Running 4 ohm speaks on bridged amp...ok?

I think you should bi-amp rather than bridge, if possible.
Remember, bridging cuts the damping factor (bass control) in half. I used a stereo amp on each of my MG3.3Rs & it worked great.

Daniel

I agree with Daniel. I used to own a pair of Acoustat 4 ohm speakers and my old Bryston 3B amp would run out of steam. I asked Bryston about bridging in another 3B and they advised against it saying that the 4ohm load on a typical elctrostat would be too hard on the bridged amps. They suggested getting a more powerful 2 channel amp which I did - 4B-ST. Then I sold that stats and replaced them with Maggie 1.5's - never had a problem yet. I know that the 1.6's are 4ohm and while they do have a relatively flat impedence curve rather than bridge I would either bi-amp or upgrade the amp to one with more power at the 4 ohm rating - Bryston 4B-ST, bigger Classe like CA-200 or 201, Aragon 8008, Marsh A400 to name a few...

Huh? Bridging the amp doesn't change the speaker's impedance. I would suggest contacting Classe and asking them if the amp can drive a 4 ohm load properly. However, if it's driving them now, it should still do so bridged.

Bridging an amp will not change the impedence of a speaker.
Whether or not an amp can handle a 4ohm load bridged is dependent on the amps power supply. The Classe' should be able to handle it.

It's true, bridging does not change the speaker's impedance
but since each channel of a bridged amp drives half the wave form, it sees half the speaker's impedance. Most manufacturers of 4 ohm (or less) speakers advise against bridging. However, some amps will drve any load so it is best to check with the amp manufaturer.