Negatron II

Negatron

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The ALR screen I linked to is AT. It's an option. It isn't as cheap as DIY options or even many other AT options, but it's one of two ALR AT screens I'm aware of and is the better of the two options.

It's up to you how you handle this. My own experience is that light control or an ALR screen is very important if you plan to watch movies during a time when it is light out. Most of my "theaters" were in dual purpose or non-dedicated spaces with windows. I had light control curtains with full blackout ability, but no matter what, some light always shined somewhere. The ceiling, floor, etc. Never could I black it out to the point of equaling no window at all. Even at night, light outside, even from the moon, was enough to raise the light level in the room a little. This reflects off the screen and raises the black floor a lot. In fact, I just did a demo in my dedicated room and needed to leave the door open (which would be the only way light could get in) and the impact on the black level of my AT screen was huge.

In my previous spaces, I tried everything and the only thing that worked was an ALR screen. Even a dark grey screen with a high brightness projector was not a workable option. This is why I say, you may want to consider an ALR AT screen. In fact, at one point I had some friends bring over their projectors to my then home theater space, a room with white walls and two screens. A unity gain white screen and an SI Black Diamond (one rolled in front of the other). The projects were my JVC RS1, a JVC RS25, an Epson 5010ub, and a Panasonic DLP model with DCI cinema mode, capable of around 10,000 optimized lumens. We tested at both 4pm when it was fairly light outside and again at 8 pm when it was dark outside (other than street lights, moon, stars, etc.). At 4 pm the Panasonic looked the best, it was most able to overcome the ambient light problems (again, with full light blocking curtains on all windows). The Epson was second best, it was the next brightest. It technically had the worst blacks, but both it and the Panasonic looked to have better blacks. None of them looked great, poor contrast with the white screen, but they all looked really impressive on the SI Black diamond. At 8 pm I expected the JVC RS25 to be the clear winner and on the unity white screen. What we found was not what we expected. While it clearly had the best contrast, none of them looked great on the unity gain screen because the light coming in the room (though very low) from outside and the reflections off the white walls were raising the black floor substantially. The Black Diamond looked the best because it was least affected by this. I kept the Black Diamond screen for years after with my JVC RS1. When I moved to the dedicated theater, I bought AT fabric and converted the black diamond, but I had a chance to compare both side-by-side for curiosity sake. In a truly light controlled room with very dark navy walls and no windows, doors shut, and no sources of light in the room, they looked nearly identical. The Black Diamond's reflective properties are different and it's a dark grey color so its blacks were still a little darker and it's whites less white (and it had a slight sparkle that the new SI screens have minimized quite a bit). Point is, in a truly light controlled room, the differences became minor, if anything, more just a difference in gain (the SI BD was darker).

So I concluded from all of this that really when it comes to projectors, light controlled means a black room with zero sources of ambient light at all. That anything else isn't really good enough in the sense that these non-dedicated spaces with light walls and windows will always compromise the black level a little bit. That this can be compensated for by using an ALR screen, and that it's even of benefit at night. If you do go with an AT screen that is not ALR in a space like this, the rise in black levels negates the benefits of the best projectors and you may want to consider a merely very good projector, in black levels, with a lot more brightness.

https://www.projectorpeople.com/screens/screendtls.asp?manu=Screen+Innovations&itmname=5+Series+Fixed
Here is a site with pricing to give you an idea what you are looking at.

What projector do you have in mind?
Thank you. I have to run an AT screen that is retractable in this room...I had hoped to go to a 200" 2.4 AT retractable, but SeymourAV doesn't make one that large, and the I largest one is max budget already. If I am lucky I will have about 6k to spend total. My last HT was a bat cave, and the 195" 2.4 diagonal worked out great, but we cannot use a fixed screen or In would try it again.

The ones you linked are fixed screen, and would take 100% of my budget. If i was still working the ones you suggested would work, but not on my retirement check.

I was hoping the 4k Laser hybrid projectors would have come down more so I could afford one. I am thinking around 3k for a screen, and about the same for a projector. Maybe I can find a used screen to save me some money. The shipping is going to be a killer to Mexico, plus 17% duty unless I bring it myself across the border (then it would be free).
 

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Thank you. I have to run an AT screen that is retractable in this room...I had hoped to go to a 200" 2.4 AT retractable, but SeymourAV doesn't make one that large, and the I largest one is max budget already. If I am lucky I will have about 6k to spend total. My last HT was a bat cave, and the 195" 2.4 diagonal worked out great, but we cannot use a fixed screen or In would try it again.

The ones you linked are fixed screen, and would take 100% of my budget. If i was still working the ones you suggested would work, but not on my retirement check.

