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Part 1 The Layout


Greets all. This is the third time I've attempted to type this up. The first time (this morning) was really verbose and I realized I needed photos so I scrapped the post. The second time (couple hours ago after I took photos) I have these photos, but just didn't have my words right. Hell, I didn't even make sense to myself, and I live here! So now I'm attempting to get this out succinctly, and hopefully get some suggestions. I tend to think out loud in my threads, so feel free to chime in with thoughts, suggestions, or to reign me in if I'm going in over my head. :whistling:

OK, first off; this is a Semi-dedicated theater room. It's my living room, but my fiance and I really enjoy our movies and computers...so she's OK with most anything I do, as long as I don't wreck the place (or my bank account :no: ). The problems I'm going to have with this room (As I see it), is that it's conjoined to a dining room, has a huge opening in the wall between the livingroom/diningroom and the kitchen, and there are no doors to close between rooms, hallways, basement etc...it's all open doorways.

My fiance and I have only been in this house a little while. iIt's our first house, and was a forclosure we scored at a decent price (before the market went to @#$%. So we are working on fixing a bunch of stuff up. Please forgive the construction mess and tools about.


Here is a quick MS paint sketch of the layout. Sorry, I don't know how to use any 3d software (the last I tried to use frustrated me so much I just fired up paint and drew this in 12 minutes). Allow me to elucidate with drawings and photos (I love photography, so I tend to take a lot)

Layout of the room. The Theater Seat with the X is my main seating position. The black box to the left of the sofa on the left was is my nearly 10 year old Wicked One 36" X 36" X 14" Sub. On a table (till I figure out layout or upgrade) is my little InFocus 1024X768 projector which was the bomb when I got it (pre-HD). The mains are Elemental Design US-6T6 with 5T5 rears (sitting on floor till I figure out where to mount). The speakers are driven by an old Yamaha DD/DTS receiver, the sub is pushed by an EP2500 and the drivers in the sub are JL Audio 10W7 DVC. I also have an old region free DVD player, Pioneer Elite Laser Disc player and some ancient device called a VHS...all of which I didn't even bother to hook up as 98% of what we watch is from the 4 year old HTPC with over 5 Terabytes of hard drive space connected to the Receiver through fiber and the projector through DVI.



Here is the layout from my POV:



And this is what the room looks like while standing on the center channel (not something you hear every day now, is it?) The blackout drapes on the right (left of seating position) cover a set of large windows.



The dining room showing the patio door, blackout drapes covering that huge sliding glass door.



Notice this back wall that gives me wonderful (midwest sarcasm) flutter echo:



This is the POV from the back wall (while balancing on the hand railing - no I'm not a circus freak, I'm just very agile):



POV from the kitchen. I cut this out because I wanted a more open floor plan. I'm framing the opening in cherry, and making a figured maple counter top for a little breakfast bar. There will be three saddle style bar stools here for extra theater seating.



Ye ol' sub. If you've read some of my other threads, you may have seen me jest about the drink stains, chipped corners and cat puke marring....Yeah...this has been used as a coffee table for a long, long time.



This is what it looks like inside:



I'm working on getting some textured black veneer and I'm going to laminate the sub to bring it up to the modern look of the rest of the place.
 

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Discussion Starter #2
Part 2: Working on Sound Treatments

Back in the day (10+ years ago) I used to enjoy building subs, speakers, tube amps, and eventually got into building my own QRD diffusers and various absorbers. I sold most of them as I just didn't have the space in the tiny one bedroom apartment. Now that we have a house and I'm setting up the garage as a decent workshop, I'm hoping to really go all out on this theater room! Here is the workshop I'm putting together in the garage:

Before:



After: (my budget ran out before I got all the cabinets purchased, more to come!)



