Can you measure speaker cable properties?

[phoenixpete]

As title really, just interested in finding out my speaker cables capacitance and resistance. Is it possible with a multimeter to measure these things?

General consensus on the web seems to indicate that quad esl57s are better with solid single strand wire with a low capacitance,low inductance.

Looking for some reccomendations for speaker cables if anyone has any ideas?
I am currently using Audioquest type 4 bi-wire with the double wires twisted together so they are now just standard wired.
I have tried Vanne damme in the 6mm but found it very poor,lacking sparkle and any real detail,tried a few others but the Audioquest is so much better, but I would really like to know it's specification so I can better understand what is needed for the quads.
Also does having the solid brass type speaker banana plugs alter the cables specifications?

Thanks
Pete.

[DSJR]

I'd blame the Audioquest as "tinkering" with the sonics, since it sounds different to everything else you've tried... The designer of the 57's just used a decent gauge two core mains lead - heaviest gauge is usually 0,75mm isn't it for two core?????

Appearing to lack sparkle could just mean lack of ringing artifacts and I think it's common knowledge how the 57's "beam" the treble at you. have you checked condition of the treble panels lately? Many 57's, although working still, are in a very sorry state inside and full of dust and crunge in general. OTA treble panels usually have more output on them I remember (maybe they now do two versions, I can't remember) so you could look to changing to these perhaps.

As for brass connectors. I don't think they're going to matter hugely as the sockets they fit into will be way worse by now. I do like the banana/BFA type of gold plated plugs though, as they're so easy to use and don't rely on a rapidly weakening spring to maintain contact -

http://www.ebay.co.uk/itm/380345641394?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

A final thought on the Van Damme - maybe the 2.5mm is all you needed, I've heard this gauge and there's no lack of sparkle if it's there in the signal passing through it...

Try this -

http://www.ebay.co.uk/itm/Fisual-Super-Pearl-2-5mm-Speaker-Cable-White-/380169878365?pt=UK_Computing_CablesConnectors_RL&hash=item5883e3fb5d

Cheap enough and should be all you need for 57's, or very much else really :)

[Reid Malenfant]

As title really, just interested in finding out my speaker cables capacitance and resistance. Is it possible with a multimeter to measure these things?
Not really no, what you need is an LCR meter ;) You'll need a damn good one to if you intend to measure the DC resistance of any normal length of cable as it'll be too low for most meters to give much if any reading - leading to inaccuracies :rolleyes:

[HighFidelityGuy]

DNM (http://www.dnm.co.uk/acatalog/Cables.html) makes two different gauges of speaker cable. They come in bi-wire lengths so if you don't need bi-wire you can buy half the amount and split it down the middle. Connectors will undoubtedly change the measurements and sound of the cable slightly but I doubt you could measure the difference accurately. I currently use the thicker DNM cable with some copper banana plugs on my centre speaker and it seems to work well. THESE (http://www.ebay.co.uk/itm/20-Gold-Beryllium-Cu-Z-BANANA-PLUGS-fit-BFA-Linn-Arcam-/290599601924?pt=UK_Computing_CablesConnectors_RL&hash=item43a9160704) are the connectors I use but you can get similar Beryllium copper ones in smaller quantities from THIS (http://www.ebay.co.uk/itm/8-x-4mm-Gold-Beryllium-CU-Z-Banana-Plug-Cyrus-Arcam-/250820401642?pt=UK_Computing_CablesConnectors_RL&hash=item3a660f99ea) seller.

If you fancy trying this option but don't fancy making the cables your self then I'd be happy to make some for you. I actually have some of the cable and connectors left over. Drop me a PM if you're interested. :)

[phoenixpete]

Hi Dave R.

Thanks for your reply,:) my 57s were fully rebuilt earlier this year by One thing with new treble panels so I know they are working well.
Thanks for the links I will have a look.

Reid Malenfant.

Thanks for your reply.
I thought as much but I thought it worth asking:)

Hifidelity guy.

I have seen the DNM recommended for electrostatics before,thanks for your offer I will PM you.:cool:

[DSJR]

The DNM only really works in lengths under 5m each, although dave W tried longer runs in recent times with good success. I'm just a little concerned because of the 57 impedance curve, which dips very low indeed at higher frequencies. Perhaps someone could confirm?

[Stratmangler]

The DNM only really works in lengths under 5m each, although dave W tried longer runs in recent times with good success. I'm just a little concerned because of the 57 impedance curve, which dips very low indeed at higher frequencies. Perhaps someone could confirm?

http://www.diyaudio.com/forums/pass-labs/192273-f5-esl-57-a.html

[DSJR]

Thanks Chris :)

[Barry]

Hello Pete,

I have only just got around to spotting your post. To answer your first question – yes you can use a (good quality) digital multimeter to measure resistance, loop inductance and the inter-conductor capacitance.

Ideally speaker cables should have as low a resistance as possible, and preferably low capacitance and loop inductance per unit length. By “low”, I mean low compared with those of the speaker crossover. Good cables will have:

< 0.2μH / foot
< 50pF / foot

Compare this with the inductance of a mc speaker: 0.2 – 2mH, and for the Quad ESL 57, a capacitance of ~2μF.

Now in general the LCR values of the speaker cable will add to those of the amplifier impedance, and so will affect the amplifier’s damping factor (= speaker impedance/amplifier output impedance), or how well the amplifier absorbs the back emf of the speaker acting as a generator. Or to put it another way, how well the amplifier stops “the tail wagging the dog”.

