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Discussion Starter · #1 ·
I recently had my Davis DL450 modified by Thumper. After watching movies for two days I wanted to let other DL450 owners know how happy I was with the whole process and more importantly the result.


After reading about Mike's success having his Davis 650 Thumperized, I contacted the man himself and inquired about having mods performed for my projector. Thumper was really great to deal with from the start, and seemed genuinely interested in helping me get the best out of my projector so I sent it off to him. Even before these mods I was quite happy with my Davis, but like all projectors that mere mortals can afford it has its flaws.


As those of you who have DL450s know, it is a great projector but it does have visible halos and the color saturation could definitely use some help. Also, I have noticed a problem with "hot whites" in certain movies, and although the black level is already good: you can never be too rich, too thin, or your black level too black. :)


The mods basically consisted of the following:

(Thumper please add or clarify anything I leave out)


Black out the clear section of the color wheel


Reduce the halo with masks around the DMD


Black out the DMD chamber to reduce internal reflections


Fine tune the internal optics


Thorough cleaning and dust removal in the light path


Thumper kept in constant contact with me while he was working on the projector, and I had it back just four days after he received it.


So how did it look?


In a word: outstanding! The first thing I noticed is that the color saturation is greatly improved. Even colors on the windows desktop leapt off the screen. Blues and reds seem particularly improved. Things were looking good: the improvement in color saturation was immediately obvious.


After a quick re-calabration with Avia I put in some favorite "torture test" movies.


I noticed the black level is noticably deeper and the "hot whites" problem is non-existent now. My best torture disk for hot whites and black level is "Pitch Black." Half the movie is shot in blinding sunlight and the other half is in ...well...Pitch Black. Before the mods the daylight part of this movie was incredibly washed out (I know, that is partly the director's intent) and had a quite noticable "hot whites" problem. Now it looks fantastic! Still very bright, but not washed out at all. I had hoped this would happen, but I was so happy to see the clear section was the source of this problem. Also the black level is visibly lower now, and it seems like I can see much more shadow detail.


My favorite test disk for color saturation is Austin Powers. The opening scenes in 1967 London have the most vibrant colors I have ever seen in a live action film. This movie looked good on the pre-Thumperized DL450, but it never captured the rich, deep colors I noticed on my 16x9 RCA direct view set. The improvement was evident right away, and Austin Powers now had the kind of deep saturation I thought was impossible on DLP. I knew the clear section was really desaturating my colors, but even now I am amazed at what a big improvement was achieved from blacking out the color wheel. To be fair, the DL450 still doesn't have the saturation of my direct view set(not surprising with 1-chip DLP), but now it is in the same ball park and I am extremely happy with this aspect of the projector's performance.


Thumper measured a 60% increase in contrast, and I will have to take his word for it. When I tried to measure the contrast with my Sper Scientific model#840020 lightmeter, I found the black level was below the sensitivity of the unit. This was definitely not the case BEFORE thumperization. So I can not tell you exactly how good the black level is, but it is now damn good!


Well, I could go on and on about the how happy I am with my Thumperized DL450, but I will stop here and gladly answer any questions fellow Davis projector owners have about the mods.


Let me finish by adding that Thumper is a great guy, and really a pleasure to interact with. He was very professional in all our dealings and kept in constant e-mail contact while working on my projector. Anyone who wants to squeeze the last bit of performance out of the DL450 should definitely consider getting these mods.
 

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How does one get a hold of Thumper for this mod? How much did it cost? Would you say your PJ is noticeably brighter or dimmer after the mod? Does Thumper offer software upgrades for the Davis 450 clones? Thanks in advance!


[This message has been edited by cutman0122 (edited 08-18-2001).]
 

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Discussion Starter · #3 ·
Quote:
Originally posted by cutman0122:

How does one get a hold of Thumper for this mod? How much did it cost? Would you say your PJ is noticeably brighter or dimmer after the mod?

B]

I just e-mailed him from the address that is in his profile here. Do a search for any post from Thumper and you can get his address from the profile.


*** here is Thumper's e-mail: [email protected] ***


I would rather not talk about price. You should contact Thumper about that directly because what he chooses to charge any one person could depend on a lot of factors that I do not know about it.


The apparent brightness seems about the same, but there clearly IS less light coming out of the PJ. That is an unavoidable consequence of blacking out the clear section of the color wheel. I think some of this light loss was recovered by Thumper from fine tuning and realignment of the optical elements in the light path, but there is simply no way to black out the clear section of the color wheel and not reduce the light output. However, in my opinion this is "Powerpoint light" and only hinders video reproduction and subjectively the image seems as bright as it used to be, but it has a lot more punch because of the improved color saturation, contrast, and lower black level.


