Drum set and a brick wall - reducing noise with a PARTIAL barrier/panel
- Thread starter spitzer
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spitzer
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mixsit: Absolutely, the sound will go around it. However, it could still be "effective". Just like a gobo, or an acrylic screen or similar concepts. I completely agree that most of its effect would be in altering the response in the room. Just as is intended.
Sometimes (not referring to this thread) these sorts of discussions are superbly off the wall. Like imagine a thick concrete block wall, but there's a 1 mm diameter hole drilled through it. 100% guaranteed an "acoustics guru" will come and say that since the wall has a leak (Oh my GOD! A leak!), it's completely useless. Which is obviously not true.
I was cleaning up my place the other day and I noticed that one corner, floor side, has an exposed plumbing pipe. I thought wth, where's the sandbag thingy I put there 10 years ago as a kind of "trap"? That's a huge leak, and a channel for vibrations to go through. But I did my measurements before I noticed it. 60 dB peaks on the other side. (I couldn't find anything as heavy as the bag that used to be there but I did a quick, lighter fix. Might measure again to see what that did.)
BTW, I'm currently investigating which frequency range is actually the most problematic. Volume-wise, what might surprise some, the bass drum and low tom are not the loudest components of the set. There's actually a significant difference. Floor tom and kick only -> 106 dB peak. Set including cymbals -> 112 dB peak. As for the frequency response, there's something in mid range that I don't like. Makes especially the cymbals sound weird (comparing different cymbals, some that elsewhere might be too bright sound very well balanced on recording and "darker" cymbals sound like the high end is not even there). That also affects the snare crucially. Have to think of something.
Anyway, despite that volume difference, the lower frequencies are harder to block or absorb so that's the focus. I think I'll do a bit of spectrum analysis. The "fundamental note" of the kick that I hear most clearly is at about 200 Hz. But is it at it's loudest there? Who knows.
Sometimes (not referring to this thread) these sorts of discussions are superbly off the wall. Like imagine a thick concrete block wall, but there's a 1 mm diameter hole drilled through it. 100% guaranteed an "acoustics guru" will come and say that since the wall has a leak (Oh my GOD! A leak!), it's completely useless. Which is obviously not true.
I was cleaning up my place the other day and I noticed that one corner, floor side, has an exposed plumbing pipe. I thought wth, where's the sandbag thingy I put there 10 years ago as a kind of "trap"? That's a huge leak, and a channel for vibrations to go through. But I did my measurements before I noticed it. 60 dB peaks on the other side. (I couldn't find anything as heavy as the bag that used to be there but I did a quick, lighter fix. Might measure again to see what that did.)
BTW, I'm currently investigating which frequency range is actually the most problematic. Volume-wise, what might surprise some, the bass drum and low tom are not the loudest components of the set. There's actually a significant difference. Floor tom and kick only -> 106 dB peak. Set including cymbals -> 112 dB peak. As for the frequency response, there's something in mid range that I don't like. Makes especially the cymbals sound weird (comparing different cymbals, some that elsewhere might be too bright sound very well balanced on recording and "darker" cymbals sound like the high end is not even there). That also affects the snare crucially. Have to think of something.
Anyway, despite that volume difference, the lower frequencies are harder to block or absorb so that's the focus. I think I'll do a bit of spectrum analysis. The "fundamental note" of the kick that I hear most clearly is at about 200 Hz. But is it at it's loudest there? Who knows.
spitzer
New member
Had a strange software hiccup, but I managed to find an isolated bass drum sound. A rough analysis reveals the absolute highest peak is at around 70 Hz and it peaks quite wide, spans 30-300 (anything around that is much quieter). Interestingly, it still has quite a bit of high end, lowpassing it as high as 6 kHz totally changes the sound. I'd have expected that otherwise but on this particular recording, the pedal had a felt beater and the drum was stuffed with a pretty big blanket and a pillow. (that's one nice thing about bass drums, they can be muffled quite a lot. For quieter practice or if that sort of sound is desired.) Oh, and this was recorded with an NT-1000 from roughly one meter directly in front of the drum. I didn't do any frequency response adjustments yet. I'm assuming the mic's pretty flat.
In any case it looks like somewhere around that low to low-mid frequency range is what I'd most need to absorb or otherwise handle. I'll also have to check the cymbal thing, is it that there's so much LOW mid? Definitely sounds like that's much higher up though, like around 1 k.
