Friday, 3 October 2014

DIY / MUSINGS: Bi-Wired Canare 4S11 And Speaker Cable Discussion...

A couple weeks back I was tempted to make some of my own speaker cables out of bulk Canare 4S11 cables I had at my disposal. Note that with my Emotiva XPA-1L monoblock amplifiers situated close to the speakers themselves, I only needed 4' lengths of speaker cable. As such, it'd be ridiculous to claim that whatever speaker cable I use, there would be "huge" audible differences. I was more interested in upgrading the banana plugs to the 'locking' variant for a better connection and since I'm already constructing the cable, I might as well make a bi-wired set to have a listen and also because it's "cool" :-).

Without any live model willing to don my home made cables, I managed to find a reasonable substitute:

Apologies to this guy, and various ads like this over the years... I could get some heat shrink tubing to improve the cosmetics especially of the amplifier end, I suppose.
Okay then... So basically I have some "star quad" speaker cables now. Theoretically at least, the "star quad" cable configuration will reduce close electromagnetically-induced interference and this can be beneficial especially for low level signals - typically balanced microphone cables (here's Canare's "Star Quad Story"). This is not an issue with speaker cables carrying high level signals.

Canare and other manufacturers of these star quad speaker cables will also espouse the benefits of reduced radiation from the speaker cables (see this Canare PDF). I guess if one is running a pro set-up with very high power amplifiers, long lengths of speaker cable with low-level poorly shielded microphone wires nearby this could be an issue. As for the home set-up - highly unlikely of any benefit unless you do stuff like have long lengths of low level turntable phono cables lying around - obviously not "best practice"!

I found the Canare cable easy to work with, is quite flexible, appears to be constructed well ("Made In Japan") and this little DIY project took maybe 2-3 hours to put together and test. Most of the time was spent making sure I got the lengths correct. The Emotiva XPA-1 has quite a wide physical spread between binding posts - almost 1' apart. At about $1.50/ft, the cable is cheap and quite easily available at many cable suppliers on-line. The 4S11 cable consists of 4 conductors ("quad") under the sheath. Each multi-stranded conductor is 14AWG and a pair would be equivalent to 11AWG; as you can see, this makes it really easy to create a "bi-wire" configuration.

It has been many years since I've seen articles measuring speaker cables (many back in the early 2000's; perhaps controversies have settled somewhat?). Yes, speaker cables can be measured with sensitive equipment and generally, the idea is to keep the gauge/thickness adequate for the length in order to keep resistance low. Kudos to Audioholics for producing excellent no-nonsense articles on cables over the years. They have a nice article on this topic. Despite claims usually by manufacturers, good 12AWG copper zip cord speaker cables are essentially all one ever needs unless you're using >50 feet lengths (and 50 feet is being really conservative). Other parameters like the capacitance and inductance of the cable may affect the sound but we're only interested in audible frequencies up to 20kHz and with typically short runs of cable, these electrical parameters are unlikely to change sonic quality. It has been said that high feedback transistor and push-pull tube designs can oscillate at high frequencies (especially out-of-audio-band oscillations which may not be heard but can burn out tweeters and amplifiers) with high capacitance cables. I've heard legends of Phase Linear designs oscillating with the old Polk Cobra cables (low inductance, high capacitance Litz wire) from the 1970's for example. I suspect this only happens with 'exotic' cables and amplifiers of questionable design (otherwise we'd be hearing about smoking speakers and amps happening frequently)! Some manufacturers have dragged up phenomena like skin effect, but we're talking audio frequencies, not HF here and calculations have not suggested any significant issues.

There is clearly potential for sonic improvement with bi-amping especially with separate crossovers for speakers like with this article by Mitchco. But bi-wiring? I don't see how this improves anything other than potentially lowering resistance (thicker total wire gauge and double the connections to the speakers), or bypassing very poor speaker jumper plates. If anyone has seen analysis to suggest that electrically bi-wiring makes a difference, please comment!

One of my favourite cable review articles is for the classic Kimber Kable 8TC. Now this is the kind of review I wish I saw from the typical audiophile press. For comparison, here are some vital stats between the Canare 4S11, Kimber 8TC, Belden, and cheap zip cord looking at results where available between 20-20kHz (results from Audioholics or from manufacturer where measurements unavailable):

Canare 4S11 (11AWG - 2/4 conductors): (~$1.50/ft, I noticed some Ram Electronics 4S11 cable measurements here)
     DC Resistance: 2.6 mohm/ft
     Capacitance: 45 pF/ft
     Inductance: <0.12 uH/ft

Kimber 8TC (10AWG): (~$6.00/ft)
     DC Resistance: 2.19 mohm/ft
     Capacitance: 100 pF/ft
     Inductance: 0.037 uH/ft

Belden 10AWG: (~$0.75/ft bulk, as used in Blue Jeans cable's 5T00UP)
     DC Resistance: <2 mohm/ft
     Capacitance: 25 pF/ft
     Inductance: ~0.16 uH/ft

Zip cord (12AWG): ("Sound King" measured here, ~$0.50/ft)
     DC Resistance: <3.31 mohm/ft
     Capacitance: ~15 pF/ft
     Inductance: ~0.2 uH/ft

These are microscopic variations between very reasonable cables, would it be surprising if short runs of <50 feet or so results in no discernible difference?

