Thanks very much Santosh & Vaughan it really makes sense now. The other question now is is find an amp with the below specs for an example. How do you choose impedance you need to use.
Stereo, 2 ohms (per ch.): 700W*
Stereo, 4 ohms (per ch.): 500W
Stereo, 8 ohms (per ch.): 275W
Bridge-Mono, 4...