Phil Allison" wrote in message
...

"

Years ago I read about a test where 2 amps could be connected to a single
speaker and if there were any differences the speaker would generate
sound.

Does anyone know of this test and can you give details?

** If you drive the left and right channels of a stereo amp with the same
signal, then ideally there should be no difference in the outputs at the
speaker terminals. A speaker connected across the two "hot" terminals
should be *silent*.

In fact, that outcome is impossible do to component * tolerances* in the
resistors and capacitors that set the gain and LF and HF roll offs in each
channel.

Even a 1% gain mismatch will mean a difference signal appears across
the outputs that is 40 dB down from the normal one.

Phil Allison's answer is correct as far as it goes. However, I believe the
test was intended to see if there were any differences between two different
amplifiers -- a Crown and an ARC, say -- not the channels of a single stereo
amplifier.