[EchiDna]

Hey Scott, some room you got there! I was off spec on my whisper call - 20dB! not 40+dB - and yeah the whispers in the crowd are annoying, but it's the mobile phones ringing that make me angry and then people have the cheek to take a call! argh!



FYI, here is a table of the 'loudness' of common everyday things:
 
Threshold of Hearing (TOH) 0 dB
Rustling Leaves  10 dB
Whisper 20 dB
Normal Conversation 60 dB
Busy Street Traffic 70 dB
Vacuum Cleaner  80 dB
Large Orchestra 98 dB
Walkman at Maximum Level 100 dB
Front Rows of Rock Concert 110 dB
Threshold of Pain 130 dB
Military Jet Takeoff 140 dB
Instant Perforation of Eardrum 160 dB

There is also a bunch of info on homt theatre rooms running around online where it seems the common denominator is that specially built rooms require a specially built room in room for equipment...

and given your plans for a projector, I got bad news for you, they aint very quiet and they are much closer to the seating position than any PC is likely to be in such a room.... that means another super sound deadening box unfortunately  

[ScottMayo]

and given your plans for a projector, I got bad news for you, they aint very quiet and they are much closer to the seating position than any PC is likely to be in such a room

I know... luckily, for movie watching a little background noise is ok. For game development.... well, I'll probably only fire up the projector for detailed video work and demos... and some projectors claim to stay below 30db. With a ceiling mount and some OC703 I hope to pull off "good enough". For critical music listening (and tweaking the acoustics of a game), the projector can stay off. It's all been a series of compromises, the projector won't be any different.

Well, the speakers weren't compromises.

I did end up designing in an enclosure for the dimmer that runs the room lighting - and I'm glad I did, because dimmers buzz. If I were doing this again, I'd probably make the dimmer exterior to the room, even if it meant running more wires through the walls.