I've been dreaming of having my own house, my own garage workshop, and my home theater room for YEARS! So within my small budget, I'm going as all out as I can! Well, this is what the garage looks like now. LOL



And here are the projects I'm working on. I've already shown you all the sub that I'm soon to be remodeling. So here are the linear diaphragmatic bass absorbers:





If you look at them from the top, they are like the silhouette of a diamond. e.g. 45 degree angle to fit in the corner, with a 3 angled face. It's MDF filled with thermafiber and bubble wrap. It's supposed to absorb starting in the 25Hz range, though we'll see about that. I built these about 8 years ago (I was a bit ahead of the curve in home theater treatment). These will be covered in some sort of fabric I figure, as black laminate like I plan for the sub would be too expensive. And who knows if these really work as well as a super chunk! They do make an audible difference, so I'll see if they are workable in this room.

Next are some leftover QRD diffusers I built a few years ago from scraps I had around the shop. These took me a weekend, and I built them just because I was bored...I really had no place for them at the time. I sold the fleet of much larger QRD diffusers I used to have because I just couldn't use them at the time.



I'm considering putting the QRD diffusers on the back wall, but I'm reading that heavy absorption is a better option. I've also though about poly-cylindrical diffusers on the back wall since they are neat lookin', and I enjoy a live sounding room, plus I've never built them before.

Next up, the (relatively ) portable super-duper-chunk. I'm using JM814 (OC703 analog) cut to a 34" face in this (probably overbuilt) cage so I can move them to different corners and take measurements with REW.





I plan on making two of these 4' tall Super-Duper-Chunks, and just carrying them up into the theater room and stacking them in the left front corner. Once they find a corner to live in, I'll be making a large grill to cover them up, or just wrap them in fabric. The two MDF absorbers are probably going to be dropped in the corners in the dining room as that's the only place they will fit (and the cats like sleeping on them) The last project that I've not started yet, is a few 4' X 4' free standing absorbers using the acoustic insulation left over from these projects. (I have plenty)




So, seeing all this, and knowing I'm decently capable with a table saw...I'm looking for some room treatment suggestions, thoughts, ways to improve my setup.....(anyone, anyone, Bueller, Bueller) I'm very excited to see what may come up in this thread!
 

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Wow, that garage is awesome! I'm jealous. We have a decent sized garage, but, it's just packed with junk right now. I've been using my deep freezer as a work bench.

One of these days.

One thing, what's with the tiny screen?
 

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Discussion Starter #6
Wow, that garage is awesome! I'm jealous. We have a decent sized garage, but, it's just packed with junk right now. I've been using my deep freezer as a work bench.

One of these days.

One thing, what's with the tiny screen?
It's 86" actually. And I've had it for about 8 years. I'll be doing a DIY 2.40:1 screen plus new projector and anamorphic lens when I can afford it. For now, I work with what I haz

I think you need to get your toes into more pictures, sort of as a reference scale. :yes:
I love that shot. I saw a shot like it in a magazine and totally had to cop it. It was the very first shot I took in fact.
 

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It's 86" actually. And I've had it for about 8 years. I'll be doing a DIY 2.40:1 screen plus new projector and anamorphic lens when I can afford it. For now, I work with what I
haz
.
Hooray!! :clap: Another cinemascope convert..:T

I'd give my right arm for that workshop..:bigsmile:

That's a very interesting sub design...It almost looks like a lay down Transmission Line, except the tapers don't look right..
Did you make that? I'd be interested to know the design philosophy..
 

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Be sure to check out the Black Widow screen thread if you like DIY. Did I notice overspray from a tele body?
I did a search and found Black Widow Screen mentioned everywhere, but I don't see the original thread. Gotta link?

If it'st he paint on, I can't do that. The walls have a textured wallpaper that would be a nightmare to remove, and at this point (And because of the layout of the room), building out the wall for a screen is not an option.

Now, building a frame and stretching a screen I can do!


As for the telecaster. That sheet I use for cutting and staining and what-not. I built a telecaster from scratch for my fiance, White Ash dye'd blue and then several, several layers of clearcoat (which I still sanded through trying to make it smooth. I'll never try and "finish" a guitar again without spray gear!


Hooray!! :clap: Another cinemascope convert..:T

I'd give my right arm for that workshop..:bigsmile:

That's a very interesting sub design...It almost looks like a lay down Transmission Line, except the tapers don't look right..
Did you make that? I'd be interested to know the design philosophy..
4th order bandpass coupled to a folded horn. I'm thinking about building another one, maybe a single 15" and extending the horn considerably...though I've not done the math to see how effective this would be.
 

