DIY - Acoustic Transparent screen

[elangoas]

Hi All,

Am a newbie to projector screen..

Considering DIY route for Acoustic transparent screen..ready made ones (perforated) cost a bomb at least to me..

- Have an LED HD 1280 x 800 native resolution PJ..
- Brightness is relatively low at 600 ANSI lumens..
- 94" is the diagonal size of the screen that i use at present..
- Idea is to use a center speaker in vertical position behind screen.. LCR if feasible..

When speaking to one of the dealers, they suggested to use "thick cotton dhotee" as screen material..

On further googling, i found two types of AT screen.. Perforated and woven..Since dhotee is woven fabric, does it qualify as an AT screen?

Below is a macro shot of dhotee fabric from my mobile.. just to confirm the weaving type..

Not sure if this is the right away, I did cover my front speakers with a dhotee for a while when watching tv channels, i didn't observe difference..

Please confirm if it can be used and any downsides if any..

 

[manoj.p]

Woven screen is better compared to perforated. Perforated screen causes comb filtering and moire visually.

All acoustic transparent screens should pass the blowing test, meaning you should be able to blow air through it. You can look at tightly woven spandex material. DIY people have good experience with it. Personally, I think dhoti is quite thin, it will cause quite a bit of light loss.

 

[elangoas]

Woven screen is better compared to perforated. Perforated screen causes comb filtering and moire visually.

Ok.. Great..Luckily have advantages..

All acoustic transparent screens should pass the blowing test, meaning you should be able to blow air through it.

Yes.. Checked it, after your post..

You can look at tightly woven spandex material. DIY people have good experience with it.

Sure.. Will check with local sources on the material availability..

Personally, I think dhoti is quite thin, it will cause quite a bit of light loss.

Would a thicker material take away the ability of AT screen..?

 

[elangoas]

Just a weird thought after looking at roller shades used in office..

A Macro shot of the fabric..

Found it to be Hunter Douglas - https://www.hunterdouglas.com/roller-shades/designer-roller-shades

On further digging, found it to be woven-fabric, not sure which material, would it make a good choice for AT screen?

I tried blowing air thru it, it passes it..

Only evaluating, since the material is stiff & can be rolled up unlike the fixed frame..

Appreciate your inputs..

 

[gainil]

Hi,

Just came across this - DIY Projector Screen 128" - Album on Imgur , seems suitable for your requirement.

Many suggest that 'Spandex' and 'Ponte Fabric' are good for Acoustic transparency

Hope that helps

 

[elangoas]

Many suggest that 'Spandex' and 'Ponte Fabric' are good for Acoustic transparency

Hope that helps

Thanks for the type of Fabric.. I will check for aval of these fabric locally in textile store..

 

[manoj.p]

Would a thicker material take away the ability of AT screen..?

There are pros and cons for it. A thicker thread will give a very tight weave, causing sound loss. It will also make you see the weave from few feet away.

A thinner thread will give lose weave which is good for sound but bad for light loss. Moreover, the light will reflect off from wall/speakers behind the screen and give poor video performance. So, for DIY, its trial and error to get right balance.
But you do want the thinner thread because not able to see the weave and good sound quality. You will get the light loss, but can avoid the reflections from behind screen by putting a black cloth right behind the screen. The new 4K screens do this.

About the roller blind sunshade/solar fabric material, you are quite close. At least two companies started in the Acoustic transparent screen using the Sheerweave 4500 material. It is a very good DIY alternative.

 

[elangoas]

I enquired abt the spandex material in local textile store, most of them were unsure abt it..

Later i spoke to one of the FM from textile town of Tamilnadu (Tiruppur) and he updated me that spandex is referred as "Lycra fine" here.. So he was able to source the material and send it to me.. Looks like it is the same material which is also used to produce undershirt for men & legging for women..

Have received the same.. Will begin the process soon..

 

[elangoas]

There are pros and cons for it. A thicker thread will give a very tight weave, causing sound loss. It will also make you see the weave from few feet away.