I was hoping the 4k Laser hybrid projectors would have come down more so I could afford one. I am thinking around 3k for a screen, and about the same for a projector. Maybe I can find a used screen to save me some money. The shipping is going to be a killer to Mexico, plus 17% duty unless I bring it myself across the border (then it would be free).
Ok I forgot you were looking to do such a big screen. That is a REALLY big screen for a home theater and will place limits on what options you have. It would be more than $6000 for the screen.

Retractable is also tough for this, the best AT materials are not self-supporting or self-tensioning and thus don't work well with retractable systems.
 

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Ok I forgot you were looking to do such a big screen. That is a REALLY big screen for a home theater and will place limits on what options you have. It would be more than $6000 for the screen.

Retractable is also tough for this, the best AT materials are not self-supporting or self-tensioning and thus don't work well with retractable systems.
The SeymourAV screen is AT, and self tensioning, but I can only get a max of 160" 2.4 screen. that is why I am only going with a 160" screen.
 

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I was going to use my 195" screen, and have it retract up the wall, but there are 2 problems..
!: it would not look good sitting there above the speakers.
2: it would have to sit almost 4' off the floor as it would have to be above the speakers.
 

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The SeymourAV screen is AT, and self tensioning, but I can only get a max of 160" 2.4 screen. that is why I am only going with a 160" screen.
Seymour AV has two materials they offer. The XD is self-tensioning and the UF is not. The XD is the older woven type that I mentioned not liking as much. The UF is not self-tensioning, it is more like spandex, but has a smoother look. The XD can cause a moire effect if the grid pattern of the pixels aligns or even slightly aligns with the grid of the material. Seymour AV addressed this by tilting the weave, but that can't be done on the size you want, and....doesn't fix the problem with 4k projectors (nor really fix the problem with 1080p all that well). The UF doesn't have the problem at all. It's also far more acoustically transparent, being more like good speaker cloth.

I did a contract job a number of years ago testing a number of screen material types for acoustic transparency. The tests were done inside a tiny anechoic chamber that I was loaned for the project. The tests involved a small full range speaker source with a screen material placed .25", .5", 1", and 2" from the source inside the small chamber. It was tested from 300hz to 20khz and is anechoic down to about 800hz, but has a correction file for the response below that. As such, it gives you basically anechoic results down to 20hz (if you like). I was asked to characterize the materials and I found a lot of problems with the course weave fabrics I was sent. This included added non-linear distortion, diffraction, comb filtering, attenuation, and response spikes at the very high frequencies that only showed up sporadically, but only when testing with the material. After 100's of tests, they never showed up unless one of the course materials was in place. While I did find (and generally believe) that this woven material is an improvement over the old perforated vinyl material, it is not acoustically transparent. In fact, technically no material was acoustically transparent, but the materials most like UF were very close. I tested some manufactured materials and various kinds of Spandex. These materials attenuate the sound and cause very slight variation in response, but they actually attenuate higher order distortion by absorbing it at a higher rate than the fundamental, and generally just cause a benign attenuation of HF's. It's as good as it gets at this point.

https://avscience.com/2015/11/dreamscreen-ultrahd-acoustically-transparent-screens/
This is a cool new AT material that I've tested a sample of. I don't think its available in a retractable form, but you could always inquire. The material is foreign, so it's possible you could import it to Mexico more easily through the manufacturer rather than AVScience. In any case, that material was the best acoustically and visually that I saw. I would have used it, but it was many times more expensive than what I have. I decided not to spend the money.
 

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Seymour AV has two materials they offer. The XD is self-tensioning and the UF is not. The XD is the older woven type that I mentioned not liking as much. The UF is not self-tensioning, it is more like spandex, but has a smoother look. The XD can cause a moire effect if the grid pattern of the pixels aligns or even slightly aligns with the grid of the material. Seymour AV addressed this by tilting the weave, but that can't be done on the size you want, and....doesn't fix the problem with 4k projectors (nor really fix the problem with 1080p all that well). The UF doesn't have the problem at all. It's also far more acoustically transparent, being more like good speaker cloth.

I did a contract job a number of years ago testing a number of screen material types for acoustic transparency. The tests were done inside a tiny anechoic chamber that I was loaned for the project. The tests involved a small full range speaker source with a screen material placed .25", .5", 1", and 2" from the source inside the small chamber. It was tested from 300hz to 20khz and is anechoic down to about 800hz, but has a correction file for the response below that. As such, it gives you basically anechoic results down to 20hz (if you like). I was asked to characterize the materials and I found a lot of problems with the course weave fabrics I was sent. This included added non-linear distortion, diffraction, comb filtering, attenuation, and response spikes at the very high frequencies that only showed up sporadically, but only when testing with the material. After 100's of tests, they never showed up unless one of the course materials was in place. While I did find (and generally believe) that this woven material is an improvement over the old perforated vinyl material, it is not acoustically transparent. In fact, technically no material was acoustically transparent, but the materials most like UF were very close. I tested some manufactured materials and various kinds of Spandex. These materials attenuate the sound and cause very slight variation in response, but they actually attenuate higher order distortion by absorbing it at a higher rate than the fundamental, and generally just cause a benign attenuation of HF's. It's as good as it gets at this point.

