Slaughter House Cinemas (Project Thread)

[carls64]

Ok I think I am at a point where I want to get serious about sound

I would like some input on what I should tackle first, I want to create a false wall so I can put all the front stage sound behind it, and maybe pack the corners with fiber. I had read that as an alternative to buying the ridged fiberglass panels and cutting them into triangles and stacking them in the front corners, busing several rolls of RXX fiberglass and just keeping them in the rolled up plastic and stacking them in the corner would work as well, no one is going to see them behind the wall.

Also I figured my screen distance to be a viewing distance of 15' from the front row which was optimum for my 120" screen size. What would happen if I moved to 2' closer and place the screen even with the false wall, my viewing distance will be 13' from the front seating area but right at 15' for the second row (my location). I am sure I have plenty of projector lens shift/zoom to accommodate that, but should I di that or build the wall around the screen and leave it a shadow box? I am just not sure. I think it would look cleaner to do that?

[carls64]

I updated the first post with new information now that the main part of the project is complete

[bpape]

Seating location should be based on proper distances to avoid room modes in the bass. Adjust screen position accordingly, don't move seats to fit the screen.

As for the corners, yes, the rolled fiberglass can actually work quite well - other than the fact that the plastic will reflect high frequencies.

Bryan

[carls64]

bpape wrote:

Seating location should be based on proper distances to avoid room modes in the bass. Adjust screen position accordingly, don't move seats to fit the screen.

Sorry I should have been clearer on what I planned. The plan was to build the false wall to conceal the speakers and sound dampening material, and move the screen forward 2'. No way I was going to move the seats! This would obviously put the screen 2' closer to the seating area.

bpape wrote:

As for the corners, yes, the rolled fiberglass can actually work quite well - other than the fact that the plastic will reflect high frequencies.

Maybe bind it with twine and remove the plastic? Lowes and Home Depot have the rolls of I think R13 for $7.00 a roll

[bpape]

Or, you could sweet talk the Mrs. into sewing you some 'pillowcases' from some Muslin (preferably black) that can be had from JoAnn Fabrics for around $2.50 per yard

Bryan

[salvasol]

. . They really look nice, everything blends together in your HT ....I'm Happy that everything is working for you ...

[salvasol]

carls64 wrote:

... What would happen if I moved to 2' closer and place the screen even with the false wall,...

I like it this way .... it will have a flush look and also you will use less material , dont forget to cover the whole front wall with insulation besides the rolls in the corners for the bass

...or build the wall around the screen and leave it a shadow box? I am just not sure. I think it would look cleaner to do that?

Same as post #123??? ....

[carls64]

bpape wrote:

Or, you could sweet talk the Mrs. into sewing you some 'pillowcases' from some Muslin (preferably black) that can be had from JoAnn Fabrics for around $2.50 per yard

Well it would be me doing the sewing she don't do that

The only problem I see, is based on the location of my speakers/subs I am not sure where I am going to place any sound material

[bpape]

Well, that's a bit of a problem - but easily rectified. Your speakers shouldn't be that close to the front wall anyway. Side wall, not much we can do about it with that big a screen in that narrow room. Pull the speakers forward a couple of feet and you'll find that not only do you have room, but you also probably have smoother upper bass response by getting them out of the corners.

Bryan

[carls64]

bpape wrote:

Pull the speakers forward a couple of feet and you'll find that not only do you have room, but you also probably have smoother upper bass response by getting them out of the corners.

Does that mean the center channel and the subs too?

[bpape]

Potentially, yes. Sub positioning is critical. Even a few inches front to back or left to right can drastically change frequency response. Use REW and play with positioning and see for yoursefl

Bryan

[carls64]

Yes I have REW setup and have been using it for some time, getting ready to do it again with the new subs.

[carls64]

bpape wrote:

Potentially, yes. Sub positioning is critical. Even a few inches front to back or left to right can drastically change frequency response. Use REW and play with positioning and see for yourself

So move the LCR forward about 2 feet, leave the subs there until I config with REW, this gives me room in the corners from some sound material, but if I move the speakers 2 feet forward, that will put them in front on my purposed false wall, is that the back of the speaker about 2 feet from the wall or is that the front of the speaker away from the wall.
Sorry to ask so many questions, I suppose that is where a forum/text does not always make the best way to converse. So many questions. Thanks for all your help!

