Speaker Cable Analysis ???

[FrankRoss]

With so many speaker cable manufacturers, configurations and theories I'm still confused about many issues:


1. What is the formula for deriving the required guage of wire for x amount of feet: ie, 5 feet requires ?? guage wire, 30 feet requires ?? guage wire, and so on.


2. "Thin" wires from inside the power amp terminate to the speaker terminals on the chassis. "Big" wires travel from the chassis terminals to the terminals on the back of the speaker. Once again, "thin" wires connect those terminals to the crossover network, then more "thin" wires connect the crossovers to the drivers.

What effect does this have on the monstrous cables that connect the amp to the speakers?


3. Is there really a difference between regular 12 guage wire and 14 guage, braided -vs- non-braided and finally stranded -vs- non-stranded?


4. Why doesn't "stacked" CAT-5 work for speaker cable?


While I take my monthly jaunts to the local high-end shops to hear what they've got, it's impossible to do real comparison shopping when they change the gear out often. I can't afford to perform my own testing at home with this new "stuff" on the equipment that I'm accustomed to.

I'm really trying to research what type and guage speaker cable I need to wire my new living room for my system. I own a pair of the Kimber 8-TC's, but they're too short for what I now need to do. I don't have that kind of cash this time around for wire as costly as the Kimbers.

Needing guidance, can anybody give some detailed explanation to the 4 questions I've posed above?

 

[HDTVman]

Cables: Mostly a load of hype

Check out this site http://sound.westhost.com/cables.htm

This is the best write up on cables I've seen. The best part is it's the truth, Rod has no axe to grind and gives it to you straight.

 

[GRollins]

Frank,
I'm sure a lot of this is covered at the link HDTV gave, but I'll drop in a few thoughts that may or may not conflict with what's said there.
1) There's no formula, per se, for gauge vs. cable length. You're free to run 20 ga. single strand if you like. The music will still get there. The biggest single factor that you run into is damping factor. The bigger the speaker cable, the lower the resistance (we're talking DC, here), which preserves the (presumed low) output impedance of your amplifier. The thing here is that it's a diminishing returns curve. Once you get to, say, 10 or 12 ga. you're most of the way there. 8 ga. is arguably better, I suppose (as are even larger wires), but you're going to have to pay lotsa money for very little benefit. To complicate matters further, there's a bit of a backlash against the idea of damping factor and how important it is in the overall scheme of things. As I'm sure you're aware, a lot of the cables these days look really huge, but are mostly insulation. There are sonic differences between cables, but they're not as all-important as some would have you believe. Keep in mind that people tend to get proportionately more excited about things that are easy to change. Cables can be changed quickly. Changing the circuit board layout in an amplifier is truly a pain in the rump. You can guess which one gets done more often. I, personally, find the prices the cable manufacturers charge to be scandalous--even when they do sound better. I just can't see paying ten grand for a pair of wires. Maybe it's just me being ornery...
2) The reactance (the sum of the resistance, inductance, and capacitance) of the various cables in a system is cumulative. The formula for resistance, for instance, takes into account the cross section of the conductor, the resistivity of the metal used (usually copper, but sometimes silver or gold are involved), and the length. Longer lengths add to the resistance. Larger cross sections take away. The resistivity depends on the metal. By the time you take all the factors into account, it turns out that a six inch length of wire, no matter how narrow (within reason), is still virtually a dead short, and due to the fact that it's so short, it has very little effect on the sound. This one can be confusing, I'll admit. The best thing to do is to get out your calculator and run through a couple of calculations for various lengths and gauges of wire until you get a feel for it. Perhaps even set up a spreadsheet on your computer so that you can change just one factor and watch everything else fall into place automatically.
3) This one could start a riot. Since I'm prone to driving people nuts just by taking a deep breath, I'll just gloss over the basics. Larger gauge lowers DC resistance--see #1 above. Braided wires, meaning those which interweave the positive and negative strands, dramatically increase the capacitance and inductance of the cable. Since, ideally, you want all three components of reactance to be low, this is rather a goofy thing to do. It's also dangerous to some (not all) amplifiers. They can break into uncontrolled oscillation, which can easily destroy (we're talking smoke coming out...) the amplifier and/or the speakers. I won't comment further for fear of precipitating the riot. Strands, meaning the individual little wires that make up a larger cable, are an attempt to reduce 'skin effect.' (They also make the cable more flexible, which is undeniably convenient.) Now, technically, skin effect is only an issue at radio frequencies. You can look up the formulas and do the calculations, and they'll tell you that skin effect is effectively zip at audio frequencies. Yet...confound it, cables that are made to reduce skin effect sound better. This isn't really that much of an issue as a wire comprised of--I forget--22 ga. strands is sufficient to take care of the problem. Since most speaker cables are made of strands finer than that, you're generally covered. If you want to take it a step further, you can individually insulate the strands. That's called Litz wire. Yes, that seems to help, also, even though the formulas insist that it's all up in the RF spectrum.
4) I'll beg off. See above.
Undoubtedly, there's a tremendous amount of hokum in audio, but there's an equivalent amount of bull in the advertising for any commercial product. The problem is that some tiny fraction of real information gets buried in the bafflegab. And, honestly, some things just aren't as well understood as we'd like.
All I know is that, no matter what brand of beer I drank, beautiful girls never swooned at my feet demanding to be taken advantage of. Even though the ads all but promised that would happen.
Pity.
Think of all the money I could have saved, drinking cheaper beer...

