cool, thanks tonygeno-
I agree that very few subs can hit that level, but we all want one don't we???

My sub can hit 115 db@20 Hz, but only one metre away. My listening/viewing position is 4 metres away from the sub, so it's 12 dB down from that, or around 103 dB.

If I'm not mistaken, it will hit 132 dB at 32 Hz at one metre, though.

Of course, these figures are with corner reinforcement -- that tends to pick the response up below around 30 to 40 Hz. Anechoic response is nowhere near as impressive. And these figures are achieve close to Dmax -- needless to say, I don't make a point of driving it that hard.

When I try auto-calibrating my new 990 for 7.1 set up, I get a msg. saying that since my rear speakers are large and fronts are small, I should switch the speakers and try again

So I tried manual calibration using my Avia disc, which gave poor results. Then I tried again using the 990 test tones which resulted in level differences of -4 to -5dB for the rears and backs.

Why are the levels so different? My guess is that when I calibrated using the Avia disc, I had the 990 in the wrong mode. What mode should the 990 be in for external source calibration?

Better yet, should I expect that the levels using the 990 internal calibration test tone will ever yield the same results as using an external (DVD produced) tone?

I've encountered the same front-rear speaker difficulties with auto calibration, but I assumed it was because I had the powered woofers on my front towers ( Polk RT2000s ) set too low to compete at the louder than comfortable volume levels of calibration. I found that if I crank up the woofer volume, auto calibration works fine.

reference levels are just that, a "reference", that doesnt necessarily mean that they will be what you prefer.

the experience is about getting what you want to out of it. be it thx reference levels or just the sound that you like the best.