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4-Way Acoustically Transparent Masking - Page 19

post #541 of 835
Quote:
Originally Posted by GetGray View Post

Call them. Explain that this project prototype is expected to result in sales of 100's of controllers. Ask to be put into contact with engineering or the product manager. Or at least a tech support supervisor. See if they will give you the functional schematic or actual schematic of the control circuits. One of us can probably help.

You also might try going through solid signal too get help. Maybe they have a better contact at Aspen. After all solid signal has seen the spike in orders as they are on backorder now..

Good luck and this has been a very interesting thread. It might drive me into spending more money on a AE3000 projector and a newer WIDER audio transparent screen. Then dumping my NEC9pg CRT projector and the over priced 110" Stewart screen.
post #542 of 835
Scott, any update?

Teecue
post #543 of 835
Thread Starter 
I contacted the manufacturer again, but never did get too much help.

However, I do have some good news. I did finally get the unmodified rotator to work again. I still don't know exactly what caused this motor to get out of sync. I messed around with it for several hours and I'm not exactly sure what combination got it working again.

I pulled the hall sensor board off of the un-modified rotator motor by unsoldering the motor connections and then I attached this board to my original vertical masking motor. Everything on my vertical masking is working fine again!
SIDE NOTE:
With regards to the two rotators that I ruined, now I think that when I cut the control wires between the control board and the hall sensor board, I must have mis-wired something when I added the wire extension. I think I fried something on both of the hall sensor boards. In theory, it should not be a problem to extend the wires, and the various components should be interchangeable. In researching the problems that I had, I found out that the technology used for the Aspen Eagle rotator motor is a probably a technology called "DiSEqC" that is typically used in satellite dish positioning systems. The various parts (set-top positioner box, control board, and hall sensor board) are sometimes sold separately as replacement parts and therefore should be interchangeable. (see sadoun.com - middle of page).
At any rate, I believe I'm back on track. I've order another rotator that I will use to motorize my horizontal masking. I've already picked up a couple of pillow-block bearings and pulleys that I need to properly move my horizontal masking (i.e., I'm finally getting rid of the remnant PVC fittings in my original set up). As soon as the new rotator arrives, I will get it hooked up and then I'll post pictures of the finished product.

Hopefully I won't have any more set-backs. I'm afraid this detour that I took has made my motorization solution seem a lot more complicated than it really is.

- Scott
post #544 of 835
Awesome solution, guys! If there's ever step by step instructions (especially including the "what I would have done differently" part of it), this is AVS Hall of Fame worthy!

Scott, one question regarding the 4-way vs 2-way system. Am I correct in my reading that the only reason you had to do 2-way is due to the projector/lens/scaler combination you used, and that it changes the height slightly? Is there not a relatively simple solution (different scaler, etc) that would have negated the need for horizontal masking?
post #545 of 835
Quote:
Originally Posted by ScottJ0007 View Post


I pulled the hall sensor board off of the un-modified rotator motor by unsoldering the motor connections and then I attached this board to my original vertical masking motor. Everything on my vertical masking is working fine again.

- Scott

Congratulations Scott.

It just didnt make sense for the motors to act up the way they did if there was no component damage. Something, probably the sensor, was not working properly.

Looking forward to the FINAL video

Teecue
post #546 of 835
Thread Starter 
Quote:
Originally Posted by miltimj View Post

Awesome solution, guys! If there's ever step by step instructions (especially including the "what I would have done differently" part of it), this is AVS Hall of Fame worthy!?

Thanks. The project has been fun... and frustrating at times. Having this thread has kept me going. The input from everyone has made it a huge learning experience for me.

Quote:
Originally Posted by miltimj View Post

Scott, one question regarding the 4-way vs 2-way system. Am I correct in my reading that the only reason you had to do 2-way is due to the projector/lens/scaler combination you used, and that it changes the height slightly? Is there not a relatively simple solution (different scaler, etc) that would have negated the need for horizontal masking?

There are a number of reasons I went with 4-way rather than 2-way.