Anyway... I was reading more about absorbers etc. and always came across constructions using rockwool. I can't use rockwool (no suitable space, can't deal with the dust etc.) I need something safer. I somehow thought of sasquatch's suggestion to use mattresses. Mattresses are too expensive, at least ones that would have the certain, correct, density needed for these traps/panels. I thought could foam rubber possibly work? I checked an industrial supply store here, they have among other things, foam rubber in several thicknesses and it's reasonably cheap.
But I have no idea what the density of foam rubber is and can't for the life of me find that information anywhere. Anyone here? The density of flooring carpets, neoprene or rubber mats, and others would also be interesting but I can't find that info anywhere either.
I was hoping to get started on building something pretty soon, but damn... there's too much information everywhere and it's not the right kind :/
In any case it looks like somewhere around that low to low-mid frequency range is what I'd most need to absorb or otherwise handle. I'll also have to check the cymbal thing, is it that there's so much LOW mid? Definitely sounds like that's much higher up though, like around 1 k.
Anyway... I was reading more about absorbers etc. and always came across constructions using rockwool. I can't use rockwool (no suitable space, can't deal with the dust etc.) I need something safer. I somehow thought of sasquatch's suggestion to use mattresses. Mattresses are too expensive, at least ones that would have the certain, correct, density needed for these traps/panels. I thought could foam rubber possibly work? I checked an industrial supply store here, they have among other things, foam rubber in several thicknesses and it's reasonably cheap.
But I have no idea what the density of foam rubber is and can't for the life of me find that information anywhere. Anyone here? The density of flooring carpets, neoprene or rubber mats, and others would also be interesting but I can't find that info anywhere either.
I was hoping to get started on building something pretty soon, but damn... there's too much information everywhere and it's not the right kind :/
rob aylestone
Well-known member
Absolute misunderstanding.
Soundproof = no sound. A soundproof room means you cannot hear anything from outside, or outside cannot hear what was inside. Akin to being slightly pregnant. Sound reduction would be a good term, but soundproof cannot be anything other than soundproof. First post 2m x 2m wooden box assuming it's tall enough to stand up in, that's pretty much a cube, or at least a very small rectangle. The latest post confuses me even more. Variables too changeable and ambiguous. Soundproofing a room with curtains is laughable, deserves going in the soundproofing with egg-box solution. 10dB is 10dB. If you can play drums at midnight without annoying anyone, what's the point of the entire conversation - If I play drums after midnight outside I can just hear the kick, coming through the concrete floor. To my mind - this means my studio is nearly soundproof. Curtains would have worked as well as timber, plasterboard and insulation? complete and utter rubbish - unless you change the definition of soundproof, which is clearly what MUST have happened.
Soundproof = no sound. A soundproof room means you cannot hear anything from outside, or outside cannot hear what was inside. Akin to being slightly pregnant. Sound reduction would be a good term, but soundproof cannot be anything other than soundproof. First post 2m x 2m wooden box assuming it's tall enough to stand up in, that's pretty much a cube, or at least a very small rectangle. The latest post confuses me even more. Variables too changeable and ambiguous. Soundproofing a room with curtains is laughable, deserves going in the soundproofing with egg-box solution. 10dB is 10dB. If you can play drums at midnight without annoying anyone, what's the point of the entire conversation - If I play drums after midnight outside I can just hear the kick, coming through the concrete floor. To my mind - this means my studio is nearly soundproof. Curtains would have worked as well as timber, plasterboard and insulation? complete and utter rubbish - unless you change the definition of soundproof, which is clearly what MUST have happened.
spitzer
New member
A quick look at the good old Wikipedia: "Soundproofing is any means of reducing the sound pressure with respect to a specified sound source and receptor.". Before you say it, sure, some of the information on there is sketchy but Wikipedia is excellent for finding out how terminology is most commonly used. Rob, complete soundproofing the way you see it is practically impossible. As far as I can tell, also everyone else on this thread looks at it as: soundproofing = blocking the sound from getting through walls (as opposed to internal treatment, which is making the sound inside the room sound better). I haven't changed any definitions, there are different interpretations of things but that's it. I can use the term "sound reduction" instead if you like, but it doesn't change any realities.
You must be a giant if you couldn't stand up in a 2 meter tall box. 2 meters is a standard height for an apartment door, it's a tiny bit less than 6 feet and 7 inches for the imperials here. But like I already said, no one is thinking of building any kind of "cube" or any other sort of box or container to stand in.
