With most speakers, bi-wiring will lead to an improvement in sound quality (assuming they are set up for true bi-wiring) -- sometimes a substantial improvement. Richard Vandersteen has discussed in several audio mag interviews (and, I think, on the Vandy website) that the advantage to true bi-wiring (not so-called "shotgun" bi-wiring) is keeping the electrical fields of the low frequencies completely separate from the mid/high frequencies. His own research on bi-wiring, which led to his decision to use bi-wiring on the 2Ce, 3A, and 3A Signature speakers, indicated that it is this separation of the electro-magnetic fields that causes the improvement in the sound quality, rather than anything attributable to separation of the crossover elements.
I have two-way speakers with two inputs. Single wire was good. Doubling the run was a lot better. Keeping the double run connected to one set of output terminals at the amp end, removing the metal jumper clip at the speaker end terminals and connecting a cable to each individual terminal sounded best. This has been true with all three monitor speakers I've used - Sonus Faber, Silverline, and B&W. If you can't split the runs at least make up a speaker wire jumper to replace that metal clip between the bi-wiring posts.
Wouldn't using two sets of cable be like doubling the "filter" on the sound... however your cables change the music, they'll do that , that much more with two sets? If your cable is very neutral in sound, then biwiring might not do much, but if you choose a cable that promotes a certain kind of sound, biwiring might make a big difference. ?
Also, it seems like it probably is system dependent. Maybe this is definitely one issue that needs an audition.
Markanetz is on the money - use a set of spades and a set of bananas on a single terminal to enable the use of two runs of wire per speaker. Make sure the "better" cable is running to the high driver, not the woofer. This works better - perhaps some of the more enlightened of the 'goners could explain why.
I'm not sure I agree with your premise that biwiring with a neutral sounding cable makes less difference. I have biwired three separate systems in the past couple of years, all using different cable (though all more or less neutral) and it never failed to make a vast improvement. But...you are ALWAYS right to audition before comitting if possible.
A good way to start would be to get borrow a pair of speaker cables that are terminated differently from what you have now. As long as it is decent cable it doesn't have to match what you have too closely. Try them out for a few days, then switch top and bottom. Try that for a few days, then go back to your original single run. Then see what you think.
As for Dopogue's experience - system synergy is a funny thing, and it is very possible that his system liked the Mapleshade cable better than the Kimber. Naim is another brand of gear than comes to mind when talking about funny preferences of cable. I do wonder what would happen with a biwired setup of the Mapleshade cables?
To test system compatibilty, I suggest getting some cheap radio shack speaker cable in, say, 12 ga. and 10 ga., then you can explore the the differences of more, fatter wire and actually biwiring. The effect of gauge can have as much of an effect as the separete termination, and the type or quality of termination could have as much an effect as a separate termination. I suggest this as a cheap way to find out while controlling the experiments. And then, If you use this wire, you have a reference to start with to get real wire, as EVERYBODY knows what it sounds like.
Very system dependent. I've tried bi-wiring several times in the past with lesser system but did not notice any improvement.
Recently I converted my bi-wired Harmonic Tech Pro 9's with mono terminations to bi-wired terminations and noticed a decent improvement.
I noticed better imaging, 3-D soundstaging, and more air surrounding the highs.
I agree with Stehno, biwiring is system dependant. I originally tried biwiring about 10 years ago, I liked it and stayed with it for about 9 years. Now I'm back to single wiring, why (?), basically because IMHO it is better to buy a better quality cable than split your cable budget on 2 cables. My speaker cable cost about $800 for a 8 ft pair, there is no way I can afford to double that, and it sounds better than the biwire setup I had before ((2) 8 ft cables that cost about $700). If you need them, there are companies out there that make high quality jumpers.
Your experience may vary, depending on many things, such as room conditions, componants, crossover design and the cables themselves. It's definitely best to try before you buy. Take your cable budget and try one expensive pair vs. 2 runs at half that price and see how it sounds in your system.