A thinner thread will give lose weave which is good for sound but bad for light loss. Moreover, the light will reflect off from wall/speakers behind the screen and give poor video performance. So, for DIY, its trial and error to get right balance.
But you do want the thinner thread because not able to see the weave and good sound quality. You will get the light loss, but can avoid the reflections from behind screen by putting a black cloth right behind the screen. The new 4K screens do this.

Thanks for enlightening..

About the roller blind sunshade/solar fabric material, you are quite close. At least two companies started in the Acoustic transparent screen using the Sheerweave 4500 material. It is a very good DIY alternative.

Thats great news.. I will check for local prices..

 

[elangoas]

A picture of my living room, where i would mount the AT screen, Flip up model using door keel is what i have pla nned..

At present there is a wooden window, which am planning to replace it with Aluminium frame and tinted glasses..

By shifting the window from the inner walls of the living room to the outer walls, i would get abt roughly 15cms to 18 cms depth, where i would be placing the center channel, possibly at ear height (or) slightly more..

Spoke to the carpenter, he suggested using 2 inch (W) x 1 inch (D) thick wooden reepers to hold the screen..

Looking for some clarity on dimensions..

80 inch (W) x 50 inch (H) is the projected image..Should i keep a margin if 1- 2 inches extra for both sides (or) should i go with precise size to make it look like frameless..

 

[gainil]

Looking for some clarity on dimensions..

80 inch (W) x 50 inch (H) is the projected image..Should i keep a margin if 1- 2 inches extra for both sides (or) should i go with precise size to make it look like frameless..

You can put thin wooden (painted) strips on the front side to give it frameless TV like look. Btw, 80" x 50" is 16:10 aspect, P531 has 16:9 output, so any particular reason you gona use this size?

 

[elangoas]

You can put thin wooden (painted) strips on the front side to give it frameless TV like look.

Not sure if i got it correct.. Could you a link or an image for reference..

I would be stretching the fabric over the frame & ping it..

Btw, 80" x 50" is 16:10 aspect, P531 has 16:9 output, so any particular reason you gona use this size?

P531 is 16:10 native.. These measurement are of the current projected image..

 

[gainil]

Not sure if i got it correct.. Could you a link or an image for reference..

design or plain wood strips like the ones on photo frames, you can use very thin ones to make borders similar to frameless tv's, something like the one in pic attached

 

[elangoas]

design or plain wood strips like the ones on photo frames, you can use very thin ones to make borders similar to frameless tv's, something like the one in pic attached

Very nice..I will share this picture to carpenter..

 

[elangoas]

Juz completed installing the Acoustic Transparent screen..

Here are some pics..

18mm plywood material used, 3 inch width reepers were cut.. 80 x 50 inch screen is what i planned.. But made it 82 x 52 inch, to give room for errors while mounting and may be get the frame decorated in the corners..

Since this is a living room, i thought of flip up model rather than a fixed frame..Idea is to flip up the screen when not in use..

Switching to Aluminium windows to the outer walls of the living room, has given me abt 18 cms of space between the metal grill and the screen.. I think sufficient to mount a Book shelf speaker behind the screen..

I have mounted the screen on the window (partially).. There is some light seeping on the back of the screen, even though i opted for tinted (black) glasses..

I tried blocking the sunlight, by temporarily putting a thick bed sheet to cut down the light seeping in behind the screen..

Below image is with 2 x 8W LED lights in the room, with daylight blocked (Partially)..

This is all lights switched off in the room and also blocked daylight (Partially)..

Images were clicked around 6PM in the evening.. Need to paint the walls..

Cost incurred..

Cost of the spandex (Lycra fine) material = Approx 600 Rs for 8 x 6 feet screen..

Cost of plywood material approx 1,500 Rs..

Labour cost 900Rs..

Totally 3,000 Rs to make a 96 inch 16:10 screen..

I plan to use a dark curtain cloth behind the screen to cut day light out..

Suggestions to improve the viewing experience are welcome..

 

[elangoas]

A thinner thread will give lose weave which is good for sound but bad for light loss. Moreover, the light will reflect off from wall/speakers behind the screen and give poor video performance. So, for DIY, its trial and error to get right balance.
But you do want the thinner thread because not able to see the weave and good sound quality. You will get the light loss, but can avoid the reflections from behind screen by putting a black cloth right behind the screen. The new 4K screens do this.