I was, and have all the while been talking about a panel. A panel. I said in a post wayyyy back, somewhere on the first page that it would be roughly 10 cm deep because I don't wan't to shrink the room too much. After doing some actual measurements, I revised the dimensions.
So. A panel that is 2 meters long, 1,5 m tall and 10 centimetres deep. Not a cube. You can think of it as a "reinforced" part of the existing wall, which is what I do. It could also be several smaller panels covering the same area. Since the drums are in a corner, having a bass trap or traps in there wouldn't be a bad idea either. The function of this device, or series of devices would be to a) have a better acoustic surface on one side of the drums, instead of the existing concrete wall and b) reducing the sound getting through to the adjacent room.
BTW, I never ever said that "curtains" would work "as well as timber, plasterboard and insulation". There is definitely a misunderstanding there. I think I did say that you could reduce the sound to the other side without treating the entire wall with tons and tons of plasterboard and mineral wool or whatever.
I'm thinking I'm gonna have to draw that diagram. But right now, I'm gonna go play music instead. It's a much better use of my time and it makes me happier.
You must be a giant if you couldn't stand up in a 2 meter tall box. 2 meters is a standard height for an apartment door, it's a tiny bit less than 6 feet and 7 inches for the imperials here. But like I already said, no one is thinking of building any kind of "cube" or any other sort of box or container to stand in.
I was, and have all the while been talking about a panel. A panel. I said in a post wayyyy back, somewhere on the first page that it would be roughly 10 cm deep because I don't wan't to shrink the room too much. After doing some actual measurements, I revised the dimensions.
So. A panel that is 2 meters long, 1,5 m tall and 10 centimetres deep. Not a cube. You can think of it as a "reinforced" part of the existing wall, which is what I do. It could also be several smaller panels covering the same area. Since the drums are in a corner, having a bass trap or traps in there wouldn't be a bad idea either. The function of this device, or series of devices would be to a) have a better acoustic surface on one side of the drums, instead of the existing concrete wall and b) reducing the sound getting through to the adjacent room.
BTW, I never ever said that "curtains" would work "as well as timber, plasterboard and insulation". There is definitely a misunderstanding there. I think I did say that you could reduce the sound to the other side without treating the entire wall with tons and tons of plasterboard and mineral wool or whatever.
I'm thinking I'm gonna have to draw that diagram. But right now, I'm gonna go play music instead. It's a much better use of my time and it makes me happier.
spitzer
New member
Here is something for you wiseguys to suck on: https://i.imgur.com/kZdlYbO.jpg
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I was looking for transition loss for typical building materials, thinking with a 'brick wall much of the low freq leakage could just as easily be through the ceilings, but no luck, gave up.
But did come across this.. pg 11
But did come across this.. pg 11
https://www.certainteed.com/resources/30-29-121.pdf
rob aylestone
Well-known member
In honesty, a concrete wall is a better reflector than most surfaces because it doesn't move easily. Your design for a screen doesn't really seem to do much, to be honest. Sorry I got the impression you were building a 4 wall plus ceiling structure. I suspect that if the wooden slats touch, then they'll reflect practically exactly like the wall would. As much of the energy gets reflected, there won't be much to be absorbed by the filler, and what eventually escapes towards the wall will be overshadowed by the direct sound going around the panel, not through it. Daft question, but what are you hoping it will do? Absorb or reflect? As it stands, you're building a reflector. As it's not shown in the sketch, how are you keeping to vertical? If you attach it to the wall, then you've coupled it back to the structure, and through a small amount of connections putting all the energy into small areas, which if they are not structural, will have the potential to increase the transmission through the wall - not important if the wall is external, not so good of internal. I guess you could use some decoupling devices, similar to ceiling or wall isolation fixings, but you seem to be putting lots of weight into a room for little benefit. It cure the direct path from drums to your wall, and that could be useful, if you can keep the panel decoupled from the wall. I don't quite get what you are trying to do, to be honest.
spitzer
New member
Rob, I'm thinking of doing a slatted/diffusing wood surface front what comes to the "planks" in the diagram. Also, correct me if I'm wrong but I expect that any kind of wood surface will produce substantially different echoes compared to a concrete wall since wood is softer and porous. Concrete is just REALLY hard and the reflections are harsh. Especially apparent in comparing e.g. a crash cymbal on the side of the wall (diagram left) and another one on the open side. The one right next to the wall is instantly reflected right back into your ears, the other one sounds much more pleasant because it's surrounded by much more air space. So this part of it is actually just changing the timbre of what's being reflected. I chose a wood surface (instead of let's say just covering the wall with very thick carpet) exactly to preserve, aka reflect, the high frequencies but taming them a little bit.
