I built an acoustically transparent screen - Page 2

Close up of the framing and support pieces. Also the left and right speakers are slight toed in a bit.

Now the insulation is installed. I left the paper backing on for the ability to staple the insulation to the baffle board.

I now cut an opening in the insulation. I also placed a block of wood to push the insulation back a bit and for additional support of the insulation.

Now I have the cleat for the AT screen installed.

A close up of the screen cleat. This simple idea just allows me to hang the screen. I can take the screen on and off pretty easily if I need to with this. I also have a small block of wood on the lower part of the screen for spacing the screen off of the frame to match the cleat.

Thanks Mississippi Man. Yeah it hit me when hanging a screen a few generations back. Hey this is going to hang at an angle. Spacing block needed here.

Now I stapled black spandex over the insulation.

Now I stapled the spandex to the box I will use for placing the speakers in. The depth of the fiberglas causes the large depression you see here, but I figured this would happen and am just moving forward.

Now I cut out the spandex from the box opening and now can insert the Minimus speakers.

LCR speakers in place. Ok, I know this isn't cieling to floor like THX suggests, but I figured I can work on this a step at a time. Also from looking at a THX photo of a baffle wall I noticed it was not one flat baffle. It seemed to be very similar to what I have. There is a baffle that is a bit 3 dimensional. This is what I decided I had here and decided to not get to worked up about my front wall being flat as a pancake.

Ok, the screen is up. When I put the black spandex over the baffle wall I did cover the bottom cleat. That was ok for me because spandex is so stretchy and I just put the screen up and stretched the spandex. The upper cleat seated into place just fine and I did not have to paint anything.

As you can see I had a window on the left of the screen. I have a plug for the window which eliminates any light. I also have skylights with plugs in them. The window was creating a bit of a problem for me. NONE of the front channels sounded alike when doing level settings with pink noise. Each speaker had its own environment to deal with and each sounded a bit different when compared to each other. Now.... That problem is changed. The left and right speaker have very similar sounds. The center is a bit more deep due to having more baffle to play off of. More on this later.

This is a shot of the baffle, speaker, screen. The screen looks tipped but really isn't this is all about camera angle and illusions. I was shooting down towards the speaker so the top of the screen looks like it is further out than the bottom. It isn't.

The other side. These speakers are sounding really good with my power amp. I am using the pre-out on my 525 into a HK 2.0 5 channel power amp. The speakers don't seem to be having any problems with this amp at all. I wonder if extending the baffle might help with getting a bit more mid bass out of these speakers? I also wonder if I got a AV receiver with equalization abilities if I could get a better match on the front three? What I am hearing so far is a hugh improvement over just letting them hang on the wall. The sound I am getting is really clear and good. Excellent dynamics with very clear vocals. Much better than when I was using the floor standing speakers! I just have no "sorry I gave them to my son" feelings.

Funny part is, my son remembers when we used these speakers in a setup when he was growing up. Now he is as old as I was then. Funny about me still liking these speakers.
Edited by awblackmon - 1/13/13 at 7:14am

When I was researching doing this project I came across a lot of postings here and on other forums that said not to do a baffle wall unless you get an engineer involved. You may not like the outcome. Here is my take. This is a hobby. I have put up at least six screens on this wall. My first was a 4x3 when using a Sony LCD projector that had a 4x3 format. I then got a Barco CRT and changed the screen. I experimented with a curved screen with the Barco projector. My nephew came over one day to watch a movie with a friend. The room, being a bonus room was pretty warm. Hot really. The ambient heat and the heat of the Barco was not a good combination. The barco sparked, arced and let the magic smoke out. Never got it working again. Moved onto a 480p 16x9 from infocus.

Well the curved screen came down. and I did another screen. When you look close on the wall you can see a bit of history of each screen. Each was just painted on and black borders put up. I used so many different paints with each new screen. The first was with Sherwin Williams which was popular with that screen. Then there was a white from Behr. Then there was Silver screen from Behr. Then I used a Lowes Valspar. Each generation was up when getting new projectors and used due to popularity or suggestions on this forum at the time of being painted.

