Biwiring

Adding jumpers at the speaker posts only moves the signal separation point from inside the speaker to just outside the speaker. In a a true biwire setup, the separation is at the binding posts of the amplifier. I have rewired my Maggies so that the bass cable only 'sees' the bass network and the mid/hi cable only 'sees' the mid/hi portion. This is the real benefit of biwiring... the speaker crossover begins at the amplifier. The results can be debated, but I noticed a more seamless and open sound. The soundstage also had a deeper presentation. I am sure there are fellow B&W types who can recommend speaker cables. I would also like to hear their opinion on biwiring.

...Since biwiring does a speaker crossover at the amplifier level, the crossover point may slightly change up or down depending on amplifier. You will feel biger difference in biwired setup when you turn on and listen to unwormed amplifier ( especially tube ). You will feel bigger differences in sound when the amp has unstable gain (on very low volume or very high volume operations ). The volume control possibilities of the biwired setup is more narrow: the sound may become harsh on very low or very high volume of the amplifier unlike with single wired setup.

All of that because the crossover point cannot be stable in biwired setup. Yes it will improve the sound if the amp is in stable gain operation...

I don't understand how there can be a crossover effect at the amp binding posts. Can someone please explain?

I'm not sure you got that exactly right, Marakanetz. The same amplified signal is sent down both runs of a biwired speaker cable--there is no crossover in the cable itself. The speaker binding posts are wired separately and pass the signal along to their respective drivers. There is no crossover anywhere in the chain in question (there could be one downstream of the speaker binding posts if it's a three or four-way speaker, but that's beside the point).

My advice--if you're a believer that not all cables sound the same--is to go with the biwired speaker cables. Most jumpers are made of relatively cheap material and not something you'd want in your signal path. Unless your jumpers are made of the exact same materials as your speaker cables (not likely) that will result in some degree of degradation of sound.

Maybe the best thing for you to do is try it yourself. As a experiment you could pick up some standard 12 AWG speaker wire and compare using single wire and biwire. (Use a short length of 12awg as a jumper for the single wire.) If you find bi-wiring works in your system the second choice is how much do you want to spend. If you cannot currently afford the cables you want, start with a single pair and then save up for the second pair for biwiring. This assumes you do not mind having two cables running to your speakers. The combined biwire cables are a cleaner package. Some people use a different cable for the high and low drivers. (MIT biwire cables actually have the cables marked for high and low frequency.) I do biwire my B&W speakers with good results. Happy listening.