Bordering on criminal, I know…


Greetings and salutations!  I recently purchased a pair of new MartinLogan 11As.  Unfortunately, all I have to drive them is a Pioneer SC-57 home theater receiver.  While I’m saving my ducats for a Pass Labs 350.8 amplifier, I am left wondering if I may be better served by bridging a couple of unused channels to power these new speakers.  Your thoughts are most appreciated!     

an10490413

Showing 1 response by almarg

It would be very surprising if bridging that amp would work ok with those speakers, and it wouldn’t surprise me if the result would be that the amp goes into a self-protective shutdown mode, or perhaps even damage.

A bridged amplifier sees a load impedance equal to one-half of the speaker’s impedance, at any given frequency. The 11A has a nominal impedance of 4 ohms, descending to 0.6 ohms at 20 kHz, so in bridged mode the amp would see that as nominally 2 ohms, descending to 0.3 ohms at 20 kHz.

Few amps would do well working into such an impedance, and that is particularly likely to be true in the case of a home theater receiver.

Regards,
-- Al