The Difference Between Biamping vs. Biwiring
Q: I've often wondered how much sonic improvement comes with bi-wiring and/or bi-amping speakers, assuming the speakers are of high quality to begin with. I would assume that bi-amping might be a better route?
There are mixed opinions about biwiring. I for one biwire my mains simply because I have the means to do so as I own a pair of specific biwire cables given to me as a gift. The sonic differences are subtle, if any. Many times people think they hear a difference because they expect to. In actuality, 12 gauge wiring should suffice for most applications. If you feel the urge to biwire and have the money for the added expense, go for it. Worst case, you can use the wire elsewhere if you don't notice any sonic improvements. Some people argue that biwiring eliminates backwave EMF when electrically separating the crossover and using separate cables. In actuality, these cables are hooked in parallel to one common amp and thus still electrically combine at the amp.
There are some benefits if you are biamping with identical amps in the system. By doing so, you are now driving the speaker system with dedicated amplifiers for the High Pass (HP) and Low Pass (LP) portions. This may help in bass response, dynamics, and overall fidelity. Another benefit is electrical isolation between highs and lows of the speaker system as they are independently connected to separate amplifiers. This has the potential to reduce crosstalk and mutual inductance, assuming the chokes in the crossovers are isolated and the speaker cables are well separated from each other.
There also appears to be a benefit in passive biamping of amplifiers with finite output impedance such as those found in receivers. Having a dedicated amp to drive the woofer portion and another to drive the mid/tweeters can offer a better degree of system control and linearity assuming the power supply is capable of delivering the rated power into all four channels. In most cases however, very little power is consumed in the HP portion of the speaker since music above 8 kHz in harmonic in nature with very little energy.
However, if you amp is already beefy and accommodates your speakers and room and listening environment, than stay with what you have. Most audible differences are subtle if at all noticeable. The true benefits of bi-amping cannot be realized with passive crossover networks of a speaker system. Bi-amping truly shines when parts of the passive network of the speaker system is replaced by active networks where each amplifier is bandwith limited at the input. For more detailed information about bi-amping, we recommend reading the following article Benefits of Bi-Amping from Elliot Sound Products.