Need 20 - 25 foot spk cables.



Having to move a pair of Sound Lab M2's to a new position in the home.  Problem is that the equi rack has to stay where it is.  So I will need 20 - 25 foot cables.  Real high end will be above my pay grade.  I had used in the past real honest to goodness, belden coax in 10 foot runs.  Roger Sanders had used this years ago with his speakers and ESL amp.  I have a ESL amp and to be honest for many years the coax sounded pretty good, but I'm sure I could do better for a long run.  Any comments appriciated.
128x128gammastrep
Driving electrostatic speakers with long runs of speaker cable makes inductance especially critical, because in contrast to dynamic speakers the impedance of electrostatic speakers reaches very low values in the upper treble region. While the impedance presented by inductance ("inductive reactance") increases as frequency increases, while also being proportional to length. And if the goal is accurate transmission of the signal inductive reactance should be kept to a small fraction of the impedance of the speaker at 20 kHz, which I suspect is probably no more than about 2 ohms in the case of your speakers, and may very well be significantly less than that.

However some cables achieve low inductance at the expense of having high capacitance, which is also proportional to length and would be undesirable because that can cause problems for solid state amplifiers which use feedback (as I assume yours does, based on its specs).

I always have great respect for Mofimadness’ recommendations, which I know are based on an enormous wealth of experience. And I found indications that the inductance of the Canare 4S11 cable he recommended is about 120 uH (microHenries) per foot (which would mean an inductive reactance of only about 0.4 ohms at 20 kHz for a 25 foot run, non-shotgunned); capacitance is spec’d as 45 pf/foot; and resistance is equivalent to 11 gauge. Those are excellent numbers for your application. In fact I suspect that a single run would do the trick, rather than a shotgun pair being necessary, in part because the impedance of the speaker is probably very high at bass and mid-bass frequencies. (Shotgunning would cut resistance and inductance in half, but would double capacitance).

I would give much less weight to recommendations by others that are not based on experience with electrostatic speakers, and/or are for cables for which those basic electrical parameters are not specified or known.

Good luck. Regards,
-- Al

KnuKonceptz Kord Speaker Wire Ultra Flex Blue OFC 10 Gauge Cable 25' True AWG on the bay. $50 shipped for what you declare is needed.
@almarg...thanks, (again) for your kind words.

I run 15 feet of Canare 4S11 per speaker, but I use (1) stick for each of the positive and negative legs per speaker.

Normally the 4S11 has (4) 14 gauge conductors per stick which would be for the positive AND negative leg for each speaker. (2) red and (2) white which twisted together gives you an 11 gauge wire. I tie all (4) conductors together for a ~8 gauge wire. This then feeds ONLY the positive (or negative) leg of the speaker. So you would need (4) total sticks for a stereo pair of speakers. I find this keeps almost all (or any) interference at bay. I know some people shotgun differently, but this works better for me.

I tried using the 4S11 in the conventional way and had great success. Once I tried my "shotgunned" way, the speakers opened up with an increase in speed and bass response and control. Of course, this is using my equipment and my room, but always with electrostatic speakers, (currently Martin Logan CLSIIA and a completely redone and modified and updated pair of Acoustat 2+2’s which are amazing). I’ve owned several pair of Soundlabs and they are indeed wonderful speakers.

I ALWAYS caution people when using/trying this cable to give it at least 200 hours of burn-in. That’s what Canare advises, but IMHO, they really need around 500 hours. I know that seems like a lot, but the outcome is tremendous.
IMO,

Always make speaker cables same length even if one speaker is closer.

Make them longer than you need now, give yourself some 'extra' leeway for unanticipated relocation.

After this and that, and reading theory ...., I decided multi-strand, small diameter, each strand insulated, all in insulated jacket makes most sense to me. Sound like Cat 5 cable?

I made my own long speaker wires, easily and inexpensively. Just buy roll of factory made cat 5, cut equal lengths, twist them, make good connectors each end.

Twist. First time I twisted a long run it was hard. Then I figured out, twist a few feet, tape there, twist other direction a few feet, tape there, repeat. Use colored tape, I have 3 sets, various lengths, different color tape. Sometimes I run 2 systems, SS and Tubes, to test, and to let others hear the difference. 

Same music, CD, LP, Reel to Reel tape, i.e. Sgt. Peppers. Everyone picks tubes over SS. Everyone picks LP over CD. Everyone picks Reel to Reel tape over LP.

Note: noise INCREASES as you go from CD to LP, and INCREASES from LP to TAPE, but, when the music starts, preferences go as I described.

It won't cost you much to make a 25-30 ft pair of twisted cat 5. Then, if you try expensive cables (that you can return), you can compare.



.
In my experience running long speaker cables often is not a good idea. Think about how much a set of Sound Labs set you back, and the simple fact that they are one of the most resolving loudspeakers on the planet. Running long cables often results in a noticeable loss of impact and resolution! 20 to 25 feet is going to have an effect and you won't be able to solve it by throwing money at the cables. In all the cases where I've seen speaker cables longer than 10 feet, placing the amps right by the speakers and running a balanced line to the amp has resulted in greater definition across the spectrum.


The problem here is no speaker cable is a perfect match for any loudspeaker and the longer you make the cable the worse this problem becomes.


Now you don't need balanced equipment to do this- you simply need a set of line driving transformers at the preamp and line receive transformers at the amp. Jensen makes excellent transformers for this specific purpose. You run single-ended to the transformers, run a long balanced line between the transformers, then convert back to single-ended.

Now if any of your equipment is balanced, you may not need one or both pair of transformers. We built our balanced preamps specifically so we could run long interconnect cables without coloration or losses- in my house I was running 28 feet of Fulton speaker cables; when I went to balanced operation and ran 6 foot speaker cables instead there was an instant improvement in clarity- IOW musicality and neutrality.


Note that most high end audio equipment (sources and preamps in particular) do not support the balanced line standard. This means they can't drive long cables and the cable you use might sound different; if everything supports the standard then the cables will be transparent. If in doubt use the transformers. They are inexpensive relative to the cost of decent speaker cables!