Looks like the price on a roll of R13 is now around $10 so if they are 18" wide I will need at least 4 high that is 6' I am bout 7' ceiling so double that's 8 so about $80. I don;t remember how much the sheet stuff was at 2" thick cut in to corners, if it's not much more I might be better going that way. I want simple and easy

I think you gave me a contact locally here in IL, close to St Louis and they had a outlet in Glen Carbon or Swansie I think that carried that stuff. Ya HERE it is.

[carls64]

bpape, is this the stuff I want, it is what Liz sent me information for. Back in July it was about $27 per sleeve (6 x 24"x48"x2", 4 x 24"x48"x4").
IIG-402.pdf

[bpape]

Actually, the 4" will only be 3 pcs to a sleeve.

Your call on the wall. I'm just trying to give the speakers some breathing room. If you can only swing 2' for the false wall, then it'll have to be the front - but it's still better than where they are now. Play with positioning on the mains also. You can tweak things quite a bit with an inch or 2 movement.

Bryan

[carls64]

Ah right, 3 pieces. I figure if I completely cover the screen wall I will need to sleeves of 2" and 2 sleeves of 4" to do the two corners. I will experiment with the speakers before deciding where to place the wall. I am going to see how much I have to work with in regard to distance of the screen and projector, I know I will loose 2' between the seating and the screen if I move the screen with the wall, which will look better visually, but maybe not be better for watching movies. Saying that with a 120" screen the optimum viewing distance is 15'.

[thewire]

When you move the left and right, try aiming them more towards the center of the room.

[carls64]

bpape, your location says Wildwood, MO (St Louis) didn't realize you were that close to me, you should know where Bethalto, Il is, I am close to Alton, IL Your Link to GIK is Atlanta, GA

[bpape]

Yeah - well, it's a virtual world. The GIK headquarters and factory is in Atlanta, GA. I work remotely via email and phone from Wildwood (far West St. Louis) Our diffusion designer, Jason, lives in Seattle, WA.

As for toe-in, MOST speakers acutally do better if you don't aim them right at you. Try toe in to point about 4-6' behind your seated head position. Not all work this way but it's usually a good starting point.

Bryan

[carls64]

bpape, Is there anywhere else I can get the mineral wool? It seems the company you gave me info for will not sell to individuals, and they are currently out of the 4" stuff.

[bpape]

Really... They're probably the best place to go. If you PM me with your number, I'll give you a call and we can work something out. When they get back in stock, I can go pick it up and we can meet somewhere.

Bryan

[carls64]

I leave for Florida on the 14th of Nov, and they said they probably will not have it before then so it will have to wait until I get back in Dec :-(

[bpape]

Lemme know what you want. I can go ahead and get it if you're sure you want it.

Bryan

[carls64]

Need to figure out how much I need too, My screen wall is 89" high, so I want two base traps in the corners, I think we talked and I need 2 x 3 sheet packs of the 4" gives me 96" for the corners at 17x17x24 ? right, then if I get the 2" material I want to cover the screen wall (Behind) and move the screen forward even with the false wall, so After the 17" on either side with the corner basetraps that leave me with 119" x 89" (153" [12'9"] - 2x17=34, = 119") I need 10,591 sq" and each piece of 2" materials is 24x48 or 1,152" into 10,591" looks like 9.19 pieces, so I would need 2 packs of 6 if my math is correct that leave me with a couple of pieces to use for some wall treatments.

So I would need to 2 x 4" (3 pack) and 2 x 2" (6 pack) so that right?

If I move my false wall forward 2' and move my screen flush with it, I will need about 6 yards of fabric to cover the area around the screen. That will make my viewing distance about 13" at the front seats and 16' at the 2nd row. I should be ok shouldn't I? If I shadow box the screen it will be more work and more fabric and then I can't get any insulation behind the screen.

[carls64]

bpape wrote:

Lemme know what you want. I can go ahead and get it if you're sure you want it.

Bryan

I have been reading so much lately, this stuff is equivalent or better then the Owens corning stuff? Its very inexpensive compared to it for sure.