Flat cable question

[Djizasse]

Hi all.
I want to wire my back speakers with 12 AWG cable. If I pass the cable through the floor, under the carpet, it's just 4 or 5 meters (12-16 feet), otherwise I'll have to work around the door and walls (triple the distance).

I can't find any cable flat enough with the 12AWG section (at least in europe) . So I was wondering if I could use 15 AWG, using two cables instead of one. I've made the maths:
12 AWG - 2,052mm diam - 3,308mm2 section
15 AWG - 1,450mm diam - 1,652mm2 section x2= 3,304mm2 section

Can I do this? Or are there adverse effects?

The speakers are Tannoy Reveals 6, amped by a Yammy 861.

 

[Exit]

Assuming the wires are for surrounds and that the surrounds are set to “small”, it shouldn’t take much power to drive them. I would try a single 15 AWG wire and see if you notice any adverse effects. You will still probably have enough power even if constrained by a thinner gauge speaker wire. You won’t blow up an amplifier or anything drastic by trying it. It is just a matter of whether power is reduced enough to make a difference. You can always try something else (such as your second wire) if it doesn’t work.

 

[Djizasse]

They'll be set to large, cause I don't have a subwoofer yet. One of the uses for the rears is multichannel games, they'll get some action for sure. I can also redirect music to the rear (I use a computer as the audio/video HQ), although this is not so critical, the volume in this case will allways be low.

Some guys use CAT 5 cables to wire speakers, many tiny cables, joined to pass one channel. This is similar, right?

I just don't want to buy more cable just to make experiments, but I guess this is part of the fun
I'll "test" them with BJC 10 and compare it with 1 and 2 AWG 15. Unless I hear someone mentioning some electrical property that I don't know about.

 

[Midcow2]

use the single 15 gauge flat wire, here is why ...

Typically wire come in even gauges, 16 gauge is slighly smaller so using 16 gauge the resistance is 4.083 ohms per 1000ft or 13.4 ohms per KM. When you calculate the resistance for your maximum distance of 16 feet is .2144 ohms

For an average 8 ohm speaker resistance your loss due to the wire resistance is 2.6% = .2144(.2144+8). This insignioficant and would not be noticeable at all. You number will be better because 15 gauge would be larger than 16 gauge and have even less resistance.

For the average 4 ohm speaker resistance your loss due to the wire resistance is 5.1% = .2144(.2144+4).
This is higher but still insignificant.

 

[Djizasse]

OK. I'll go with the single 15 AWG. If I get anal I'll just add another one.

Case closed Thanks

 

[gene]

Always remember the rule of thumb when you combine two identical gauge cables the effective gauge is 3AWG lower than the single cable solution.

So in this case 2 pairs of 15AWG wired together yields an effective gauge of 12AWG.

 

[Djizasse]

Thanks. That is a very nice rule

 

[MDS]

They'll be set to large, cause I don't have a subwoofer yet. One of the uses for the rears is multichannel games, they'll get some action for sure. I can also redirect music to the rear (I use a computer as the audio/video HQ), although this is not so critical, the volume in this case will allways be low.

You can still set them to Small without a subwoofer. Just set subwoofer = no and the bass will be redirected to the mains.

 

[Alex2507]

As I understand it, having the resistance of your speaker wire equal 5% of the speaker's impedance is right about where you would start to be able to here a difference. Here's a link with a nice little chart that tells you what gauge is good for what distance. 16ga is good for 48' on an 8 ohm speaker!

http://www.roger-russell.com/wire/wire.htm#wiretable

So in this case 2 pairs of 15AWG wired together yields an effective gauge of 12AWG.

Are there undesirable effects to separating + and - conductors like that? Or is that one of those cases where theory and audibility never meet?

 

[mtrycrafts]

As I understand it, having the resistance of your speaker wire equal 5% of the speaker's impedance is right about where you would start to be able to here a difference. Here's a link with a nice little chart that tells you what gauge is good for what distance. 16ga is good for 48' on an 8 ohm speaker!

Most likely not at 5%. The example what a 1 ohm resistor in series will do on an 8 Ohm speaker, a 12.5% resistance, can be audible at the 300Hz and 10kHz sections.
Similar to level matching at .1dB. It is well below audibility, not that at .12 or .15dB you will hear the difference.

 

[Face`]

If you haven't purchased anything yet, Goertz/Alpha Core makes 13ga flatwire.

Mike

 

[Djizasse]

Does that stuff exist in Europe?