# How to fix these walls I have?



## thewire (Jun 28, 2007)

The builder that built my HT decided to save some cash by not installing insulation in my interior walls. I stopped them midway but they had already finished half my wall dividing the two spaces in the foundation. On one side is the HT room and on the other is the lobby and closet space. The closet space is without insulation. To make matters worse, they decided to install the cheapest shelving out of furring strips and plywood sheets. They nailed these furring strips directly to the drywall and studs. I plan to tear down these walls or repair them somehow. :bigsmile: I would like to know if insulating this area with pink then new drywall will be good enough or if I will require a higher STC. Would I be better off to have blown in insulation and add a second layer of drywall over the furring strips? Is there another inexpensive way to fix this? Here are some photos, a waterfall, and a RTA 1/12 measurement averaged of a movie playing in the HT at -10dB from reference level. The movie was the ending of "Disturbia". I had already seen the movie so I did some testing instead. I also checked this playing in the lobby and the garage above. Not meant to be accurate but it does give an idea what I'm dealing with here. If there is a better way to measure what I may need to treat please let me know. Do you think I should treat the corner in the closet with absorption also? All three rooms are in the same concrete foundation and it is steel/concrete above. The foundation is a square, 21 feet length & width and close to 9 feet high. How should I go about fixing this and is this in fact the problem I am seeing? When I place thick boards along the left side of my HT next to the equipement closet area, and in the corner also, the null at around 60Hz gets less worse and for a relatively small size area. The size of the HT is 13.5 X 20.5 X 7.5. For questions about the equipment or for other info please use the seach feature or look at my profile in advance.

Note: Measurements were taken before that hole in the wall.


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## bpape (Sep 14, 2006)

Filling the wall with pink is just fine. 

Guess I'm either being dense or just haven't had enough coffee yet but I'm not getting what you're doing with the board about the null.

Bryan


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## Space (Jul 18, 2007)

Gotta keep a close eye on contractors.

Rather then tear it all down, could you build a 2X4 frame and place it against the new/existing sheetrock. Then fill that frame with typical home insulation, covered with fire retardant material?


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## salvasol (Oct 31, 2006)

Space said:


> Gotta keep a close eye on contractors....


I agree :bigsmile:



> ... Rather then tear it all down, could you build a 2X4 frame and place it against the new/existing sheetrock. Then fill that frame with typical home insulation, covered with fire retardant material?


I think this will be cheaper 



> ... I be better off to have blown in insulation and add a second layer of drywall over the furring strips?


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## thewire (Jun 28, 2007)

bpape said:


> Filling the wall with pink is just fine.
> 
> Guess I'm either being dense or just haven't had enough coffee yet but I'm not getting what you're doing with the board about the null.
> 
> Bryan


In the white areas circled is where by placing a reflective surface, what looks like a null will be reduced. I was able to bring the furthermost point of the null as far as 5dB higher by placing a surface in the front left corner or by placing a large round cooler in the back right area of the room.










I was just using some things I had laying around to see what effect I could have on the null. I don't have any idea exactly what I would do about it. If it is an axial mode caused by the closet area will improve that, I want to be sure I do it correctly.

It also might be something to do with my measurement technique or devices used. There is apprarantly a more than usual amount of current being displayed in my graphs and this is not good.:rolleyesno: Here is a rerun from another post in the REW forum area that may be relevant to the issue. The adpater I refer to is my laptop power supply adapter.



> Here is a loopback measurement of my soundcard using the identical settings I use to measure my subwoofers. The first is with the adapter and the second is without.


Thank you for the suggestions Space and salvasol.


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## Space (Jul 18, 2007)

salvasol said:


> I agree :bigsmile:
> 
> 
> 
> I think this will be cheaper


"Would I be better off to have blown in insulation and add a second layer of drywall over the furring strips?" /quote


It will also produce a 3rd leaf if I am reading it the way I am reading it


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## thewire (Jun 28, 2007)

Somwhere between another meaurement program, my lap tops power adapter the above signasl in question in occurred with the 60Hz line voltage showing. Thats not an issue anymore as I have figured out how to avoid it.

Placing some insulation between the ceiling of the next room and the ceiling in the HT has made a pretty good difference. I added each peace of insulation above my ceiling tiles to strategic locations each time checking them in REW. There were some corners that needed to be filled but the area above the closet made the largest impact down low. I also moved my subs to each left/right wall midpoint prior to testing and half way through the proccess a first reflection point panel fell off my wall because eather the room has more bass or the Velcro decided to give up at the particular time. I bought some hangers to space them off the wall instead and so far, two are completed. The absorption off my back wall will have to go since not all in the family agree it looks good. I also replaced my subwoofer amplfiers with better ones. Made some progress I think.

