See my remarks in context, below ...

Quote Originally Posted by spookybathtub
Ah I see. Well that's kind of a bummer.
My thinking was this:
The speakers are 150W max, so they're probably about 75W RMS. Therefore 100W per channel on the amp is a good number.
The "maximum power" rating of speaker is generally irrelevant for in-home use -- you don't need to have an amp that puts out that much power. ('Sensitivity' is the more useful specification.)
And I think 100W at 8 Ω is a bit more than 100W at 6 ohm, right? Does anybody know the equation to find that?
There is no useful formula. If an amp were perfect, it would deliver twice the power into 4 ohms it does into 8, but there are very few amps that will do this because they don't have a large enough power supplies to supply the current and/or they can't handle the extra heat that would be produced.
Now I realize it's actually a bit less than 100W per channel, but I suppose it's still in the right ballpark.
Sure, you won't have a problem.
Thanks guys, for the reassurance that it will work.

The receiver's manual does say to "use speakers with a nominal impedance of 8 Ω to 16 Ω. No mention of 4 Ω.
Aren't your Pioneers actually 8 ohm? If so you have no problem. If they were 4 ohm you'd be very ill-advised to use them with that receiver.

Oh yes, and I forgot to include the asterisk definitions:
* Measured pursuant to the Federal Trade Commission’s Trade Regulation rule on Power Output Claims for Amplifiers.
**Measured by Audio Spectrum Analyzer.