SVS cracking mortar joints (1 Viewer)

[Joseph*K]

This may sound odd, but (I think) it's a serious question: Has anybody ever had issues with subwoofers breaking mortar loose in a glass block wall?
I'm still in the planning stages of my HT (thinking about dual 20-39 CS+), but the glass block wall is already in place.
I'll be emailing Tom and Ron in the near future with a room design, etc., but has anyone heard of or had issues with mortar joints cracking? Can these subs be THAT good?

 

[Steve K.H.]

K, for real, the proper way to install a glass block wall is with cement (recessed) and grouted thereafter. The grout should be approximately 1/4 think at minimum.
a) The mortar is a weaker composition of concrete. Typically it has better flexibility than concrete combined with a stress rate of some 400 psi. Masonry won't crack from your sub (or we'd have a few people worrying about their footings... )
b) There is no viable concern for the grout to crack either, or people with tile applications (on hearths or floor ceramics) would have raised this issue. Grout as well is both durable and flexible.

 

[Gary PT]

Joseph,
If you're playing your subs at those kind of SPL's for those lengths of time, you should probably be charging admission at the door! But seriously, with my SVS 20-39, the only "structural" damages (so far) have been the occasional picture vibrating off the wall in the dining room down the hall or a bottle shaking off the refrigerator in the kitchen two rooms away. But then again, I've only owned my SVS for about 10 days! Maybe Ron and Tom should sell insurance policies for these things.

 

[JoelM]

I have the dual 25-31CS+/sampson package. I cranked the pod race the other day and my windows were shaking beyond believe. Not to mention it shifted my crystal chess set almost to the dropping point. If your wife has a lot of nick-nacks and stuff either glue them down or support them. I would run a low test to isolate your rattles and shakes but other then that I wouldn't worry about it screwing with the foundation of your home. I mean my car gets into the 150DB range and it still is in one piece.

 

[Mike Strassburg]

On the other hand, drywall coming loose can be a reality...

 

[Steve K.H.]

It is going sideways a bit, but I've got to address the drywall item before people think that ceilings are going to fall down by having subs running.
Drywall coming loose is a reality in any residence, as evidenced by nail pops. This is a product of fasteners not holding in the wood, or being driven too deep into the drywall.
If you have kids and if they jump around, the movement of the joists will transfer along the framing as well. Another way to create a pop is simply running into a wall. One more way is if there is any form of warpage on the stud itself, causing more stress in differing areas...
Much like a chain, the fasteners have strong and weak links. Unfortunately you will not get equal fastening depth and/or tension on the fasteners across the board (pun... blah)...
Structural property changes in the studs are contributors as well. As the framing dries or goes through cycles of humidity and lack of humidity, the tension on the fastener changes as well.
This said, a sub "could" cause vibrations to loosen the odd fastener or drywall from the fastener (usually a product of too deeply fastened to begin with). Your sub isn't the prime candidate for causing this though, unless you tiptoe through your house.
Now hopefully your contractor used the recommended # of 35 fasteners per drywall sheet... if they cut back to say 12, buy a hardhat.
(That was overkill, wasn't it?) :frowning:

 

[Mike Strassburg]

Steve,
Kinda vague in that reply
I'm sure he skimped on the number of nails. So do I want to use screws or nails to fix it??
Actual problem is the loose drywall smacking against the studs during loud bass scenes. At first I thought it was the sub bottoming. Took a little while to figure it out. NOT a pretty sound...