Speaker cable length for L/R channels critical?


I have a good system that utilizes some older discontinued speaker cable that I like a lot. It is 10 feet in length and I need that length to reach the left speaker. The amp is not (and cannot be) located center between the speakers.
The problem is I wish to biwire and have an opportunity to buy a 6 foot pair. The question is this: Can I run both 10 foot cables to the left speaker and run the 6 foot pair to right without any wierd effects like "ghosting" or have one channel be clearer or louder than the other? Any ideas? Thanx
ceb222
My guess is that it probably wouldn't matter....but I personally wouldn't do it. I'd wait from a 10 ft. pair for the R.
Recommedations have always been to keep the cable lengths the same, regardless of speaker distance from your amp. It has to do with keeping the timing the same between your left and right channels.
At the speed that sound travels, I'm not sure you could hear any "timing" differences in 4ft of cable. I've done it both ways without hearing any differences. However, if the cable differences were say, 10ft or more, there may be some audible timing issues. Recommendations seem to be to keep everything as symetrical and equal as possible (cable length, toe-in, speaker types, etc).
Mt10425...At the speed sound travels, (about 1000 ft/sec) a 10 foot difference would matter. But what travels in speaker cables is electricity, not sound, and at about 982 Million feet per second there will be no measurable timing difference between speakers. Loudness, and tonal quality will get you an argument about 10 feet. (But the same would be true about 6 inches!)
The speed of light in a vacuum is 974 million feet
per second.

Electricity in copper travels at about 94% of the speed of
light in a vacuum.

Therefore, the signal travels at 916 million feet per
second in the cable.

Therefore, the difference in timing for a 4 foot difference
in cable length is about 4 nanoseconds[ billionths of a second ].

An easy rule of thumb is to remember that light travels
about 1 foot per nanosecond.

Dr. Gregory Greenman
Physicist
In context of speaker wires, the difference between 982 Million feet per second, and 916 Million feet per second is something that only a Physicist would worry about :)
I have heard many times that electricity travels at the speed of light through a conductor. Dr Greenman says in a vacuum it travels close to that. I do not have a Phd but I do have a degree in electrical engineering and what I believe to be true (at least what I was taught) that electricity, which are the valence or free electrons in a given conductor travel very slowly, they crawl so to speak, and it is the effects of electricity that appear to travel at or near the speed of light. For example: You throw the light switch in a dark room and the light comes on. The effect is almost instantaneous. It is only the next free electron in the circuit waiting to be pushed by the electro motive force (120V) that was located closest to the filament. Sorry for the rant but I get tired of hearing that electricity travels near the speed of light. IT DON'T!
Ceb222...But what is "electricity". I think it is the disturbance, not the matter, and the disturbance does propagate at or near light speed.
Remember your brain/ears are resolute to time and phase response as well as frequency response.The more resolute the rest of your system is the more cable length will matter..It all is additive..Tom
Theaudiotweak...Not to belabor the point, but a 20KHz wave traveling at 916 Million ft/sec is 45,000 ft long (about 8.7 miles). Ten feet represents 0.000218 of a wavelength, and corresponds to a phase angle of 0.078 degrees.

My brain/ears are not that good!

This is an example of misapplied science so prevalent in audiophile circles. True, science says that there will definitely be a phasing discrepancy, but a very little bit of math (conveniently neglected) shows that it is completely inaudible.
You cannot hear time and phase errors while your speakers swing free air like a pendulum. Tom
Theaudiotweak...Why not? Don't the instruments move around a lot while they are being played and recorded?
Theaudiotweak...Tom...there are several quite straightforward questions that you are avoiding answering, (criticizing my system or my ears instead). Come on: give it a try.

1. When a speaker weighing 50 pounds or more, is suspended by three feet or more of chain, so that its natural (Pendulum) frequency is 1 Hz or lower, how can this frequency be excited by vibrations at 20 Hz, and up? (In other words: what makes you think the darned speaker will move?)

2. What about the instruments moving around as the musicians play them? Why isn't this more significant than speaker motion?

3. What about the fact that midrange sound is radiated by a cone that is moving 1/4 inch or more to reproduce the lower frequencies, and/or moving at subsonic frequency (unrelated to the music) due to record warp?
Although the timing of the electricity going though an extra 4 ft of the cable won't be audible, the electrical characteristics between the 2 cables will be slightly different. Cables have a certain amount of capacitance and inductance per/ft. Since its already an imperfect transmisison line, (perfect = output impedance = cable impedance = speaker impedance, at all frequencies), you may actually hear a difference. IMO...
Hmmm. It seems then that the substantial issue is matching the potential colorations and/or volume impacts between the cables. That is, one shorter cable could potentially offer less of the cable's sonic imprint on that channel.