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Cool Thread! It looks like you are really into optimizing the sound in your HT. Thats a great shop you have. My table saw is currently sitting in the corner of my apartment bedroom. I've got the toys, but I can't play. :crying:

From the look of the pic with the mic on the tripod, you have done some measurements of your room. Are you using REW? can you share some graphs so we can see what you are dealing with?

linear diaphragmatic bass absorbers:
Are those sealed boxes and are they completely filled? It would be interesting to see what and how much they absorb.

My general impression of panel/diaphragmatic absorbers is that they are not that efficient, but they offer a way to absorb frequencies too low for broadband absorbers to handle effectively (if you have a problem down low).

I am pretty much a noob at this and am just working my way through the Master Handbook of Acoustics. It will be interesting to see what the effects of different types of absorbers and difusers will have on your room.
 

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Discussion Starter #12 (Edited)
Yes, this is what I have so far.







I'm still figuring out REW, and I'm getting a little frustrated because I'm feeling very limited with my options of change on the old Yamaha Receiver I have. I have a crossover at 90 and I have large/small/none as speaker choices. My REW measurements look really good if I kick in the surround and measure (which I was told I shouldn't do), but then when I go two channel the sub is +12 db or so.

Every change I make that I think is going to be a big change does almost nothing, and all the little changes I make make huge changes to the setup. I spend most of my time calibrating and trying to minimize the Variables so my measurements can be comparitive. :wits-end:

Last night I spent 4 hours flipping the folded horn around to different parts of the room (I say flipping because at over 100lbs two people struggled to gently move it around furniture). After moving, testing, moving, testing, moving, testing, and testing again I've come to three conclusions:

1) after all that work, my original location sounds better in the theater seats, and measures better in REW. I should just trust my ears and go with what sounds good and saved myself 4 hours of smashed fingers and chipped MDF.

2) I really need a sub that can go down to 15Hz pretty solidly. This folded horn has a huge peak around 40Hz and drops like a rock below that. No room placement is going to fix that.

3) Super Chunks to slight improvement, but not as deep as my diaphragmatics. I'm considering building new ones that are floor to ceiling by cutting these two apart (for the material inside) and starting fresh.


Fred, I feel your pain...I was in a one bedroom apartment with stuff stashed at friends and parents houses for the past 10 years after a nasty break up that lost me a house. So I'm very happy to be a house that's *mine* and nobody is going to muck that up this time around.

The diaphragmatics are layered with Thermafiber and 1" (big) bubble wrap. From the original papers on the CWAL absorbers (which don't exist online anymore) the bubble wrap acts as highly dense air, and the Thermafiber works like any other acoustic insulation by converting sound to heat. So the CWAL is literally layered T-B-T-B-T-B-T-B-T from back to front. Each sheet cut to fit the diminishing shape of the 45 degree corner. I built these 10+ years ago by now. And when I first dropped them into the corner of my listening room/home theater (1 bedroom apartment living room), even the least audio-interested persons went *wow* to the change in sound...so I've kept them around even though I have no way to measure the change till now.

Too bad I don't have a sub that pushes hard in the 25Hz range. :no:


eugovector, thanks for the link on the Black Widow. It looks like a good option, I'm just not sure I can do it without building up a whole new layer of drywall over the textured wallpaper, and then painting that. It almost seems easier for me to get screen material and build a frame and go that route. But it is an option I guess.
 

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Discussion Starter #13

Thanks for that link. While researching Black Widow I ran into the BOC method (which I had to research as well), which lead to me using Laminate that can be purchased from Home Depot and the like.

So I've decided I'm going to build a 54" X 129.6" Grey laminate screen with a 4" velvet boarder, all mounted on a thin pine frame. I plan on mounting this frame directly to the wall using small cleats (so as little of the textured wallpaper gets damaged in the process and the screen is "floating" off the wall), and then I'm going to backlight the border of the screen with LED Rope Lights...which should look quite nice on the blue wall!