I'm hoping to block/absorb as much low end as possible. I have also been researching 45 degree angled bass traps (since after all, that is a corner in the room) but I suppose that's a different issue.
The backing material (grey in the diagram) is supposed to achieve NOT coupling the thing to the existing structures. Whether it's felt or rubber or something else, its job is to reduce the mechanical vibration from the 2x4's to a minimum. So in effect the panel WOULD be decoupled from the wall. I'm aware of sound going around it, but like I keep stressing, even a barrier like this, in that position has to be much, much better than nothing at blocking or absorbing sound.
I have to go again, other things to do. I'm still thinking on my feet, and this is in no way a "final" design. If you can think of something that would improve it within the dimensional constraints, please go ahead.
Later.
I'm hoping to block/absorb as much low end as possible. I have also been researching 45 degree angled bass traps (since after all, that is a corner in the room) but I suppose that's a different issue.
The backing material (grey in the diagram) is supposed to achieve NOT coupling the thing to the existing structures. Whether it's felt or rubber or something else, its job is to reduce the mechanical vibration from the 2x4's to a minimum. So in effect the panel WOULD be decoupled from the wall. I'm aware of sound going around it, but like I keep stressing, even a barrier like this, in that position has to be much, much better than nothing at blocking or absorbing sound.
I have to go again, other things to do. I'm still thinking on my feet, and this is in no way a "final" design. If you can think of something that would improve it within the dimensional constraints, please go ahead.
Later.
rob aylestone
Well-known member
I'd lose the reflective components altogether - a trap works well for bass end, and absorbers for the high end. Timber's actually very reflective - having done quite a few recordings in oak panelled spaces (think Hogwarts).
spitzer
New member
Rob: I don't want to absorb the high end. Actually, ages ago the place used to be covered in lots of carpets, blankets etc. on all sides. That was worse than just the concrete. (btw, the surfaces are actually "plaster cement", I'm sure it could be misleading as I keep saying "concrete" but I have no idea what else should I then call it). Absorbing the highs makes it just a super bassy boomy space with no clarity, which is why that soft stuff was removed. I had the idea to add wood surfaces already over a decade ago but the situation changed and other things took priority. Now I have time etc. and actually a reason to do it.
I already got some of the materials, the inner surface is going to be beadboard. I asked the guy at the store what kind of boards do you have and which one is the most dense (adding to the blocking effect). They didn't have oak paneling, which I know is heavy... and several times more expensive than other woods typically used for construction, which I also knew. It actually crossed my mind that I wouldn't want oak even if it was a little cheaper since it's distantly possible it'd be too hard. But I'm 100% sure any of the cheaper and most commonly used woods for construction are less reflective, more diffuse and sound more pleasant than a stone wall. Definitely to me, in this space, in this location. In a larger room it would be a different story.
mixsit: that's an interesting question, since I don't actually know how the ceiling is constructed. The surface from inside is covered with some sort of thin-ish panels, and it sounds like it's hollow. I don't know, even if it wasn't so high I don't think I would want to tear it apart. At some point things just get too out of hand.
I already got some of the materials, the inner surface is going to be beadboard. I asked the guy at the store what kind of boards do you have and which one is the most dense (adding to the blocking effect). They didn't have oak paneling, which I know is heavy... and several times more expensive than other woods typically used for construction, which I also knew. It actually crossed my mind that I wouldn't want oak even if it was a little cheaper since it's distantly possible it'd be too hard. But I'm 100% sure any of the cheaper and most commonly used woods for construction are less reflective, more diffuse and sound more pleasant than a stone wall. Definitely to me, in this space, in this location. In a larger room it would be a different story.
mixsit: that's an interesting question, since I don't actually know how the ceiling is constructed. The surface from inside is covered with some sort of thin-ish panels, and it sounds like it's hollow. I don't know, even if it wasn't so high I don't think I would want to tear it apart. At some point things just get too out of hand.
spitzer
New member
I updated the original post. I now have enough materials to start actual construction.