All along I really was thinking of doing a AT screen. I just couldn't come up with how to get it done. That is, what fabric do I use? I found a posting on the White Ponte. I built the screen. Hence that project was how this whole posting got started. Anyway when I had to redo the ponte screen I decided to go with spandex. I am here to tell you spandex is better. Ponte has a texture that caused HD to go soft. Spandex is much sharper image wise. My wife saw the difference when we watched the film HUGO with the grandkids. She loved the near 3D effect of HUGO even though we were watching it in 2D. The difference she was seeing was the much sharper image off of the spandex.

When I did the curved screen I did not have a border on it. The image just kind of floated off of the wall. With the room being as dark as it was the effect was pretty cool. My wife liked the effect. So later when I did the spandex screen I returned to the floating images idea and dumped the black borders idea.


Well after the infocus I got my present projector. It is the Mitsubishi 3800. I got it as a demo unit at the local home theater retailer. The deal was the projector, hanger mount, and new bulb for a price I wanted to pay. So far it is the best projector I have had.

As for the engineer designing my unit. I forgot to hire him. So with humor I say the following. I was not afraid of the world tilting off of its axis. I was not afraid of planets leaving solar orbit if this project did not work out. It is a hobby for crying out loud. Don't like it, move on to next step or idea. I know this may not work for everyone. Especially if you have to hire the work out. For me it is a DIY gig.

So with everything I was reading, and with past experience I have had with using Minimus speakers for home theater I decided to move forward with the project. My experience with these speakers is that if you do recess them into a wall they actually sound better. You will get sound an octave lower than if you just put them on the shelf. Hmm. Sounds like just the speaker for me to be used on a baffle wall. These speakers also have no back port so no problem. Doing a baffle wall it was suggested not to have a port on the back side. Perfect so far.

So with the speakers playing a bit deeper that when just hanging on the wall the subwoofers come in just where I need them. I have the cross over at 80 hz right now. There is a mid bass hump in my room so any gap, which is minimal, gets taken care of with my room pumping up bass in the mid bass regions right where the hump seems to be.

Well for now my wife and I have a date night so I will post more later and my impressions of the sound of this project. In a nutshell, it was worth doing. Oh, and the world is still rotating on it's axis. So all is well.

Going out to a movie just proves to me we have a better experience at home than we can get at theaters. I won't go into that because there has been volumes written on that already.

Getting back to my own theater. I am very pleased with the results as I had posted earlier. Again the bass of the main speakers was extended due to the baffle. I have a little more work to do on either the center channel to get the mid bass reduced a bit. The left and right speaker does not go down as low in frequency as the center channel. My Harman Kardon 525 does not have any equalization ability so for now I will live with what I have.

I watched Dredd last night and I was IMPRESSED. The 7.1 DTS MA track was really one of the most amazing mixes we have heard in a very long time. I do wish that most sound mixes could be mixed more like this one as a norm rather than the exception. The front channel mix was really good. Sound panning across the front of the screen was solid. I think the baffle made it even better sounding than it would have been without the baffle. The room improvements I have made over the last year has really made a hugh improvement in my being able to enjoy a good movie in my home theater.

The dynamics of Dredd seemed to really come out very well. Bass was pretty strong throughout the film and at no point did I feel something was wrong with how my system delivered it. The only problem I have to solve is one of my skylight covers seems to rattle a bit during some dynamic scenes. I will be working on that this next few weeks.

I have read where the sound mix for Dredd has been mixed with DTS 11.1 in mind. Hearing it in 7.1 and having what I heard was impressive I just wonder what it could have been like with a 11.1 playback? Ultimately I want to move toward having front hight and wide channels. It may be awhile but that is the direction I am moving. I did install enough speaker wiring twelve years ago to have front wide and hight channels. I have to say I was thinking of doing that because of Yamaha's presence channel ideas back then. I thought "what if" about the idea of front high channels catching on one day. Seems it just might.

