Honest1, I'm glad somebody else has their head on straight. Couldn't have said it better. |
So your speakers are about 8 feet apart, right?
Well you're right about all the extra speaker cable, to say nothing of the extra money if it's decent cable. (Because if one of them would be over 10 feet, it would be good to have them the same length.)
Personally, a better way to do it, both in terms of economics AND sonics, would be to place the amps between the speakers using a longer pair of ICs from preamp to amp (I guess about 10 feet based on your information?) and then a pair of 6 foot +/_ speaker cables. Or you could place an amp next to each speaker (but using two ICs the same length) and use really short speaker cables, maybe 3 footers. That would be the best IMO.
If you can used balanced XLR ICs to connect the preamp with the amp, that is desireable, but not essential. |
Porziob is correct about the speed of light, etc. however speaker cable length over 10 feet tends to diminish the damping factor -- the amp's ability to accurately control the woofer, necessary for clean bass.
This is even more important if one is using a tube amp, since output transformers have inherently limited damping capability. That is why (unless they are just driving the high frequencies) you so often see tube amps sitting right next to speakers. |
Bob, Mr. Abelson states "That some audiophiles fall for this cable hoo-hah is evidence that you CAN fool some of the people all of the time. What put Monster on the map was marketing. And that's all the high-end cable business has ever been."
So it seems that you have both taken the position that it's all hoo-haa. I'm good with that. And I hope you'll both be very happy with your hoo-haa systems until you hear something better, ha ha! (or was that hoo ha!) |
Pabelson, your thinking is not incorrect, but if you only consider these characteristics in relation to their effects (or lack of them) on frequency response curves, then you aren't going far enough.
One of the most important qualities of a good IC or speaker cable it that all frequencies arrive at the "destination end" of the cable at the same time. If they don't, then you get what is called "time smear" IE, a range of frequencies that started out together at the same microsecond at one end of the cable, arrive at the other at slightly different times. Time smear is the result of many factors, including capacitance and inductance as well as the construction materials and topology (the way the conductors are laid out.) Achieving low (or no) time smear is the holiest grail of cable designers. Its effects are not heard as sonics in the sense of frequency rolloff etc., but rather as a diminution of air, imaging, and and accurate holographic presentation of the sonic picture.
In the case of speaker cables (in addition to time smear) inductance can greatly affect damping factor (the ability of the amp to accurately control the woofer travel -- or more specifically, getting it to stop and "turn on a dime" at each end of its travel as determined by the signal. If it overshoots, you get muddy bass with no slam or (if you listen to mostly classical) musicality. Inductance not only produces an electromagnetic "drag" on the signal every time its polarity reverses, it also increases the "reactance" seen by the amplifier -- that's an equal and opposite signal generated back through the cable and caused by the movement of the speaker itself, acting like an electric generator. The amp has to work harder to drive the "real" signal against this electonic "headwind" and so the less it has to deal with the better. BTW, electrostatic speakers don't produce reactance, which is one of the reasons for their inherently good transient response (not just their lightweight diaphragms.)
As you pointed out, these characteristics are additive, and although typically small in value, have a tremendous affect on time smear (resistance and capacitance) and damping (inductance). People use all kinds of techniques to help reduce these effects (cable lifters, network boxes, etc.) but one of the easiest, especially with budget cables, is to keep the cables, particularly speaker cables, as short as possible. |
Bob, with regard to reactance and inductance (and to a much smaller degree, resistance) I was commenting on the bass quality (damping factor) and not stereo imaging.
Unequal cable lengths probably won't effect image balance, up to a point as Mike indicated, so long as one is using well designed cables that don't have excessive timing problems. |
First of all, I think Bob goes too far with his ten million-to-one ratio. Only really high quality cable with great timing characteristics is forgiving of differences in length, and then who cares because you're probably not going to invest in a lopsided pair of Siltechs or Purists anyway, are you?
On the other hand, the imaging performance of unequal lengths of lower priced (IC) cables suffers more from time smearing (eliminating t/s is the main cost driver of high priced ICs IMO) than unequal lengths of as much as even 3 to 1
Pabelson, Bryston used to have a really great damping factor vs. wire gauge vs. wire length chart for their amps. And if your amp is SS and (for now) you're going to use some cheap, big gauge Monster or Home Depot zip cord, stay under 25 feet for the longer run and you're done. If you have a tube amp, however, I think the best source of info (about recommended wire size vs. length) would be the manufacturer -- who could also tell you what the best you could expect out of their units would be if you used the shortest/fattest possible speaker cable (essentially a pair of jumpers between amp and speaker). One day though, when you decide you'd like more resolution, and to give your equipment the chance to be all that it can be, your not going to buy (special order probably) an unequal length pair of quality speaker cables. C'mon !!?