One thing that came to mind, since some people see attaching things to walls as the biggest evil in the world, what is the problem there and how big of a problem is it in reality? If I just drive a 3 inch nail through a plank and through the plaster concrete, how much vibration is that nail alone going to conduct? And if I use wall plugs, the vibration becomes a non-issue, right?
One thing that came to mind, since some people see attaching things to walls as the biggest evil in the world, what is the problem there and how big of a problem is it in reality? If I just drive a 3 inch nail through a plank and through the plaster concrete, how much vibration is that nail alone going to conduct? And if I use wall plugs, the vibration becomes a non-issue, right?
rob aylestone
Well-known member
I just don't get this at all. I have no understanding what it is you are trying to do. 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?
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 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?
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 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?
spitzer
New member
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 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?
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 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.
rob aylestone
Well-known member
I don't think we have your strange sort of plaster here in the UK, apart from in old Victorian houses with damp problems. Our plaster, going back to wattle and daub has always been hard, some hard enough to be more like concrete than plaster in our traditional sense. I see your topic as a bit like a student proposition for research work. Some assumptions, a desire for a particular outcome and then myopia in responses. You're sure it will work, I'm less convinced, but of course to me it doesn't;t matter, but to you, it's important. I can't balance my understanding, flawed though it probably is in the physics, to yours. I see surfaces in terms of barriers that do different things - reflect in various amounts from not at all to completely. I see surfaces that are mirror like in their reflective properties, or have varying degrees of dispersion because their surface is not perfectly flat. In my experience, the sound bouncing back from brickwork sounds different to concrete, but not to concrete block with a similar surface. Block and brick have different transmission figures of course. Plaster, plasterboard and MDF sound different to my ears. Plasterboard probably because of the surface treatment, plaster - the shiny surface type sounds exactly the same as MDF too my ears. The paper coated plasterboard sounds different once it has a couple of layers of paint on it. Real wood sounds, on my few exposures to studios using it, very similar to plaster/concrete/MDF. What can I say? I can only describe what my ears tell me. A screen/gobo covered in wood would be something I'd consider not worth experimenting with, because I believe it would sound like a 'wall'. As there already exists a wall, I'd mover the kit closer to it for the same effect.
The problem is that as a sceptic, I am convinced your idea is more effort than it is worth because it will be pointless. You believe the opposite, because you wish it to succeed. If you build it and love it, I still would not be convinced because of the fulfilled desire effect - you wanted it to work, and even if it doesn't, your memory will convince you it does, because you cannot remove it to do a side by side comparison. I put it in the same boat as when people put new drivers in guitar cabs. Very rarely are they not happy.
Would your newly completed 'wall' sound drastically different from the real wall the same distance away? Yes - I think it would, in the same way that drummers feel their sound changes when enclosed in a perspex drum screen. Not totally convinced that playing with the wall to the rear would be drastically different, but facing it might be, if the real wall is still going to be direct path to your ears, because you'll have two path lengths which you didn't have before. Maybe this will thicken the snare, or dull the kick? Who knows. I'm totally up for experiments where you are testing for random things that may/may not be positive. My intrigue with your entire project is that I don't know what it is you expect from it? What is the point? What do you hope it will do? What services exist to counsel you afterwards - especially if it falls over and squishes your kit flat!
If you want to tease us - don't get grumpy when we bite or don't bite.
Adding a wall makes me wonder what's in your head. Doing this is a transmission thing, as it replaces a hard surface with a hard surface. You seem so wavering with your approach. If you want help and advice and perhaps criticism, don't add in red herrings or bait? It just makes us wonder if your just trolling to see what develops, as does changing the rules as we progress, and going back to the first post and 'upgrading it' really did change how we saw it - the sense changed, the rules are stated, making following posts less coherent. It's also bad netiquette. Even adding the word 'partial' to the title changes the flow. Sorry but I suspect you've just been winding us up, to be honest, so I'll leave you to your project, and I hope it makes you happy - I'm actually sure you will be very pleased with it, because that seems to be the aim. I wish I knew what you were really wanting, but I don't - sorry.
The problem is that as a sceptic, I am convinced your idea is more effort than it is worth because it will be pointless. You believe the opposite, because you wish it to succeed. If you build it and love it, I still would not be convinced because of the fulfilled desire effect - you wanted it to work, and even if it doesn't, your memory will convince you it does, because you cannot remove it to do a side by side comparison. I put it in the same boat as when people put new drivers in guitar cabs. Very rarely are they not happy.
