My ridiculously large sub

[j_garcia]

What does "short wall" mean. Short as in extends into the room or is it a half wall? I'd try to get the big sub into that corner by the short wall. 9'6" doesn't leave a ton of room for that big sub though.

 

[darien87]

Well I found out one reason for why I wasn't totally blown away by this sub.

AIR LEAKS!!

I was talking to the guy I got the stuff from the other day and he said that if I push on the radiators, the sub should push out, but go back in slowly. He stressed that the sub shouldn't just snap right back into place. So I tried this and sure enough the sub just went right back to position as soon as I released the radiator. I climbed on top of the box so that my face was hanging over the edge right above the woofer and did this again and was treated to a blast of air right in my face. Seems the top of the sub wasn't sealed very well. Who knows where else I might have had leaks.

So I took all of the speakers out and bought some bathroom caulk at Home Depot and proceeded to caulk up all of the corners of the box, around the speaker terminal hole, and around the hole for the sub and both radiators. I can't believe I didn't do this before.

I think I've got it pretty well sealed now. But the sub still goes right back to position when I push on the radiators and let go. But when I think about it, it doesn't make sense to me that the sub would stay out when I push on the radiator. I'm not sure what is supposed to be going on in there.

Anyway, I think maybe I'll buy some more caulk in clear so that I can just go around the outside of the woofer and each radiator and try to seal them up from the outside as well as the inside. Maybe this wasn't such a great idea.

 

[j_garcia]

They sell a product for sealing drivers, sort of like soft tape, that gets compressed. Bathroom calk probably isn't the best idea, but it will work.

 

[Stereodude]

Supposedly the outgassing of the caulk isn't good for the surround of the drivers. Be sure to let it air out before putting it all back together.

 

[darien87]

Supposedly the outgassing of the caulk isn't good for the surround of the drivers. Be sure to let it air out before putting it all back together.

****. Too late for that. Well at least the box had an open hole until I put the last driver in. With my luck I just screwed the whole thing up.

 

[j_garcia]

I've used RTV silicone to seal the inside of enclosures before, but never the drivers to the box. IMO, just keep an eye on the surrounds; they will probably be OK.

 

[Alex2507]

****. Too late for that.

It's not too late. Yank the driver back out and let it de-gas into free space if you're worried. First of all that silicone thing is known to affect foam surrounds IIRC. Is your surround foam or rubber? ... and can someone verify this rumor?

 

[STRONGBADF1]

 

[darien87]

So I ended up buying some DAP Silicone adhesive/sealer at Home Depot on Friday and went around the outside of the sub and each PR. The box seems pretty well sealed to me.

But it's still the same. When I push on the PR's, the sub goes out, but bounces right back to position when I let go. When I think about it, it doesn't make sense that the sub should stay out, then return slowly when I press on the PR's. If the box is basically sealed, then I would assume that pushing on the PR would cause the sub to push out and then go right back to position, just like it does. I would think that if there were air leaks, that is what would cause the sub to go back to position slowly, as the air would be escaping from the holes and not allowing the change in air volume cause by pressing on the PR to push the sub out.

I don't know whatever. I'm done messing with this thing though. It still sounds pretty good.

 

[average_male]

reminds me of the amp that Marty McFly blew in Back To The Future. ha ha, dang, that thing will cause an earth quake or break some windows at least. Your neighbors will love you..

 

[darien87]

reminds me of the amp that Marty McFly blew in Back To The Future. ha ha, dang, that thing will cause an earth quake or break some windows at least. Your neighbors will love you..

Yeah it's pretty crazy. Luckily my neighbor in front recently moved out and the only other neighbor I share a wall with is totally cool and has never complained, even though I know I must be rattling stuff off of her walls.

But we'll be moving into our new place in a couple of months, and then there will be no more sharing of walls.

I've been re-watching a lot of old demo material and this thing really pounds! I did a FR test with a disc from AVS and it has considerable output down to 11hz!

 

[Alex2507]

What do you guys think of this layout?

I would be tempted to just run the 15" alone. I know Davemcc has had a weird stroke of luck running dissimilar subs but even he admits it's strange to have the addition provide a room cancellation in a previously spiked area. Barring that I wonder what would happen if you put the 12" behind the couch as well to get a little more room gain. That doesn't make any sense following the last thought but experimentation is the key ... so long as it's somebody else doing the work. Let's not forget the stack option. I ended up going with that because of my two placement options in the front of the room, one of them produced a smoother response so I went with that location ... twice. It's still a different position technically because of the vertical difference and will aid in providing a smoother response across a wider area according to something I read.

I know you know but Gramma, Gramma, Gramma ... even if you have them leaned up against the wall ... they'll make their way under the subs eventually.

 

[j_garcia]

I have to agree, the 15 will probably be enough. I see no reason to stuff your grandma under your sub whether she is leaning against the wall or not... Yes, a Gramma is a must IMO.

 

[darien87]

I have to agree, the 15 will probably be enough. I see no reason to stuff your grandma under your sub whether she is leaning against the wall or not... Yes, a Gramma is a must IMO.

I'll try it both ways and we'll see. If the 15" is indeed enough, I'll move the 12" upstairs to the bedroom and sell my old 10" Boston sub.

What is it that the Gramma actually does? I don't understand how it works. I find it a little hard to get myself to spend that kind of money on what is essentially a big piece of foam.

 

[ParadigmDawg]

I don't know if all Grammas work the same or not but mine is an awesome cook, reads to me and is just really sweet.

What is it that the Gramma actually does? I don't understand how it works. I find it a little hard to get myself to spend that kind of money on what is essentially a big piece of foam.

 

[j_garcia]

I'll try it both ways and we'll see. If the 15" is indeed enough, I'll move the 12" upstairs to the bedroom and sell my old 10" Boston sub.

What is it that the Gramma actually does? I don't understand how it works. I find it a little hard to get myself to spend that kind of money on what is essentially a big piece of foam.

I am not sure how exactly to describe how it does what it does, but the result is clear that bass is a lot cleaner in my room with no other changes. The floor picks up sympathetic resonances from the cabinet that creates additional sound that is not part of what is being played. The Gramma removes that.

 

[darien87]

So the pre-wire on the great room is done. Used 12 gauge wire throughout. Got speaker wire, RCA cable for one sub and HDMI cables for the TV all in the walls. They did the insulation yesterday and should be dry-walling today or tomorrow.

I can't wait. It's gonna be so awesome to set the system up and have no wires showing other than the speaker wire going from the wall plate to the speakers.

 

[darien87]

Also had them put in two 20amp circuits to be safe.

 

[gmichael]

Also had them put in two 20amp circuits to be safe.

Good. One for the sub and one for the rest of your system.

 

[Patrukas777]

I don't know if all Grammas work the same or not but mine is an awesome cook, reads to me and is just really sweet.

I don't know how I missed that...thats hilarious!