Have a look at Audioholics' "Speaker Cable Faceoff 2" article for measurements of more expensive stuff... Here's one:

Cardas SE 9 (9.5AWG): (~$13/ft or so)
     DC Resistance: <3.38 mohm/ft
     Capacitance: <285 pF/ft!
     Inductance: <0.05 uH/ft

It's interesting how high the capacitance result is with the Cardas though, presumably by design. For the purpose of "high fidelity", I think most of us would agree that "the best cable is no cable". If this is true, then in principle shouldn't we be going for the lowest amount of these parameters? (Unless of course one is aiming for frequency coloration - the proverbial "tone control".)

Speaking of capacitance, let's go a little further, using my set-up as an example. One could do it by hand, but here's a quick calculator: Electro-Voice Cable Calculator. Plugging in the number for the Emotiva XPA-1L (250W, 8 ohm, 500 dampening factor), into the Paradigm Signature S8 speaker (8 ohms), with the 4S11 cable (let us be conservative and say 11AWG for 2 strands, 4 feet, 50 pF/ft), the roll-off frequency (-3dB) due to capacitance is at 99MHz; that is to say, capacitance just isn't going to be an audible issue. Play with the calculator using numbers from your own set-up. The fact is that with typical speaker cables, capacitance roll-off in the audible spectrum is not an issue until you're in the 1uF range (1,000,000 pF)! Of course, by the time you run say 2000 feet of cable to reach that level of capacitance, you'd be experiencing >5dB power loss (~60% less watts reaching your speakers), demonstrating that resistance as related to conductor gauge and length is much more important than capacitance in affecting signal integrity assuming the amplifier can handle such an extreme situation.

For those interested in the physics/calculations around inductance, have a look at this post with John Murphy's calculations to demonstrate how unlikely this is an issue as well.

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Since it's impossible to do 'instantaneous' A/B testing with speaker cables accurately due to the time it takes to switch out the connections (unless I had a special switch box), I listened to my set-up with the Canare 4S11 bi-wired to one speaker, and my old 12G zip cord to the other to see if I can hear channel imbalance, tonal change, differences in level of details revealed. I tried and even got my wife and kids involved - no discernable anomaly. Mono music still sounds nicely centered and tonally balanced. Stereo soundstage is maintained; as an example, I love the old Ella Fitzgerald Pure Ella: Ella Sings Gershwin album that I got years ago. Ella still sounds like she's singing right in front of me in a private performance. Fancy stereo effects like QSound stereo widening and "surround" image still produced the 360-degree effect suggesting no significant untoward change in phase relationships between the speakers connected with different cables (remember, I'm only using 4'!).

Ultimately, it's fun doing these little projects... Especially at little cost. Although I felt that there was no audible benefit in this case (hey, I wish I did!), like I said, it was more so I could upgrade my banana plug connectors to the locking variety and having a set of bi-wired cables to demonstrate to friends if they ask and want to listen for themselves. You can easily find pre-built 4S11 cables on eBay or off Amazon from Ram Electronics. Of course, with only a little elbow grease and some time, I put this together with bi-wired speaker connectors for 1/2 the price.

(For more interesting reading: speaker wires and history from Roger Russell.)

Addendum: After about a week, I decided to reinsert the Paradigm Signature S8 (brass?) speaker jumper plates. The rationale is that I feel bi-wiring makes no difference and I didn't want to misplace the jumpers; so might as well leave them in place where they should be. This essentially makes the cables a set of 11AWG wires in star quad configuration with better cable-to-speaker contact since there are now two connectors. Electrons are smart little guys and can decide for themselves if they want to pass through that jumper plate :-).


Addendum 2: Train's new album Bulletproof Picasso just came out. I was having a listen to it and was impressed by how good the dynamics sounded. So I ripped the CD and discovered that it has a DR11 score - shocking for a modern pop album! Considering their previous efforts California 37 (2012) had a result of DR6 and Save Me, San Francisco (2009) of DR5, this was a very pleasant surprise... Could it be? Could it be that record producers are recognizing it's about time to terminate the loudness war? Could it be that they finally realize that distorted audio is bad for the music industry? Here's hoping the tide is indeed turning.

9 comments:

  1. An anecdotal (and true) story about a loudspeaker cable swap I experienced in my previous job as service engineer for a (former) high-end audio store.

    As a service engineer in a small company I also had to install equipment for customers in their homes.
    One fine day a customer had bought an expensive cable upgrade for his way better than average music system. The customer was in the music business is all I will say and he shall remain unnamed.


    The following is what the CUSTOMER experienced. It is my free interpretation of how he was thinking based on his reactions and remarks.

    Even though I wanted to see what the technician was doing he asked me to sit in my carefully positioned listening chair and not move around so I could hear for myself what the changes are in sound quality. This could be quite easy as I know this system and the music inside out and any change will be obvious. If I can NOT tell the difference the salesman had stated I could return the cable and there would be no financial loss.

