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Discussion Starter · #1 ·
I need a little help. I'm wanting to build a hushbox for my LCD projector, but am not too mechanically inclined. I've done a bit of research and have seen what others have done.


My main question has to do with the ventilation. How does it work? Do I need an exhaust port? Or just some fans inside the hushbox with a couple of vents around the box?


I'm aware of the Whisperflow and have considered it. But I'm not too crazy about the look of the plexiglass and would rather build one out of wood.


Any help would be appreciated.


Thanks,

Anthony

 

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I built a real cheapo version of a hush box, and it cut the noise by 50%. I'm striving for almost a 90% reduction, but not done yet.


What I did was put a fan on the back of my box to push air into the box, and my D-ILA unit exhaust fans are hooked up directly to two dryer type vent exhausts (the aluminum tubes). The exhausts are routed right up into the attic.


Interestingly enough, I haven't had to switch on the fan to push air into the box, the inside of the box is actually pretty cool.


But the fan is there anyway and will remain should I need it. I need to take temperature readings to see what my average temp is.


-Brian
 

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Discussion Starter · #3 ·
This may sound like a dumb question, but wouldn't heat from the attic be a problem?


The reason I ask, is that I've thought of doing that. But being from Texas...
 

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Epson 6050UB projector, Denon 6300, 7.1.4 setup, M&K THX speakers and SVS subwoofer
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bwiklem: greetings from another person from Orange County. I'm about to undertake such a project and am curious how you deal with the issue of dust in the attic not coming down the dryer hose you have in the attic?
 

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I'm no expert, but you'd probably need microfilters in your hushbox designs.


Dan


------------------

STOP DFAST and The MPAA!!
 

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With regard to the microfilters - I'd visit the

local hardware store and see what they have in

stock.


Many air purifier machines use HEPA [ High Efficiency

Particulate - Air ] filters. The hardware stores stock

replacement filters for these machines. I'd select one,

and then build the hushbox to accomodate that filter.


Greg

 

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Discussion Starter · #8 ·
So other than the filter issue, do I simply need an intake fan on one side of the box and an exhaust fan on the other?


If so, which type of fan would work best? Obviously a very quite fan with ample output. Any particular model?


Thanks,

Anthony
 

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Anthony:


I have been where you are now. I wanted a hushbox for my DILA that worked, but was also asthetically pleasing. See the description on my website at www.woodht.homestead.com.


I tried a variety of configurations. One of the design concepts that I feel significantly reduced the noise was to locate any fans as far from the unit as possible. Any fan placed at the hushbox will (by definition) be not only close to the seating area, but will transmit the sound of the projector's fans through its own opening. By locating my fan remotely, I was able to fully seal the hushbox around the projector. The reduction in noise was dramatic.


I have not had any hushbox/heat related problems since I installed it 9 months ago, but I realize that it will take a different design for each particular installation setup.


Good luck on yours!


------------------

Perry
www.woodht.homestead.com
 

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WW - a suspended ceiling is ideal for a hushbox; it appears that yours was basically OK just by being open on the top (into the plenum area) and also much larger than the projector. If we need a smaller, closed box, maybe the best config would be to use two fans located at the remote ends of ducts (assuming there is room over the box) - one fan blows cool air in, the other pulls out. They could even be put into another room, outside wall, etc.

BTW, what does that "Sears switch" do - is it a temp controlled switch or current activated?
 

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Discussion Starter · #11 ·
So it would be okay to have the box completely sealed off from the HT room as long as there is ample ventilation and exhaust inside the box? And I can do this with some ducting to/from another nearby room? I guess it's not as complicated as I first thought. Or is it?


Thanks,

Anthony


P.S.

Woodworker, nice job on the theater and website.
 

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bbordner:


The Sears switch is indeed a current activated switch that turns on the ventilation fan when the projector is on. That way the ventilation fan is not always on and I don't have to remember to turn it on when the projector comes on. The switch was only $20 and has a second "switched" outlet that can be used for a second fan or powered screen or lighting, etc.


Anthony:


Thanks for the compliment. Hope the info helps.

It really isn't that complicated at all. Again, I feel a completely sealed hushbox is the key to reducing projector noise. Ducting should work, if done right.




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Perry
www.woodht.homestead.com
 

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I always wondered if a quick fix Hushbox out of styofoam type packing material could be done. I don't really want a permament hush box, but the fan noise generated from my Proxima is more high pitched than anything.


I was thinking something like a cooler chest made out of Stryo or Plastic lined with styro. Since these tend to be great for isolating heat and cold, they should do quite well with deadening, or minimizing sound as well.


