AudioGrotto Build Diary

[bassman]

More bass traps going in and rockwool over them.....

-ashley

[bassman]

The soffit wall is coming along nicely. The carpentry is tricky since they have a slight angle to them. Fill with normal insulation and cover in two layers of drywall. we relocated the two electrical outlets into the soffit wall to meet code and get juice to the TV in the right spot. Conduit was installed to get wires to the TV and speakers.

-ashley

[Soundman2020]

Oh wow! Major advances! You are making me turn green with envy at the progress!

It's looking good!


- Stuart -

[lilith_envy]

great job,
I think you need wool those clouds!
How high are your speaking (L and R) they seem really low?

[bassman]

Hello lillth,

The speakers are PMC AB-1's and their tweeters are fairly high in the cabinet. They are aiming right at ear level. See the chair in the pic. The speakers actually point a bit down to ear level.

Yea, I've run out of wool from those darn bass traps! Got another 10 bags on the way!

-ashley

[bassman]

Treatment update: Progress continues in both control rooms getting the soffits finished and the rear wall stuffed plus some corner traps in the second control room.

Piccies.....

-ashley

[bassman]

We started to lay out pew pieces in the shape of the console to start thinking about its design.

-ashley

[bassman]

On to a new subject: noise complaints from our neighbor during a particularly loud drum session this weekend. This guy was hitting the crap out of the drums! 105 to 110 dBC at the kit!!! At the inside of the large stained glass window, we read around 100 dBC. Outside the window, drums were 80-85 dBC. Their house is 5 feet from that window. I guess we have a problem now.....

Well,


Right, our neighbor happens to be a retired judge who specializes in property law and zoning. How's that for luck? Actually, he is a reasonable man and we are going to work this out. The drums are really too loud over there. So, help me figure out a way to knock another 20 dB from the sound coming out of the windows. The pics show it all.

We can't really do glass block for two reasons: Historical preservation might not go for it even though these windows are on the side of the building and not part of the facade. A large glass block structure like this needs to be made from the 4" block and we only have barely 3.5" from the brick to the wood frame.

So, my current plan is to see how much 1/2" tempered glass is going to cost in order to cover these 9' x 15' windows from the outside. Currently, there is a think (1/4") layer of plexiglass covering the stained glass. We would take that off and replace it with the 1/2" tempered glazing. I know laminate would be a couple dB better but the cost is more than double AFAIK.

Thoughts?

-ashley

[xSpace]

Two things. What can you do on the inside of your window area to mitigate this issue? Simple things like drapes, plugs, etc.

Would installing a dense glass panel over your neighbors window be helpful?

[bassman]

Well, let's think about it.... The big window is 15' tall and 9' wide. Anything on the inside to get a 20dB drop would be pretty massive. I don't think drapes are going to work. The plugs would have to be HUGE!!! and hard to move in and out.

On his window, we are proposing putting on good storm windows to seal it up on his end. I just had a conversation with some friends here in the city and we are now thinking that glass block might be a possibility. I have some calls to make on Monday to find out about this. Glass block would definitely do the trick IMO.

What is the STC of 4" glass block??? I can't remember...

-ashley

[xSpace]

Right, big hole. It just seems that you are going to confront this from many different angles for it to be effective.

So small adjustments with your additional steps can start solving the concern..

Spending some money on the next door neighbors window, looking into tempered or laminated, might be better then a simple storm glass, as your last line of defense before sound enters his home.

4 inch glass block is rated at STC 44, give or take, but I don't know what the TL is and that is going to be important for your overall isolation.

[NativeLuv17]

I really like your soffit build Ashley, can you tell me how the wall doesn't create a triple leaf, since it seems as if you built the soffits against gb, and then went over them with gb?? I'm looking to do something similar.

[Soundman2020]

Currently, there is a think (1/4") layer of plexiglass covering the stained glass. We would take that off and replace it with the 1/2" tempered glazing. I know laminate would be a couple dB better but the cost is more than double AFAIK.

1/4" Plexiglass? No wonder you have a problem! Plexiglass is less than half the density of normal glass. 1/2" of tempered glass would be roughly 4 times the mass of the existing plexiglass, so by mass law alone you should get around 12 dB extra isolation, just from replacing that 1/4" plexiglass with 1/2" tempered. If you could go to laminate, then you'd probably get even better, maybe 14 or 15 dB. Theoretically, of course.

About the idea of also putting another layer of glass on the neighbor´s window: I'm wondering if that might create a four-leaf system? With only five feet of air space separating your window from his, and considering the sound levels that we are talking about, I'm wondering if that might already be 3-leaf system that you are about to turn into a four leaf system, which would probably be even WORSE isolation at very low frequencies?

Maybe I'm barking up the wrong tree here, but to my limited understanding, it does seem like a possibility. Maybe you should ask the acoustic experts here to figure out if this really is a 3-leaf that you are about to make into a 4 leaf.

In that case, perhaps a better solution would be to replace his existing window glass with 1/2" tempered (or laminate) glass? Even if it is already 3 leaf, that would still add another bunch of mass, which should gain yo another few dB.

One more question: Are you sure that it is only the WINDOW that is the problem? Could it be that there is another issue too?

I also agree with Brien that maybe drapes, shutters or a plug would be another way of adding just a little more to the total. After all, if you can't do one big step that adds 20 dB of isolation, maybe you can do 20 small steps that add one dB each!


Just thinking out loud here.



- Stuart -

[bassman]

Well, this is all good advice as usual, thanks! I don't think we have to worry too much about a fourth leaf effect. There's not too much real low end coming through now and the mass of a storm window is not significant in relation. It would just help with the sealing on his side of the issue.

The plan of the moment now is going with 1/2 or perhaps 3/8" plate glass (maybe tempered if required by code) on the outside placed in neoprene gaskets all around. If we need more, we can add another 3/8 pane on the inside for serious STC. I know that makes for a three leaf system in my wall but the added mass will outweigh that effect. The idea of a plug could come into play as well later on. This would have to be the biggest plug ever made!!! We were thinking of hanging it on barn door sliding rail to move it in and out. Won't that be fun?

OK, glass contractor and building inspector on the way. Oh the joy of owning a recording studio!!!!!

-ashley

[Soundman2020]

The plan of the moment now is going with 1/2 or perhaps 3/8" plate glass (maybe tempered if required by code) on the outside placed in neoprene gaskets all around.

Sounds like a good plan!

The idea of a plug could come into play as well later on. This would have to be the biggest plug ever made!!! We were thinking of hanging it on barn door sliding rail to move it in and out. Won't that be fun?

Time for an image upgrade! New name: "Ashely's Stained Glass Cathedral Barn Studio".

Oh the joy of owning a recording studio!!!!!

Yeah, but you do have to admit that it ain't boring!


- Stuart -