Would your newly completed 'wall' sound drastically different from the real wall the same distance away? Yes - I think it would, in the same way that drummers feel their sound changes when enclosed in a perspex drum screen. Not totally convinced that playing with the wall to the rear would be drastically different, but facing it might be, if the real wall is still going to be direct path to your ears, because you'll have two path lengths which you didn't have before. Maybe this will thicken the snare, or dull the kick? Who knows. I'm totally up for experiments where you are testing for random things that may/may not be positive. My intrigue with your entire project is that I don't know what it is you expect from it? What is the point? What do you hope it will do? What services exist to counsel you afterwards - especially if it falls over and squishes your kit flat!
If you want to tease us - don't get grumpy when we bite or don't bite.
Adding a wall makes me wonder what's in your head. Doing this is a transmission thing, as it replaces a hard surface with a hard surface. You seem so wavering with your approach. If you want help and advice and perhaps criticism, don't add in red herrings or bait? It just makes us wonder if your just trolling to see what develops, as does changing the rules as we progress, and going back to the first post and 'upgrading it' really did change how we saw it - the sense changed, the rules are stated, making following posts less coherent. It's also bad netiquette. Even adding the word 'partial' to the title changes the flow. Sorry but I suspect you've just been winding us up, to be honest, so I'll leave you to your project, and I hope it makes you happy - I'm actually sure you will be very pleased with it, because that seems to be the aim. I wish I knew what you were really wanting, but I don't - sorry.
spitzer
New member
Oh, one more thing.
About absorption. This is also something that no one has definitively answered, even though it's a simple yes/no question and certainly someone who actually knows the science (as opposed to "I've built a dozen studios by following this tutorial I found and they all turned out great") behind all this would be able to answer in less time than it takes me to type 'absorber'. Actually, I think no one has answered this yet, period.
I'll elaborate a little bit. People talk about rooms being "boomy", aka too bassy and to correct this, they get (usually multiple types) absorbers (bass traps are included in this) installed in the room. Absorbers work by converting sound energy to heat. If the sound energy of something is indeed converted to heat, the sound (pressure) waves no longer exist in the air. Conversion is conversion, not multiplication and also it is absolutely impossible for a passive device, like a hanger, resonator, or corner trap to amplify (increase energy content) a wave. The energy must be either the sound OR the heat, they can not both exist simultaneously. The question: Since after the absorbtion there is less energy left, the volume (aka energy transmitted to) outside the room must also be less than without the absorbers. Is this not correct? Yes or no?
If your answer is "no", please refer me somewhere that specifically explains this astounding phenomenon. I have spent many, many hours reading about this and related topics and I haven't seen even a single paragraph claiming a) this would be true b) explaining how. Regardless of this, a very large amount of people seem to be of the opinion that room treatment ("acoustics") and sound reduction ("soundproofing") are distinct, different, and unrelated things. I can not agree with something that is obviously impossible and would require breaking the laws of physics.
I'd want to see the light.
About absorption. This is also something that no one has definitively answered, even though it's a simple yes/no question and certainly someone who actually knows the science (as opposed to "I've built a dozen studios by following this tutorial I found and they all turned out great") behind all this would be able to answer in less time than it takes me to type 'absorber'. Actually, I think no one has answered this yet, period.
I'll elaborate a little bit. People talk about rooms being "boomy", aka too bassy and to correct this, they get (usually multiple types) absorbers (bass traps are included in this) installed in the room. Absorbers work by converting sound energy to heat. If the sound energy of something is indeed converted to heat, the sound (pressure) waves no longer exist in the air. Conversion is conversion, not multiplication and also it is absolutely impossible for a passive device, like a hanger, resonator, or corner trap to amplify (increase energy content) a wave. The energy must be either the sound OR the heat, they can not both exist simultaneously. The question: Since after the absorbtion there is less energy left, the volume (aka energy transmitted to) outside the room must also be less than without the absorbers. Is this not correct? Yes or no?
If your answer is "no", please refer me somewhere that specifically explains this astounding phenomenon. I have spent many, many hours reading about this and related topics and I haven't seen even a single paragraph claiming a) this would be true b) explaining how. Regardless of this, a very large amount of people seem to be of the opinion that room treatment ("acoustics") and sound reduction ("soundproofing") are distinct, different, and unrelated things. I can not agree with something that is obviously impossible and would require breaking the laws of physics.