Of course, when people see a Coleman strapped to the top of the ceiling, they may think I've gone completely mental.


Next to Woodworker's excellent Hushbox, this would be an absolutely appalling solution, but Last time I checked, hacking apart a stryo ice chest was extremely cheap, and easy. Now the question is mounting a fan for exhaust into the sucker... perhaps a PC high output fan that is relatively quiet, or if it deadens the sound from the front, that would be ideal for my solution.


My FP is not sitting directly above the seats, but about 2 feet behind the seats, (check out www.klutzoplex.f2s.com to see my setup) so a large airhole at the back may suffice in killing the sound coming to the front where the audience is.


Then again, I could be mental... again. =>


------------------
Klutzo,

the newbie HT Boy.

BA mains, Energy surrounds and sub.

Proxima DX3 main FP

Sharpvision Backup FP

Sony Wega aux monitor

Dalite 2.8 Gain screen

Sega Dreamcast (various controllers)

www.klutzoplex.f2s.com


[This message has been edited by klutzo (edited 06-01-2001).]
 

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Paid a visit to my local London Drugs (Western Canada mini walmart type retailer) and checked out the styro chests. I think they will do the job nicely for a really quick fix, or a cheapie beer budget solution. There are quite a few different sizes, but most seem quite deep. I have to look out for a more shallow one.


So those of us with relatively small FP's (Asks, Proximas, Infocus etc.) this may be a quick and dirty solution for the higher pitched whine.




------------------
Klutzo,

the newbie HT Boy.

BA mains, Energy surrounds and sub.

Proxima DX3 main FP

Sharpvision Backup FP

Sony Wega aux monitor

Dalite 2.8 Gain screen

Sega Dreamcast (various controllers)

www.klutzoplex.f2s.com
 

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Anthony:


I've used 3/4" MDF for many projects and it is a great material. It machines well, and finishes beautifully if the finish is paint, of course, not stain.


My only reservation might be the weight. This stuff is HEAVY.


Good luck.


------------------

Perry
www.woodht.homestead.com
 

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hey Klutzo,


Even though straight styfoam might do the trick for you, you might get better performance by adding weight to your impromptu hushbox. In other words, if you have heavy boards built around your styrofoam container, it will do wonders for bringing the sound down.


The science behind it is that the styrofoam will absorb the higher frequencies and the weight of the boards will prevent the chest from vibrating. Most recording studios are built on these principals.


BTW London Drugs is more like a pharmacy store (CVS, Duane Reade...) on steroids. http://www.avsforum.com/ubb/wink.gif
 

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Piece of advice from someone who literally boiled his processors through failing cooling equipment: make sure you have a failsafe of some kind! That is if the fan fails the projector should shut down or turn off. Else you're so going to hate yourself the day your PJ breaks due to overheat and the exaust fan didn't work.


------------------

/frode
 

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Discussion Starter · #18 ·
I'm planning on using 3/4" MDF for my hushbox. I'm thinking this would be better than plywood for sound isolation. Is there any other material that would be better at a reasonable cost?


Anthony
 

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Of course the main concern IS for making sure proper ventilation is enabled.


I did a quick impromptu test with a just bought 1 inch thick stryo ice chest. It does indeed cut down alot of noise, but I haven't yet cut the holes into the chest that I want to. I have a feeling that it will cut down much of the noise, but not to silence it completely.


- I'd say that right now 100% noise

- with the styro chest full on the projector 20% noise

- with the holes cut in? probably about 50%


Woodworker,


what type of plastic/glass did you use on the front of your hushbox?


Bluedevils,


I used to work at Londond Drugs, so I consider it a mini walmart (just not as huge!) Where else can you buy car stuff, computers, high end AV equipment, and of course Toothpaste and drugs? =>




------------------
Klutzo,

the newbie HT Boy.

BA mains, Energy surrounds and sub.

Proxima DX3 main FP

Sharpvision Backup FP

Sony Wega aux monitor

Dalite 2.8 Gain screen

Sega Dreamcast (various controllers)

www.klutzoplex.f2s.com
 

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Klutzo:


I used a high quality glass from a local glass supplier here in Tulsa. My 5" square piece cost less than 5 bucks. Sorry I don't have a manufacturer name or URL. I don't notice any distortion and I'm pretty picky about video quality.


There's an ongoing thread about glass from Edmund Scientific. You might check it out. I've heard good things.


------------------

Perry
www.woodht.homestead.com
 
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