I know what I am hearing, but I don't understand it. Can someone please explain?
Referencing Mr. M Code, Post #5 in this Amp FAQ thread
: Onkyo TX NR-717 125wpc 2 channels driven. I am driving 5.0 speakers, so 125/5 = 25 wpc, approximately.
: The 5.0 system is mismatched with speakers, but has a pair of huge Klipsch CF-4 (two 12" woofs, one 12" horn) for L/R. Center is a Dayton Audio MTM with 7" Usher mid/bass drivers and an Usher 1" dome tweeter. The surrounds are Bose 301 II's, with 8" woofs. Don't laugh, it really sounds pretty good.
The Onk Audyssey matches them up pretty well, and relative to reference, Audyssey sets the Klipsch at -5, the center at +4, and the Bose 301 at +3. At reference which is 82 on the 717, with 5.0 driven it plays as loud as I can stand it. My math says that 25wpc is driving each speaker pair, and seems to do the job quite well; it can rattle the pictures right off the wall, with chest thumping mid-bass. The sound quality is great, at all SPL levels.
What I don't understand is if I put the Onk into "All Speakers Stereo" it gets REALLY loud, maybe "punchy" is a better word. When I set the Onk to "Stereo Only" where it drives only the CF-4, it does not seem to be as loud, and usually doesn't sound as good as "All Speakers Stereo." My logic says that putting the full 125wpc into the CF-4 ought to be magnificent and sound better than everything else, but it isn't, it just sounds really good.
Granted, that I don't push anything to its full upper SPL limits, and 86 on the dial is as far as I push the Onk. Feel free to point out flaws in my logic, perceptions, or math.