What are OHM's?

[hunkiemunkey]

Hi there,

I currently am awaiting the arrival of an Sony STR-DB780 receiver, and when looking at the tech specs, noticed that it has switchable 4/8 Ohm.

What exactly are Ohm's? And is 4 or 8 better?

The speakers I am using are Mission M73's, so what "Ohm" do you recommend I use?

Cheers

John

[auldendunn]

Ohm is the unit of resistance/impedance.
The impedance of a loudspeaker coil varies with frequency. So a nominal impedance is quoted ( fora certain frequency).
The output stage of an amplifier also has a nominal impedance value. Best results are achieved, in theory, when these are the same value in ohms.
Your Mission 73s should work on either 4 or 8 ohm setting as they are quoted 8 ohm optimal and 4 ohm minimum. You should get best results with the 8 ohm setting.

I think this is right, but there are many here with much greater knowledge than mine and if I am wrong they'll be along in a minute.