First, I actually built my screen and masking before I bought my projector. Even though I knew what projector I wanted to buy and had done all of the calculations on throw distances, I still wanted the fudge factor that the 4-way masking would provide.

Second, I want my theater to have some level of "future proofing". I know I will update my projector over time, and I want flexibility in case a new projector has different throw characteristics. I don't want to have to rebuild my screen wall for a new projector in the future.

Third... (this one will probably be a little controversial and most likely deserves its own thread. I have thought about starting a thread on this subject, but I'm a bit too busy right now)... After having my setup for over a year, I've come to the conclusion that for most of us a 100% "Constant Image Height" (CIH) set up is a pipe-dream. The reason is that it is not practical to scale, stretch, and/or zoom all aspect ratio formats to always fit a constant height. The easiest example for me to try to explain this is in the case of an aspect ratio of 2.40:1. (Bear with me here. If you don't like math and numbers, this will get boring). Let’s start with a 16:9 screen that is 51” tall and 90.7” wide. In native format with no scaling or stretch, a 2.40:1 movie will fill the width, but will only be 37” tall with black bars on the top and bottom (90.7 / 2.4 = 37). If you are using the horizontal stretch method to accomplish CIH, you must first vertically stretch the image using a scaler. Here is where the first problem arises. In order to fill the CIH of 51”, you must vertically stretch the image by 37.84% (37” X 1.3784 = 51”). For me, I am using a Panisonic AE-1000U projector to do the scaling. It only has one vertical stretch mode, which is fixed at 33.33%. This means that I cannot stretch a 2.40 movie to fit a CIH of 51”. My projector will only stretch it to 49.3”, therefore I STILL have black bars of about 1” at the top and bottom of my screen. Now, if you have a very expensive scaler or you run your movies through a Home Theater PC with the right software, you might be able to vertically stretch the image by a customizable ratio which would fill the image height of 51”, but that does not fully solve the problem. You still must horizontally stretch the image to fill a 2.37 screen (120.87” wide in this example). To do this, you must have an anamorphic lens. The problem is that almost ALL anamorphic lenses are FIXED to stretch the image by 33.33%. So even if you could vertically stretch the image by 37.84%, you would still have a slightly distorted image if you horizontally stretched it by only 33.33%. In my case with a fixed vertical stretch option, I could use a combination of an anamorphic lens with the “zoom method” to fill screen, but my projector doesn’t have zoom memory like the Panny AE-3000U. And even the Panny AE-3000U only has one zoom memory option and you would need several for all of the various possible ratios.

Another tricky situation for CIH is the 1.85:1 aspect ratio. On a native 16:9 screen (51” X 90.7”), the width would be filled, but the image would only be 49” tall (90.7 / 1.85 = 49"), leaving black bars on the top and bottom of the image. To technically have a correct CIH image, you would have to vertically stretch the image by 4.08% and then have an anamorphic lens that would horizontally stretch the image by 4.08%. To my knowledge, there are no such lenses available. You could of course use the zoom method, but some CIH purists don’t consider the zoom method to be an ideal option.

While the above examples can be overcome with a fair amount of customizing at the start of each movie, I’m not too interested in spending a lot of time and money on fancy scalers and having to try to mix both the zoom method and the anamorphic lens method in order to achieve true CIH. For me 4-way masking is a better solution which also meets my other needs mentioned above.
post #547 of 835
I considered doing CIH but decided against it when I discovered it would result in a smaller 16:9 size than desired. This was due to my room not being wide enough. So I decided to go with a constant image area (CIA) screen. The aspect ratio is 2.05:1. This configuration pretty much requires a 4-way system since part of the screen will always need to be masked.

The other reason I wanted a 4-way is for maximum flexibilty. I want to vary the screen size depending on the quality of the source. If I'm watching broadcast HD which is generally full of compression artifacts I can make the screen smaller so they will be less noticeable. My plan is to vary the screen size anywhere from 136" wide 2.35:1 down to 96" wide 1.78:1.

