Something doesn't seem right about this...


When a speaker cable is designed with the positive lead(s)
intertwined with the negative (I'd name names but almost everyone does it),
won't this cancel out some signal?

When an amplified audio signal pulses down the + wire (to your speaker)
it does some work (i.e. makes some sound) then exits in the - (minus)
wire to ground and completes the circuit.
If these wires are next to each other, the incoming signal (+) will be affected by the outgoing (-) won't it?

What am I missing?
128x128dweller
If these wires are next to each other, the incoming signal (+) will be affected by the outgoing (-) won't it?
Yes, it will. The result of that will be a reduction in inductance, which is generally a good thing.

As described in this Wikipedia writeup, "a changing electric current through a circuit that contains inductance induces a proportional voltage, which opposes the change in current (self-inductance). The varying field in this circuit may also induce an e.m.f. in neighbouring circuits (mutual inductance)."

So the voltage induced by the current flowing in one conductor, which would tend to oppose rapid changes in current flow (i.e., which would tend to attenuate high frequencies), will be partially cancelled by the equal and opposite voltage induced by the current flowing in the other direction in the other conductor. Which amounts to a reduction in inductance, and therefore a reduction in the degree to which rapid changes in current flow will be opposed, compared to the situation where the two conductors are separated.

Regards,
-- Al
Here is a link to a good primer on cable design, and what is going on electrically. It's on a cable manufacture's website, but it is not pseudo science.

http://www.absolutefidelity.com/thedesign.html
Two wires, positive and negative, together reduce electromagnetic and capacitive noise pickup. They also reduce noise radiated from these wires. It is because noise is being picked-up (or radiated) by both wires that are at opposite polarities thus cancelling. Twisting wires greatly helps because both wires are exposed more evenly to external fields. Speaker output is also (in most cases) an input to amplifier and wire acts as antenna for noise.

Twisting wires reduces inductance, as Al stated, but also increases capacitance. In case of the speaker wire capacitance does not play as much role as inductance. In interconnects it is just the opposite but twisting is still used to reduce noise pickup.
Are you guys suggesting that it can be a good thing to have the + and - speaker cables together and/or twisted? I have a pair of Tara speaker cables that separates them. They give you 4 separate runs of cable.
Hi ZD,

I agree completely with all of the comments Kijanki provided, as I usually do. (My response was narrowly focused on interaction between the signal currents flowing in the two conductors, which appeared to be what the OP was asking about). And, yes, we are saying that it CAN be a good thing for the two conductors to be twisted together.

I have no particular familiarity with the Tara speaker cables, but presumably if some of their models keep the + and - conductors separate their designs are either giving priority to factors other than those that have been mentioned, or are controlling those factors in ways other than by twisting.

Best regards, and happy holidays!

-- Al
@ Almarg, Yes, Taralabs is controlling the inductance and capitance in other ways than twisting the conductors!, The result with their top models is one of the best at doing so in the bussiness!, Look into every white paper they have available, check the specs on the omega gold that I own, I'd say, very well done., Happy Holidays.
High capacitance speaker cable can have an impact on your amplifier e.g. Naim amps do not like high capacitance speaker cables.

It really depends on the design of your amp.
Williewonka ... is there an amp that "likes" high capacitance speaker cables.
Bifwynne - Judging by the number of people reporting great sound from Kimber Kable I would say there are many...

e.g.
Kimber 12 TC is rated at 1400pF/ft

Van Den Hul D-352 is rated at 32.5pf/meter

I think Naim cable is around 22 pF/meter

I believe the issue is high capacitance cables can cause some amps to oscillate.

But it is due to the design of the amp, so it does not apply to all amps.

I have not heard that Low Capacitance cables affect the operation of any amp to my knowledge.

Again, it the type of thing you have to try before you buy unless otherwise stated by the amp manufacturer.

The same thing probably applies to interconnects and source components.

Probably why some members report great sound with one cable brand versus some other name brands.

Williwonka ... I have no idea if this is good, bad or neutral, but here's the specs on my Kimber cables:

DUT: 8PR 2.5m bare wire ends.

(Cp) parallel capacitance: 742.0 pF @ 20 kHz
(Ls) series inductance: 0.459 µH @ 20 kHz
(Rdc) dc loop resistance: 0.021 Ω
(Xt) total reactance: 0.057 Ω @ 20 kHz
Frequency response ± 0.5 dB: dc - 50 kHz

***************

I picked these cables up quite a few ago from a dealer. Is 742 pF @20kHz a lot, a little or just right? My amp is an ARC Ref 150 tube job that uses output trannies. I would appreciate your thoughts. For some reason, I think that capacitive loads are hard to drive, requiring current. I wonder how my rig would sound with different speaker cables??

