BTW, a bridged amp is not the same thing as a monoblock. In a conventional amp, one of the loudspeaker terminals is connected to 0 volts (the black one) and the other terminal (the red one) swings positive and negative to drive the loudspeaker. A bridged amp (usually) uses two conventional amps connected together so that neither of the loudspeaker terminals is connected to 0V. Instead, one terminal is driven positive and negative by one amp while the other terminal is driven negative and positive by the other amp. That gives you twice the voltage swing you would have if you only used one of the amps.
In practice this is usually done by using a stereo power amp which has a bridging switch to turn it into a bridged-mono amp. However, it would be possible to do it with any stereo power amp if you also had an outboard device to generate an extra, out-of-phase, signal in addition to the original signal.
Hmmm... I wonder if there's a market for such a device
I doubt it