Originally Posted by sccr64472;13699461
You'll find that there is a lot of confusion regarding dc resistance and ac impedance. No speaker in the world offers a stable load to an amplifier since the impedance is never fixed. Impedance varies with frequency, so you can basically forget the 4 ohm, 8 ohm, etc resistance ratings and buy a quality amplifier with a beefy power supply. In theory, a power amplifier can double it's output as the resistance is halved, but you'll find that's clearly not the case with 95% of the amplifiers out there due to insufficient power supplies.
Edit: Btw, try to buy an amplifier with 2 db of dynamic headroom if possible.
Impedance and sensitivity are the critical metrics in determining how power hungry a particular speaker will be.
Do not confuse if they will sound good or not with power.
In series Z1 plus Z2 =
In paRallel Z1*Z2 / (Z1 + Z2)=
If you want to know the true current capability of a receiver, check the value of the rail fuses. These fuses are either located near the power transformer and filter capacitors, or on the amplifiers circuit board. There are usually two fuses per channel. (Do not confuse these with the AC line fuse normally found near the power cord.) Check the ampere rating written on the rail fuse. If, for example, each fuse has a 3 amp rating, the amplifier is capable of 6 amps per channel. It's that simpleEdited by Spooony - 6/6/11 at 8:33pm