Art
Regarding that man is not equipt to ´hear´ if L/R speakercables are of different lenght with potential phase and coloration errors - It was a fact a few years ago that we couldn´t hear much over 20Khz as well.

Speakers and sound reproduction mediums has evolved a bit based on what we can not ´hear´.

M
Art: If a cable colors the sound, then it is typically true that the longer it is, the more it will color the sound. (The exception: if what's coloring the sound is the circuitry within a network box, then cable length doesn't matter.) Whether cables *should* color the sound is a philosophical question, with no answer. Some audiophiles try to avoid such cables; for them, minor differences in length do not matter.

M: It is still a fact that we can't hear much above 20kHz. No amount of audio technology is going to change that.
I have my left cable at 25ft. and my right one at 10ft.
I can't tell any difference.
It is likely that you wont hear any difference. I have heard shuch systems with different speaker cable lengths, and I could not tell the difference.
Pabelson - Yes, I know our ears capability. Explain how come man can tell difference between a tweeter rolling off at 22Khz and a tweeter rolling off at 33Khz, when we should not be able to.

All the music reproduction industry is barking up the wrong tree stretching up their equipment above 20Khz?

OTOH I think it would take very special conditions for anybody to hear difference in cable leghts. One could probably sit very satisfied with such a sollution if other will not work.
I, on the other hand knowing that there is a mismatch/phase/coloration problem ( how ever tiny ) in my gear, would not accept that. But that´s me. Or as I thought the audiophile ´must-be-perfect-sickness´ ; )

M
Explain how come man can tell difference between a tweeter rolling off at 22Khz and a tweeter rolling off at 33Khz, when we should not be able to.

Simple: The tweeters also differ in the audible range. As for why companies are making such tweeters, why do amp manufacturers make amps with 0.01% THD, when nothing under 0.1% (and probably 0.5%) is audible? Possible answers: Because they can, because there are people who will buy them for whatever reason, because there's nothing wrong with building in a little extra margin, and because there's the challenge of taking something to the limit.

As for cable lengths, we agree more than you might imagine: I don't think different cable lengths matter, but I keep mine the same length anyway. Habit, perfectionism, superstition, whatever...
My experience suggests that the overall sense of hearing extends well beyond the frequency at which a pure sine wave test tone can be heard. In other words, introduction of roll off by a filter, say at 16KHz is easily sensed by someone who can't hear higher than 12KHz in a hearing test. I observed this in my own case and of course I wanted an explanation. I think that the reason is that the sense of hearing perceves not just the change of air pressure, but also the rate of change, and an irregular waveform, like music, has steep wavefronts. A tweeter with extended frequency response can generate these steep wavefronts, and sounds better than a tweeter with frequency response that only corresponds to the "official" audio frequency range.

Also note that the difference between 22 KHz and 33 KHz is not as much as you might think...only one half an octive.
Also:
2 tweeters that roll off at the example freq or 22khz and 33khz will also have a phase shift difference even well below their roll off freq, in the audioable range. Much of music is composed of impluses which are composed of the fundamental freq and some harmonics of that freq. If the phase relation of these harmonics are affected by the tweeter roll of freq, then you change its sound.
does this explain why, when I turn on my sub, the entire frequency range that the main speakers produce, top to bottom, sounds richer to me? I've wondered about this recently.
Thanks,
Art
OK, so here is a question.

What is better? To have a 4 foot and 10 foot run? or to have two 10 foot runs where the excess cable will end up spooled on the floor?
I would definitely have the 2 10-foot runs.
At one time I had a similar unequal run of Cardas Cross to my Aerial 10ts & it always sounded funny & flat & I always had to move my chair around. I switched to equal lenghts of Cardas Golden Ref (still have them--great, smooth cable, even in extra-long lengths) & everything clicked into place. I would never have an asymetric set of any cables--just bad karma.
All speaker cables have some flavor - complex reactance
Cables with less flavor will exhibit slight differences based upon the interactions with your specific components.
It's like comparing 10 licks of a chocolate ice cream bar to 6 licks. You are getting more "chocolate flavor" in the 10 ft set.

If you have well matched, very revealing high end components - I believe variations in speaker cable length should not exceed 25%. For most "good" systems - it will be hard to detect a difference.