2 X 2 acoustic tiles on walls as well as ceiling?

Hello all. I could not find this in the searches. I'm finishing a basement for a client. I am building her sons a music room with double wall construction between it and the house with insulation in the cavity. There isn't time or budget for extensive acoustical design and construction so we are just doing the basics. I will be doing T bar dropped ceiling with 2 X 2 acoustical tiles, with Rockwool insulation above and in the joist cavity. Is the room in your opinion likely to sound better if these acoustical tiles are also on all the walls instead of drywall? It's OK if a little more of the sound passes through to the house. The outside walls of The double wall construction will have drywall on them. I'll make it look finished, just want opinions on the sound. We will be doing a few room treatments after. This is in western Canada. 9 feet wide by 17 feet long with 9 feet to bottom of joists. Concrete floors. Front wall is concrete with a stud wall in front no wallboard on it yet. Thanks for you input Keith b

I will be doing T bar dropped ceiling with 2 X 2 acoustical tiles, with Rockwool insulation above and in the joist cavity.

It seems to me that either you aren't describing the situation completely, or you don't need any isolation. You mentioned that you are doing two-leaf construction, which implies you have an outer leaf on all sides and an inner leaf on all sides. But then you say you are doing a drop ceiling... Is that in addition to the inner leaf ceiling that should be there if you want isolation, or instead of it? If all you have is the sub-floor above and the drop ceiling, then you have no isolation. It is limited by Mass Law and air-tightness, which are pretty lousy for most basements. So if your "inner leaf" ceiling is just acoustic tiles, which suffer from the exact same problem, then you have no isolation...

Is the room in your opinion likely to sound better if these acoustical tiles are also on all the walls instead of drywall?

No. The "acoustic" part of the name "acoustic tiles", is just a name. They actually don't have great acoustic properties at all for studios. They aren't much use for isolation, since they are light weight and porous, and they aren't much use for treatment either, since they are not very diffusive, not very reflective, and not very absorptive. Replacing drywall with acoustic tiles is a really bad idea. They are meant for entirely different purposes. The best way to isolate a room, is to design the complete isolation system, taking into account all the parameters and goals, as well as acoustic tests. The best way to treat a room is to fully design the complete treatment, taking into account all the parameters and goals, as well as acoustic tests.

There isn't time ... for extensive acoustical design ...

Then there isn't much chance of a good result, either. Sorry to be so blunt, but that's the way it is. Rooms that have no acoustic design, have no acoustics. If you can't take the time to design the isolation and treatment properly, in accordance with the needs of the situation and the dimensions of the room, then you won't get a useful result. It will just be random. The room should be treated based on the way it needs to be treated. If there are objectionable modal issues, they should be dealt with in the normal way. If there is flutter echo then it should be dealt with in the normal way. The total number of sabins of absorption can be calculated based on the target decay time for the room, based on its purpose, the room dimensions, and the construction materials. If there are undesired specular reflections, they should be dealt with in the normal manner. All you will accomplish by putting the exact same treatment on five sides of the room is to make it sound equally bad in all directions. Acoustic tiles have a very specific spectrum of absorption coefficients, diffusion coefficients, and reflection coefficients. If all the surfaces are treated identically, then you will only be providing that specific spectrum of treatment, regardless of weather or not the wall in question needs it. So the room will end up sounding dull, boomy, honky, and lousy. It would be similar to just gluing carpet all over the walls and ceiling...

9 feet wide by 17 feet long with 9 feet to bottom of joists.

So the room has a square section? 9' high x 9' wide? So you have multiplied modal issues? What are your plans for dealing with that rather large problem?

Front wall is concrete with a stud wall in front no wallboard on it yet.

