Bi-Amp v. Uneven Speaker Cable Runs (Pass Labs B&W 802D)
Equipment: Classe CP-800, Pass Labs XP-15 Phono, VPI Super Scoutmaster with Lyra Delos, Marantz NA-11S1, Pass Labs X-250.5, B&W 802D, Audio Sensibility Statement SE XLR and RCA cables.
I am torn between the many options to deal with this, and could use any advice given (or other ideas of course):
Option 1: Pick up another Pass Labs X-250.5 and vertically bi-amp. Run a long XLR to the left channel (25 foot), and a shorter XLR to the right channel (5 foot), and get a shorter set of identical length speaker cables. Am I gaining anything from this?
Option 2: Run non-identical length speaker cable, 28 foot to the left, and 6 foot to the right. Besides saving money on the right channel cable, I am not having to coil up (or deal with) a massive amount of unneeded extra cable.
Thoughts?
I have no theoretical explanation for this, but when we were setting up our home hifi, it became very clear to us that speaker wires do differ in the sound they offer. Purchased and sent back Kimber, Sonic Link and a few others until we settled on Kubala Sosna, which by the way was the most painful option, but it gave us the best sound. |
2 opinions: 1 - spiraled speaker wire is of (arguably) limited benefit, but if you feel you prefer it, if you think you hear a difference, you can easily spiral regular speaker wire by anchoring one end, extending the wire fully, and inserting the other end in a drill. Give it a few turns and then stretch the cable to help lock in the spiral. Now you have spiraled wire. 2 - If less cable looks ugly (which for the most part I would prefer not to see any at all) dress the cable to conceal it. So for the OP, you have to decide what your budget is and what you are trying to accomplish. If you have a spare $8000 lying around for another amp and you like the way it looks, it's your money to spend and I'm sure there are salesmen and manufacturers who would appreciate your donation to their bank accounts. If you want great sound and are on a budget or don't care about conspicuously trying to impress someone, the solution would be to do nothing, or better yet, to remove the unsightly extra cable coiled up, cut each lead to the length necessary. Spend some time reading through the Roger Russel article linked above. He was the former head of acoustic research at McIntosh, so knows a thing or two about high end audio. His site is pretty fun to read through (http://www.roger-russell.com/) Whatever you decide to do, have fun and enjoy your system. |
Any particular reason not use this Belden wire - seems like a much better option. What's up with the pricings on their site?. http://www.awcwire.com/mfg/belden/part/1312a |
Mr_hosehead, this is my first post on A'gon, but I have to say that re-reading that Roger Russell site you linked to brought back some memories. I had to laugh when he made mention of the fad of green lining the edge of cd's in the name of better sound. I think I read this article for the first time back in college or shortly after (undergrad degree in Radio/TV). As for the OP's question, the speed of electricity is orders of magnitude faster than the speed of sound. (50% to 99% the speed of light per wikipedia) so timing differences would not be perceivable. Differences in resistance may have a very slight measurable impact, but I doubt it would be audible if the wire gauge is sufficient. Pretty much what vtvmtodvm said above If you are really concerned about it, you could also do a test by figuring out the resistance in the short lead, then buy some cheap wire from the hardware store of sufficient size to match that resistance for the length of the long run. The Roger Russell article that mr_hosehead linked to in his post explains this quite well. Without doing a test, this is merely a hypothesis, but I would suspect the air flow from your central heating/cooling fan would effect the timing of the sound from each speaker greater than would any timing difference through the wires of unequal length. Well, assuming your air vent blows across the room and isn't centered directly on the mid-line perpendicular to your speakers, either blowing with the sound wave or against the sound wave. Actually, has anyone considered the red shift or blue shift effect of HVAC on audio? Maybe that is another thread altogether, and I don't want to hijack this one. |