Steve
post #548 of 835
Thread Starter 
Quote:
Originally Posted by Steve Smith View Post

I considered doing CIH but decided against it when I discovered it would result in a smaller 16:9 size than desired. This was due to my room not being wide enough. So I decided to go with a constant image area (CIA) screen. The aspect ratio is 2.05:1. This configuration pretty much requires a 4-way system since part of the screen will always need to be masked.

The other reason I wanted a 4-way is for maximum flexibility. I want to vary the screen size depending on the quality of the source. If I'm watching broadcast HD which is generally full of compression artifacts I can make the screen smaller so they will be less noticeable. My plan is to vary the screen size anywhere from 136" wide 2.35:1 down to 96" wide 1.78:1.

Steve, I'm a huge fan of your line of reasoning... Go with the largest screen that you and your room can comfortably accommodate, regardless of the ratio, then mask to get all of the other aspect ratios. Especially for people who are new to front projection home theater, I find that they don't really know what size they will ultimately want. Therefore, go big. With 4-way masking you can always get smaller if you want, but you are stuck if you start with a screen that is too small. I think that having as much flexibility as possible is generally a very good way to go and will result it the greatest level of long-term satisfaction with your setup.
post #549 of 835
Scott I'm not sure if I've thanked you for the work you've put into this thread, so if I haven't THANK YOU.

I'm wondering if you wouldn't mind putting more picture of your screen wall as well as the masking. I'm thinking of building something similar to yours and have some questions about some of the building that I can't figure out from your current pictures. I'm interested in how your removable panels were made and covered. How you attach them to your framing. How you attached the false wall to your floor and ceiling (over rug or rug rolled back and cut, ceiling cut back or just attached to) and those kinds of things. From your pictures I'm pretty confident I can do the masking and screen part, but I still need more information about the rest of it before I can get started.

I'm planning to get an RS10 (hopefully cheap) in early 2010 and will build this wall around that time.
post #550 of 835
Quote:
Originally Posted by ScottJ0007 View Post

Thanks. The project has been fun... and frustrating at times. Having this thread has kept me going. The input from everyone has made it a huge learning experience for me.

There are a number of reasons I went with 4-way rather than 2-way.

First, I actually built my screen and masking before I bought my projector. Even though I knew what projector I wanted to buy and had done all of the calculations on throw distances, I still wanted the fudge factor that the 4-way masking would provide.

Second, I want my theater to have some level of "future proofing". I know I will update my projector over time, and I want flexibility in case a new projector has different throw characteristics. I don't want to have to rebuild my screen wall for a new projector in the future.

Third... (this one will probably be a little controversial and most likely deserves its own thread. I have thought about starting a thread on this subject, but I'm a bit too busy right now)... After having my setup for over a year, I've come to the conclusion that for most of us a 100% "Constant Image Height" (CIH) set up is a pipe-dream. The reason is that it is not practical to scale, stretch, and/or zoom all aspect ratio formats to always fit a constant height. The easiest example for me to try to explain this is in the case of an aspect ratio of 2.40:1. (Bear with me here. If you don't like math and numbers, this will get boring). Let's start with a 16:9 screen that is 51 tall and 90.7 wide. In native format with no scaling or stretch, a 2.40:1 movie will fill the width, but will only be 37 tall with black bars on the top and bottom (90.7 / 2.4 = 37). If you are using the horizontal stretch method to accomplish CIH, you must first vertically stretch the image using a scaler. Here is where the first problem arises. In order to fill the CIH of 51, you must vertically stretch the image by 37.84% (37 X 1.3784 = 51). For me, I am using a Panisonic AE-1000U projector to do the scaling. It only has one vertical stretch mode, which is fixed at 33.33%. This means that I cannot stretch a 2.40 movie to fit a CIH of 51. My projector will only stretch it to 49.3, therefore I STILL have black bars of about 1 at the top and bottom of my screen. Now, if you have a very expensive scaler or you run your movies through a Home Theater PC with the right software, you might be able to vertically stretch the image by a customizable ratio which would fill the image height of 51, but that does not fully solve the problem. You still must horizontally stretch the image to fill a 2.37 screen (120.87 wide in this example). To do this, you must have an anamorphic lens. The problem is that almost ALL anamorphic lenses are FIXED to stretch the image by 33.33%. So even if you could vertically stretch the image by 37.84%, you would still have a slightly distorted image if you horizontally stretched it by only 33.33%. In my case with a fixed vertical stretch option, I could use a combination of an anamorphic lens with the zoom method to fill screen, but my projector doesn't have zoom memory like the Panny AE-3000U. And even the Panny AE-3000U only has one zoom memory option and you would need several for all of the various possible ratios.