Below are some pics clicked thru mobile..

I have temporarily put a bedsheet behind the screen, blocking window..

The bedsheet traces are visible and the frame too..

Here is an other picture clicked with no light in the room from mobile.. Here too black traces of the bedsheet is visible..

One more picture, which shows darker cloth behind the screen improves contrast.. First half of the subscribe button looks red which has the bed sheet slightly behind screen (3 - 4 cm), second half looks pale red which doesn't have bed sheet..

Just a thought.. I see you had suggested a black cloth behind screen.. But, would it be good idea to stretch the white spandex material over a black spandex on the frame?

Will be placing the center channel behind screen.. If it is double layer of spandex over the frame, would there be loss of sound?

 

[elangoas]

Not an ideal test conditions..But an other picture for comparison purpose..

First half from the top is AT screen (backed a dark bedsheet), while the bottom half is Vinyl screen..

Note : This is with day light in the room..

I think the contrast on the top half of the screen is better with reduced brightness, while the bottom half is juz bright..The flower petal looks better (top half) with some additional details which is not seen on Vinyl screen (bottom half)..

 

[elangoas]

This was clicked with full fabric screen, with a dark cloth behind..

I feel the contrast is better with reduced brightness..

 

[MJ23Bulls]

Hi Elangoas,
Nice DIY effort. Kudos to your try.
Quite a few pointers pop up when I've finished going though your thread and these aren't necessarily a/v related though.
1. Have you treated the plywood with some kind of primer/paint/varnish thing? In the long run, this will help the ply's longevity and guard against moisture & termites.
2. With the window installed on the exterior side of the wall, care should be taken to properly seal the gaps. This is to prevent water seepage during rainy days.
3. If using a black lycra cloth at the back, rinse it first with water so as to remove the dye. This is to prevent the white cloth from the black dye in case of any accidental spillage.
4. For a TV like finishing (as some FM has suggested): There are ready made wooden beading available in different sizes. Strips as thin as 6mm are available. These can be painted matte black & nailed to the frames so that you get a nice TV like frame. However, please ask the carpenter to cut miter cut (45 degrees) like in photo frames.
5. Flip up might be okay now; however, the other side of the screen may not be presentable in a living room. For that, you can try a slide up mechanism with pulley and rope. (Just like how some cloth drying lines mechanism work).

 

[elangoas]

Hi Elangoas,
Nice DIY effort. Kudos to your try.

Thank you..Since ready made screens were 30 -40K, this pushed me to DIY at 1/10 cost.. Trying to make it better..

Quite a few pointers pop up when I've finished going though your thread and these aren't necessarily a/v related though.
1. Have you treated the plywood with some kind of primer/paint/varnish thing? In the long run, this will help the ply's longevity and guard against moisture & termites.

Nope.. Didn't consider treating them.. Anyways before re-doing the second layer, i will get it painted with primer atleast..

2. With the window installed on the exterior side of the wall, care should be taken to properly seal the gaps. This is to prevent water seepage during rainy days.

The window was snug fit on all 3 sides, except on one side, there is little gap..There is a sunshade to prevent rain water getting in.. Will need to pack these with silica gel (or) an M-seal adhesive..

3. If using a black lycra cloth at the back, rinse it first with water so as to remove the dye. This is to prevent the white cloth from the black dye in case of any accidental spillage.

Oh k.. I was thinking these are pre (chemical) washed..

4. For a TV like finishing (as some FM has suggested): There are ready made wooden beading available in different sizes. Strips as thin as 6mm are available. These can be painted matte black & nailed to the frames so that you get a nice TV like frame. However, please ask the carpenter to cut miter cut (45 degrees) like in photo frames.

Sure.. Will check them..

5. Flip up might be okay now; however, the other side of the screen may not be presentable in a living room. For that, you can try a slide up mechanism with pulley and rope. (Just like how some cloth drying lines mechanism work).

I like the pulley & rope :thumbsup:.. Hope you mean the screen will be suspended from ceiling..Should be really nice..With toddler around, i will consider this option a while later..

Thanks again for your inputs..