Speaker cable: what matters

I suggest you first read my previous article which addresses the question of whether speaker cable matters. While this article implies that it does, you have to ask if it does warrant attention in your case.

General considerations

Aesthetics
Does it match your system and appeal to your preferences?

Pride of ownership
Are you really willing to pay for the name?

Safety
Amplifier damage can occur if the leads are shorted while the amplifier is on. Most cables offer no protection here, pro cables being the exception.

Wiring errors
It should be easy to see + and - so you can wire them up correctly.

Child proof
Do you have children who might pull them out or possibly even short leads out?


Secure connection
This can be an issue with banana plugs - not all of them offer a secure connection.

Cost
Don't be fooled - cost is not the best indication of quality.

Sonic considerations

In terms of sound quality issues, I suggest that there are three parameters that warrant your attention - resistance, capacitance and inductance. The impact of those parameters are relatively subtle and I don't consider other issues to deserve attention.

Resistance

Ideally resistance should be as low as possible. This can be achieved with short cable runs and thick cable. The cable gauge required is related to distance. If you have a long run of thin cable, then losses can result. Resistance also has an impact on the damping factor an amplifier can provide. It could be tempting to simply use very thick fat speaker cables, but in practice this is not necessary and this would likely make compromises in other areas.

Capacitance

Cable capacitance is one parameter that can create problems for some amplifiers. Naim is one notable example. Some of their products are not stable with cables that have relatively high capacitance. They are a relatively rare exception to the rule and most amplifiers should not have a problem.

Inductance

Inductance has an impact on high frequency extension, where a higher value causes roll off. This is likely to count for a large part of sonic differences heard between cables, where high inductance may cause treble roll off. As a result we would like inductance to be as low as possible, especially with long cable runs.

The inverse relationship between L and C

Inductance and capacitance have an inverse relationship - you can only lower one by raising the other at the same time. Spacing + and - apart in a figure of 8 configuration reduces capacitance, but increases inductance. This makes for a general purpose cable that is safe with any amp, but falls short of the ideal. A better choice except in the rare case where the amp can't cope is to lower inductance and accept a higher capacitance. This is what most high end speaker cables aim to do in various ways. This is done with some attention to cable geometry, where both conductors are closely coupled to reduce inductance. One of the best cables for this is actually not a dedicated audio cable.

The ideal cable is?

High power antenna cable! RG213/U which is a coaxial cable. The coaxial geometry achieves a very low inductance and this is essential for it's intended application where very high frequencies must run over some distance with minimal loss. The centre conductor has low resistance and the shield can be used for the - cable.

Other popular choices include Cat 5 network cable configured in various labour intensive ways or ribbon cable with a series of + and - cores running in parallel.

RG213/U simply requires lead out wires on the ends and some form of termination.

My own recipe

My own recipe for audio cables includes:

1. RG213/U coax for low inductance
2. Lead out wires on the ends
3. Pro 4 core speakon connectors to suit my active speakers and prevent wiring errors or shorts
4. Techflex sleeving for an attractive finish
5. Heatshrink to finish it all nicely

I will be displaying them when they are finished. The connectors are different to what is normally seen in home audio.