impedance question


Hi I'm trying to understand ohm's and power. My b&k 200.5 is rated at 200 watts per channel at 8 ohms and 375 at 4 ohms. Now some of my speakers are rated 4 ohms and some are rated at 6 ohms. My question is does the amp just feed the power differently to each speaker accordingly? ie, 4 ohm speaker will receive 375 watts and the 6 ohm somewhere between 200-375?

2nd question is i had my sub woofer wired parrellel to my mains, everything seems to be working fine but I just read that I really put a load on my amp by dropping it to 2 ohm? is this correct? Is this a bad thing to do? I don't know how else to wire my sub because for some reason my rca sub output on my receiver doesn't seem to work. any suggestions?
monterey
Also, the impedance rating of a speaker is its nominal rating; most speakers will have an impedance function, and associated phase angle (a function of the driver/cab design and crossover type), that vary widely across the operational bandwidth. And, most listening is performed at levels with the amp cranking out, again nominally, 1 watt or less.
So can I attach my sub to my mains via a parallel connection safely?
Yes, given that it is a powered sub (i.e., it has its own built-in amplifier, and an AC power cord that plugs into a wall outlet), and given that the sub has provisions to accept speaker-level inputs from the outputs of the main power amplifier.

Regards,
-- Al
Keep in mind that the 4 ohm speakers are most likely less efficient than the 6 ohms speakers (ie 85db vs 87db) so the increase in wattage output won't be as drastic as you think.
Since I got your attention, what is the phase knob for on my sub and where should it be set at?