CurtPalme.com Home Theater Forum

Ironman1965 · Joined: 28 Jun 2007 Posts: 98

Been tossing around hush box ideas. I have an XG135. Noisy as all hell. Here's my thoughts. It would seem to me, to get the most efficient silencing would be to completely contain and dampen the offending noise. What I'm considering is a completely sealed system, using sound dampening foam on the front side cut to fit snugly around the lenses and having a secondary duct network to provide cool air into the box. I suspect I'd have to remove the front cover from the PJ to provide enough lens to seal to. Anybody think there would be any issues with this idea?

dturco · Posted: Fri Mar 12, 2010 5:14 pm Post subject:

Yes. Are you exhausting the air? I think your suggesting that with duct system, but...

Tim in Phoenix · Joined: 21 Oct 2006 Posts: 4409 Location: Phoenix

Hello

You might start with identifying all the fans in the projector, add up all the cfm they provide, and that would be the minimum cfm that your ducts would have to provide to avoid baking the machine.

Ironman1965 · Joined: 28 Jun 2007 Posts: 98

Yeah, I plan on following the SOP for hush boxes. The only difference will be that the front around the lenses will be sealed with foam and a secondary duct for cool air in, will be added. The exhaust fan will still be used. I have a fan that I got from a friend of mine, who is a cop. The fan came from a busted grow op. and it is very quiet and will suck the warts off a toad at full speed. I'll probably couple this with a temp sensor system that will adjust the fan speed to keep the box at a fairly regulated temperature, or at least use a dimmer switch to adjust the speed. Will probably add some kind of furnace filter or something to keep the dust out as well. Will I need to direct the air flow inside the box to move it to certain areas of the PJ, or will the volume of air moved into and out of the box be enough? Also would it be good to use the sound dampening foam through the whole box, or would the fiberglass tiles be recommended?

garyfritz · Joined: 08 Apr 2006 Posts: 12088 Location: Fort Collins, CO

Make sure to use sufficiently large ducting for the airflow you're planning. Small ductwork adds airflow resistance and turbulence noise.

greg_mitch · Joined: 03 May 2006 Posts: 5320

Have had the hushbox on my for it seems like 6 months and never got around to installing the cheap fan solution. Have watched probably 40 movies. No issues.

Am I pushing my luck? I doubt it. My box isn't air tight and has enough space around the unit to not suffocate the original fans. If I cut out a few hundred hours of life, it really doesn't bother me at this point. Have watched for over 3 hours straight and notice no difference in picture quality.

Just one persons opinion.

Ile · Posted: Fri Mar 12, 2010 7:31 pm Post subject:

Your idea sounds quite similar that my hushbox. Completely sealed from "theater room" and lenses are sealed with foamed plastic. No ducts was needed in my system, I used hollow wall as duct for cooling air. Hot air is going through wall via cardboard funnel.

Very quiet and cooling is good because system takes cool air from floor level.

Heres more photos and info.
http://www.curtpalme.com/forum/viewtopic.php?p=121244#121244

Ironman1965 · Joined: 28 Jun 2007 Posts: 98

Can't remember for sure but the fan I have uses either 6 or 8 inch ducting. There should be no problems with air flow. So nobody thinks I need to direct the air flow inside the box (ie. to the area's where the stock fans are located)? The volume alone should be sufficient?

dturco · Posted: Fri Mar 12, 2010 9:56 pm Post subject:

Yes, the volume alone should be sufficent. In fact I think Mike Parker showed that directly blowing air on to the heatsinks caused some distortions in the waves on a scope, so it could be detremental to P/Q doing so.

Airflow is good, but direct blowing of air, is maybe not good.

garyfritz · Joined: 08 Apr 2006 Posts: 12088 Location: Fort Collins, CO

Yes, as long as the air around the PJ (inside the hushbox) doesn't get hot, the PJ's own fans will take care of the rest. 6" ducting should be plenty.

WanMan · Joined: 19 Mar 2006 Posts: 10270

Anyone thought of chill water and radiator to capture heat and take it out? That way the box can be sealed. Moisture shouldn't be a problem as a seal box will not allow moisture in beyond the initial amount.

zaphod · Joined: 16 Jun 2006 Posts: 2002 Location: Cloverdale

and a pump for the rad, and a hush box for the pump ....

AFryia · Posted: Fri Mar 12, 2010 11:54 pm Post subject:

IMO and experience you don't have to completely seal to get great noise reduction.

You want the primary seating position to benefit the most. So you can vent and exhaust to the room and get very good results. With my simple box I've measure 24-25 db at the primary seating position.

No matter the design you want to insure a healthy air exchange rate.

WanMan · Joined: 19 Mar 2006 Posts: 10270

zaphod · Joined: 16 Jun 2006 Posts: 2002 Location: Cloverdale

too bad your brain doesn't see the humour. yeah i know damn well the pump would be outside the room.

Mark_A_W · Posted: Sat Mar 13, 2010 10:16 pm Post subject:

Here is my fibreglass hushbox.

Flash shows you the details, but also brings out the paint touch-up which is not visible to the naked eye.

bbfarmht · Posted: Sat Mar 13, 2010 10:40 pm Post subject:

Jester · Joined: 27 Jan 2008 Posts: 90 Location: Villa Park Ilinois

OFF TOPIC, I find that if you shine the harsh lite of day/camera flash on my theater it looks like crap, keep the lights low and its magic! seems I am not the only one. Smile

Mark_A_W · Posted: Sat Mar 13, 2010 11:54 pm Post subject:

It's the matt paint, it marks easily.

And bbfarm, I don't remember the 70's.