Question Advice on speaker cable needed

bofh

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I'm using QED silver anniversary at the moment but I now need longer cables. I want something with much the same tonal balance as these but more detail, control etc. I'm willing to go up to £15 per metre. Any suggestions?
 
Anything, it all sounds the same :)

Seriously, for low impedance, low voltage, low frequency cables of less than 20M, the resistance, capacitance and inductive values will be so similar between cables of the same outside diameter as to be virtually unmeasurable and in my opinion, audibly indistinguishable.

The snake oil merchants have done a very good job selling directional, super pure, oxygen free bamboo clad wunder cables that show no measurable difference to mains cable.

Stick with the QED, it's mechanically well made, easy to terminate and not too expensive.
 
Oddly enough, I bought 5 metres of 16A mains cable only this afternoon... it'll be interesting to compare it with the SA.
 
I'm using QED silver anniversary at the moment but I now need longer cables. I want something with much the same tonal balance as these but more detail, control etc. I'm willing to go up to £15 per metre. Any suggestions?
Can you explain "tonal balance" to me?
 
Basically, as the signal travels along the cable, differences in voltage and frequency cause the otherwise inert cable to exert magical properties upon the signal. The tiny changes in the signal that constitute detail are magically enhanced, while the combination of snake oil and the salesmen's smile make the cable exhibit more control of the voltage, stopping it exiting at an odd angle, which can create phase vortexes in the copper continuum.

OK, I will stop being quite so flippant.
Low level, high impedance analogue signals are without doubt affected by the cable, with capacitance and inductance causing changes in frequency response - which can be at varying degrees for different signal levels. This can be measured and heard. A good quality cable reduces these affects and with cables of a few meters, real gains can be had. It is also argued about matching the impedance of the connectors to the cable reduces cable reflections and improves connection losses, which should improve signal accuracy. This is moot, as it does make a difference at RF frequencies but the affect at AF is very reduced to almost zero. The shielding also affects possible interference from external sources, but use the wrong materials and the capacitance in particular of the cable can change.

With speaker cables, the effects are massively reduced. The voltage and current levels are higher, the impedance much lower and the chances of interference basically zero. Looking at the electrical theory, so long as the cable is sufficiently heavy duty enough not to create a voltage drop over the length, then the cable should not affect the signal at all.
 
There are three main parameters for Speaker Cable - Resistance, Inductance, and Capacitance. I happened to have the full specs on several Speaker Wires, from low cost to moderately expensive, so I began calculating when and where those parameters would start effecting the sound.

Resistance - Generally 5% cable resistance relative to the speaker impedance is considered acceptable, but for normal length runs to the Front speakers, it is very easy to achieve much less than 5%.

Some speaker manufacturers recommend that the wire resistance not exceed a fixed value of 0.1 ohms. Which relative to an 8 ohm speaker represents 1.25% cable loss. To a 4 ohm speaker, it is 2.5% cable loss.

Capacitance -
In all my calculations, never did Capacitive Reactance (resistance) have any effect in the Audio Range.

Inductance - As the cable gets longer, Inductance gets higher, and it starts to trim away at high frequencies. But using a very common QED 79 Strand (2.5mm²) at a length of 15m (50ft) (from memory) the signal loss due to Inductance at 3500hz was 3% and at 12,500hz was about 10%. When converted to dB (or loss based on what you hear) even 10% is still less than 1db which is insignificant.

There are other parameters such as Skin Effect, which is the tendency of the electricity to move from the core of the wire to the surface or 'skin' of the wire. For 14g wire (2.08mm²)(and from memory) the Skin Effect Frequency, where the signal starts to move from the core toward the skin is about 6200hz, which is above any fundamental note made by a person or musical instrument. Keep in mind 6200hz is not where it is at the 'skin' but where it starts moving toward the skin. To reach 100% skin transmission, the frequency would be higher.

Further, Skin Effect effects the ability to handle current, however, quite nicely, the flow of current at high frequencies is much lower than at bass frequencies. For RF or very high frequency transmission, Skin Effect can matter, but for Audio, and assuming decent size wire, it really has no effect.

Which bring up the last aspect of Skin Effect, oddly, as the wire gets heavier, the Skin Effect Transition Frequency get LOWER. The heavier the wire, the lower the skin effect frequency. Though the spec charts that this comes from are for solid core electrical wire, not multi-strand Audio Wire which will have more surface area.

