Originally Posted by dschulz
And no one listens to movies in a home theater at the decibel levels that are common in a movie theatre.
Where did you get that idea?
If you turn it down you loose the physical impact and sense of powerful sound.
Movies with a good soundtrack sounds best at reference, they were made to be played at that sound level.
And this experience is not limited to a few enthusiasts with mega-systems in large, dedicated rooms.
When I have casual visitors in my demo room, they appreciate the overall quality of the sound and the powerful impact of full frequency range bass - at reference level.
Small room, small system, normal people - not meaning to offend us enthusiasts, but I think you get the difference - they like it, and when asked if this is like in the cinema, no - not at all!
You can experience this for yourself, if I pick you up at the airport it is a 15 minute drive to get to my demo room. You are welcome.
Thing is, in a small room with a decent, properly calibrated system, the quality of the sound is much better than any cinema can provide.
Proper calibration is important - decent frequency response, and levels must be adjusted to account for early reflections. If you use pink noise only to calibrate level in a small room you will usually end up with a too loud calibration.
I think there are a lot of misunderstandings among film production professionals regarding acoustics.
There is no physical law that states sound in a small room is louder than in a larger space.
A given spl is the same, regardless of size of space.
The difference lies in the resulting soundfield, which is determined by room acoustics and speaker radiation patterns.
A small room is prone to have stronger early reflections, and this will make it sound louder, but that can be fixed.
A large room has true diffuse reverberation, and this is more difficult to achieve in a small room, but that does not really contribute to loudness.
Measurements from cinemas and dub stages shows that the direct sound dominates at mid to higher frequencies, just like it will in a small room with proper acoustics and decent speakers with controlled directivity.
The recent SMPTE report (TC-25CSS B-Chain Frequency and Temporal Response Analysis of Theatres and Dubbing Stages) provides a lot of information on quality of sound reproduction systems in cinemas and dub stages. The report shows that the calibration standards are being followed at least to some degree, but since the main problem is the standard itself, the sound is also all over the place, with huge variations between venues. I also recommend reading O Toole's recently published AES paper (The Measurement and Calibration of Sound Reproducing Systems FLOYD E. TOOLE - free access to this paper), where he explains the fallacy of the x-curve and its implications.