Grey

 

[GRollins]

In 2 above when I said that reactance is the sum of the resistance, capacitance, and inductance, I should have said impedance. Reactance is the term specifically for the non-resistive components, i.e. the capacitance & inductance.
I realized that I'd said the wrong thing and tried to get back on, but got one of those annoying three tone whistles and an "All circuits are busy" messages.
(Grumble)
Okay...hopefully, I've fixed my kharma for today.

Grey

 

[dice45]

Re: Cables: Mostly a load of hype

Originally posted by HDTVman





Check out this site http://sound.westhost.com/cables.htm













This is the best write up on cables I've seen. The best part is it's the truth, Rod has no axe to grind and gives it to you straight.

Hello HDTVman,











found a lot of engineering talk in the link you posted. Subtle naysaying talk IMO (I have problems with messages telling why something cannot work, I like to read how something works; it is a question of attitude, of how one looks at the world).











Of course, a lot of true facts there, but they are spiced with a certain amount of un-backupped opinions. I find it extremely biased against the "subjective" perception of the listener. But, hell!, audio equipment is meant to be for listening to music, for enjoying music, it is made for the "subjective" perception of the listener.











Rod Elliot can make all those statements, no problem, but please, for himself only. Anyone of us has got his own ears and his own brain, and anyone can check it for him self, whether cables, monoblocks, capacitors, whatever help him influence and shape his own sound to his own sonic preferences.
And if it all is self-delusion, so what, it's fun.










I have done a lot of listening comparisons for myself and I have come to the conclusion -- for myself -- that nearly all of the items adressed in Elliott's text have sonic influence -- in a positive or negative or in a to me unimportant way.











I suggest anyone tries it out himself. As far as the cable issue is concerned, I suggest Allen Wright's supercable cookbook.This book describes how to make your own super cables for pennies and, yes, some super-super cables costing a bit more. The book will entertain you well, be assured.




As far as capacitors are concerned, I found an industrial cap costing $10 for 1µF and to my ears, it vastly outperforms all super-expensive audiophile caps I know. Allen's cables do about the same for me and my phono cable design I was using years before I read this book is very similar to one of his designs. Suits me. What suits you, please try it out yourself.









What I want to add: I do not think we DIY fellows should pay $$$ for fancy audiophile snake oil stuff. We should be open-minded enough to find out ourselves




* what is a hoax and what not




* how the fancy audiophile snake oil stuff really works




* how we can make it ourselves cheapo-cheapo.

 

[HDTVman]

Hi dice45

I don't agree with everything Rod sez but I find the basics of it true. In my many years of tinkering I have used almost any thing you can think of for speaker cable. My favorite is 25 pair phone cable. It has 25 twisted pairs of 22 gage copper. I have never paid for any of this cable. When offices at the place I work are remodled they pull out hundreds and hundres of feet of this stuff and it goes in the trash. I just ask the phone guys to save me some and get more than I can use.

I just divide up the pairs into plus and minus and add what ever termination I need. 25 of the 22 gage wires makes about 8 to 10 gage conductor. I think that the lowest DCR that is reasonable and a balance of L and C (moderate value / ft.) generally give the best result.

You can of course get amp/speaker combos that need the cable to do some matching for you but I would call that a bad matchup of equipment and a special case.

 

[dice45]

Hello HDTVman,

Originally posted by HDTVman

I don't agree with everything Rod sez but I find the basics of it true.

I was not doubting that there is a lot of facts in what Rod Elliott wrote.

MY disgust was triggered by the emotional tone and the fact so many facts were spiced with not many but effective unbackupped opinions.

This is the way high-performance propaganda works. And, I admit it frankly, Rod was writing down nearly anything I experienced to be valuable in my audio universe. No question that everyone of us has his own audio universe, and right so. But I object to handing out the own opinionatedness as a lecture about general rules. That's why I spoke up. I want a little more mutual acceptance and not so much crusading in our world.