Another tricky situation for CIH is the 1.85:1 aspect ratio. On a native 16:9 screen (51 X 90.7), the width would be filled, but the image would only be 49 tall (90.7 / 1.85 = 49"), leaving black bars on the top and bottom of the image. To technically have a correct CIH image, you would have to vertically stretch the image by 4.08% and then have an anamorphic lens that would horizontally stretch the image by 4.08%. To my knowledge, there are no such lenses available. You could of course use the zoom method, but some CIH purists don't consider the zoom method to be an ideal option.

While the above examples can be overcome with a fair amount of customizing at the start of each movie, I'm not too interested in spending a lot of time and money on fancy scalers and having to try to mix both the zoom method and the anamorphic lens method in order to achieve true CIH. For me 4-way masking is a better solution which also meets my other needs mentioned above.

I know what you mean. Currently I just have the pj setup with about 1" of overscan on top and bottom. That takes care of the 1.85 and 2.4 issues and hides the pincushioning. I'll likely do the same thing in the future.
post #551 of 835
Hey Scott its been awhile. I was looking for some diy masking ideas and low and behold you have a new project. Thats quite an impressive system. It looks a little over my head though. I hope all is going well.
post #552 of 835
Thread Starter 
Quote:
Originally Posted by 68sting View Post

Hey Scott its been awhile. I was looking for some diy masking ideas and low and behold you have a new project. Thats quite an impressive system. It looks a little over my head though. I hope all is going well.

Good to hear from you again. I'm guessing I'll always have some sort of a project going on with my theater. I keep telling myself to stop tweaking, but I can't.

Quote:
Originally Posted by gobrigavitch View Post

I'm wondering if you wouldn't mind putting more picture of your screen wall as well as the masking. I'm thinking of building something similar to yours and have some questions about some of the building that I can't figure out from your current pictures. I'm interested in how your removable panels were made and covered. How you attach them to your framing. How you attached the false wall to your floor and ceiling (over rug or rug rolled back and cut, ceiling cut back or just attached to) and those kinds of things. From your pictures I'm pretty confident I can do the masking and screen part, but I still need more information about the rest of it before I can get started...

Below are a couple of pictures of the wall framing. The panels that go over the framing are simply made out of 1X2 pine and then I stretched GOM fabric over them. They are just screwed onto the wall framing. I built the wall when I was doing the whole theater, so the wall is attached directly to the floor and the ceiling. The carpet was installed afterward.





post #553 of 835
Thank you. That helps.

One more question. Are your panels removable? If they are screwed to your framing do you have to unscrew them to take them off? Is it just your side door style panels that open? I was under the impression that the bottom and top panels also came off easily going from the pictures you posted before. If they are screwed on, did you just run the screws through the GOM fabric? Did it leave holes?
post #554 of 835
Thread Starter 
Quote:
Originally Posted by gobrigavitch View Post

One more question. Are your panels removable? If they are screwed to your framing do you have to unscrew them to take them off? I was under the impression that the bottom and top panels also came off easily going from the pictures you posted before. If they are screwed on, did you just run the screws through the GOM fabric? Did it leave holes

The top and side panels are screwed in with two screws each. I just ran the screws through the GOM. The screws are black and are barely noticeable. The screws do make a small hole in the GOM, but it is not a problem. The panels come off pretty easily, but do have to be unscrewed.
The two bottom panels just sit in place (held there by gravity). They are super easy to remove.
Quote:


Is it just your side door style panels that open? ?

