New HT Project: Construction questions

[DucatiR]

Riser is now completed. Construction pics follow....

I used 1x2 furring strips under the ends of the riser and joists to span the crown in the floor. I was concerned about head clearance with the false ceiling that will come later. But I think the 3/4" addition from the strips will be ok. Spray paint on the 2x8's was a mask step so I could tell more precisely where to put the strips when I moved the assembled framing halves out of the way. Screwed and glued the strips to the floor. Glued the 2x8's to the strips and used 3" deck screws through the 2x8 to the subfloor.


Insulation going in. R30 fits perfectly for 2x8's.


First part of the decking using 3/4" plywood. Glue and screws again (shouldn't be much in the way of squeaks - I hope). I've read a number of posts suggesting mdf for riser decking due to the additional mass. I'm still debating in my own head whether to do that or not. I will be using 40oz felt under the carpet so hoping that will help with some sound. Not the same mass as mdf though. The empty slot down the center was just temporary for easier walking from one end to the other.


And the finished riser as viewed from the screen wall.


Next up is track light installation while I wait for the carpet order. In the last picture you can see the bare bulb fixtures I've been using during construction phase. Track lights will start at those junction boxes. Paper on the left is fixing a texture/paint issue at the air return grille.

[Ted White]

DucatiR wrote:

Here is the door from the equipment room into the HT. It is solid core and I used extra long screws in the hinges. I'm thinking of mounting 5/8 wall board to the HT-room side of the door with a bit of Roxul stuff between it and the door. Just a bit of extra soundproofing. Not sure if this is needed or advisable? but I put a lot of work into the rest of the HT surface area.

I would not recommend using drywall on anything that moves. Material fatigue will happen and drywall is so brittle.

Make sure the door is sealed well. The bottom of the door usually has a large opening that won't ever be properly sealed with weatherstrip.

You could add MDF instead of drywall. Installing insulation between layers will get you no improvement. I'd suggest getting a single tube of Green Glue and laminate the MDF to the door. Secure with screws.

[Bruce Fisher]

great article Ted - thanks for sharing. I can attest to the solid core door... we had 3 replaced in our room - you can instantly tell the difference. I purposely didn't have them trimmed yet because I was waiting for our carpet to come in (installed 2 days ago)... I plan to have as small of a gap to the floor as possible.

Ducati - what's the value of the extra long hinge screws you mentioned?

[DucatiR]

Ted, thank you for the article link and the mdf suggestion. I like that a lot better anyway - I won't have open drywall edges. For the bottom gap I'd actually planned on using an automatic door threshold. But the block and sweep could be just as (nearly as?) effective and much cheaper.

Bruce, I did a fair amount of reading on hanging doors and a few tips from my father who's hung a number of doors. From my reading the top hinge bears a large portion of the weight of the door. Long screws are sometimes recommended for solid core doors to help prevent jamb sag. If I'm putting additional mass on the door (mdf) then the hinge will be taking even more weight. So the long screw is intended to help solidly anchor the door to the studs behind the jamb.

DucatiR

[salvasol]

DucatiR wrote:

So the long screw is intended to help solidly anchor the door to the studs behind the jamb.

Good idea

Are you using the self/automatic closing hinges??? (I don't know how they're called, but after you release the door they close it)

[Bruce Fisher]

Time to make sure my construction guy used long screws

I'm curious about the autodoor seal too. I read somewhere they are made to work with hard surfaces... not sure if they'd work on carpet. Would love to hear someones findings on that.

[Ted White]

Auto door bottoms can seal up to a door threashold, or a smooth, hard surface like an oak threshold, marble, etc. They will not work on carpet, as you can't seal up against all that fiber

[DucatiR]

Cross post regarding anamorphic projection questions which will affect my screen wall construction decisions:
http://www.hometheatershack.com/foru...tml#post168814

For screen wall I was inspired by Carl's Slaughter House Cinema design at the following thread and will following this concept pretty closely. Thanks to Carl and the contributors to that effort!
http://www.hometheatershack.com/foru...thread-11.html

[DucatiR]

I've been brushing up on my reading of sound treatments as I get ready to build the screen wall. I'm curious if anyone has thoughts on two different approaches for the bass traps:

1) similar to Carls in the Slaughter House Cinema build thread. In this approach triangles of OC-703 are stacked solidly from floor to ceiling, or
http://www.hometheatershack.com/foru...thread-11.html

2) similar to Ethan Winer's room in his YouTube video. In that approach the bass trap panels stand vertically and span the corner leaving a void space behind.

http://www.youtube.com/watch?v=lbLVjHfHahg

http://www.youtube.com/watch?v=lbLVjHfHahg

The attraction of Ethan's approach is the cost savings by having to purchase fewer OC-703 panels. Any opinions on these options?