Thanks

Bruce
A correction to your post, Willie, if I may. The specs for Kimber 12TC, and as I recall for many of their other cables, are for a length of 2.5 meters. See this page. ("DUT" presumably stands for "Device Under Test"). So the 1400 pf number represents only 171 pf/ft.

Very few speaker cables approach or exceed 1000 pf/ft. Some of the Goertz models are among the few that do, as are the old Polk Cobra cables.

I would add that speaker cables having capacitance that is high enough to approach, but not to reach, levels that might cause a given amplifier to oscillate, can nevertheless cause effects such as frequency response peaking, overshoots, ringing, and phase shifts that may have audible consequences. Particularly in the case of amps that use a lot of feedback. Those kinds of effects could perhaps be subjectively appealing in some cases, especially if not too severe, but are inaccurate in any event.

Regards,
-- Al
All, as always you are correct - it was for 2.5 meters - my mistake

I did look a couple of times, because I thought it was high, but missed the cable length

Thanks for spotting that.
Al and Williwonka, I mentioned here (to be posted) and/or elsewhere that I own the Kimber 8PR speaker cables. I checked the Kimber web site for the specs. Frankly ... I feel like I just had a Space Balls or Ben Hur "deja vu" experience. [Remember the Space Balls scene where Dark Helmet and crew were on the starship and increased speed to light speed, hyper speed and then they went plaid. Or Ben Hur, the boat started out at cruising speed, then increased to battle speed, and then ramming speed.]

Ok, here's my take-a-way from the Kimber site. First we start out with the cheapy "pure copper" version -- PR; then we move up to the line to the "ultra pure copper" version -- VR; then finally we go plaid, the "hyper pure copper" version -- TC. Now ... the capacitance and total reactance specs for each version (2.5 meters) are as follows: (PR) -- 742 pF/.057 ohms; (VS) -- 744 pF/.047 ohms; and TC -- 821 pF/.044 ohms.

Please help me here gents. The minute differences in these specs are about as meaningful to me as pondering how many angels can sit on a pinhead.

Bruce
Hi Bruce,

Those are all reasonable numbers, and unlikely to account for any sonic differences that may exist among those cables, or between any of them and the majority of other cables.

The most notable spec difference between the three cables is their rated bandwidth, those numbers being 50, 150, and 300 kHz respectively (for response within +/- 0.5 db). Whether each of those numbers would result in sonics that are better, worse, or the same as the others is a function of many system dependent variables, and conceivably also on the RFI environment, meaning that the answer is unpredictable IMO.

Best,
-- Al
Thanks Al. In a somewhat difference context, your comment about the possible impact of speaker cables on RFI reminds me about our earlier posts that we traded about the Spatial Computers Velocity Bridge (VB1). As it turns out, it was an extremely expensive RC circuit.

For reasons still unknown to me, inserting the VB1 in the amp/speaker circuit in parallel resulted in an unpleasant brightening of the acoustic presentation, almost to the point of being grainy and fatiguing. The VB1 was supposed to filter out ultra-high frequency RFI and thereby improve the sound, ... which as just stated, at least to my sorry-old ears, it did not.

Back to the cables. I surmise that as one climbs up the Kimber ladder, with the PR grade (made of copper) being the lowest rung and the TC grade (made of hyper, super-duper, ultra pure copper) being the highest rung, the price would correlatively increase. I haven't gone down "cable lane" yet, and have no present intention of doing so. That said, if I spent a heck of a lot more for speaker cables touted as being made of hyper, ultra, super duper pure copper that resulted in no cognizable improvement in sound, I could easily see myself going "plaid" ala Space Balls.

Thanks for the reality check.

Bruce
Actually; Kimber's Varistrand Silver, in the Select series, would be their top rung for conductors. The Select cables(KS-3038 or 6068, "plaid" if you will) do represent a marked increase in audible performance(realism), in a resolving system.
Rodman ..., checked out the Kimber Select cables, but I didn't see the specs. Did I blink or a specs listed elsewhere on the web site?
Hi, Mr Bi- Nope; you missed nothing. Your last post mentioned a, "cognizable improvement in sound", as a factor. It was on that basis that I mentioned the Selects as the higher Kimber rungs(plaids). I've always based my cable choices on their presentations, the closest to live music being the most preferable. To tell the truth; I can't remember ever paying more than a passing attention to specs, in recent years. Happy listening!
Bruce - re: your cable specs and are they suited to your amp and will moving up the Kimber ladder be beneficial...

I did try Kimber 4PR and 4TC speaker cable for a DIY project and the 4TC was the better performer in that instance with those components. It was noticeable, but subtle and such improvements very much depended on the components used, which, with other components may not reveal any benefit at all.

Increasing the gauge however should improve bass performance and dynamics - e.g. moving from the 4TC to the 12TC - at least that was my findings with a similar upgrade with the Van Den Hul brand of cable.