Most moving coil speakers have a cone mass that is quite large compared with the polymer diaphragm of the ESL 57. The mass of the diaphragm is thus sufficiently low that it has very low inertia: hence the speaker has an excellent transient response and can be driven by an amplifier with modest damping factor. (The Quad 303 amplifier has an output impedance of 0.1Ω, quite high compared with the damping factor of other solid-state amps (typically 0.01Ω), yet it is an excellent amp with which to drive the ESL57s.)

Were you to have asked the late Peter Walker of Quad, and designer of the ESL57 speakers, what were the requirements of a speaker cable, he would have replied in his typically trenchant and sarcastic fashion:

“The first and only important requirement of a speaker cable is that it is long enough to reach between the amplifier and the speaker. After that, the only other requirement is that the colour of the insulation should match the décor of your listening room.”

He might even have answered, when asked what makes a good speaker cable: “ the best ones are those that conduct electricity.”

These apocryphal aphorisms should be taken cum grano salis, but do contain some truth: just use good quality but inexpensive cable. Quad themselves used 10amp two-core lawnmower cable (the type with the orange coloured jacket) in their demonstrations.

I use QED 79 strand speaker cable with my Quad ‘57s. These are a ‘figure of eight’ cable, whose conductors have a cross section of 2.5 square mm and a current rating of ~ 20A. Measured loop resistance is ~ 0.015Ω/meter. I use two lengths: 16m to feed the left-hand speaker and a 6m length for the right-hand speaker, and have used this arrangement for the last 30 years.

Regards

[Reid Malenfant]

Hello Pete,

I have only just got around to spotting your post. To answer your first question – yes you can use a (good quality) digital multimeter to measure resistance, loop inductance and the inter-conductor capacitance.
Superb post as usual Barry :) I'm just interested though, how can a multimeter measure capacitance & inductance without some kind of add on? :scratch:

An LCR meter could do the job, but i can't see how virtually any multimeter could (as standard), always willing to learn though :)

[phoenixpete]

Thanks a lot Barry for your in depth reply.:cool:
I know what you mean about Peter Walker's sense of humour when asked these sorts of questions.
Really what I am trying to do is find out which types of cable are best suited to quad esl 57s as I realise they may not require the same type of cables as most cone derived speaker systems and from what I have read it seems quite a few people recommend a single solid core cable over multi stranded types or Litz cables or cables that are twisted together as these cables can have high capacitance and or high amounts of resistance etc.
Maybe a solid core mains cable as used in the household mains would be good?
Or the solid earth cable, run as seperate single wires to each speaker connection?
Just a thought.

[Barry]

Superb post as usual Barry :) I'm just interested though, how can a multimeter measure capacitance & inductance without some kind of add on? :scratch:

An LCR meter could do the job, but i can't see how virtually any multimeter could (as standard), always willing to learn though :)

Hi Mark,

An LCR bridge would of course be the best option, but what I had in mind was one of these (http://www.maplin.co.uk/digital-multimeter-with-capacitance-inductance-and-frequency-measurement-4393).

Regards

[Barry]

Thanks a lot Barry for your in depth reply.:cool:
I know what you mean about Peter Walker's sense of humour when asked these sorts of questions.
Really what I am trying to do is find out which types of cable are best suited to quad esl 57s as I realise they may not require the same type of cables as most cone derived speaker systems and from what I have read it seems quite a few people recommend a single solid core cable over multi stranded types or Litz cables or cables that are twisted together as these cables can have high capacitance and or high amounts of resistance etc.
Maybe a solid core mains cable as used in the household mains would be good?
Or the solid earth cable, run as seperate single wires to each speaker connection?
Just a thought.

Well I would avoid Litz cables, but otherwise I don't really have much preference.

I suppose if you want to absolutely minimise resistance, an economic choice might be the 2.5 sq mm twin and earth cable used in house wiring, but it would be rather stiff, ugly and unwieldy. Unless of course you ran it under the foor boards, or buried in the plaster of the wall. :rolleyes:

How long are the lengths you propose using?

[The Grand Wazoo]

Twin & earth isn't too stiff if you strip off the outer insulator & remove the earth wire, then twist the remaining conductors together (an electric drill set to a low speed makes things easier).
I used this for a long time - it's fine.

[Barry]

Twin & earth isn't too stiff if you strip off the outer insulator & remove the earth wire, then twist the remaining conductors together (an electric drill set to a low speed makes things easier).
I used this for a long time - it's fine.

Was that the solid core type, or the pre-metric version known as 7/029 (seven strands, each 0.029" in dia)?

[The Grand Wazoo]

The solid core type was what I used. Yes it's still fairly stiff, but workable & much less bulky than if you keep it inside the outer insulator.

[electric beach]

Give this a go Pete, it will cost you £10 :eyebrows:

http://theartofsound.net/forum/showthread.php?p=54598#post54598

[phoenixpete]

Thanks again for the very helpful replies:cool:

That multimeter looks good, never seen one with capacitance, inductance etc.
My power amp sits in between the quads so only need about 1.5mts per side.
I have seen those "Anticables" and there is a hi/fi shop on ebay selling them.
http://www.ebay.co.uk/itm/290431969943?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

I will look at the Maplin stuff and give it a go as it is so cheap,might be nice to compare it with the anticables to hear wether there is much difference?

[Reid Malenfant]

Hi Mark,

An LCR bridge would of course be the best option, but what I had in mind was one of these (http://www.maplin.co.uk/digital-multimeter-with-capacitance-inductance-and-frequency-measurement-4393).

Regards
Ah, gotcha :) Cheers for the link Barry, a useful bit of kit if you don't happen to already have something that would do the job ;)