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

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.

There is nothing complicated about a 92 db speaker possibly falling within perfect range of a basic surround receiver not needing to be adjusted, as he stated a few speakers were dead on without moving channel levels. 92 db happened to make this occur, if they were 88 db, it would guarantee with that speaker the levels would be moved up a bit, and with 96 db speakers probably would have been well over the 75 db benchmark making those levels back off into the negatives on the channel gain levels to match the master volume, thats all I was saying... And I was simply giving a little explanation to his final question SEE above not about the 92 db question, cause yes they will work fine 92 or 102 just trying to build example's to follow, but maybe not the best explanation... first post
" what exactly does the efficiency rating mean?>??"

I see where you are confused, and so am I... I kinda combined the Effectiveness of it Vs. what could happen via difference's in Db ratings, which was part 2 of the first question.. So I did over do it and should have been a little more clear on the basic question and ended up answering as one reasoning behind the theory. Sorry, sometimes I write half and come back while at work on the computer then submit the post, thoughts float around and not always land in the right spot.