Hey,

I'm interested in making one of these projectors but how loud are they? I don't expect it to be whisper quiet (but I'll try making it as quiet as possible with silent fans and perhaps soundproof the box where possible) but at the same time I don't want to feel as if I have an open fridge in my room.
Will speakers at an appropriate volume drown out the noise?

Thanks
Morien

The PJ can be almost as quiet as you want them to be, just use a multi-silent fan design. That way it'll have sufficient cfm but yet stay quiet at the same time. I recommend using filters on all intake fans to keep the dust off the lenses.

Using my htpc's as a guage, i'd say your home audio equipment will completely drown out ambiant fan noise, especially if you're using fans rated at 35db or less (below 30 db would be icing on the cake imho).

Does the MH light setup cause any audible noise? Like a fluorescent light? Is the Eballest quieter?

Supposedly, some coil ballasts can have a hum, but it depends upon the type of ballast. E-ballasts should be dead silent as far as I know. Don't take my word for it because I've yet to own one. It's a bit rich for my blood at this point. Maybe a couple months from now I'll let you know.

The projector can be very quiet if designed right. I use interior AC mains crossflow fans in which the case baffles the noise and all you hear is the air coming from the exhaust. Electronic controlled ballasts are very quiet. Core coil ballasts do produce a hum similar to flourescent ballasts. I've heard the toroidial coils are quieter, but I've yet to have one. I strongly suggest becoming a customer so you'll have a wealth of information that's in the protected forums.