My theater room is not as large or as fancy as I have seen here but I really am enjoying it. It is exactly the theater room I want. It will be going through a lot more changes. With each change I am really enjoying it more and more. I have been going out to movies less and less. We go out now mostly to just get out or to see a movie we just don't want to wait for. I find though that I can wait more than I used to be able to.

I hope that what I have placed here will help anyone. I am not a expert so whatever I put on the table is just me sharing what I have been able to do with my own theater to make it more fun to be in. If my experience can help you have the same fun I am having then go for it. I have been really enjoying reading about the experiences of others and I have moved on many of the ideas shared here. I look forward to reading more about these experiences and deciding if they can be used in my theater in the future.

Any critiquing you want to do, I look forward to it. Your ideas may spark how I can make some really great changes and next steps to consider. TIA
Edited by awblackmon - 1/13/13 at 7:04am

I am glad that you were able to get something out of my project and the writeup. I am really enjoying the theater room a lot. I am going out to movies less and less these days because I know if I wait it will be more enjoyable at home. One or two come along that I just want to go and see now but that is happening less and less. I hope you will do a posting on how your project is coming along.

Great. I will be looking forward to seeing your build.

Today I did a bit more work on the room. When the house was in the framing stage I built in some boxes for the Paradigm inwall speakers. I have liked how it looks but sound... Over time I have thought the separation of the two back channels was way to close. At the time I was just working with what I had but years later I just don't care for the results. The Dolby web site does call for a bit more spacing apart of the back speakers than what I settled for in the beginning. So I went to Lowes and got some of the on wall product for cable and wire. I considered going up into the cramped area over the theater room to make this speaker change but decided against it. I have been up there a few to many times for a big guy like me and this was way easier.

I also decided to install the speakers higher than what the inwalls were installed at. The inwalls tweeter is about 60 inches high. The new speakers tweeters are 30 inches higher. Oh and as you can see, I did install my trusty Minimus 7 speakers.

When I first built the room, I had a odd thought of putting in an electrical box that the inwall speaker wire came to from the amp. Then more speaker wire continued to each of the rear surround channels. I put a blank plate over this box and forgot about it for the next 14 years. Today that plate was removed and I was able to easily access the speaker wire from the amp. I then put the on wall wiring product and ran new speaker wire through it to the new back surround speakers. I recommend some out of the box thinking if you are building a theater room today. Try as hard as you can to think ahead about any changes you might want to make. Even if you never make a change it is better to have an easy out should you, like I did, think maybe today I want to do something new. This allowed me to do it with very little effort. Translated, I did not have to go into the cramped area over the theater room and do drilling and speaker wire re-runs. If I don't like the change I can go back easily to the way it was without crawling back up into that cramped area.

So how do I like it. As it turns out I think the sound is better now. In my opinion the in wall Paradigms sound a bit nasally compared to the Minimus 7s. I had never really paid attention to this the past 14 years but today was a bit of a ear opener so to speak. Running the test noise to set the new speaker levels sure made it known that the difference in sound quality from my left and right side surrounds is more nasally when the test noise passes through them. The rear surrounds now are much better sounding and closer in quality to the front sound stage. Well, I guess we shouldn't be to surprised with that should we. I guess the next project will be replacing the side surrounds. I am brain storming how to do that now but that storm will be brewing for awhile.

I also think that the higher point on the wall of the back surrounds makes for a better experience. When I sat in my chair and reclined often the rear surrounds ended up putting the upper pillow of the recliner between my ears and the speakers. Kind of defeats the purpose of having 7.x in the first place if the sound gets blocked off. Now the speakers and my ears have a straight shot to one another. I have not so far listened to any 7.1 DTS MA or Dolby HD tracks from a Bluray. I did though turn on a sporting event that was broadcasting with surround effects. I was using my Logic 7 decoding of the event and the surround space offered up was pretty nice. I have a Directv HD DVR playing into my Harman Kardon AVR which is set to DOLBY DIGITAL OFF. I then played the movie Adjustment Bureau recorded off of a premium cable channel. I did a A/B of Dolby Digital on, and off and really, I like the sound of Logic 7 processing better from my HD DVR vs. Dolby Digital on with the rear surrounds turned on or EX mode. Next weekend I may try a Bluray to see how the new speakers sound. First impressions, they are better being higher and spaced further apart even if they are old school Minimus 7s.