https://avscience.com/2015/11/dreamscreen-ultrahd-acoustically-transparent-screens/
This is a cool new AT material that I've tested a sample of. I don't think its available in a retractable form, but you could always inquire. The material is foreign, so it's possible you could import it to Mexico more easily through the manufacturer rather than AVScience. In any case, that material was the best acoustically and visually that I saw. I would have used it, but it was many times more expensive than what I have. I decided not to spend the money.
Interesting... I have a 195" 2.4 XD that was cut tilted when i purchased the fabric, and I had zero problems with the screen.Maybe I got lucky? I wish I could find someone that made the retractable minus the screen material...otherwise i will have to figure out an acceptable way to mount my fixed 195" screen and retract it if I can not find an acceptable retractable screen.
 
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Negatron

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If I am able to reuse my screen it def leaves more money for a new projector. I could fly up to see Craig, and bring the projector back on the plane for less than what shipping and Duty would be.
 

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I think I have an idea that will work... I put up a set of light blocking curtains, and then...
1: I take my old screen, build a new frame, cover the back of the screen with black blackout cloth (use the screen as a normal screen not as a AT screen), and mount 2 rails with linear slide bearings to the wall above the windows. This will be electrically lowered.

2: I then make a 2nd set of curtains to match the first set, and install them to conceal the screen.

The only problem I see is that the screen can only come down to the the tops of the front channel speakers unless I eliminate the center channel speaker. The speakers are about 3' tall unless I mount them the way they normally go...then they are about 2' tall, and would need to be angled upward.


What do you think?
 
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Negatron

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Tonight we went to a small theater, and the screen was above our line of site, and it was ok, but was not a good as when the screen is lower. What made it seem not as good was that the speakers were below the screen instead of behind the screen.
 

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I might have a solution... my room is 19' wide, and my old screen is 15' wide, so it means I have 2' per side of space. If I can make a wall mount 3' out from each wall I can run a track on each side To run the screen frame in. Then I need to figure out how to have it go up, and down easily...preferably electric.
 
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What would be a safe distance to run from the turntable to the phono stage? The phono stage has about 3' of cable to go to the preamp too.
 

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Looks like I will have some changes as the wife wants to have mirrors on the wall on the loft for her to practice dancing. This means I will no longer have 10' for the audio rack, but maybe 4' max, and still only a little over 2' high. The speakers will still be next to the windows but the doors will not be used behind the speakers (a plus for me), only the glass door to the left will be used. Room darkening curtains will be used, but not black, and a couple of carpets will be used for the floor too...again not black, but grey or blue with some white stripes (best compromise I could get as we will be getting the, from Costco).

On a 19' wide room, I will have to leave about 3' per side since we will be using the door which opens inward on the left, and we have the fireplace on the right. Not as much as I had wanted. Should I skip The center channel?

The old JBL speakers which are angled at 45 degrees as I recall will be set up as height channels, and as Auro3d channels. How do I calculate the height of them?

Would it be best to run side surrounds or rear surrounds, With the heights above them?
 

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After talking with my wife...she said I can use the loft wall side which is 19' long instead of the 10' long wall! This means we do not need to install a railing to prevent people from falling as the will not be able to get any closer than 2' from the wall. I love my wife!

Now I have to decide how to make the rack, as I cannot use that much space without using it for bluray space, and I do not want my whole collection in view. If I box it in it will awkward as the loft top has about a 6" top of Cantera tile... I do not want to have it removed, and have new 2' tiles in its place as it will be a mess.

To take as little space as possible from her dance floor if it is boxed in...could I vent frontward? Or would it look better to have a open rack design for the equipment, and cabinets on the sides? Cabinets would be faux white like the kitchen cabinets.
 

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Update...my wife has given me the whole 19' wall against the balcony. I am going go make the t channel rack in the middle of the wall, and then have some white washed cabinets for the remaining wall area. I had thought about having a 3' x 15" x 15" sub on each end of the loft, but I am not sure it would be any good being above our heads...any ideas?
 