I'm still looking for ideas on the room treatments. I have lots of my own (mostly random) thoughts, but hoping someone who's worked through a room like this might have some suggestions to help me avoid some pitfalls.
 

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Eric

Overall, I think you have the right ideas though I'm not real fond of the lack of symmetry left to right - but doesn't look like you have a lot of other choices.

The left front corner and side wall directly beside the speaker is going to need to be well treated to deal with boundary issues off the close wall and to try to introduce some pseudo-symmetry.

Front wall in a home theater setup should be 100% dead. In your case, since you're kind of limited in space, I'd probably recommend 2" 703 or equivalent.

I'd also recommend getting the L and R mains up more around 1/3 to 1/2 of the screen height.

Bryan
 

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Eric

Overall, I think you have the right ideas though I'm not real fond of the lack of symmetry left to right - but doesn't look like you have a lot of other choices.

The left front corner and side wall directly beside the speaker is going to need to be well treated to deal with boundary issues off the close wall and to try to introduce some pseudo-symmetry.

Front wall in a home theater setup should be 100% dead. In your case, since you're kind of limited in space, I'd probably recommend 2" 703 or equivalent.

I'd also recommend getting the L and R mains up more around 1/3 to 1/2 of the screen height.

Bryan
My Hero!

Thanks for chiming in Bryan. I've been looking forward to your thoughts.

I have 2" JM814 ready and waiting for whatever plans I come up with. And I can easily pick up a bunch more as my budget will allow. I was originally going to put movie posters on either side of the screen, but reading several dozen of your posts all saying 100% dead front end had me revising that. At *very* least I'm going to do 2" or even 4" of JM814 behind the gear, right up to the chair rail. I'm not sure how I can get away with covering the front wall without completely changing the look of the room...but it sounds like it's necessary.

I plan on raising the speakers about 8", I'm just mulling over the best option for how to do this. I was thinking about building something like the Sub-Dude for the LCR, or maybe even a frame filled with JM814, sorta like your end tables. But it sounds like you want me to go higher with them....shouldn't the L-C-R be on even level? Is there a reason the L-R should be so high? What's the theory behind doing that?

I will layer up the absorption big-time on the left wall to try and approximate the open right side as best as I can. I've also thought about making a 4' X 4' free standing unit with JM814, but having a hard back on it to help simulate what the left wall will sound like. What's your thoughts on that, am I beating a dead horse trying to build fake walls?

Lastly, my back wall. I'm really thinking about building some polycylindrical diffusers, and using some JM814 in the rear wall/ceiling corner and left-right of seating position. Considering I have ~10' between my seating position and the rear wall, should I be diffusing, absorbing, or a mix of the two? With the drop out in the 300-1500 range, I *really* have to do something...I'm just not sure what at this time.

Thanks again, and I really appreciate you're taking the time to peek into my thread. I'm learning so much from reading through your guidance of other theater and listening rooms...I know mine is one of the more difficult ones. :bigsmile:
 

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Don't try to muck with the right side. Just leave it as is and treat the left wall.

Speakers need to be up higher. I'd raise them at least 2'.

Front wall - don't go too crazy. 4" will likely be too much in that application.

Bryan
 

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Yup. Gotta get them up off the floor a ways - they're not designed for that and the boundary will be mucking up bass response - not to mention being way too low to lock to the video right.

Oh, and you need to wear white socks when listening...:bigsmile:
 

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Yup. Gotta get them up off the floor a ways - they're not designed for that and the boundary will be mucking up bass response - not to mention being way too low to lock to the video right.

Oh, and you need to wear white socks when listening...:bigsmile:

I don't know about the white socks...wouldn't I have issues with light reflections and high frequency absorption?

Maybe we can compromise on this...I have a nice pair of Merino wool and Polyolefin blend with silver threading (silver is a natural anti-bacterial) in a nice grey/black herringbone pattern. Should be a good balance of warmth with neutral absorption/reflection and less stinky to boot! :nerd:

Any thoughts on the rear wall?
 
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