Need advice re bi-wiring/bi-amping

I wouldn't waste my time, you will not hear any difference in the sound.

 

As someone who has biamped planar speakers (solid state on the bottom... tubes on top.. hard to get right but when it is right... wow!) it can make a dramatic difference. It is not as simple as plugging in two amps but if you really want to pursue this the differences can be tangible.

M.

 

Biamping - compilcated but can yield very good results.
Biwiring - useless.

IMO.

 

Irshad---There is a great deal of confusion, brought about recently by "high-end" type audiophiles and manufacturers as to what bi-amping actually is. Bi-amping is the practice of splitting the speaker signal into high and low bands between the preamp and amps with a device called an electronic, or active, crossover. The amp that drives the woofer is fed only the low frequencies and that amp is connected directly to the woofer terminals. The amp that drives the tweeters is fed only the high frequencies and that amp is connected directly to the tweeter terminals. This practice goes back to the 1930s in motion picture theater sound and has always been called "bi-amping". Passive bi-amping is the practice of splitting the signal between preamp and amps with a passive network at line-level instead of using an active circuit, the signal is still split before the amps just as with regular bi-amping. This practice dates back at least as far as the 1950s. In neither method are passive crossovers at the speaker level used or amplifiers driven fullrange. The recent trend in high-end audio of running 2 amps FULLRANGE and then running the amps to the high and low legs of the SPEAKER'S passive crossover confuses the issue and shouldn't be called bi-amping, I don't know what to call it but it isn't bi-amping as the term has been understood by professionals and engineers for over 60 years. Some call it "fool's bi-amping". I'm at a loss as to what benefits such a practice would possibly give. Real bi-amping lowers distortion and increases dynamics. Also, as Mark mentioned, it lets you tailor the amps to the drivers. Like Mark I use SS on woofs and tubes on tweets, though with an Altec horn system instead of planars. The slam and control of SS on my basshorns and the sweetness of tubes on my compression drivers, the best of both worlds.

 

I wouldn't bother with biwiring. I tried biwiring my two stereo systems and was not impressed with the results. It didn't do anything.

On the other hand, I recently biamped my main stereo system in passive mode (I know it isn't the ideal way), and the improvement was obvious. The soundstage is wider, the highs are smoother, etc. I have an NAD C 370 stereo integrated amp biamped with an NAD C 270 stereo power amp. These amps were made for biamping (it is discussed on NAD's web site and in the owner's manuals for the two amps), and they are gain-matched. The integrated amp drives the tweeters and the power amp drives the drivers, and I have RCA cables running from the pre-out 2 jacks on the integrated amp to the pre-in jacks on the power amp. The set-up is very simple.

I have not bothered with active biamping because active crossover components can be expensive, and I did not want to disable the crossover circuitry in my speakers. Still, I am very pleased with the passive biamped set-up.

 

Keith---Indeed, many speakers today have a great deal of passive EQ built into the passive crossover for speaker voicing. Traditional bi-amping with such speakers would bypass the EQ and give a different tonal balance than intended by the designer. "Real" bi-amping is best left to DIY speaker builders or those using speakers originally using simple crossovers.

 

Bi-amping is one of the best ways to improve the sound of your system. A lot of 'bang for the buck'. An active crossover is very cheap to build yourself, if you have any experiency at all. A couple of op-amps, a dozen or so passive components, a wall wart power supply, and you are there. You need another aamp, of course. The other amp doesnt need to be the same as the one you have now, but if it is, thats fine, too. Use the lower powered amp for the mid and high end, as the power requirements are lower there than for the bass. I'm not familiar with the term 'vertical' or 'horisontal' bi-amping, but I have an idea that they are talking about how utilise the 4 channels of amplification. If your amps are different, then you want to use one 2 channel amp for both bass channels, and the other 2 channel amp for the mid/treble range. As I mentioned earlier, use the lower power one (if the power output is different) for the highs. On the other hand, if the two amps are identical, then you are better off using one 2 channel amp for left, and the other 2 channel amp for the right. That way each amplifier power supply just needs to cope with one bass channel (since bass will put the highest demands on current from the supply).