Someone else wants to repair all the holes in the drywall rather than to have new layers added. I'm not sure I know how to argue that one.


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## salvasol (Oct 31, 2006)

thewire said:


> Someone else wants to repair all the holes in the drywall rather than to have new layers added. I'm not sure I know how to argue that one.


onder: What about saying: "..... We can repair those holes, but the wall will not be strong enough because of the damage, if we add another layer of drywall that spot will be strong as new and the rest of the wall will be stronger" :bigsmile: :R


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## MatrixDweller (Jul 24, 2007)

Really what I would do is rip down the existing drywall on one side of the wall and start over again. The blown in stuff will be more expensive because you'll either need to have it done by a professional or need to rent a machine to do it. Also blown in insulation tends to settle over time which would leave a voids in the wall. Batts will fill the cavity better and I would go with Roxul Safe n Sound for maximum effect. It's about the same price as fiberglass anyway. The money you save on insulation would pay for the drywall that you need to replace I bet.


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## thewire (Jun 28, 2007)

That is a good suggestion and might have been what would have considered. Now we want to eliminate the door at the closet area where it is located currently and drywall over that, then install a leaverd door from the closet to the lobby area. This will make the front area of the HT air tight and symetrical. Insulation would not be neccessary. This will also allow the hush box vent to have the air going out of the HT portion of the space and allow better cooling inside of the HT. 

Plans I am also looking into are:

1: Removing the wall heater or relocating it elsewhere.
2: Moving the back row up against the back wall
3: Moving the front row seat to the back row for a row of four
4: Modifying the steps on the riser or leave it as one large 12" step.
5: Removing a portion of the rear Helmholtz resonator to allow the spacing for the seating to be moved back.
6: Get newer speakers with wide horizontal disperation and good off axis response.
7: See about having the beams removed. Constractor said wait one year and get an opinion.
8: Move equipment to the equipment closet and run wire/cables. What an engenous idea that is right? 

There may be a few other things to consider but this is the list for now. I regret not better communicating the importance of correct design otherwise this would have been done right the first time. The builder was acting out of his own reconnasince while the contractor was away on vacation and there was little I could have done. He was payed 50$ for the closet out of pocket not by myself. I did not know he was there and I had been watching them 24/7 on scheadule of completion.

Some things we did save are:

1: There was going to be no step in the lobby until we mentioned the fact. It would have been a door into the next area of the house about a foot or two lower and people would have had to duck to go to the next area of the home.

2: The new deck and steps went so far into our previous deck there was no space to walk around.

3: The concrete floor of the HT was not flat. They wanted to build half the room as a concrete shelving space over the uneven area and leave a 9ft walkway around it.

4: There was no HVAC until I suggested this to be installed and showed them how it was possible. I have had a HVAC class.

5: They installed a hallow door as the entrance to the HT instead of the exterior door I requested. I had them replace it with the correct one but the door is not located exactly where requested.

6: They did not want to use insulation anywhere.

7: They were about to install my riser on the opposite side of the room.

8: They had sent the incorrect slidding exterior door of the lobby wrong 3 times from Lowes. The went the wrong direction.

9: They were not correctly installing the dedicated electrical circuits. I fixed them.

10: They would only take any instruction not from me, but by the people paying to have it done although they had specifically stated I had authorization. This made each step of the HT in the 3 week proccess it was desinged/built take at the very least one full day extra to compete. Many times I sent them home.

11: I should have kept my blue prints under lock and key. It was thrown away 3 times therefore I had to design the HT 3 times.

12: I inspected numerous times so many that I can not recall where a stud or other item was not properly secure and it needed to be redone, or improved upon. Most I did myself.

There are many more things that went wrong but that is the short list. Me and my father will be building and remodeling the HT very soon after the older outside decks railing is redone.

By the way there are houses around here that are junk. Septic tanks under the bed, small rooms up large steps, poor driveways, dryer and washer in seperate areas of the home and much much more.


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## thewire (Jun 28, 2007)

I will also see if I can get help paying for the insulation/drywall with help of another family member. If not I could just pay full cost myself.


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## thewire (Jun 28, 2007)

They want more seats. I will see what they think of this. Are there any suggestions? I measured the room and the front three seats except the one next to wall being fixed work right now. The middle row would have at least one good seat and the back row would be a no go. They don't mind if it doesn't sound good. :foottap: Everything seems to be going as expected. :R:help:


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## thewire (Jun 28, 2007)

On topic I expect the peak to loose about -4dB or more and the extention to go about 2Hz-4Hz lower with that wall fixed. The response is now a few Hz lower and the ringing is much lower. This an 85dB measurement. REW volume level was 3 and this is a new soundcard driver.. It is just a sanity check and not the exact location but within a foot of where the seat tested might be. This is the seat furthest from the right wall in the sketch and in the front row.