Without knowing whether the designer of your amp built it to handle high or low capacitance cables, then the only way to know is to try them first.

Should you try a different brand?

Again, try to get some loaners to audition first before buying

Are your cables high capacitance?

They are approximately twice the capacitance of my Van Den Hul d-352 cables and as such would be considered high for Naim amps by Naim customer service.

For most amps Kimber speaker cables must be within acceptable operational limitations - I.e. just based on the number of members that find they perform very well.

Let's face it - if they presented anything close to a significant problem, it would be all over the WWW.

Do they sound nice to your ears? I.e. not harsh or grainy - then I would say they are most likely not impacting the performance of your amp.

I have not heard that low capacitance cables present a problem to any amp, so if anyone has experienced otherwise please post a response.

Regards
Thanks Willie .... as Al (Almarg) has mentioned in other contexts, technical specs and stats will take one only so far. Beyond some murky point, there are just so many variables in play, you gotta go with your ears. Seems like the same holds with cables, and pretty much equipment in general.

At the risk of starting a speaker skirmish, let me briefly segue to touchy subject. I've been reading reviews, member comments and bench test reports on various speakers.

One darling of the audiophile community is the Wilson Sasha WP. It's a Stereophile 2013 Class A Recommended component -- no surprise. What I find interesting is that based on just Stereophile's bench test report, I would not have automatically jumped to that conclusion. In contrast, the Sasha has a bumpy frequency response. Consequently I might have surmised that the Sasha's acoustic presentation is significantly colored. Yet I don't recall reading any comments to that effect.

So, seguing back to cables, I get that specs and stats alone will not tell the whole tale. Problem is there are not that many B&M stores around and even less dealers who are willing to allow home trials.

Happy New Year again.

Best

Bruce
OK Bruce - just took a look at your system and based on those components, upgrading speaker cables may well reveal details currently unheard.

But - If it were me I would probably opt for a different brand.

Here's my thinking - you are already using a 9 gauge cable that uses good quality copper with low resistance - moving up to the 8 gauge 12tc would probably result in only subtle improvements in detail and dynamics

Significantly improving on your systems current performance would probably require a change in materials and design used in the cable's construction

e.g. maybe a cable that introduces silver coating or a silver/copper alloy and/or a significantly larger diameter cable.

That would be the direction I would proceed.

Hope that answers your question.

Good luck with the search

BTW - what power cable do you use :-)
Thanks Willie .... btw, I think I mentioned that my speaker cables are the Kimber 8PRs. At this point, my power cables are stock ARC, which I understand are "good" PCs.

As a point of interest, when Stereophile reviewed my amp in 2012, the reviewer whose name escapes me switched out the stock cables for a Sain brand PC, which is the cable ARC supposedly uses when testing gear. I think Sain cables are "plaid" priced.

Until I hit the lottery, my next tweak is to improve power delivery by installing dedicated AC circuits to my system. Will probably do the AC circuit upgrade when I freshen up my basement/listening room/man-cave in early 2014.

In the meantime, I'll keep an open eye for some speaker cable inspirations that may do better than just improve my system by a subtle difference.

Thanks again,

BIF
Bruce - just looked at the Sain - that's a little outside my snack bracket :-)

BTW - Could you explain "plaid" priced please

Currently I'm using DIY Furutech 10 gauge to the amp and 13 gauge Furutech on the source components - all with silver-plated copper connectors.

I'm about to try (in the mail) the Silver Resolution power cable - a silver/copper alloy cable from Signal Cables, just to see how it compares to my Furutech's - recommended by a fellow Agoner with an amazing system who has also auditioned many of the boutique brands and prefer the Signal brand.

See - Silver Resolution Power Cable

Another Agoner highly recommends their silver-copper alloy interconnects also

I guess I'm just a sucker for the little guy :-)
Thanks for the Silver Resolution PC site. I'll check it out. My reference to "plaid" is explained in my 12/27/13 post just above. I don't know how old you are, but you'd have to have seen the Mel Brooks side splitter, Space Balls to get it. If you haven't caught any of his flicks, check out Young Frankenstein and Space Balls. I guarantee the next time someone tells you to "walk this way," it will never be the same for you. :) :) :) This post earns 3 happy faces.
Bruce - just installed the Silver Resolution yesterday and already it's performing better than my Furutech 10 gauge - even with only 24 hours on them.

The dynamics are the biggest i provement - this is a very fast cable.

I would recommend the connector upgrade offered by Signal Cable - I ordered their stock connectors because I have a preference for a silver-on-copper connector - once I replaced the stock's the cable became less harsh and much faster.

It also provided...
- a deeper image
- smoother and more detailed sibilance
- more clarity and air around instruments/vocalists

A very worthwhile upgrade from my perspective