Fat v skinny

[Covenant]

Speaker cables that is. I am inclined to think that a beefy cable will be better than a thin one but there are many highly regarded ones in the latter category. Extending the argument further it could be that bi-wiring, often considered to be of dubious benefit, might sound slightly better because of the larger area of cabling.
Any thoughts?

[Puffin]

Jerry, I have had many many types of speaker cable over the years (most of them are languishing in large plastic crates in the garage) (and yes I even had some QED Silver Anniversary Bi-Wire)

Now I don't think that it is purely psychological, but I have found that larger cross-sectional cables perform better (for me) than skinny ones.

I picked up some QED Genesis Silver Spiral some years ago at a very good price. This retailed at £30 per metre. It is silver plated ofcc and is made up of multiple strands in buches that are insulated from each other (I think there are 12 bunches in total), so it makes a hose-pipe of a cable. I think it is excellent. I used this until I got another bargain.....simply to compare hoses

Sterling (Black?) Mamba. This is is what I have used since it went in to the system about 3 years ago. As far as I am aware this is just no-nonsense OFC. I think there was a thread on here about it.

So...it is Phat for me!
Rob.

[Barry]

Hello Jerry,

Fat or thin? Well the most important aspect of speaker cables is their loop resistance, so obviously the larger the cross-section the better. But the resistance is also proportional to length; so short speaker cable lengths are to be encouraged. This is why many audio enthusiasts place the amplifier between the speakers to minimise the length.

As far as the amplifier is concerned, the cable resistance appears in series with the speaker impedance, so some of the power will be dissipated in the cable.

As far as the loudspeaker is concerned, the cable resistance appears in series with the output impedance of the amplifier, so reducing the effective damping factor. The damping factor is the ratio of the load impedance to the amplifier output impedance, and expresses how well the amplifier controls the speaker: that is to say “stops the tail wagging the dog”. The higher the damping factor the better.


In general, a good rule of thumb is for the loop resistance (that is the total resistance of both conductors) of the speaker cable to be no more than 5% of the nominal speaker load impedance. That way, the cable loss will be no more than 0.21dB. Assuming a nominal speaker load of 8Ω and an amplifier output impedance of 0.02Ω, using cables having a loop resistance of 5% of the speaker load, the damping factor is reduced to 19.

In practice any cable of 20A rating will be sufficient. If you choose copper cable having a cross section area of 1.5mm² (current rating 19.5A), this has a resistance of 12mΩ/m. So for the cable to have a loop resistance of no more than 5% of 8Ω, cable lengths of up to 16m long can be tolerated. If you choose copper cable of 2.5mm² cross section area (27A current rating), then this has a lower resistance of 7.4mΩ/m; allowing speaker cable runs of up to 27m.


Don’t worry about the loop inductance or of the capacitance per metre the speaker cable possesses, they will only be a tiny fraction of the effective values of the speaker’s crossover network.

As to copper, silver-plated copper or solid silver, well the use of solid silver will reduce the resistance by about 6.5%. Whether this small improvement justifies the additional expense is something only you can decide.

[Puffin]

Hello Jerry,

Fat or thin? Well the most important aspect of speaker cables is their loop resistance, so obviously the larger the cross-section the better. But the resistance is also proportional to length; so short speaker cable lengths are to be encouraged. This is why many audio enthusiasts place the amplifier between the speakers to minimise the length.

As far as the amplifier is concerned, the cable resistance appears in series with the speaker impedance, so some of the power will be dissipated in the cable.

As far as the loudspeaker is concerned, the cable resistance appears in series with the output impedance of the amplifier, so reducing the effective damping factor. The damping factor is the ratio of the load impedance to the amplifier output impedance, and expresses how well the amplifier controls the speaker: that is to say “stops the tail wagging the dog”. The higher the damping factor the better.


In general, a good rule of thumb is for the loop resistance (that is the total resistance of both conductors) of the speaker cable to be no more than 5% of the nominal speaker load impedance. That way, the cable loss will be no more than 0.21dB. Assuming a nominal speaker load of 8Ω and an amplifier output impedance of 0.02Ω, using cables having a loop resistance of 5% of the speaker load, the damping factor is reduced to 19.

In practice any cable of 20A rating will be sufficient. If you choose copper cable having a cross section area of 1.5mm² (current rating 19.5A), this has a resistance of 12mΩ/m. So for the cable to have a loop resistance of no more than 5% of 8Ω, cable lengths of up to 16m long can be tolerated. If you choose copper cable of 2.5mm² cross section area (27A current rating), then this has a lower resistance of 7.4mΩ/m; allowing speaker cable runs of up to 27m.


Don’t worry about the loop inductance or of the capacitance per metre the speaker cable possesses, they will only be a tiny fraction of the effective values of the speaker’s crossover network.

As to copper, silver-plated copper or solid silver, well the use of solid silver will reduce the resistance by about 6.5%. Whether this small improvement justifies the additional expense is something only you can decide.

Wow, as Ian Drury said "there aint arf been some clever b'stards". Stuff I never knew. Thanks.

[Covenant]

Thanks chaps, you can't beat a bit of education.

[Marco]

Speaker cables that is. I am inclined to think that a beefy cable will be better than a thin one but there are many highly regarded ones in the latter category. Extending the argument further it could be that bi-wiring, often considered to be of dubious benefit, might sound slightly better because of the larger area of cabling.
Any thoughts?

The other fact, Jerry, is that the only 'fat thing' that matters, with cables, is the size of the signal conductor core!

Therefore, the fatness of the overall cable could mean almost bugger all, if said fatness is only due to the thickness of the insulation/dielectric and outside sheathing...

So, forget about how fat or thin a cable looks from the outside and judge it most importantly by its AWG rating: http://en.wikipedia.org/wiki/American_wire_gauge



Marco.

[goraman]

Barry.
Please explain loop resistance.

[Barry]

Barry.
Please explain loop resistance.

All interconnects and speaker cables use two conductors. These conductors may not necessarily be identical - they aren't in coaxial cables, but are in balanced line and semi-balanced line interconnects.

In virtually all speaker cables, the two conductors are identical. The loop resistance is the total resistance of the current loop. In the case of speaker cables, it is the total resistance of the current path from the amplifier out to the speaker and back again. The loop resistance, in this case, is thus double that of one of the single conductors used in the speaker cable.

[goraman]

Thank you Barry it makes sense, but you would think speaker cable resistance would be nothing compared to the 8 ohms from the speakers load.

Unless your using very tiny speaker cables.

[goraman]

I failed to tell what I'm using for speaker cables.
6 AWG very fine stranded silver plated copper mil spec in heavy teflon terminated in silver plated AN bananas @ 10ft.
My cables came out of a Sea Wolf Class submarine ,sadly only 3 where made. http://www.youtube.com/watch?v=v-FAS07WZJw
My wire is simaler to this but much larger , I had a hell of a time getting them to fit in the bananas,
http://www.ebay.com/itm/Silver-plate...item4ac0e1778c

My amp has a dampening factor of 5.

A nice read on speaker cables.

http://forums.audioholics.com/forums...delines-4.html