you could get some expanding sleeve and cover the first part. I wouldn't normally recommend Maplin, but they do this: http://www.maplin.co.uk/productsearch?criteria=Cable Sleeving Black

Have you considered wiring the speakers permanently into the area concerned?
 
No, it won't do either of those, but most 2-core shielded is too small copper area for the job.

As I've said, and others, just go for heavy gauge multi-stranded cable. No harm in using 4-core if you can get it, but I'd still aim for more than 1mm2 per core.

It will cause distortion because of the shared return e.g. left speaker's return current will cause a voltage over the shared return path, which will impact the voltage over the right speaker. And vice versa.

It will cause damage if your output is push and pull e.g. +L/-L rather than +L/0, because you will be shorting -L and -R outputs.

Short answer is, use 4 conductors.
 
That's an interesting change of position. I have efficient speakers so the power required to drive the tweeters is very low - the cables to the tweeters probably carry no more power than the interconnects, yet you seem to think that one is a good idea and the other is unthinkable

No change of position - I'm not talking about sending speaker power (even small ones) over cat6, but low level audio interconnect between equipment - there is a considerable difference.

It's only "unthinkable" in the sense that I can't think why anybody would want to do it, when there are far better ways. Even if you join all the cores together to get a reasonable mm2 of copper, it doesn't offer any advantage over a piece of cheap 1mm2 (or bigger) multi-strand cable - which would be cheaper to buy and easier to terminate.
 
It will cause distortion because of the shared return e.g. left speaker's return current will cause a voltage over the shared return path, which will impact the voltage over the right speaker. And vice versa.

It will cause damage if your output is push and pull e.g. +L/-L rather than +L/0, because you will be shorting -L and -R outputs.

Short answer is, use 4 conductors.

I didn't think we were talking about sending both channels up the same bit of twin/screen cable - that would certainly be a bad idea!
 
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