Generally Speaking

I would go with single run of your "A" cable!

My answer would depend on the speakers in use. If the speakers were TRULY isolated between the low and mid / hi frequency drivers when you pulled the jumpers, i would opt for "good" quality individual / seperate runs to each set of binding posts. If the drivers were still electrically connected internally after removing the jumpers, i would opt for a more expensive single run with good jumpers.

There is NO benefit to "bi-wiring" when you keep both signals in the same cable and simply split or share the cable. If you MUST split the cable or already have a pair like this, i would leave a good quality jumper intact for the lowest possible resistance between the two positive and two negative terminals. I know that this "voids" the idea behind "bi-wiring", but that is what i see as working best from an electrical standpoint. Sean
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I have run many different cables and I have found a benefit to biwiring with my current speakers. I compared a biwired pair of cables to the same brand but better model single run cables with jumpers and the biwire sounded better.

I cant explain it and Im sure that speaker design has something to do with it. I know that my speakers have an odd crossover design that makes them ineffecient. (I think it doesnt use compacitors in the crossover) Perhaps that has something to do with it.

I have heard the technical argument and I agree in theory it sounds as if their shouldnt be a benifit but I also know what I heard.

Cornfedboy has a point in pricing. The lower model biwire retailed for $300 more then the better model single run.

Have the best of both worlds, buy the cables used and get 2 runs of cable 'A'. That one was not too hard to figure out, lol. I think it would be speaker dependent, i.e. if speakers x-over networks are there storng point or not. I personally use a shot-gun(external) biwire set up, and found that I have much better bass with this set up.

If I remember correctly the reason I was told bi-wire sounds better is that when the drivers travel in the oppositte direction that they send a little interference back into the other driver. The extra length helps dissipates this interference. I cant swear by this but it was what I was told.