rothman wrote:

The Manual says "don't add less than a 4 Ohm load in bridged mono as this
can damage your amplifier"

Okay, that's fine, then.

How do two speakers with 8Ohm impedance each combine to produce 2 Ohms? I
thought it would combine to make 4 Ohm load.

Two speakers with 8 ohm impedance combine to make a four ohm load.
1/8 + 1/8 = 1/4.

But, in bridged mono, each side of the amplifier is seeing half of the
load impedance. So if the amplifier is rated for 4 ohms in bridged mono,
it should be rated for 2 ohms a side in stereo. Again, you can think of
bridged mono as having the two sides of your amplifier in series with one
another. It doubles the voltage produced but it doesn't produce any more
current.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."