[This message has been edited by Jim Tittle (edited 08-18-2001).]


[This message has been edited by Jim Tittle (edited 08-18-2001).]
 

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I note these "Thumper mods to a Davis" posts with great interest as when the Plus's where being modded I communicated with Thumper about what may or not be possible with a DL450 as that is what I am currently enjoying...


At the time Thumper was actually looking for a brave soul to be a test pilot as he was sure he could get a improvement but wanted to try one.. What stopped me going forward was not the fear of damage (Thumper promised any problems he would take care of and repair) but that my PJ is a daily usage TV and as we all know the DL450's are not over bright to say the least... He was pretty sure that calibration and adjustments would drop light output by a significant amount so its great to hear that this has not been too much of an issue...


In Fact us Davis owners are getting a bit of a shot in the arm this week as we have the possibility of Gamma adjustments as well...


Glad to hear that we are getting even more out of these bargain machines and its still amazing to find them at such cheap prices .


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

[email protected]
HTPC without using windows... GUI Front Ends for Home Theater
 

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Discussion Starter · #5 ·
Quote:
Originally posted by Tim Smith:
How about the halo corrections? Did the mask around the dmd work?


Any idea what material was placed on the color wheel? Will it last forever? If you don't like the lumen drop can you take it off?
Tim,


the DMD masking was quite effective. The rop and bottom halo are now completely invisible to me. These are by far the most important parts of the halo for me, because the vertical compression of my panamorph will bring the top and bottom parts of the image onto the area of the projection screen and visible halo would have been a real problem. The left and right halo are slightly visible, but you have to look hard to see them and they are much dimmer than they used to be. When watching a movie I simply do not notice any halo whatsoever now.


Regarding the blackout material: I do not know a lot about exactly what Thumper used, hopefully he will post here with the details. What I remember from previous posts about these mods is that the blackout substance he uses is very heat resistant and has been in use for quite a while on many plus and infocus projectors owned by our fellow AVS forum members. Also I believe Thumper has said that the mod on the color wheel is completely reversable, but once you see the color saturation improvement I can not believe anyone would want to undo it. I do not know how much light has been lost from the mod, but the projector LOOKS basically as bright as it previously did and I have absolutely no regrets about the lost light. Another important point is that I found I could set the Contrast (white level) higher after the mod because the "hot whites" problem is no longer an issue.


As I said above regarding price: please just e-mail Thumper (his address is in my first post). The price he charges includes such things as return shipping which varies for each customer, and I just am not going to talk about pricing in this thread. Thumper is a nice guy and I'm sure after hearing what kind of improvements you are looking to get he will quote you the exact price he will charge for his mods.

 

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How about the halo corrections? Did the mask around the dmd work?


Can you give us a general price range?


Any idea what material was placed on the color wheel? Will it last forever? If you don't like the lumen drop can you take it off?


Thanks,

Tim
 

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Jim, thanks for all the info. I think I might look into this. I might also look into seeing if he can quiet down the wheel. My dl450 does not have the rubber grommets to isolate the chassis from the wheel.
 

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Discussion Starter · #8 ·
Quote:
Originally posted by Phat Phreddy:
This is as easy as changing the bulb..
I put in my new Philips 6000 hour bulb right after getting my DL450 back from thumper. This was the first time I had opened up the case, and I was amazed how easy it was to change the bulb. It was about as difficult as changing a light bulb in your house, except for the fear of dropping the light and being out $400 http://www.avsforum.com/ubb/smile.gif


One thing you can tell when opening the case is that the optical path is not protected from dust at all. Fortunately I have sealed off my Whisperflow hushbox now, and all air coming in to cool the projector must pass through a filter.


I'm still enjoying the improved contrast and saturation quite a lot, and I am even finding the image quite watchable with some ambient light in the room. I always shut out all the light for movie viewing, but when I am using the projector for web surfing (like now) I leave the windows uncovered and I have a very readable and satisfactory image even with daylight streaming into the room.

 

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Yes Tim this is easy as changing a light bulb. Just remember that when removing the upper chassis not to pull the ribbon cable loose from the mainboard. Your bulb will have hexagonal bolts (2) that attach to the top of the lamp assembly. Just unscrew these two and detach the power cord and replace with new assembly with its new power cord attached and tighten the two bolts and thats it( dont worry about the power cord as it will fit only one way). While you have the chassis open you might as well clean your unit. I installed my 6000 hr bulb into my DAVIS 650 clone and it took 5 minutes to install. I spent 10 minutes cleaning the unit. I then spent 45 minutes reinstalling the unit to its ceiling mount and centering the picture. The bulb assembly is the same for the DAVIS 450 and 650.
 

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