It is not THX who set the reference sound levels, it was the Society of Motion Picture and Television Engineers - SMPTE - and it is embodied in their standards and the equivalent ISO standard. THX just extended it to home theaters. However, there is a significant perceptual difference between a 500 (or more) seat cinema and a small home theater, where those sound levels are often considered to be uncomfortably high, especially with the recent addition of "loudness wars" in which sound tracks are compressed to take advantage of the additional useable dynamic range that digital offers. It is not a technical issue, it is often the judgment of the director who from the back of the mix room shouts "louder" "louder". . There are cinemas that compete to be the loudest in the neighborhood. A current problem is that cinema audiences are complaining, walking out, which has caused the movie industry to revisit the situation. Cinemas sensitive to business, have been known to reduce playback sound levels by as much as 10 dB!. An additional problem is blown drivers in cinemas not designed for sustained high sound levels. Of course, film mix engineers are exposed to imprudent sound levels for hours at a time - hearing loss is an occupational hazard. There is work to be done.Let's see if we can get @avkv or @Floyd Toole to help us with the questions in the posts above (#13034 and #13038 ).
I'm also curious about max power handling of tweeters and SPL capabilities of Revel speakers.
2) Since company rated sensitivity of F206s is 88 dB SPL/w(2.83V)/m, if F206s can handle 200W(40V) continuous input with no compression, F206s can produce 111 dB SPL at 1 meter = 105 dB SPL at 2 meter in anechoic chamber.
The THX reference level is 105 dB SPL for peaks. I can't imagine listening to music (like a CD with very little dynamic range) at 105 dB SPL for any amount of time.
Transient peaks hitting 105 dB SPL hurt my ears if they have much frequency content above 2 kHz or so. Dr. Toole has discussed hearing damage here, please be careful to protect your hearing listening at high volume!
Rating the power handling capability of loudspeaker systems is an almost impossible task. The real situation depends totally on the spectral and dynamic content of the program being played. Any test resulting in a number is almost certainly based on a steady-state signal attempting to replicate the "average" program listened to by an unknown population. Then, any number generated by conscientious engineers has a chance of being enlarged by an eager marketing dept.