Is it good to drive the magnepan 3.6?

It sees half as much impedance because it has to supply twice as much current for a given voltage. With most amps the red speaker terminal swings back and forth from plus to minus while the black is fixed at ground potential. So lets say at some instant your red terminal is at 8V across 4 ohms and you'll have 2 amps of current flowing. If bridged to mono you'll be hooked to the other channel's red terminal which will be at -8V while the other is at +8V for a total of 16V across the 4 ohms which causes 4 amps to flow. If you ask 8V to supply 4 amps it is seeing a 2 ohm load.

"It sees half as much impedance because it has to supply twice as much current for a given voltage"

Well if voltage is given but current is doubled then impedance should drop to the half - BUT it cannot be because speaker impedance does not depend on amplfier, weather and other extreneous factors.

In your own example - 16 volts across 4 Ohms - supply twice more current,4A, then 8 volts across THE SAME load, 4 Ohm i.e. 2A.

Just follow the Ohm law (V=IxR) and everything will be just fine.

You missed the point. You no longer have 8V across 4 ohms when you are bridged.

When it was not bridged it was 8V across 4 ohms for 2 amps. As you say, Ohm's law. Bridged you have 16V across 4 ohms so 4 amps. The difference between +8 and -8 is 16.

plus 8V------- 4 ohms ------- minus 8V so 4 amps will flow.

The 4 amps flows out of one terminal and into the other. If each terminal is developing 8V but supplying 4 amps then it is effectively a 2 ohm load. 8/4 = 2 = ohm's law.

Back to the original question, will this stress the amps? I think not. Your amp is capable of delivering a large amount of current as evidenced by the 1,600W rating into 4 ohms. Your ears would start bleeding before you got close to that limit. Try it and see how it goes.

Hello Herman,

Spectron was the only one in this thread who answered or tried to answer the questions posed by Vinhd.

He also expressed some irone in old expression that "amplifier see...." Amplifier does not have glasses to see and must obey Ohm law as each and every one must.

and word "voltage" really means difference in electical potential and as you pointed out in your example if at one end there is 8 volts across 4 Ohm load and on another also 8 volts then total DIFFERENE in electroncal potential is 8+8 and rest you can count.

Can you can add something to the questions posed in this thread - we all would love to hear it. Otherwise its kindergarten.

I have operated various power amps "bridged" over the years. Most of the time it was to drive a center speaker bridged across a stereo amp that was simultaneously driving a pair of front speakers. (Invert one channel's signal to do this). The resulting load was always well below what the amp was rated for, but I never had any problems. I think this is because with the two channels driven out of phase the power supply is evenly loaded on plus and minus rail voltages.