the receiver i use the dgs910 as speaker sets for A and B so biwiring doesn't connect too the same terminals unless it's the same terminals internally.
It would be the same terminals internally, through a set of select switches.
I see it more as a gimmick than a functional improvement
Well, bi-wiring can theoretically create an improvement, but whether you will hear depends on some variables.
The standard debate is that the superposition theorem states bi-wiring cannot produce a benefit. But, this assumes that the bi-wire speaker cables present a zero impedance, and that distortion from one driver will not affect the performance of the other driver.
Superposition only holds true for a linear system. Bi-wiring will only theoretically be a benefit when drivers distort and linearity is no longer maintained.
With sufficient voltage a driver can deviate from ideal linearity so the current in the connection between the low output impedance of the amplifier and the woofer (in this case), will carry harmonic distortion components which can create intermodulation products. In a simple non-bi-wire situation, the tweeter driver terminals will see these distortion components through the speakers low to zero impedance straps (when a single non bi-wire set of cables is used).
The theoretical advantage is now valid if you assume a set of bi-wire speaker cables has some finite impedance (obviously, the longer the cables, the more pronounced the effects will be). When bi-wire cables are used rather than single wires with straps, the distortion components (caused by the woofer driver) will have a lower impedance path to the amplifiers low output impedance sink, rather than travel back and down the tweeters speaker cable.
Yeah, you're right, it's a small advantage and you could argue that the tweeters crossover would help to reduce the problem, but I suppose you could argue that the harmonic and intermodulation products will be at a higher frequency and may pass through to the tweeter driver.
The entire advantage is gained by asking this question. From the perspective of the woofer driver terminals, which is the lower impedance path to the tweeters driver terminals? Is it a set of straps in a non bi-wire situation, or is it the route of a set of bi-wire cables that has a theoretical ideal voltage source (amplifiers low output impedance) in the path?..........
brucek