Is that stud framing in contact with the concrete wall behind it? If so, then it won't be a proper fully decoupled MSM two-leaf system... - Stuart -

Thanks for the reply, Soundman. New question at the bottom. Okay, so the big takeaway is, drop ceiling to isolate from above, use drywall. Got it. As for the other issues: Yes, the room, without treatment will sound like @$$. And I've told her that. But I don't have the skills, and she doesn't have the budget, to a) bring in someone, or b) pay me to do a whack of research and then blow through wads of her cash to make it sound great. The main concern is isolation to the rest of the house, to benefit she who is paying the bills. Then it will be up to the boys to get/build room treatments after. Interior front wall of MU to concrete - here by code there has to be a gap between the concrete wall and stud framing. It will be 1" Room width/length are set by existing walls/rooms/posts/client desires. I think all I can do within these constraints is drop the ceiling more to change height to width ratio. By the way, I've heard of skewing walls/ceiling, and don't know if it would help, but to nip that in the bud now, it's not in the budget. Question: In light of the fact that this is such a small cavity(1377 cu. ft.), are we better off dropping the ceiling down more, say, to 8' to try to address room modes, or to keep the volume, and therefore the higher ceiling? Thank you for your time. Keith.

Okay, so the big takeaway is, drop ceiling to isolate from above, use drywall. Got it.

Right, but for good isolation it needs to be decoupled. Either on wood or metal joists that rest only on the new inner-leaf walls (for highest isolation) or on hat channel hung from proper acoustic isolation clips (Eg. RSIC clips) attached to the bottom of the existing floor trusses above you (which would be cheaper, but not quite so good).

Yes, the room, without treatment will sound like @$$. And I've told her that. But I don't have the skills, and she doesn't have the budget, to a) bring in someone, or b) pay me to do a whack of research and then blow through wads of her cash to make it sound great.

It doesn't need to be either of those! That's the entire purpose of this forum: Free help with inexpensive solutions. There are simple assumptions that one can make about the room, and simple treatment that can be made by practically anyone in a few hours, even with only very basic DIY skills. The result might not be Abbey Road, but it can still make a substantial improvement, and take the room from being "unusably terrible" to "quite acceptable".

The main concern is isolation to the rest of the house, to benefit she who is paying the bills.

Then your basic plan is fine, as long as the new walls are decoupled (disconnected mechanically) from the existing walls AND ALSO from the floor above. That's the key. You do have plenty of height their (9' to the joists), so it would be simple to put new joists across the new walls and hang your drywall from that, for maximum isolation.

Then it will be up to the boys to get/build room treatments after.

When the time comes, send them over here so we can help them out with that...

Interior front wall of MU to concrete - here by code there has to be a gap between the concrete wall and stud framing. It will be 1"

:thu: Excellent!

Room width/length are set by existing walls/rooms/posts/client desires. I think all I can do within these constraints is drop the ceiling more to change height to width ratio.

Not necessary! In fact, the opposite is true: try to keep the height as high as you can. You don't need to go crazy looking for the best ratio, but you should still stay away form the bad ones, such as exactly square dimensions. As long as you can be more than about 5% different, that's great. From what I can see, it should be relatively simple to do that.

By the way, I've heard of skewing walls/ceiling, and don't know if it would help, but to nip that in the bud now, it's not in the budget.

Great. because it's a myth. A very well circulated and regurgitated myth, but a myth nevertheless. It can help, yes, but is never actually necessary, since there are other ways of dealing with flutter echo. So you don't need to do it anyway, even if you did have the budget.

Question: In light of the fact that this is such a small cavity(1377 cu. ft.), are we better off dropping the ceiling down more, say, to 8' to try to address room modes, or to keep the volume, and therefore the higher ceiling?

Both! :) In other words, try to keep the ceiling as high as you can for greatest room volume, while also attempting to stay away from the really bad room ratios. If I had to choose, I'd go for more volume. Modal issues can be treated reasonably well, but you can't "treat" a lock of room volume... But do warn the "boys" that, because the ceiling is kept high to make the room sound good, they WILL have to do some treatment to deal with that. No doubt at all. For certain. It's not complex, nor expensive, but is very necessary. - Stuart -