Thickness of speaker cables?

[Wendigo79]

How thick shoud speaker cables be? I use 4mm2 and 2.5mm2 cables in my two systems. Especially 4mm2 is plenty. I believe. But is there a method to calculate the actual need for thickness? I mean, low frequency bass signal uses more current than high frequency. But how thick the cable shoud be in more powerful system? So that all lowfrequency oomph goes through?

 

[MZKM]

No clue about wattage, but for power loss:

You can see why 70V is used for professional PA installs.

To go from AWG to mm2:
https://www.rapidtables.com/calc/wire/awg-to-mm.html
2mm2 is 14AWG

You can go ~10ft with 14awg and even at 2ohm you’d only lose 0.5dB.

There is also damping factor, but that is dependent on the output impedance of your amp.

 

[Lero]

12AWG should fit every possible application, for very long runs 10 AWG.
of course oxigen free cables and good isolation* is an important requirement.
edit: shielding*

 

[Chrispy]

It's just about gauge for the impedance / length, nothing special required for "oomph" This is a good site to learn all sorts of things about speaker cables http://roger-russell.com/wire/wire.htm

 

[dominikz]

The relevant parameter will be cable resistance and required thickness will be inversely proportional to length for a given resistance.
You can use the excel sheet at the end of this Benchmark article on damping factor to estimate cable resistance for a specified thickness and length, and it will also calculate expected maximum frequency response variation for a given speaker impedance and amplifier damping factor.

To give an example of a pretty bad case - my amplifier has a very low/bad damping factor (~15) and with a very thin 2m speaker cable (0,75mm2) to a 6 Ohm nominal impedance speaker I got ~1,2 dB estimated (and measured) maximum variation in frequency response. Note that in my case the amp damping factor is the limiting factor much more than speaker wire thickness.

Even that is still a lot less than the influence room and speaker will have on the full system response though, so probably not worth worrying to much about it

 

[pozz]

of course oxigen free cables and good shielding is an important requirement.

OFC are marketing talk and shielding is not necessary for speaker cables.

 

[Lero]

The relevant parameter will be cable resistance and required thickness will be inversely proportional to length for a given resistance.
You can use the excel sheet at the end of this Benchmark article on damping factor to estimate cable resistance for a specified thickness and length, and it will also calculate expected maximum frequency response variation for a given speaker impedance and amplifier damping factor.

To give an example of a pretty bad case - my amplifier has a very low/bad damping factor (~15) and with a very thin 2m speaker cable (0,75mm2) to a 6 Ohm nominal impedance speaker I got ~1,2 dB estimated (and measured) maximum variation in frequency response. Note that in my case the amp damping factor is the limiting factor much more than speaker wire thickness.

Even that is still a lot less than the influence room and speaker will have on the full system response though, so probably not worth worrying to much about it

I used the wrong term, didnt mean shielding, i meant isolation. u are right.

 

[Katji]

That's ok, I give you credit for the mm2 table.

[This Xenforo needs more BBCode pack.]

 

[Wendigo79]

Thanks for quick answers! I have usually used that 4mm2 cable which i get from a shop nearby. But when i was building my second kit, i found that it was out of stock temporarily. So i bought thinner 2.5mm2 wire. Then started to think that maybe that was too thin wire. Especially when those wires are about 5m in lenght.That is about 15ft. Both my systems have bookshelf speakers. And both systems have 6ohm loudspeakers. But when lookin those charts I found that no worries! I actually could use 14awg in both kits. Yeah, this is good place to found actual answers. In some other forums, talk would have gone to "emotional throughput of different materials"

 

[GeorgeBynum]

To go from AWG to mm2:
https://www.rapidtables.com/calc/wire/awg-to-mm.html
2mm2 is 14AWG

If you like mathematics, You can calculate AWG from square mm via 17-4.27*LN(mm^2). LN is natural log.

 

[MZKM]

If you like mathematics, You can calculate AWG from square mm via 17-4.27*LN(mm^2). LN is natural log.

I have my degree in mathematics.
But even then, who’s got time for that.

 

[NTomokawa]

It's just about gauge for the impedance / length, nothing special required for "oomph" This is a good site to learn all sorts of things about speaker cables http://roger-russell.com/wire/wire.htm

A shoutout to this article. I can't recommend it enough. Reading this "Wirebusters" article is what started my scientific audio journey.

 

[Speedskater]

It comes down to:
a] total end-to-end resistance of the cable
b] impedance/frequency curve of the loudspeakers.
* * * * * * * *
Long cables need to be heavier than short cables.
Loudspeakers with nasty impedance curves need heavier cables.

 

[Chrispy]

I used the wrong term, didnt mean shielding, i meant isolation. u are right.

OFC is little different from ETP and even CCA is useable with sufficient gauge.

 

[Shazb0t]

OFC is little different from ETP and even CCA is useable with sufficient gauge.

12AWG OFC speaker wire is already pretty cheap from places like Monoprice. I would just stick with that.

 

[Chrispy]

12AWG OFC speaker wire is already pretty cheap from places like Monoprice. I would just stick with that.

True enough but somewhat depends where you are and what's available.....just saying OFC isn't necessary.