Sonus Faber Extrema..bi-wire or not??

Definately not bi-wired. It will sound better single wired(more resolution). Try not to use jumpers. Pull your midwoofer out & reattached your tweeter connections unto your midwoofer terminal (it's simple , no soldering neccesary). Hope this helps....sagger.

I have had very positive results bi-wiring this speaker. I have found though that the price of bi wire is the difference of a higher grade of sigle wire. You are better off with the higher quality single run.

I have found bi-wiring to help on my Guarneri's. I went from a single run of AQ Argent full ragne, to internally biwired Argent to a double run of Clear SE with significnat improvements in resolution, extension, and soundstaging along the way. Of course, this is an altogether different speaker, and your mileage may vary. I think PerfectImage is right. If you can afford a double run of high quality wire, it's definitely worth trying. Perhaps you can borrow another run from The Cable Company and see what it does in the specific context of your system. At a minimum, you shoud dump the SF jumpers and go for short lenghts of the same cable you are now using full range. The SF jumpers that came with the Guarneri's are VERY pretty, but not easy to make a tight connection with. BTW, I'm about to go back to internal bi-wiring with single run of Dragon. Hope the better wire offsets the move away from full range double bi-wire!

As far as "weak bass", the Extrema is a very amplifier demanding speaker. As expected, you get great lower midrange on up with tubes on this speaker, but the bottom-end would prefer solidstate for maximum control and authority. You'll have to decide which is most important to you. (Single run of "the best" speaker cable provides the best cohesive sound, top to bottom. Double-runs of the same "the best" wire did provide small improvements, but the cost is excessive given the gains.) Just my .02. Goodluck