Loudspeaker Wiring and Connectors.. I recommend using AWG #12 stranded all-copper (not “CCA”, meaning copper- clad aluminum*) wire for power amplifier-to-loudspeaker cable runs. An excellent version is available from Belden. Their #8673 is a premium grade AWG 12 duplex primary cable that’s optimum for this use. It has superior insulation, also less tendency to kink than the #12 wire (CCA?) imported by local retailers. Buy Belden #8673 from Allied Wire & Cable: http://www.awcwire.com/mfg/belden/part/8673. Despite what you hear to the contrary, it is neither necessary nor beneficial to maintain identical linear lengths for the left and right channel wiring runs. Given the speed that electrons travel, there will be no audible phase delay difference if one stereo side has a longer wiring run than the other side, nor will there be any difference in signal amplitude that might theoretically arise from niggling variance in series impedance. Just cut the wire to accommodate your physical requirements. Do not consider any of the esoteric speaker cable that’s promoted within the hi-end audiophile community. There is nothing that will outperform basic Belden #8673. As noted by Peter Aczel, who founded The Audio Critic: “The transmission of electrical signals through a wire is governed by resistance, inductance, and capacitance (R, L, and C). That’s all, folks! (At least that’s all at audio frequencies. At radio frequencies the geometry of the cable begins to have certain effects.) An audio signal has no idea whether it is passing through expensive or inexpensive RLC. It retains its purity or impurity regardless.” Assuming that both your power amplifier and your loudspeakers utilize dual banana jack posts (spaced 0.75 inch on-center apart), terminate your wire with compatible dual banana plug connectors. Some nice quality gold-plated dual banana plugs with side entry wire access (desirable), are available from Parts Express... For red (right channel): http://www.parts-express.com/gold-dual-banana-plug- red--091-332 For black (left channel): http://www.parts-express.com/parts-express-gold-dual- banana-plug-black--091-334 My preference is to shorten the length of these dual banana plugs by discarding their knurled end posts and substituting #8-32 x 0.75 inch flat point set screws. Drive those set screws with a 5/64 inch Allen hex key wrench—or with a 5/64 inch hex bit (more elegant!) from Chapman; refer http://chapmanmfg.com/. *Most “speaker wire” is now CCA; claims of “pure copper” refer only to the cladding layer. |
I would suggest going to Home depot and picking up 2 - 28ft runs of cable and 1 - 6ft run. That way you can compare 2 equal long runs of cable vs a long and a short runs. Even if you hear no difference you haven't spent a lot of money to answer you own question. Also never coil a cable because it acts too much like a coil choking off power. Instead run the cable in a zig zag pattern |
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You probably already have your answers above - either do basically nothing or just go with your differing speaker wire lengths. And if you feel you need someone with a little more background to weigh in with their approach... well, every decade or so I wind up answering something with the link below. I'd always thought that Roger Russell seemed pretty knowledgeable and did have some level of experience and success in this industry and once I'd read his comments I stopped worrying and obsessing about lots of this and started listening more and focusing on stuff like finding more great source material. http://www.roger-russell.com/wire/wire.htm |
I anticipated the same exact logistical challenge as our house was being built and used 12 gauge wire certified for in-wall use, ran it through the basement and up to wall plugs near the speaker locations. Put similar wall plugs near the expected equipment rack location. They run roughly 30' long but you only see a few feet of "real" speaker cable from the wall to the speakers. Don't know if you can do the same - have a basement, but if not, I would try using the thickest possible gauge wire for long runs like that. After all this, I got a bunch of flack from my buddies about how much signal I'm losing by using crappy (and very long) speaker wires. So one evening when they were over for a few brews, and with the wife out, I got tired of their harassment and we disconnected the rack and moved it over near and in the middle of the speakers. Hooked everything back up and guess what, no one could tell a difference. Needless to say, everything went back to where they were and no more bugging from the "audiophile" friends. I do admit I don't have super top of the line components so YMMV. |
There have been a number of threads here about the question of equal vs. unequal length speaker cables, with the expectable lack of consensus. My opinions on the subject are stated in my two posts in this thread. In this specific case what I would be concerned about as being undesirable is utilizing a 28 foot speaker cable in conjunction with a speaker having a very low impedance in the mid and upper bass regions, regardless of whether it is on both channels or just one channel. Also, my impression (not based on personal experience) is that vertically biamping B&W speakers with identical amplifiers can often be beneficial. So my feeling is that if the cost is acceptable the best course of action is likely to be option 1. Also, given John Atkinson’s measurement of "close to 600 ohms across the audioband" for the CP-800’s balanced output impedance, I would suggest that the XLR cables you would use under option 1 be chosen to have low capacitance per unit length. Meaning something like 20 pf per foot or less. Good luck. Regards, -- Al |