[Ted White]

Ethan knows his stuff

[DucatiR]

Just called around looking for the OC-703. The guys that put the insulation in the theater room have a box of 24 pieces of 1" 2x4 panels of Johns Manville acoustic insulation. It is excess material from a previous job and said he'd sell me the box for $25! He referred to it as IP-53 though I didn't see that at Manville's website. I called Manville's and they said acoustic properties of the material I described would be similar to their Spin-Glas board insulation.

The 1" would be nice for panels at first reflection points with my vaulted ceilings since I'll have narrow head clearance already. Key question: can this material be effective for my bass traps as well? I could double up the panels for a 2" thickness in the corners using Ethan's method. 10-1" sheets would give me 5 panels for behind the screen wall (2-vertical corners, 2-vaulted corners, 1-ceiling). That would still leave me plenty for the back wall and a few reflection panels elsewhere in the room.

But, I've never read about Johns Manville products here that I can recall. Any experience with those products? Did I luck into a really good deal or should I keep searching for the OC-703?

[bpape]

JM will be just fine. For bass control, you'll want at least 4 layers though.

Bryan

[Prof.]

DucatiR wrote:

2) similar to Ethan Winer's room in his YouTube video. In that approach the bass trap panels stand vertically and span the corner leaving a void space behind.

This is the type I used..Flat panels 6" thick floor to ceiling in the front, and 4' high 6" thick panels in the rear corners..
Works well..

[DucatiR]

Still waiting on the OC-703 to arrive. I ordered a bit extra to accommodate my requirements. Given space constraints and feedback on specs for effective traps I've concluded I have to go with the stacked triangles in the front/rear wall corners vs. panels.

In the meantime, I've got all the trim painted and installed, got my track lights in, a key piece of equipment finally installed, speakers shelves up and a rather unorthodox (I think) equipment rack. Pictures follow.

Here is the HT room with track lights and one of the speaker shelves. Unopened speaker boxes are against the back wall where the screen will eventually be placed. Hope to have some initial sound this week but maybe not until early next week. Of course, the sound will be pre-traps, but still - progress! I know speakers right against the wall are not ideal. Space constraints may limit me in this regard but I may end of moving them around after screen wall and furniture are in.



Speaker wire run into the equipment room thru the conduit over the ceiling to the back wall for LCR and front sub.


Now here's an important piece of equipment when your room is far away from the main house (ok, relatively far ).


Now, for the equipment rack I did a lot of research and brainstorming. My current, 20 year old all-in-one stereo system is inside a cabinet and pivots on a diy lazy susan bearing assembly to allow access to the rear of the components. It is functional but less than ideal as the gap is barely wide enough for my head and part of my shoulders. A vent at the top back of the cabinet allows heat to escape but not the kind of heat I'll be seeing with the Onkyo 876.


There are a number of nice rack systems I could have bought that allowed the components to be pulled out and turned around but space and cost again became limiting factors. Additionally, a number of racks pivot on the center which would consume a good chuck of real estate. I finally landed on a solution that I think will out great and it cost me less than $100.

Here is the equipment rack with one shelf installed. It is comprised of 1-1/2" galvanized pipe firmly attached to the floor and ceiling. Shelving brackets are bolted to the pipe. The entire assembly rotates on the pipe floor flange.


The brackets are normally installed with bolt holes aligned horizontally. In this case I needed to off-set the bolt holes to eliminate bolt interference.


Here is the floor assembly. 4" toggle bolts through 3/4" plywood and the 1" floor substrate. The galvanized floor flange is bolted through the plywood. I inserted the pipe as far as possible into the floor flange and then backed it off 1 full turn to allow rotation. The threads have been lubricated to minimize thread wear. I don't plan on rotating the shelves frequently so wear will be less an issue than static load strain.


The heaviest component, the receiver, will be mounted lowest. The top of the pipe was stabilized using a similar construction. Toggle bolts through plywood and the wallboard.


A second block was attached to the plywood with screws and has an angled face to align with the pipe. Before attaching the angled face block I recessed holes in the back side for 2 bolts to protrude from the face. A metal strap is attached to the protruding bolts to secure the pipe at the top. You might be able to make out low-friction sliders I inserted between the strap and the pipe to facilitate rotation.