I'd want to see the light.
spitzer
New member
Rob, please believe me when I say that I'm not trolling or teasing here. I do not mean any disrespect whatsoever. It was meant as very light-hearted humour, not to be actually offensive. Happens to me as well, very often -- on the Internet it's harder to tell the tone.
The "plaster" thing, is a possible terminology issue. It might be regional or I might be wrong, but I think people in the US use "mortar" for the hard stuff. I'm from neither and the weak stuff, literal plaster (as in 100% lime), is very, very rare here as well but it does exist. One dividing wall in my previous apartment was made from that or something like that. Could just as well use cardboard and paint it white (but that would violate the fire code).
I'll have to get back to this later but I find it curious that we can't seem to understand each other at all. Adding a (whole) second wall is an extremely common and standard technique for sound reduction, it has even been suggested to me in this thread by another member.
It wasn't long ago in the least when I said that if it doesn't work, I'm fine with that. In that case I would dismantle it and use the materials for something different. You are making seriously bizarre assumptions, frankly. I have NEVER said anything to the effect that "it will work no matter what you say". No. I have been hoping for your advice in helping to make it work.
And Rob, very, very importantly... the drum set (standard right handed setup) is oriented "sideways" in that corner. The panel is NOT to the rear of the set, the panel is to the RIGHT of the set. That is why I made the example of the hits on the right and left crash and switching them around. I made that example and said that the left crash is surrounded by lots of air on every side. How do you even just assume a variable (the way the set is oriented) of such critical importance here? IF the new wall would be behind the set it wouldn't make sense, that's something we can easily agree on. But that is not the case.
For anyone else confused about this, I guess I'll need to make a new diagram! In the meanwhile, think of the red box as: drummer facing you, bass drum front facing you, ride cymbal and floor tom on picture left, hi-hat on picture right! (Again, standard right-handed setup)
The "plaster" thing, is a possible terminology issue. It might be regional or I might be wrong, but I think people in the US use "mortar" for the hard stuff. I'm from neither and the weak stuff, literal plaster (as in 100% lime), is very, very rare here as well but it does exist. One dividing wall in my previous apartment was made from that or something like that. Could just as well use cardboard and paint it white (but that would violate the fire code).
I'll have to get back to this later but I find it curious that we can't seem to understand each other at all. Adding a (whole) second wall is an extremely common and standard technique for sound reduction, it has even been suggested to me in this thread by another member.
It wasn't long ago in the least when I said that if it doesn't work, I'm fine with that. In that case I would dismantle it and use the materials for something different. You are making seriously bizarre assumptions, frankly. I have NEVER said anything to the effect that "it will work no matter what you say". No. I have been hoping for your advice in helping to make it work.
And Rob, very, very importantly... the drum set (standard right handed setup) is oriented "sideways" in that corner. The panel is NOT to the rear of the set, the panel is to the RIGHT of the set. That is why I made the example of the hits on the right and left crash and switching them around. I made that example and said that the left crash is surrounded by lots of air on every side. How do you even just assume a variable (the way the set is oriented) of such critical importance here? IF the new wall would be behind the set it wouldn't make sense, that's something we can easily agree on. But that is not the case.
For anyone else confused about this, I guess I'll need to make a new diagram! In the meanwhile, think of the red box as: drummer facing you, bass drum front facing you, ride cymbal and floor tom on picture left, hi-hat on picture right! (Again, standard right-handed setup)
mjbphotos
What?!?
You really don't want to be reflecting those cymbal sounds at all - take it from someone with tinnitus from standing besides a drum kit in loud rock bands for too many years. After reading everything you've written here, I still go with my original suggestion - build a 'bass trap' (they are really full-frequency absorbers) the size of the 'reflector/absorber' you were planning on. Forget the wood slats - at least to start out with. If you decide the sound is 'too dead' from that side, you can always add them.
I was thinking about this when I read it last night and I think the short answer is yes. But in the context of transmission reduction, how much? I was trying to sort this out.
Let's say I put one of my large solid center panels (6x5' 3/4 ply + fiberglass) along my front room tracking space' wall bordering the bed room, with the kit next to it.
It represents say 30-40% of the wall area.
Will the kick's level between the baffle and wall be lower? I suspect it would be.
But we know especially low freq stuff resonates, excites' and travels around and throughout the rooms. So the question becomes 'how much' does a partial reduction in level, in a portion (30%? 50%?) of the one wall -let alone the ceiling paths.. pan out to 'level reduction in the adjoining room?
So in the end, I don't know. But I suspect, not much.