In my many years of tinkering I have used almost any thing you can think of for speaker cable. My favorite is 25 pair phone cable. It has 25 twisted pairs of 22 gage copper. I have never paid for any of this cable. When offices at the place I work are remodled they pull out hundreds and hundres of feet of this stuff and it goes in the trash. I just ask the phone guys to save me some and get more than I can use.

So you do try it out yourself and listen! just what I suggested.

BTW, just what I did with Tefzel-insulated solid-core network cabling

I just divide up the pairs into plus and minus and add what ever termination I need. 25 of the 22 gage wires makes about 8 to 10 gage conductor. I think that the lowest DCR that is reasonable and a balance of L and C (moderate value / ft.) generally give the best result.

I guess you would find your cable (or a very similar) in Allen's cable book.

I read it, tried it out. Since then I agree with Allen that cross-sectional area should be as small as tolerable in combination with needed DCR. Hence: monoblocks allowing ultrashort speaker cables. TME interconnects can be as long as needed provided speaker cables are as short as possible.

Allen also points out that a good audio cable should be one conductor only as thin as possible atleast in one direction. So if cross-sectional area is needed, he uses a 25mm wide and 50µm thick silver foil, having about 1 mm² cross-sectional area.

You can of course get amp/speaker combos that need the cable to do some matching for you but I would call that a bad matchup of equipment and a special case.

If the cable achieves considerably more detail resolution and µdynamics, I would not call this a bad match.

4 weeks ago, I had to rewire my tonearm. The MC cartridge now is connected by an unshielded twisted pair of lacquered copper wire of 100µm diameter. A very nice improvement to the 250µm thick shielded twisted pair used before . Lesson learned: avoid shielding if possible. You may complain about 10Ohms DCR in the phono lead now and so do I. But sonics are convincing.

BTW, it is one piece of wire from cartridge to preamp input, which BTW is a signal transformer. Gosh, am I glad R.Elliott was not aware of the use of signal transformers, otherwise he would have written them bad, too. Bernhard, shut up, you are getting mean and very biased now!



Can you imagine, sonics improved with the use of signal transformers? This crashes with usual engineering knowledge. But iron man Thomas Mayer has nine signal transformers in his tube amp chain and detail resolution of his system is top-notch, life-like; coloration is not an issue.

 

[HDTVman]

Well dice45 I can hear your axe grinding.

Every one is entitled to there view an any subject you care to bring up, but please try to stay on subject.

Maybe I should have been more clear. If a amplifier and speaker combination with a zero length speaker cable does not sound as good as when some length of special cable is used, then the amplifer is reacting poorly to the load. This could be an amplifer with poor stability or low damping factor. It could be that the speaker is a very reactive load. In any case I still call this a special case and a poor equipment match. If you want to "tune" the system with the speaker cables I have no problem with that, but lets call it what it is.

As for changing the configuration of your phono cable, that is a high Z circuit and an entirely different matter. As for transformer coupled amplifiers OK, but what does that have to do with speaker cables other that the output transformer and it's impedance match to the load?

As for your blowing off steam you seem as guilty as those you condem.

 

[dice45]

Hello HDTVman,







okok, my steam is off and maybe Rod Elliott is also member of this forum and I do not want to appear disrespectful to him. And I know I can appear quite strong, even if filtered via email. What anyone of us does with his audio is not my concern (if I can be helpful,I try to) and I know there are different religions within audio. It was the attitude getting me more alive than maybe healthy

Originally posted by HDTVman



Well dice45 I can hear your axe grinding.

What means "axe-grinding"? Please explain this saying to a non-native speaker

Every one is entitled to there view an any subject you care to bring up, but please try to stay on subject.

C'mon, the most intersting issues arises from off-topic. Just wanted to throw in another interesting piece of audio voodoo and i would terribly like to know why those §$%&in' trannies sound so terrific although according to textbook and bench, they should not.



My primary issue is that in audio there is a huge lot of voodoo, inexplicable effects and that we should not ignore or offend them just because we don't understand them.

Maybe I should have been more clear. If a amplifier and speaker combination with a zero length speaker cable does not sound as good as when some length of special cable is used, then the amplifer is reacting poorly to the load. This could be an amplifer with poor stability or low damping factor. It could be that the speaker is a very reactive load. In any case I still call this a special case and a poor equipment match. If you want to "tune" the system with the speaker cables I have no problem with that, but lets call it what it is.

I agree completely with you that effects and problems should be called by the name and I am the last one seeking beautifying excuses for flaws. And if the flaw sounds terrific, well, 1st, I admit "I do not understand why" and 2nd, I maybe have to re-shape my opinion what a flaw is



Low damping factor is such a case; I would not dare to give a general statement here as I have heard low DF amp/speaker combinations having a controlled and speed-of-light fast low end behaviour. Particularly tube amps with zero loop feedback seem to excel in that, be they SE or PP, the PP working a bit better. Subjectively more information about what is happening in the bass is handed over to the listener.
Not with all speakers of course. For my open-baffle subwoofer I do not even dream of using a tube amp. I do not want to run a pair of 211 cherry-red in order to achieve hardly 50 Watts. I will use Hugh Deans gorgeous AKSA amp (100W version).