Here is the rack in a closed postion...


and roated to the open position to allow access to the rear of components.


The base will be covered with carpet and still figuring out what I want to cover the top to hide the bolts and straps. The shelving bolts will also be painted white. It is a bit industrial looking but that fits with the overall look I'm going for in the equipment closet anyway with exposed wires, cable trays, and eventually some themed paint.

I've already tested this by loading the shelf with weight and repeatedly rotating the assembly. No sounds of strain at any part of the assembly that I could tell during loading or rotation.

[Bruce Fisher]

Looking great! I give you credit for waiting on the sound... I couldn't do it - I had to temporarily wire my speakers so I could listen while I work

[Prof.]

DucatiR wrote:

Here is the HT room with track lights and one of the speaker shelves.

The lighting looks good, angled on the ceiling like that..

Here is the equipment rack with one shelf installed. It is comprised of 1-1/2" galvanized pipe firmly attached to the floor and ceiling. Shelving brackets are bolted to the pipe. The entire assembly rotates on the pipe floor flange.
Attachment 14586[/quote]
That's a very clever idea..
Do you think you'll get enough support on those shelves with the brackets splayed out from a central point..particularly with a heavy AVR.?
The support points on the wall will certainly help in the closed and open positions..But what about when you are moving the equipment between those points?

[salvasol]

Prof. wrote:

The support points on the wall will certainly help in the closed and open positions..But what about when you are moving the equipment between those points?

Good point Prof.

What about doing the same (as the first pipe) in the other side of the rack, but this time use the pipe with a wheel so it will move when opening, this will support the equipment all the time...

[Prof.]

Double post

[DucatiR]

Bruce Fisher wrote:

Looking great! I give you credit for waiting on the sound... I couldn't do it - I had to temporarily wire my speakers so I could listen while I work

Bruce, I think we are similar in that regard. I intended to say that I will have the speakers running shortly but it will not be the best sound as I still don't have traps/panels installed yet. I got all the speakers except my subs wired tonight. Hopefully tomorrow I can get them fired up!

Prof. wrote:

Do you think you'll get enough support on those shelves with the brackets splayed out from a central point..particularly with a heavy AVR.?
The support points on the wall will certainly help in the closed and open positions..But what about when you are moving the equipment between those points?

That is a good question Prof. and was one of my principal concerns. For clarification, the "support points" you refer to are actually a door stop and bumper to keep the rotation shelf corner from hitting the wall. Close ups of these points:



I deliberated on the weight support and considered the following. The vertical struts are normally mounted some horizontal distance apart and attached to studs (I use this same stuff in my garage where the struts are are separated by 32"). When the struts are screwed to studs the brackets I have on the bottom shelf have a manufacturers rated load capacity of 400lb (181kg).

At this point I get into supposition. Screws can rip out from wood and wood is obviously softer than galvanized pipe. I used bolts with lock washers on the pipe. I tried to stagger the bolt spacing so as not to have stress from one bolt impinging on another or the pipe material from being simultaneously stressed by the load from adjacent bolts. I figured that two sets of equally constructed shelves, one on wood studs the other on pipe, with struts and brackets equally spaced and loaded, would find either the wood studs failing from excessive load or the struts/brackets or bolts failing before the galvanized pipe gave way. But I have no data to support that.

Will the struts and brackets still support up to 400lb in the configuration I have used? Probably not. Will they support a 60lb AVR? Probably not if screwed to a 2x4. But I think the pipe/bolt assembly will hold. I have loaded the shelf with weight to test the capacity and have observed no issues so far. Of course, metal fatigue can be insidious and less observable than a stud cracking or screw beginning to pull loose.



In short, I guess what I concluded is that I would not try this with a shelf load >100lb given the strut configuration and uncertainty of pipe strain, bolt strain and concentrated load where the struts join.

[hddummy]

I don't believe the configuration of your shelf supports really affects their load capacity. What does however is the fact that the center of the weight is more or less out at the tip of the shelf support. In a normal installation, the center of the weight would be closer to the base of the supports. Even so, if they are normally rated for 400lbs, I think they will still be good for 200 in your setup.

Personally, I think the idea is rather ingenious and I don't think you'll have a problem with it failing. If anything, I would come up with something a little more solid for the top of the post....a U-bolt or something. That thin metal strap looks to be the weak link in this design.

