Biamp a Bryston 4b sst Bass with a Classe ca3200

Is it possible to biamp a Bryston 4bsst (Bass)with a classe CA 3200 (mid range and Treble)?
Yes. If the gain of the two amps is not the same, you'll have to insert an attenuator into the path of the amp with the larger gain. You want the voltage levels at the speaker posts to match.
• Bryston 4bsst
• Gain, unbalanced input: 28.7x, 29.5dB (with input switch set to 1V)
• Output noise, 8-ohm load, unbalanced input, 1k-ohm input termination: wideband 0.260mV, -80.7dBW; A weighted 0.067mV, -92.5dBW.
• Output noise, 8-ohm load, balanced input, 600-ohm input termination: wideband 0.307mV, -79.3dBW; A weighted 0.083mV, -90.6dBW.

Classe CA2200

(balanced inputs) CA-2200
voltage gain 29.1dB
sensitivity 1.4Vrms

Are these gains close enough?
The specs I see for the 4B SST is 29dB on the 1V setting. Compared to 29.1dB for the CA-2200, I'd guess that's close enough. You'll very likely have more than a 0.1dB imbalance in your room due to furniture anyway.
I tried to biamp using two amps with same gain but different input sensitivity (such is your case with Bryston and Classe), did not work well.
Both gain and sensitivity must match.
Don't forget input impedance. Is this proposed bi-amp passive or active? If active you'll be fine.

Sashav, why does the input sensitivity have to match? I can see if they are wildly different one amp would reach its max power way before the other, but I don't understand why they have to match. My understanding is that for a given input voltage we want to have the same output voltage for each amp, so gain is the only determinant.

This is exactly what I thought, I was beating this question to death on various forums, was getting different opinions, and finally tried it myself.
Had two amps of exactly the same gain, one of them was also 4B SST with 29db gain in 1V position, but different sensitivity (the other was 0.7V).
I tried various combinations (the one with 0.7V driving MF/HF, or just HF), no matter what I tried the one with 0.7V always produced noticeably higher level of frequencies it was driving.
Sashav, thanks for the response. Did you verify the voltages at the input and output of both amps? Or did you just accept the manufacturer's gain spec?
I did not verify voltages, I was going by gain specs.
But what could manufacturer benefit from publishing incorrect gain values?