speaker efficiencey?? Starting point...? 92db??

A speaker's efficiency rating is customarily the average midrange sound pressure level produced by a 1 watt input measured at 1 meter on the tweeter axis under anechoic conditions.

I say "customarily" because what's actually being measured and claimed varies somewhat from one manufacturer to another, but I figure you weren't looking for a long drawn-out answer. That 92 dB efficiency is considerably higher than average, assuming the numbers aren't somehow inflated.

The 92 dB efficiency rating of your speakers has no bearing in the setting of your channel levels - just follow the Yamaha manual as you have done.

Duke

Well average efficiency I would say is somewhere in the 88db to 92-93db,, anything above is just gravy and starts to get into the super speaker range. But with your receiver showing you that you did not have to change anything on a couple channels tells you that from your average listening position those distances just happen to already fall in range of the 75db mark which is fine(as long as you set up your Db meter at ear level of the center seating position in the room)it should be pretty even and flat thru the room. Some might take more some less. But the 92 db absolutly has something to do with your channel levels, cause if they were 89 db vs. 92 db that means they would take 100 watts more of power to reach the same white noise level at 75 db that your 92db speakers do not take, so 89 db would have probably made you boost up the channels 2-3 db on your channel leveler during the test vs. not upping it at all on a few channels. Every 3 db more efficiency the speaker has more or less means the amplifier needs to produce about half the energy to retain the same sound pressure level.. in general from my tinkering and understanding.

Matrix wrote:

"But the 92 db absolutly has something to do with your channel levels, cause if they were 89 db vs. 92 db that means they would take 100 watts more of power to reach the same white noise level at 75 db that your 92db speakers do not take, so 89 db would have probably made you boost up the channels 2-3 db on your channel leveler during the test vs. not upping it at all on a few channels."

Matrix, I think you're making this more complicated than it has to be; I read that sentence several times and I'm still not sure exactly what it's saying. You are correct that an 89 dB speaker would require twice the power of a 92 dB speaker to reach a given sound pressure level, but at 75 dB measured at the listening position we'd be talking about tenths of a watt difference, not 100 watts difference.

All Dzigon has to do is set the levels according to the instructions. He doesn't have to take the speakers' efficiency into account - setting the levels according to the processor's instructions automatically does that and more.

Duke