As for changing the configuration of your phono cable, that is a high Z circuit and an entirely different matter. As for transformer coupled amplifiers OK, but what does that have to do with speaker cables other that the output transformer and it's impedance match to the load?

See above for transformers . It just was another example of audio voodoo. Phono cable: the source impedance of a low-output MC cartridge is in the range of 3 Ohms. And the cable is 10 Ohms. And the load impedance of the trannie's primary is about 30Ohms. Total load impedance of 40Ohms. Not milliOhms, but certainly lowZ.



In my textbook this is genuine BS allthemore as 25% of the precious phono signal is transformed to heat.

As for your blowing off steam you seem as guilty as those you condem.

Right, I blew off steam, and if I overdid, I apologize but please do not twist my words, I was not claiming Rod Elliott to blow off steam. I said something quite different and who is interested can read the former post. Sorry for appearing too strong, ok? Anyway, I did not intend to offend, I wanted to trigger thinking on the open-mind vs. naysaying issue.







BTW, I am surprised you respond kind of angry to my second post and not my 1st one in this thread, I thought I was steering back into calm water with the 2nd one. I felt not angry at all, rather happy, writing my second post. Can it be the 1st post's message had an extra day to sink in ?

 

[R. McAnally]

Re: Re: Cables: Mostly a load of hype

I have done a lot of listening comparisons for myself and I have come to the conclusion -- for myself -- that nearly all of the items adressed in Elliott's text have sonic influence -- in a positive or negative or in a to me unimportant way.

Actually, Rod never says that cables are in no way audible. He states that the differences cannot be *seen* to a certain degree using measurements. While resistance and reactance of RCA and line cables can vary to a degree the difference is in RF range if you want to see any difference in electrical measurements. He also mentions speaker cables can indeed affect sonics by increasing output impedance "seen" by the speaker to the amplifier.

 

[dice45]

Re: Re: Re: Cables: Mostly a load of hype

Originally posted by R. McAnally
Actually, Rod never says that cables are in no way audible. He states that the differences cannot be *seen* to a certain degree using measurements. While resistance and reactance of RCA and line cables can vary to a degree the difference is in RF range if you want to see any difference in electrical measurements. He also mentions speaker cables can indeed affect sonics by increasing output impedance "seen" by the speaker to the amplifier. [/B]

Randy,
I was not intending to challenge any of Rod's actual technical facts, sorry if I expressed myself misunderstandable. I was adressing the general tone of the text and the conclusions in it.
I admit, I did not read it from 1st to last word, I crosschecked some issues important to me and my disagreement comes from own experience wit the matter. I like to have things working fine and i like to learn how this can be achieved. I had too much talk about why things cannot work in my life already.

 

[Thatch_Ear]

I made my own out of old WE celonese covered 24awg copper telephone wire. Recently went to a DIY tube oriented group meeting and took the cables. Something that happened was that some flat cable(Goertz?) was hooked up and slowly everyone drifted from the room. I changed to my DIY using everything else including the music the and slowly the room filled back up. Go figure! 12 strands braided tightly in 5' lengths. I don't know but I've been told that twisting reduces band width. This I do know, use only one metal. Silver coated copper does not work well, or at least not for me. Different conductivities don't seem to mix. Also I believe that cables that sound great with SS can sound lousy with tubes and vice versa. I believe that braiding is good if you are using single strands and shielding is money out the window. By the way guys, I got my first isolation transformer set up for my analog today and that was an instant improvement. A few more days and I will have one for the Dig as well. I hope it does as much for the sound as the first one. New power cords and plugs are in the works and I will let you know how that goes. Later!

 

[soongsc]

This seems a suitable thread to call back so here goes.

Recently working with a full range speaker, I have been overwhelmed by how much 45cm of internal wiring effected the sound, and decided to find out what can be done to determine some trend. I used SoundEasy V13 and hooked the test setup like I would normally hook up for impedance testing except that the reference channel is not connected to avoid improper readings per distortion testing with SE. A power amplifiers is used to ensure equivalence to real world conditions. Using the Analog THD,IMD tool, I ran a single sweep to look at the harmonics contents and the THD using the speaker system changing the internal cable for each test.

As a result, the more correct sounding internal cable always had obviously lower harmonic contents, and there was lower THD in the low frequency range as well. I have not spend time to do this on external speaker cables, but I suspect the results would be similar in trend. I think anyone with distortion testing capabilities can run this kind of test.

I'm sure others will appreciate it if anyone else conducts this kind of test to see if trends are similar.