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## thewire (Jun 28, 2007)

He changed his mind and he now wants the older plan of two rows of three. The back row will not be up against the back wall. 

Edit: Four in the front (two arm rest) and two in the back (two arm rest) also works. I will test to see if it works for the subwoofers.


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## thewire (Jun 28, 2007)

The demolition proccess has begun. First we continue to remove the walls (with older attachments) and each nail, screw, or staple so that the wood may be reused elsewhere, or burned. Some is done already but much is to go still.


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## thewire (Jun 28, 2007)

Now we must buy more wire because the rest is stuck behind our walls and isn't going to budge because it is though holes in each stud very tightly. The rear surround wires will have to go up the rear wall exposed until the newer speakers are mounted near the ceiling. There was not one inch left of the previous intallation. The good news is, I don't need a longer RGB cable. The bad news is I will be walking to the next room to operate the system for awhile. The doorway is not going very well as we can't seem to agree or decide what would look best, and work best. I think we are making a hole in the wall the size of the older door, and deciding what ventalation will be needed, and what door will go there later. 

I wanted to insulate the wall from the lobby to the equipment closet but they think that I am being overly critical, but will do so anyway. Isn't it going to help not to have an empty wall running next to the HT wall? :scratchhead:

This is two photos I layed over eachother and is not a very good pic.


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## thewire (Jun 28, 2007)

Here are some of the new tools and building materials. The DW is 5/8" which is thicker than the previous. Not shown is screws, twist ties, wire, etc. The drywall we will try to add a knock down finish like the other walls have. I will practice with the sprayer and on some older DW we have leftover from another project and there will be some other things to pick up we already have. We also need a junction box and some Romex to run the dedicated HT circuits over to the closet area. We don't have the paint ready and the door we are looking at is over $600.00, but we have not ordered one yet as we are still thinking about it. It has a rounded top to it. The unfaced R19 is for inside the HT above the walls, but isn't the last place getting more.


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## thewire (Jun 28, 2007)

Alot has been done in the HT and the equipment closet thus far. Here is the closet and the new wall on the other side in the HT. A subwoofer cable and a cable for the mic is going into the far right wall by the corner (about 2 feet) into the other side just bellow the new subwoofer outlet. There is a large PVC pipe conduit installed and the wires and cable are all done at that area with the access panel. The other side of the wall still needs more trim, and the panels need to spaced at the bottom. The area of the carpet the where the outlets are at need to be cut out. I decided that I will get some larger trim (one on the left side isn't going there) and use the smaller ones pictured to run along the front wall for decorative purposes and to keep the screen frame more steady. They stay in bewteen the two spaces without attaching them. 

I'm also working on the pair of track lighting in the back of the room. The romex was already ran on the switch. I am going to see about attaching it to some new rear ceiling tile peices I made out of cork board. It came with some anchor screws. I also filled my rear Helmholtz Resonators filled very heavily with insulation and filled gaps above my steel support beems and the corners above the walls (non weight bearing) with pink so that there is no space left undone. The hushbox also has a decent amount added now above that. I will update my dedicated build thread eventually but this one will need some closure. :bigsmile:


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## andru (Aug 19, 2008)

Hi,
Had you considered a layer of "deadsheet" stapled to the drywall, then covered with another layer of drywall. It could give you better low end absorbtion (from flexing) and more acoustic insulation. (on the internal listening wall) 
Especially when combined with the fibreglass insulation in the new void that you are already creating.
However sound does tend to behave like water, in some regards, and find the path of least resistance to escape. So plug all the holes...

I hope I understood correctly.
Andru


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## thewire (Jun 28, 2007)

You mean something like Acoustimat? Nope that would put us over budget. I'm not sure what you mean by creating a new void. Where?


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## thewire (Jun 28, 2007)

I used small strips of felt at ear height while seated between the DW and the studs, about two dozen tubes of caulk and the white foam (more recent) or silicone (done earlier) in all the outlets and holes. I stuffed the spray foam in the new holes I made in the stud above the ceiling also. It is in the walls at the bottom of the studs and the sides also. The HT is air tight except for the conduit , AC/HVAC duct in, and the projector hush box fan vent in that corner. The wall with the wires in it has insulation on and behind the wires. I did not bother with felt on the new DW where the door was because it is held in place by only 2 X 2's attached to 4 X 4's. These are some really old photos.



















The studs next the concrete are all attached using liquid nails.


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## andru (Aug 19, 2008)

I thoguht, perhaps wrongly, you were building another false wall with an air space between the walls.
Sorry if I was off target.
Andru


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## thewire (Jun 28, 2007)

Thats okay. Yes it is just a false wall or a partition wall. The veiw of the new opening for the door is just from the lobby and there is a steel door to the HT room seperate from this room. :yes:


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