In short, Skin Effect for Audio doesn't matter.

Certainly you want quality cable of sufficient size, and generally it is best to restrain the cable length to less than 50ft, though the consequences of going a bit over are not extreme. Typically such long lengths would be for Surround Speakers were full fidelity is not that critical.

So, what does matter, well no parameter of wire or cable that can be measure beyond making sure you have reasonable quality wire of sufficient size for the Impedance of your speakers -

fivepercentcablec-jpg.560958

threepercentcablec-jpg.560674

twopercentcablec-jpg.560673


onepercentcablec-jpg.560672


If I recall the QED Silver Anniversary Cable is a braided cable. I think you can see though the insulation and see the underlying cable with a cross-weave or braid similar to the shield found in Line Level RCA Audio cable. That is an attempt to create low-inducatance wire. Because of the cross weave, the cable winds in both the clockwise and anti-clockwise direction, so the inductance cancels itself out ... to a degree.

But notice that even the very standard non-fancy QED 79 Strand, is still functional at 50ft. Inductance is starting to trim away at the high frequencies, but not enough to really notice and very likely not able to notice in Surround Sound Speakers which is where 15m or 50ft would most likely to be encountered.

So, you can spend whatever you want, and I'm not one of those that would say difference cable designs make no difference, but the difference is small and you have to have very higher end very revealing equipment to hear that difference.

Myself, because I'm not against spending a bit more on cable, I tend to make the total wire and cable cost a portion of the total equipment cost. In a limited survey, a vast majority of people in the USA and the UK spent less than 5% of the total system cost on ALL wire and cable.

UK -

cable-cost-png.696799


USA -

syscostwire2-jpg.696894


Also, keep in mind that it cost money to make cable look fancy - the jacketing, the cable pants (it's a thing look it up), the fancy banana plugs, those all cost money. They are purely cosmetic, but that aspect does drive up the price of a cable.

Here is a local thread discussing this material cost aspect -

Wire + Fancy Jacket + Fancy Pants = £££Wire$$$

Which is really based on this thread in another forum -

Have a look at these Beauties!!!! How to make your OWN "High End" Cables!!! - AVS Forum | Home Theater Discussions And Reviews

The guy took common Monoprice wire and dressed it up to look like fancy high-end wire. The overall result was very nice cable for considerably less than the Big Boys charge. I think he started with cable costing US$0.70/foot (US$2.30/m or £1.86/m), and by the time he was done, the cables cost about US$25 each (£19.45). But even $25 is pretty cheap for nice looking cables. Though he did not count his labor.

Another parameter is - How much Power can a given speaker wire handle. Answers can be found here -

Speaker Wire in Prespective -How much is Enough?

As an example, AWG 14ga wire (2.08mm²) has a Working Peak Power Rating of 1800 watts. But that same cable has in excess of 8000 watts peak failure limit.

Here is another thread that might be of interest to those looking for Speaker Cable/Wire -

More DIY Cable - for those interested

In short, spend as much as you want, but you are not likely to get any more than you would get from this cable which is 2.5mm² and 99.99% Pure OFC Copper at £2.35/meter.

Fisual S-Flex Studio Grade Black Speaker Cable 2 x 2.5mm - By Brand - AudioVisual Online - Home Cinema and Hifi Specialists

Or ... £19.05 per cable at 3m length with Banana Plugs on both ends.

And, keep the Speaker and other Cable cost in reasonable perspective to your system. It doesn't make sense to get £500 speakers then add £500 speaker wire to it. Much better to get a £900 speakers, and £100 speaker cable. Though in reality, it would make more sense to get £950 speakers, and add £50 speaker wire pair.

Still ... your money ... your life ...spend what ever you want. But keep it reasonably restrained and in reasonable proportion to the rest of your equipment.

Steve/bluewizard
 
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Thanks for all your replies. I just updated the QED SA in the end. The speakers cost £470. In 1991 mind... The cable I just bought cost £26 without terminations. As for all the technical measurements, I understand that one speaker cable shouldn't sound different to another but... they do. However, there is a law of economics that cannot be broken - The Law of Diminishing Returns!
 

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