Cat 5E cable used as speaker cable?

**JK200SX** · 05-01-08, 01:31 AM

Are their any issues with cat5e cable used as speaker cable for run <20m?

Application is for ceiling speakers used in various rooms around the home. If it is suitable would you use 1 condutor for + and one conductor for -, or could you use a pair or multiple pairs for each polarity?

I have both cat5e utp and shielded cat5E at my disposal?

Thanks,

JK

**z80** · 05-01-08, 01:47 AM

The purists will object, but I say go for it.

Use the colours for one, and the wires with a trace for the other.

What could possibly go wrong....

**JK200SX** · 05-01-08, 02:16 AM

Thanks J.

From what you're saying, use 1 condustor from each twisted pair for + and the other for -. WOuld their be any differnce if 2 twisted pairs were used for + and the other 2 for -? (ie which would give the best noise shielding?, and or would their be more benefit to use the shielded cat 5E?)

Thanks,

JK

**Armers** · 05-01-08, 02:58 AM

nothing wrong with it

Enojy

Armers

**antus** · 05-01-08, 04:53 AM

Originally Posted by JK200SX

Thanks J.

From what you're saying, use 1 condustor from each twisted pair for + and the other for -. WOuld their be any differnce if 2 twisted pairs were used for + and the other 2 for -? (ie which would give the best noise shielding?, and or would their be more benefit to use the shielded cat 5E?)

Yep, what z80 said. Using all pairs will decrease the resistance in the wire which would make a difference for long runs compaired to if you only used 1 pair, and + to colours and - to whites would give better shielding, twisted pair style.

Same problems occur as using cat5 for power over ethernet, and can be improved the same ways.

Note that if using one audio source and just hooking all speakers in parallel or series that will give you problems too - either too high total resistance for series (too quiet) or too low total resistance (bang! goodbye amplifier) for parallel, depending on number of speakers.

**antus** · 05-01-08, 05:02 AM

another tip - keep it away from fluros, you'll pick up 50hz hum if you get too close. Maybe go for foil shielded and ground the foil to help with that.

**typan** · 05-01-08, 05:12 AM

I used Cat5e data cable for my rear speakers years ago with no problems, go for it mate

**JK200SX** · 05-01-08, 05:19 AM

No fluoros from what I know - should a minimum distance be kept from 240V cable?

Also, if I us the shielded cat cable, will it still be better than non shielded even if the shield is not grounded?

**bit_pit** · 05-01-08, 06:28 AM

I've used Cat4/5/5E/6 for all sorts of stuff, including speakers.
Technically, you should use baluns to match the impedance, if you are not a purist you can get away without it.
Try to keep the signal in a twist, i.e. Blue+/BlueWhite- sort of thing, this keeps noise / crosstalk etc. down.
240v is usually no issue, as long as you dont run parallel to the 240 for any distance, try to cross at right angles.
As to the shield, you will need to earth 1 end. Earthing both may introduce a current loop and hum.
Not earthing can make it like a big antenna, piking up all sorts of crap and defeating the purpose.

**watchdog** · 07-01-08, 08:09 AM

A couple of things to consider. Since it is going to be running ceiling speakers then I would say that you are not talking high power, just background music. If your amp is configured for 4 , 8 or 16 ohm O/P you could use barbed wire with no ill effect. Just make sure you do your load calculations properly or you could POP the O/P of your amp.
If your amp is configured for 70V or 100V line o/p then you need to ensure your insulation is not going to break down. If you are talking high power >50W then I wouldn't take the chance , 24x.020 fig 8 doesn't cost that much.
Noise induction at audio o/p level is not an issue.
Impedance matching at audio frequencies is not an issue.

Just go & buy some fig 8