I just don't get this at all. I have no understanding what it is you are trying to do.
Neither do I. I wouldn't be asking the questions I have been asking, if I knew exactly. Do you get it now? The whole thing is experimental, it is an exercise (in acoustics design)
You don't want to absorb, you want to reflect, but not the same reflection as the plaster wall, so you want to reflect using timber, and then fill it full of insulation for what....? I can't see this as anything other than an exercise in futility?
You see it that way because you misunderstand or misinterpret things. Where did I say I don't want to absorb? Look closely. A simple answer to that first part is actually: I don't care. I do not care if "the device" absorbs, reflects, blocks, or shoots the sound out of my neighbours chimney, as long as the isolation is improved a little bit and the room is sounding better, I have achieved what I set out to do. Fundamentally, the whole thing is nowhere near as complicated as you describe it.
Truly respectfully, if you don't understand something, why don't you ask
for clarification? I'm not only happy to do answer, I'd want
to do that. It's part of the process. I'm not an acoustician or an engineer, there's a ton of stuff that I simply don't know. However, I read a lot, I constantly research and learn things new to me. I can try to answer a specific question better. So now, what's your question precisely? That ".....?" is a tricky one.
A drum set is physically large and asymmetrical. The right side is almost touching a concrete wall, on the left side there are only much
softer barriers 20+ times further away and positioned diffusely. How would you suppose that effects the sonic balance of the set? What happens when you strike a crash cymbal on the right side? How about striking the one on the left? If recorded, would the frequency spectrum of these two cymbal hits perhaps be different? Would they have very different decay times?
You are phrasing everything as "wanting" to reflect or absorb or do something else to a set of sound waves, in theory
. That is not relevant to anything at all if the context is not understood or like in this case, there IS NO CONTEXT. Are you a musician? Are you aware that the acoustical properties of a space are meaningless if there is no sound?
I'm installing a wood surface on that wall because I'm 100% sure the reflections from the wood paneling will be vastly superior to those of the concrete wall.
I'm leaving a gap between the wall and the new surface because that provides a multitude of possibilities for reducing the sound energy that reaches the other side of the wall.
I'm NOT "filling it with insulation
", it just happens to be that for example felt works as both an insulator and an absorber. And I happen to have extra felt around.
You are extremely welcome to suggest small changes and improvements, and I'm still waiting to hear from someone: If, as you say, this will "not work" (whatever that means...), explain to me WHY wouldn't it work. Or do you after all actually find it plausible that it will work?
It's wrecked many responses to your original question now you've changed the questions, and altered the intention. As for the bit about how much vibration is a nail going to transmit - people spend ages trying to find exactly this kind of problem when their insulation appears to fail. The idea to uncouple structures from each other is pretty solid stuff - and a wall plug, that by design is a solid fixing, and semi-structural in strength is not a barrier to transmission, quite the opposite.
I have not altered anything at all, what I did was provide more detailed information of exactly the same concept I proposed originally. But let's just let that go.
What I said about the nail was somewhat of a bait, I have to admit. Hook, line, and sinker
There's been a dampening layer in my plan from the very beginning. I didn't think for a second that just nailing a bunch of wood to the wall would achieve what I wanted. Even if I covered the entire wall with 2x4's or some sort of board (the "adding raw mass approach"), it would still be relatively uneffective without any insulation or a gap.
I think you should just build the damn thing freestanding and then play the drums and see what happens. I'd never do it myself, it appears rather pointless, and frankly, I still have no idea what exactly you are expecting it to do?
I could very well build a standing panel like that, perhaps a smaller one, and see what happens. Or with much less trouble, and like I think someone already suggested, I could move my gobo next to the drums and see what it does. I expect that being behind the gobo compared to out in the open, would drastically
alter the sound of the drums heard. I should actually remind myself to make a recording of that for comparison purposes, since it's very rarely these days that anyone else plays the set.
Small note: do remember that the brick wall covering is plaster concrete
. I decided I'll refer to it as just "concrete" to avoid complete misunderstandings. That is since there exists the sort of plaster that you could easily punch a hole through with your fist, and the sort of "plaster" that is literally hard as a rock. The covering here is of the hard variety and it is around 4 inches thick. I assume it's both sides of the wall as well (there's a bookshelf on the other side, so the other side is inaccessible).
Until next time.