amp question

my amp has "dual" or "separate" power amps that can be run mono bridged, or in stereo. I'm thinking about adding a 2x10 that's 8 ohms, and my current cab is 4 ohms. If I were to run the amp in stereo, would I get a 4 ohm output of one side and 8 ohms out of the other, or would it end up at 2.6 ohms as if it were connected in parallel?? The manual is of no help to me on this one.

 

If you ran the amp in stereo, you would have two separate amplifier outputs, each with it's own impedance match/mismatch situation.

Depending on the nominal output impedance of either amplifier, (let's say it's 4 Ohms), when you have a match at 4 Ohms, you get maximum power transfer to the load (the speaker cabinet).

A 4-Ohm output driving an 8-Ohm cabinet would be mismatched, and the amplifier would not deliver it's maximum power. This is mainly an efficiency issue. In this case, the combined impedance (4-Ohm output in parallel with 8 Ohm cabinet) becomes 2.6 Ohms for that one amplifier.

Without the jargon stuff, if you have plenty of headroom (watts) the mismatch is not critical and should sound fine.

FWIW,

O

 

That's what I thought. Thanks for the input.