Uneven speaker wire runs

I am thinking of buying ViaBlue SC4 cables. The reason I asked is that they can be ordered in various lengths hence the question about whether I should keep the mains the same. Never really thought about it before but I am setting up my system in a new house. Nautilus 802 driven by Lexicon 2x250 amp, Lexicon DC-1 processor.I plan to upgrade to Lexicon MC-8 or MC-12 and Bryston 6B SST. Reference:
http://www.oregondv.com/Viablue_SC-4_Biwire_Speaker_Cable.htm

Just throwing my 2 cents in. I would keep the lenghts the same for the technical reasons mention above. While you may not hear the difference why wonder if you are missing something. Plus resale will be easier. I purchased speaker cables a little longer than I needed just in case I ever wanted to sell them I would have a standard size. I have N802's and would be curious to hear how they sound with the 250 watt lexicon amp. I found mines don't really sound good unless I pair them with high current amps capable of pushing 300 - 400 watts per channel. A friend has the new diamond N802 paired with a Theta which delivers 250 per channel. Despite what the dealer told him they are no where near as open and full sounding as mine with 480 wattsr

It's not the delay that can make a difference but other factors such as capacitance and impedance that can add up in cable length. I wouldn't recommend using 21' speaker cables at all. If you must, use low capacitance (teflon dielectric) 12 gauge wires, or more. You can also look at Ultimate Cables which is willing to do custom orders.

If you are going to the trouble of bi-wiring (dubious from an engineering perspective if this will make an audible difference given a low impedance SS amp driving your speakers) then I would go for exactly the same length wires to be safe (after all you are spending a lot of money - so why not spend $200 more and eliminate any doubts/worrries)

Keep the wires the same length, use 10awg and if you bi-wire make them a true bi-wire. Two seperate runs. Impedence, inductance and capacitance needs to stay consistant and to do this the wire needs to be the same length. The amp has a different effect when the variables of the wire changes. Two 10awg speaker wires from two differnt mfg's will most likely sound different but the bits and pieces may travel at the same speed with some of the bits and pieces getting smeared along the way. It's like comparing the speed of your thoughts to your vocals with a major hangover to the speed of your thoughts to your vocals without the hangover. Somehow there is less smearing when sober. Believe me, you don't want to start talking about skin effect.