Next up, change the side surround speakers, but like I said before, this may not be done for awhile. Other stuff on my list to work on. Translated, honey do list. I got excused from it this weekend.
Edited by awblackmon - 1/28/13 at 5:47pm

I did a search on THX WALL and it was very revealing as to why a THX certified theater can sound better than most. In a nut shell it allows the front channels to allow a better sound field. Stereo effects can pan better across the screen. Dialog that is mixed to come from screen left or right actually sounds more left or right with this type of set up behind the screen. Another benefit is the large sound absorbing panel behind the screen soaking up reflective sounds in the room. Also with this kind of panel the small speakers tend to have a lower bass response. I have purchased a Onkyo NR818 to replace my older HK 525. I have run the audessy setup on the Onkyo and the results of the setup have been very interesting. The small minimus 7 speakers have pretty good bass down to around 80 to 90 hz now. When you put them on a shelf the play well down to 120 hz. If I recall correctly the audessy setup has set the cross over point at 90 hz for the center channel and 100 hz for the left and right channel. Not exactly THX standard but it is sounding pretty good. Mid bass impact is not disappointing for me at all. Gun fire scenes does not sound like a pop gun going off at all. The minimus 7 speakers are handling the output of the Onkyo very well.

So the project of making this baffle wall has been successful for me. I would do it again, only sooner.

I like the sounds of your project. Good luck with it. I had seen a AT screen much like you describe. It could be removed to do any work behind the screen. Panels were placed on the wall that made it appear to be one large fabric wall. He had not done a baffle behind the wall but had treated it with absorbing material and set the speaker on small stands. From the front of his screen to the treated back wall was about 1.5 feet. Sounded good. He had used a awning material that was pretty good at being transparent sound wise. His web research at the time prompted him to built his screen with this material. Since then Spandex has been found to work really well. I can only imagine the cost of the spandex is much better than the awning material. Also the weave of spandex is much tighter which will allow the HD to be displayed better.

My room does not allow 120 inches but I am still happy with my results at 108 inches. I am glad this has been of help to you. Hope we see some pictures soon.

http://www.thx.com/professional/cinema-certification/speaker-layout-and-baffle-wall/

Check out this link for what the baffle does.

I fell off the fence and bought a new AVR. I have praised my HK 525 for awhile and now that I have a new AVR I have to say I am glad I pulled the trigger. I got an Onkyo TX-NR818. First impression was WOW.

I sold the 525 the day after I installed the Onkyo. The new owner is loving it. I am glad he is enjoying it. He says music sounds so much better now.

I installed more speakers in the front for front wides and front highs. I played several tracks using the DTS neoX processing for front wide on Master And Commander of the Far Side of the World and was very impressed with how much wider the sound stage was. I actually had water wave noises coming off stage of the screen. I stuck my head between the left and wide left speakers and you could hear the water noise was coming off stage of the screen. On screen left speaker had noise coming from onboard the ship. DTS neoX does a really fine job.

The audessy XT32 did a great job of setting up my speakers. The surround is much better defined now compared to my HK. EQ is much nicer. I never had the ability to do EQ before. Before it seemed some soundtracks had limited surround. Now, the limits have been broken and movie soundtracks and TV soundtracks have so much more going on. I am glad I made the change.

So for those asking if neoX adds anything to sound tracks, I have to say for me it has. My setup is LCR with left wide and right wide, left and right high. Left and right side surround. Left and right back surround. I have added an external amp doing back surround duty. While watching a film my selection options are for wide or high speakers. I don't have it setup to do both. I can also defeat wide and high speakers and do just 7.x if I want to.

I see all the summer film previews and I am thinking how much fun it is going to be next fall to be in my theater room watching them with the family. Even my 85 year old mother is liking going up there to watch films with us.