Bi-amping is running two amps into one loudspeaker. Does it make sense to consider this?

Bryston speakers, among many, are set up to allow bi-amping. The top set of binding posts connects to the mid/tweets. The lower set goes to the woofs. There are jumpers connecting the top/bottom posts so you can run a stereo amp straight in and call it a day. If you bi-amp, you must remove the jumpers before connecting the additional amp.

A fine stereo amp does a quite credible job at this task. But let’s analyze this a bit more.

Back EMF

When your speaker’s drivers move back/forth, they throw a back wave at your amp. Think of this situation as a pipe carrying water from the amp to the speakers. As the speaker moves forward it accepts more water. As it moves backwards, it shoves water in a back wave towards the amplifier. In a perfect world we would like the best grip on that water path between your amp and speakers, in both directions.

The back flow of the entire array of drivers is different and less specific, than if an amp saw only the woofers, for example.

If you could dedicate one amp for the woofs, and another for the mids/tweets, you’ll have not only more power due to having two stereo amps (4 channels) but you’ll derive a better GRIP because each amp has a more specific handshake on certain frequencies. Better control equals cleaner, tighter sound.

Practicality

Is it practical to run two stereo amps for this configuration? You would need two amplifiers of the same input sensitivity. Or, you would need at least one of the amplifiers to have input level controls. Further, the quality of these two amps would have to be better than one terrific sounding power amp for this project to make any sense.

Bryston Power Amps

One way to make this a very successful outcome is to run two Bryston power amps. They have the same sensitivity. You start by running a 4B Cubed ($7500, 300×2) full range. When you have some more money in your piggy bank, you could buy a 3B Cubed ($6000, 200×2) to run the mids/tweets. This combo is a FABULOUS solution and highly recommended.

Buttt, what we USUALLY see is, a customer starts with a garden variety Chinese built amp with no particular strengths beyond a cheap price with lots of watts. Adding another similar amp with perhaps a few less watts- and kludging it all together to try to blend- is sure to be a waste of time and money. You would have been better off to bag the first Chinese built amp and start over. But the world has changed…we have a perspicacious alternative now.

A New Solution!

The Bryston solution above is awesome. You’re all in for $13,500. What if you don’t have 13 plus large to dedicate to this project?

Atoll of France is the best alternative option to the Bryston amps above. You could start with the fabulous Atoll AM200 ($2200, 120×2). When you come up with another $2200, buy a mate. Now you can run one on the woofs and the other on the mids/tweets. You’re all in for $4400 and as close to Bryston as possible, for about 9k less.

Atoll Power Amps

All Atolls are made in France with a 3 year warranty. They all use large, dual transformers, a big array of filter caps and a good number of MATCHED MOSFET output transistors. Please visit Dave’s Faves Atoll Power Amps to read the specifics.