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Screenshot_20180711-090634.jpg
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View attachment 8850 View attachment 8849 View attachment 8849 I am getting a little confused on setting up my height speakers for Auro3d... it says I should have a 30 degree angle (calculated from a standing position)for the mounts, and then aim them at the mlp with a 28-48 degree angle. My JBLs are @ a 20 degree when mounted with the flush mount brackets. With a 19' wide room... how high would I wall mount the speakers, and then how much do I need to change the speaker angle on the brackets...or do I even need to change the speaker bracket angels? I am sorry, but I know zero about Trigonometry which is what I am reading you need to know to calculate this. I will be drilling into our clay walls, and want to get this right the first time. I will not be doing a center height channel(not recommended, but I would like to, or a top (voice of God channel)).
 
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I did a quick measurement by eye with a makeshift support, protector, and laser, and it looks like the surrounds(bottom of speakers) will be right up against the bottom of the loft.They will have to be angled left to right in the corners, and also the angle up and down might have to be changed...unless I get lucky or do not adhere 100% to the specs. The front heights will be easier as they will mount right above the windows just like I had hoped.

I am thinking maybe I can make a wooden triangle, and then attach a turnbuckle to it for the top, and bottom to adjust the angles. Does that sound like a good way or do you think it will vibrate loose?
 
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Matthew J Poes

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I did a quick measurement by eye with a makeshift support, protector, and laser, and it looks like the surrounds(bottom of speakers) will be right up against the bottom of the loft.They will have to be angled left to right in the corners, and also the angle up and down might have to be changed...unless I get lucky or do not adhere 100% to the specs. The front heights will be easier as they will mount right above the windows just like I had hoped.

I am thinking maybe I can make a wooden triangle, and then attach a turnbuckle to it for the top, and bottom to adjust the angles. Does that sound like a good way or do you think it will vibrate loose?
I don’t see any reason it would vibrate loose. Maybe make sure your anchor points use course screw threads, glue, and/or bolts with lock washers. Take extra steps to prevent it.
 

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So should I use washers, and extra nuts (and/or locktite) so the adjustments do not change on the turnbuckle too?
 
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I also have a bit of a dilemma as to how close I get to the Auro3d specs. They are for 30 degrees for each front channel from mlp...if I do that it would put my front speakers in each corner angled toward the mlp. The problems are...
1: The speakers will be outside of the edge of the screen partially.
2: We were thinking of running the tracks to raise the screen in the corners, and surrounding them with the bass traps, which could be a problem due to the 4' high x 2' wide x 30" deep horns if They are in the corners. Then again it may be easier... I am not sure as the fireplace is 8' 11" from the wall behind the speakers, and sticks out 2'10" from the side wall.
3: Then there is the problem as to how to make the first reflection panels if the speakers are angled out in the corners vs being 3' from the side walls, and angeled just a bit.

The horns are K402 horns which will be mounted vertically not horizontally which will give a 60 degree vertical dispersion versus horizontally which would give a 90 degree dispersion. I can go either way. If they are installed vertically I only need to angle them upward a bit in the front where as if I install them horizontally they would need to be installed on 2' high stands which also makes them much harder to conceal if we continue with the idea of concealing them.

Suggestions?
 
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I have a little bit of progress on the new home theater. I ordered 3 amp cases so I can move my amps close to the front 3 speakers (no progress on the synergy style horns yet though). I also made a little progress on the new equipment rack. When I switched the design I forgot I would need more angled aluminum, screws, and nuts for the t channel. I should have the rest in the next few weeks to complete the rack. I still need to get 3 or 4 more shelves made, and get a piece of stone that matches our living room floor for the top of the rack.
 

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Here is my progress on the rack...I still need to get the last 3 shelves mounted...the top 2 are just mocked up, and get the stone top made. I know the Xbox 360 is upside down...I hooked it up from the rear, and still have to find the power cable, but it has been flipped over so it is right now.
 
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Finally have some progress...
1: fiber HDMI cable is on the way
2: 5 50wpc amps on the way
3: amp kit cases on the way
4: 4 small horn waveguides on the way,
5: When we get back from Europe I will have 4 DIY Klipsch Belle bass bins ready to go...which will be used as main channels until my k402 synergy speeakers are ready. Then they will be my surrounds.
6: last few pieces for the rack shelves are at the powder painter now.

We are awaiting an estimate for my wooden trough/acoustic panel holders to be installed above the windows and on the other 3 walls.
 

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The rack is 90% done...the one missing shelf had a huge crack so it is clamped while I wait for the glue to dry. I will install the last shelf tomorrow. The only thing left to do is to get the Cantera Stone top cut, and installed. The stone will be just like the stone to the right of the rack in the picture. When we get back from vacation. I will be starting on the Belle bass bins, hopefully have enough cash to get the Dirac boxes...so I will have balanced crossovers for the B&O amp module boxes I am also making. I will have 170w for each horn, and 450w for each bass bin.I am hoping to have the part of the journey done by Xmas this year.
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