As for fatigue or anything of that sort, it really only happens with repetative loads or motion. Your case has static load 99% of the time, so if you load it up and it holds then you should be good.

Maybe you can test it out with some exercise weights or something else not so expensive as a new AVR. If you don't have weights, go buy four 80lb bags of concrete from Home Depot and return them when you are done.

[Prof.]

DucatiR wrote:

That is a good question Prof. and was one of my principal concerns. For clarification, the "support points" you refer to are actually a door stop and bumper to keep the rotation shelf corner from hitting the wall.

OK..I didn't realize they were buffers..

My concern was as hddummy just mentioned..The front of the shelving looks like it doesn't have much support..It may tend to flex a bit..
The back support is no problem..

One thing I would suggest is to keep your heavy equipment on the lower shelves..That should help to reduce strain on the top mounting..

Hopefully it will all work for you, and that you will have constructed a unique rack system!..

[DucatiR]

Houston, we have lift off! H O L Y C O W!!

I bought the Hsu Research speakers: 5-HB1 bookshelves, 1-HC1 center, and 2-VTF3 MK3 subs. I only have 1 sub hooked up now and only music thru the AVR but my enthusiasm for the project has been completely renewed after so much time. The sound, without treatments/traps, is light years ahead of what I have currently.


Furthermore, I finally know that all of that effort at sound control outside the room has paid off. I ramped the sound up to 100dB inside the room using my SPL. In the main house I can barely hear a rumble. In the upstairs bedroom, the primary concern, you can make out some of the bass if you pay attention. Nothing like before and these speakers are generating a lot more energy than my little garage bookshelves I'd used to check sound levels pre-construction.

So, while waiting for insulation to arrive I can get the HT door completed, the Xantech IR setup and clean up my wire runs. All while listening to beautiful sound.

Prof. and hddummy: thanks for your comments on the shelving. I do have free weights and loaded up 70lb on the lower shelf. No noises or obvious deflection. I also checked the top support assembly by using both hands and pulling/pushing at 90deg axis. I think I'd have to throw my whole body weight behind a pull to make it move at the top in any meaningful way.

The Onkyo876 is rated at 56lb and will be mounted on the lowest shelf as low as possible on the struts. Blu-ray (6lb), cable box and PS3 will be on the other shelves with brackets rated at 250lb.

I will be monitoring bolts, threads, straps, etc. continuously for quite a while to observe if there are any changes. But I think this is going to work!

[bpape]

Very nice. Getting into the home stretch. Keep the updates coming.

Bryan

[Prof.]

That's all good news..
Looking forward to the final touches..

[DucatiR]

Construction update: sound treatment and bass traps. I lost 2 weeks getting the run around from one of the local shops on my OC703. Finally gave up and went to another place.

Here is the screen wall getting full treatment on the wall and the corners.


I was stumped for a bit on how to keep the triangles in place in the vaulted and ceiling corners. I stumbled, almost literally, across a solution when I noticed the shape of cut-offs from ripping my 1x3's for the wall panels. You might be able to make out the bevel in this picture which traps the edge of the OC703.


Anyone that has browsed the Forum will recognize the panel construction...


and the typical edge bevel.


I used this pipe bracket strip on the two panels that hang horizontally towards the front of the room to minimize wood distortion.


Here is an overexposed picture of the room showing the front screen wall again after putting up speaker grille cloth. I initially guesstimated location for the two horizontal panels. To make sure I confirmed with the mirror/laser pointer method to identify 1st reflection to the primary, front row center listening position. The horizontal placement perfectly covers 1st reflection from each of the three front speakers.


The surround imaging is distinctly better after the sound treatments. Which I'm sure is not a surprise to the veterans here. I had never really given treatments much thought before. I am now an enthusiastic supporter! I watched Transformers and Dark Knight before and after. What a difference!!

Here is a view of the back wall with panels in the vertical and vaulted corners. I also put a panel on the door. It was a very flat, painted surface so thought there might be a bit of reflection there too.



While waiting for insulation I also managed to equip the equipment rack. Here it is in closed and open positions. This worked really nice for wiring things up. The Xantech IR system works beautifully from the closed HT room.



Two final pictures. One of the room in current condition with a normal exposure. I also got rope light put in on the edges of the riser both going into the room and at the front step. I attempted to capture that in a picture. You can clearly see the short strip at the door. If you look closely you might make out the back of the couch below the riser.



I have the screen ordered so need to get moving on the screen wall framing now.