Yes, the two side doors open. They are both on cabinet hinges.
post #555 of 835
Thanks again. I think I'm going to make multiple small doors across the bottom like cabinets so I can use the space down there for storage. That makes sense to screw the top panels up as they aren't likely to need to be removed very often. I haven't decided if I should make them acoustically transparent or not though


I was wondering if you gave any thought to having 3 identical speakers across the front. Many people use an AT screen so they can do just that, but I noticed you used the more conventional horizontal center speaker. Was there any particular reason for that?
post #556 of 835
Thread Starter 
Quote:
Originally Posted by gobrigavitch View Post

I was wondering if you gave any thought to having 3 identical speakers across the front. Many people use an AT screen so they can do just that, but I noticed you used the more conventional horizontal center speaker. Was there any particular reason for that?

If I were buying new speakers, I would absolutely get three identical speakers. I bought the speakers I currently have before I completed my theater.

However, even with these speakers, the room still sounds amazingly good. I used Terry Montlick Labs to help me with the design of my acoustical treatment. The room is "alpha certified" and is featured as one of Terry's showcase projects on his web site.
post #557 of 835
Any updates Scott?
post #558 of 835
Thread Starter 
I ordered another rotator for my horizontal masking. It arrived this week. However, I won't be able to work on it for a couple of weeks due to my work schedule.
The rotators are getting hard to find. One web site I saw said that they have been discontinued by the manufacturer.
post #559 of 835
Quote:
Originally Posted by Jonathan Furst View Post

Thanks for the kind words, everyone!



The actuator will stop at any point along its stroke. It has a feedback potentiometer built in and I'm trying (begging) an electrical engineer friend of mine to help me use an IR relay board I bought to get it to stop at various positions. Right now, it goes up and down as long as you're holding the buttons on the remote down. I'll post the final design details in this thread once they're completed.

Jonathan,

Can you supply the make/model of the actuator you used? Also, any luck with getting the IR control finished?

Thanks,

Ben
post #560 of 835
There are obviously some smart people on this thread. I'm no electrical engineer (civil instead), but I found these two devices and keep thinking they could be made to work in a masking system if placed in the right hands:

http://www.pololu.com/catalog/product/425/resources

http://www.acroname.com/robotics/par...2Y0A710YK.html

Am I off base?

Ben
post #561 of 835
Quote:
Originally Posted by ScottJ0007 View Post

I ordered another rotator for my horizontal masking. It arrived this week. However, I won't be able to work on it for a couple of weeks due to my work schedule.
The rotators are getting hard to find. One web site I saw said that they have been discontinued by the manufacturer.


Why are you using a rotator? Only Hams use rotators. These are nothing but a DC gearmotor. You can find these on the internet all day long, even eBay.

DB
post #562 of 835
Quote:
Originally Posted by Ben Harper View Post

There are obviously some smart people on this thread. I'm no electrical engineer (civil instead), but I found these two devices and keep thinking they could be made to work in a masking system if placed in the right hands:

http://www.pololu.com/catalog/product/425/resources

http://www.acroname.com/robotics/par...2Y0A710YK.html

Am I off base?

Ben

Not off base at all Ben, at least with the Pololu motor driver. I do think you also need to add a microcontroller and some type of IR interface and a lot of programming. For the past few months I have been working with a Basic Stamp 2 and a Little Step-U stepper motor controller to drive the masking system. It's not easy for a non-programmer to do, I'm still stuck on the first 5 lines of code that reset the system and sends it "home"
post #563 of 835
Quote:
Originally Posted by Don Bond View Post

Why are you using a rotator?

If you read the whole thread you'd know the reason for selecting the specific rotator Scott did. It has IR function and the controller has the capacity to program and save 99 positions. Plus it was affordable, not $600 like a rotator for HAMS

Quote:
Originally Posted by Don Bond View Post

Only Hams use rotators.

In the words of Vincent Vega, "That's a bolt statement"...