This is one reason folks who like to biamp often combine SS for the low end, with a tube amp for the highs and mids, where damping control is easy even for a tube amp. And it's also the reason why those who prefer no more than one amp per speaker, are always looking for the best of both worlds, usually expressed as "The most musical solid state amp ever made!" I think the darTZeel is currently the poster child for that award.
The moral of the story is: Unequal lengths? Sure, go ahead, you're likely talking about using cheap stuff anyway, so who cares?
Want better performance and better cables? Never going to need to sell them for ANY reason? Sure, buy an unequal length pair of Kimbers or whatever (you're gonna be sorry, ha ha!) |
Not inductance only! Cable topology, and wire composition (not just material, but the stranding and shape are big factors) determine how fast the different frequencies propagate.
What most folks forget, is that an audio signal is a wave in a metallic (usually) medium. And although electricity (electric potential) may transmit at the speed of light in a theoretically perfect medium (ever hear of "super-cooled super conductors"?) an electric "signal" does not, and is very much medium dependent. What do you think the doctor is looking for when he/she checks your reflexes? Wants to see if your cables are deteriorating. |
Oh gosh! Maybe it was my tubes and not my cables!! |
Bob, I think you should have this conversation with someone like Bruce Brisson (Monster, MIT cable designer -- invented the "shotgun" SE cable) I don't think he'd agree with you. I've run out of science . . . . . |
Whether either of you guys want to admit it or not, what sells anything ultimately is results, not white papers, not hype. (You remember the one about fooling all of the people some of the time etc?)
What put Monster Cable on the map way back before you'd remember, was the shotgun design with its multigauge, multilength, separately insulated stranded conductors, with dual symmetrical signal path and floating shield. (A blueprint for a new, quieter more coherent SE cable, not hype.) Before that there was only single conductor coax for SE cables -- and if I had my way, that's all you guys would be allowed to use! Shouldn't bother you though, cause everything else is just a lot of pseudoscience, right? |
Pabelson, why don't you do something that involves science you can trust? |
Bob, please read the following and you will understand the reason for the importance of direction in the use of shotgun-type ICs (which is probably 80 or 90 percent these days.)
Though many mfrs. put arrows on their cables (just to look cool, I guess) the original use of them was when Bruce Brisson designed the shotgun IC for Monster Cable (which was made Monster Cable the ONLY cable to use at that particular moment in history.) He eventually left to start MIT, which he still owns. Until the Shotgun, all single ended ICs were coax -- single center (plus) conductor surrounded by a braided shield which also doubled as the (minus) conductor (a lot like TV coax today.) These ICs were susceptable to RFI pickup and ground loop hum. Bruce used two identical signal conductors in the center (double-barreled 'shotgun' - get it?) and a shield around the whole shebang. One conductor (plus) was connected to the RCA pin at each end, and the other conductor (minus) was connected to the RCA ring (ground) at each end, BUT the shield was only connected to the outer ring (ground) of the RCA plug at one end. Thus it could shield the signal conductors, and drain noise to ground, but it couldn't conduct a current and of course didn't have to carry the minus signal either. (A side benefit of the shotgun arrangement is that the two signal-carrying conductors are identical, which helps reduce time smear problems.) Bruce put an arrow on the cable pointing to the end where the shield was connected to ground (this is called a "floating" shield, because one end isn't connected to another ground point, so it, well, floats!). In order to avoid long explanations to electronically challenged audiophiles, he said "you point the arrows in the direction of the signal flow." What he really was trying to do, was make sure that the end of the IC where the shield was connected to ground (the arrowhead end) would wind up at the preamp, (which is the only component that should be grounded to the AC outlet) creating what's called a "star grounding" system, where all the components' ground noise or hum drains to ground through one point -- the preamp, and the protective shields also are all connected to ground at the preamp. WITH ONE EXCEPTION! As you can see, following the "arrow points in the direction of signal flow" rule between amp and preamp won't work! You still want the end of the IC where the shield is connected to ground, to be at the preamp. Thus the arrows on amp-preamp ICs have to point "backwards." A better rule, which I tell everybody, is "all arrows point to the preamp" and I let it go at that! Most mfrs. do use the Brisson design for their single ended ICs now. These include Audioquest, Monster, Straightwire, MIT, Cardas, some Nordost, XLO, and most of the other big names. Some exceptions are Purist and Magnan and I guess a few others, but that's another conversation.
And even though Cardas ICs are "balanced" (they don't like to say "shotgun", because it sounds like they're copying MIT, which they are!) their ICs don't have arrow because they are "double floating shielded" with each shield connected to ground at the opposite end from the other shield. So it really doesn't matter which way you orient them. So point all your arrows to the preamp and you'll get the best performance out of 90% of all SE ICs.
You still have a great deal to learn about the signal carrying characteristics of different alloys, cable construction/stranding etc., but from what you've revealed so far ("signals transmitted over cables IC, speaker etc)are AC, thus flow in both directions not at the same time of course!"), I'd say you have plenty of time ;~)) |
