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Discussion Starter · #1 ·


I just wanted to write a quick note and let people know that I'm very pleased with the results from my Whisperflow Hush Box. The owner of Whisperflow (Dave Beatty) has been great to deal with and very interested in suggestions on how to improve the product. I sent away for some acoustic foam from another manufacturer that I used to line the inside of the Whisperflow and it is working wonderfully. I'm going to post more information about the acoustic foam and where to get it later. With some additional tweaks that Dave and I have discussed at length, we were able to get the sound of both the projector and Hushbox to be extremely quiet. About the same volume and characteristic of the soft "whoosh" sound that comes out of a heater/AC duct. Very quiet indeed!!


Whisperflow has a new website ( www.whisperflow.com ) and Dave has added an option to remove the rubber boot (for existing and new Whisperflow owners alike) and replace it with Optical Glass. I highly recommend the optical glass approach as it cuts down the sound level to almost unnoticeable levels. Dave has also redesigned the Whisperflow to increase air flow while also making the unit quieter.


If you are like me and need/needed a Hushbox, give Dave a call. It's great seeing small cottage industries like Whisperflow and Dilard cropping up to help out hard core enthusiasts like ourselves.




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Behold the power of cheese!
 

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Mark,


Did you, or have you heard of someone else trying, filter the air coming into the Whisperflow? I am aware of other custom enclosures including filtering . I use a K&N air filter to do that for my D-9015 but there is no attempt to quiet it down. Filtered air for the Whisperflow ought to improve sound levels and almost totally avoid dust if you use the optical glass. That capability would mean an immediate phone call to Dave by me. Do you have to use an IR repeater to communicate.


Vince


[This message has been edited by Vlubbers (edited 05-06-2001).]
 

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Discussion Starter · #3 ·
Hi Vince,


Filter screens are an excellent idea. It would be very easy to add external filter screens to the Whisperflow, but my enclosure did not have them. My G11 already has a filter screen in it, so an external screen doesn't buy that much except for some additional noise muffling. For your D-9015, you may wanna give Dave a call and see if he can add screens to the Whisperflow. I know Dave supports many different projector types besides JVC DILA's, so it would be worth a call.


Cheers,


Mark


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Vince, a K&N? That must give you at least an extra 30 horsepower http://www.avsforum.com/ubb/smile.gif


Dave Beatty is a great guy. I talked to him for about 30 minutes on the phone one day about my Whisperflow. He also explained to me how to modify my older Whisperflow to allow for more airflow. I love my Whisperflow and plan on purchasing some optical glass soon.


Mark, I'm interested in hearing about the acoustic foam, so please let us know when you have all the info.


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-Matt
 

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Does anyone know what make/model fans Whisperflow uses? Or some spec's on cubic feet of air per minute? I have a thread going on cooling requirements, but this topic may get more attention.

Thanks

Randy
 

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Hi Mark,

I share your positive experience with Dave Beatty. Very straight forward, co-operative, and good to his word. The product works well and I've posted a favorable review when I received mine about 9 months ago. I'm going to call Dave about the opitical glass...and discuss air filtering.

Can you give us any more information about the foam you've used to cut down the fan noise?

Good Viewing,

John G
 

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Yeah,


I've also had good experiences working with Dave as well.


I am also going to upgrade my baffle for more airflow, as per Dave's new design.


The optical glass is intriguing as well, but I'm not sure if it will work with my ISCO lens because the D-ILA lens and anamorphic external lens need to be as close together as possible to prevent image cropping on the corners.


-Dean.
 

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Dave sure seems to be a great guy and has emailed me a few times. He has yet to produce a picture of the hush box we discussed. Thats ok because it has given me tiome to engineer a few of my own.


As for fans. The shack has a nice 2.5 inch fan that cost about $15. 273-239. It is around 15 CFM and rated to 20dbs of noise. I picked up the big honker of 4.74" for $18. It was rated at 85 cfm wich might be true. However the noise leve was listed at 48dB. That is a bunch of bull I get 50dBs on my meter at 11 feet and 72 dBs at 1 foot. The Shack will nost likely let you take the thing out and play with tehm in the store. My advice... PLAY WITH EVERY FAN THERE!


I am on my second return.


[This message has been edited by Darian (edited 05-15-2001).]
 

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Discussion Starter · #10 ·
Sorry for taking so long to follow up on this. At any rate, I took some photos of the final product and also added some more info.


The bottom line is that my fans are now running at 4.5V vs 7.5V and with the addition of the acoustic foam it is very quiet.


Here are the details:

HOW TO: Acoustic foam for the Whisperflow


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Behold the power of cheese!



[This message has been edited by Mark Petersen (edited 05-17-2001).]
 

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Mark,


Thanks for the graphic illustrations. Did you have the Whisperflow built oversize in anticipation of the foam? Is it 'tight' in there? Is it an issue, I am not sure that it is. A fan blowing in would by-pass any supplemental air filtration via the normal intake. Say again why you choose not to put both fans on the exhaust side and pull air in the normal inlet. Thanks. Vince


[This message has been edited by Vlubbers (edited 05-17-2001).]
 