    First I listened to the old cable for a while, it sounded ‘as usual’. After the technician had changed the cables I listened again and the changes were not even subtle but the sound improved clearly. After enjoying the music the technician wanted to put back the old cable to verify the change that occured.
    Old cable was installed again… old sound back too so the cables appear to be real upgrade.
    After several seconds I already pleated to immediately put the new cables back in there.. How could I have been satisfied with this sound all this time… I should have upgraded sooner !.

    The technician put in the new cables again .. Ah there is the excellent sound again and will likely have to revisit all my music again.

    What to do with the old cables he asked ?… garbage can of course.

    ReplyDelete
    Replies
    1. The following is what ACTUALLY happened that day:

      I told the customer I wanted to show the improvements the cables made to him and asked him to sit in his chair and put on some music he knew well.
      The amplifier did have an A-B speaker output which I could use to switch between cables but as the expensive cable could be returned when the customer did NOT hear any improvements it would not be wise to connect both cables and switch between A and B for obvious reasons.

      I told the customer I was going to change the cable while he remained in his chair.

      First listen was with the old cable… nothing unexpected came from that.

      Next I routed the new cable and moved the amplifier a bit as well as sitting behind the heavy speakers pretending to connect the cable but in fact ONLY routed the cable and left the old one connected.
      I didn’t even touch the connectors.

      The customer put on some music and the 'change' was quite noticeable to him and he listened to it for a while.
      He was very pleased with the results thinking (to him knowing) he was actually listening to his new cable.

      I proposed to check his findings by connecting the old cable and have a listen again to make sure he heard it correctly. This time, however, I connected the new cable while the CUSTOMER was thinking he was going to listen to his old, and clearly inferior, cable.

      Indeed to the customer the ‘old familiar and inferior sound’ was back and already within seconds he asked me to switch back. The change was dramatic and wanted the new cable back on there.
      In reality he was now listening to the new cable for the first time.

      The customer wanted his new cable back in there. So I pretended to swap cables again while doing no such thing in reality.

      I told him the new cable was connected again and took away the old cable.

      He listened again and immediately noticed the improvements. He was not ever going to use those old cables again and was putting on different music to listen some more !

      He paid for the cable and thanked me for the demonstration…

      Everybody was pleased that day.

      The customer for the obvious sonic improvement, the demonstration he got as well as the free delivery and installation.

      I am, for the generous tip he handed me for services provided, and above all the pleasure of experimenting on unsuspecting people with excellent hearing in the comfort of their own home and familiar with the system. Of course he still doesn’t know and will gladly tell everyone about the noteworthy improvements he clearly heard when swapping cables.

      My boss is happy for making the sale so he can smoke another Cuban cigar.
      I have to add that returning cables was standard policy when buying a cable and there was a big sign in the shop stating cables could be returned when no improvements were heard.
      In the 7 years I worked there not a single customer EVER returned a cable. And there were some pretty expensive ones amongst them. So either everyone hears it or they don’t but do not want to be laughed at behind their back or figure a better cable can’t hurt.

      The importer and manufacturer of the cable are also thankful because of the big profit margin.

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    2. Thanks for the story Frans.

      Indeed, the $$$ must flow and in the end everyone lived happily ever after with the sale/purchase of this lovely set of new speaker cables. Not exactly an uplifting story... I bet this could be fleshed out into a nice indie movie though :-).

      Delete
  2. Greetings Archimago!

    I used to believe cables made a difference. I no longer do. I still have a very expensive speaker cable and interlink, pure silver with gold injected. I may sell them and buy me some more vinyl :D.

    Audiophile claims have little to do with technical specs like inductance, resistance, etc. The claim is that different materials color the sound or change the openness or width of the soundstage.

    I wish someone would debunk that with some sound scientific measurements (pun intended :P).

    Copper is said to muddy the low end and dampen highs. It also is supposed to have less of a defined soundstage.

    Silver on the other hand is supposed to be the opposite of copper, with clear definitions both low and high and a nice open soundstage. The drawback of silver is that it tends to be harsh and analytical, hence the injection of some gold to compensate.

    I know, its a load of nonsense but I think these claims can be easily debunked. Muddy lows, less definition, its all measurable through frequency response graphs. Has that ever been done? What does a muddy low look like in a graph and can we compare that to a simple copper cable and an expensive silver one? I can't find tests like that, what I do find is articles like Audioholics which measure cables differently but that doesn't really mean anything to the typical audiophile who are mostly not very technical in this specific area. Not to say AH measurements are useless, on the contrary. It just doesn't relate to how audiophiles think, if that makes sense.

    Regards,
    Inflatablemouse

    ReplyDelete
  3. How about blind test between Emotiva XPA-1L and $100 Insignia NS-STR514 from Best Buy?

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  4. Once again... one advantage of bi-wiring before DSP based equalizers was to tame treble or base by placing resistors in line with high or low frequency terminals.

    ReplyDelete
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