Quote:
Originally Posted by Pascal Sijen  -20dBfs = 85dBc or 0dBFS = 105dBc. This is PER CHANNEL, at the reference listening position. Not to mention that the LFE channel has an extra 10dB of headroom above the 5 main channels...
... it all adds up!
Cheers! |
Or from digital to the analog world -20dBFS = 0VU = +4 dBu = 85 dB SPL (79 small room) + the rest of what you said <g>. Since we have stereo subs and a sub/sat system, we send L and LS to the left sub, R and RS to the right one, C to both and LFE to both, and we cal with a spectrum analyzer as well as the venerable RS analog SPL meter. Our first experiments in calibrating the room in 1997/1998 involved consultation with Jim Hilson of Dolby and he was a great help in coming up with a reliable methodology for calibrating (it should be noted I designed the system before small studio bass management systems were commercially available, so we were really dealing with systems integration combining products from various manufacturers...life is much easier now!).
Oh yeah, we use bandwidth limited pink (and no, I won't go round and round with those who would disagree with me! For sub/sat, it simply is the most appropriate). There's a footnote in Bob Katz's first mastering book citing my measurements of various versions of pink noise and it's been so long ago, that frankly I've forgotten the results, although I do remember I used Spectrafoo to measure Dolby's, Holman's, and as I recall Digidesign's version (yuck ptoooey).
Back to my lair...I hope I don't regret breaking out of lurk mode!