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Discussion Starter · #12 ·
Hi Vince,


The Whisperflow design is already quite large, so adding the foam doesn't create any problems. For example, the crucial gap above the air intake on the G11 is larger even w/ the foam than when the G11 is sitting on a flat surface in a typical floor mount. In other words even w/ the large 2" foam that I used on the top, the foam doesn't touch the feet of the projector (which are above the projector due to it being ceiling mounted.


I believe that the latest Whisperflows are 1" less deep than the one I have, but that is still more depth than what is really needed.


You are correct in that the reversed fan does allow intake air to bypass the normal intake baffle of the Whisperflow. There is no added filtration on the intake baffle however so it doesn't really affect filtration.


The basic idea of reversing the right fan (ie turning it into an intake instead of exhaust fan) is this: All of the heat leaving the projector is on the left side, so it makes sense to try to remove it as quickly as possible before it has a chance to intermingle with air going into the projector intake. Meanwhile, all the cool air flow should be on the right side top (by the G11 intake).


With the typical Whisperflow configuration (both fans used as exhaust), the right fan does little to move air over the G11. It basically grabs cool air from the right hand intake baffle and vents it directly out before it has a chance to cool the projector. By reversing this fan, a nice venturi effect is created which helps force the airflow in the right direction (from right to left). This helps the left fan vent the hot air, while also ensuring that fresh cool air blows directly onto the G11 air intake.


Overall, heat transfer is much improved which translates into running the fans at a lower voltage and therefore the fans themselves are quieter.


I should point out however that the fan locations on my Whisperflow are not typical. Most Whisperflows have both fans mounted on top. In that arrangement, I'm not sure how helpful reversing one fan would be. I would recommend using caution with any other fan arrangements.




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Mark,


I understand. Given that I have clearance above my projector, the default fan locations will probably work for me. I am keen to filter incoming air.


In your opinion, would putting 4 inch PVC elbows atop each top-mounted fan reduce noise by acting as mufflers of a sort? They could be aimed away from the seating position. TIA


Vince
 

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Mark,


I understand. Given that I have clearance above my projector, the default fan locations will probably work for me. I am keen to filter incoming air.


In your opinion, would putting 4 inch PVC elbows atop each top-mounted fan reduce noise by acting as mufflers of a sort? They could be aimed away from the seating position. TIA


Vince
 

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Discussion Starter · #15 ·
Hi Vince,


If you apply the acoustic foam, the dominant noise source (by far!) coming from your Whisperflow will be from the front rubber boot (assuming that your unit came w/ the boot). You can do a simple test to see how much quieter the unit is with the boot replaced with optical glass by placing an object (a dvd case works well) over the boot.


With the acoustic foam and optical glass, your unit will be so quiet that you won't want to hassle with the PVC.


Oh and should you decide to experiment w/ the fan arrangement and make one fan an intake, you'll find there are tons of filter screens available that will fit your fan and are a simple bolt-on arrangement. It's much easier to filter the air with this approach than try and jury rig something across the intake baffle.




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Calibrated G11, 7' 16x9 Greyhawk, Radeon HTPC, Lexicon MC-1+, B&W Nautilus 804's, HTM1, SCM1s
 

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Discussion Starter · #16 ·
Hey Dean,


I'm curious as to how you currently attach your Isco-II to your projector. Are you using the rubber boot on the Whisperflow? I've found that the rubber boot actually prevents the projector from being mounted close to the front of the hushbox. The difference isn't much, but if you have a vignetting problem, a little may be all you need. I have a Panamorph on order and I think that I can get the G11 lens closer to the lens using the optical glass than the stock rubber boot. The enclosure thickness is only 3/8", so that is the space between the projector lens and the Pan/Isco lens. How close are you currently able to get your lens?


Regards,

Mark



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Mark,


First off, I have the ISCO 1 lens, which is a bit smaller than the new ISCO II lens, which causes a bit more image distortion and shading on the edges (although it's not bad).


I have an external shelf and the rubber boot sealing the lens, but I shaved the bottom-outside of the boot so that the ISCO lens mount actually touches the front panel plastic.


The actual FPTV lens sets back about 3/8s of an inch, but that's due to the protective metal lens surround of the projector, which I don't think is removable.


Potentially, with optical glass I could put the whole ISCO lens and mount inside the enclosure, but it wouldn't get the ISCO any closer to the D-ILA's lens because currently the metal lens surround pokes through the hole in the fron panel, almost touching the ISCO mount.


If I added a layer of optical glass to the inside, it would add 3/8"+ the thickness of the glass to the distance from the D-ILA's lens and the ISCO lens.


If I wanted to try adding optical glass, I would have to move the lens inside to minimize the distance between lenses.


Vince,


I measured the bottom vent hole to be 4" X 17 7/8" wide with radiused corners.


-Dean.
 

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FWIW, just received my new face plate from Dave with the optical glass. Once installed I could not really tell the difference between the previous (boot model) and the new optical glass in terms of picture quality.


I put up one section of foam on the rear internal wall and plan to do the rest sometime today.


This does make a difference.


We opted not to do the new intake fan at this time.


We want to keep the box structure as is until the Panamorph arrives.


Anyhow, recommended if you are particular about sound.


hth


Chuck
 
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