Are you absolutely positive that Antenna Rotators are just for HAMS radio antennas ? With off-air digital tv the use of large UHF antennas has increase quite a bit , do you not think that maybe there are cheaper rotators for us non radio operators to use with our HDTV's ? Just a thought [/quote]


Quote:
Originally Posted by Don Bond View Post

These are nothing but a DC gearmotor.

Don't forget a micro-controller box that can store 99 locations that we use as the positions of the movie's AR.


Quote:
Originally Posted by Don Bond View Post

You can find these on the internet all day long, even eBay.

The Eagle Aspen rotator seems to be "Out of Stock" in just about every site that sells it...
Thanks for you for your help !!


Scott:

Have you looked at the Phillips SDW1850 or Channel Master 9521 rotators ? The both have a IR remote and memory function.
post #564 of 835
Thread Starter 
Quote:


Scott:
Have you looked at the Phillips SDW1850 or Channel Master 9521 rotators ? The both have a IR remote and memory function.

I did not try those but I bet they would work. I had seen the Channel Master and it seems to be pretty readily available. If I would not have found another Eagle Aspen, I would have tried the Channel Master. Does anyone know if the Channel Master uses a hall sensor for positioning? I would assume it does, but am not sure.
post #565 of 835
Quote:
Originally Posted by ifeliciano View Post

If you read the whole thread you'd know the reason for selecting the specific rotator Scott did. It has IR function and the controller has the capacity to program and save 99 positions. Plus it was affordable, not $600 like a rotator for HAMS

Just seems like killing gophers with a Claymore. Not sure what Scott paid for this, but seems like overkill. But, I guess you can rotate an antenna at the same time.

So, what if you had a motor, microcontroller, IR receiver. Cost? About $100. Just add software and stir.
post #566 of 835
Thread Starter 
Quote:
Originally Posted by Don Bond View Post

So, what if you had a motor, microcontroller, IR receiver. Cost? About $100. Just add software and stir.

Don,
You have a very good point, but my issue was that I have never been able to find (and figure out) the combination of the above components. There have been pages and pages of posts in this and other threads where people have been trying to come up with an easy and inexpensive DIY solution to motorized masking using "a motor, microcontroller, and IR receiver for $100". It sounds simple, but so far, I've not seen anyone come up with an actual system.

I'm not enough of an engineer to figure it all out on my own and that is why I opted for the rotator. It has the positioning system, controller and software all built in. I just had to jerryrig it up to a more powerful gear motor. It actually works great, but even this turned out to be more work than I was originally hoping for. I was hoping to come up with an easy solution that the typical non-programmer, non-engineer, DIY hobbyist could use for motorized masking.

I am always open to trying to learn more about this stuff. I have tried to post my successes and my failures in an attempt to help all who are home theater enthusiasts who are trying to accomplish some of the same things that I am working on. One of the things that I have enjoyed so much about this tread is everyone's willingness to share. I have learned a lot from others who have taken the time to post their knowledge. I am very appreciative.

If you know a source for a motor, microcontroller, and IR receiver for $100 and know how to easily hook it up with at least 5 memorized locations and nonvolatile memory to run a masking system I would be most appreciative if you could post how to do it. Pictures would be great too (I think we all like the visual!) Please share your knowledge with us. I think there are many here who are looking for the exact solution you have described.

- Scott
post #567 of 835
Quote:
Originally Posted by Don Bond View Post

So, what if you had a motor, microcontroller, IR receiver. Cost? About $100. Just add software and stir.

Yeah that's easy Scott. What's holding you up?
post #568 of 835
Quote:
Originally Posted by Don Bond View Post


So, what if you had a motor, microcontroller, IR receiver. Cost? About $100. Just add software and stir.


Get on it then. Let's see you have an complete working solution,for $100, let's say... 90 days..
post #569 of 835
Quote:
Originally Posted by Don Bond View Post

So, what if you had a motor, microcontroller, IR receiver. Cost? About $100. Just add software and stir.

Can you also have in a retail package so we can all buy it. After all your going to be working miracles, might as well do two miracles instead of one
post #570 of 835
My wife will kill me for even entertaining the thought, but what would a masking motor and controller be worth to the DIY community?
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