Drum Room Construction

How thick should my walls be, should I float my floors (and if so, how), why is two leaf mass-air-mass design important, etc.

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beeros05
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Re: Drum Room Construction

Post by beeros05 »

Soundman2020 wrote: Since we are talking about room size, what are the final dimensions of your room, now that the inner leaf is completed? Since the room is empty right now, with no treatment, it is the perfect time to measure the room accurately, and post the dimensions here. Based on that we can predict what some of the problems will be, and confirm the prediction with the measurements that your friend will make.
2.85 L, 2.45 W, 2.05 H.
Soundman2020 wrote:but what you will need without any doubt, is a LOT of bass trapping in that room. Very deep, very large bass traps.
Damn, i thought so...how deep? 30-40cm would be OK?
Soundman2020 wrote:What type of panel are you talking about here?
Sorry...forgot to mention it. The classic panels with wooden frame, rock-wool covered with some type of fabric. Broadband absorbers, right?
Soundman2020 wrote: Actually, it's the other way around. Small rooms need LOTS of treatment, and LARGE treatment.
I understand, what i actually say is not less treatment. I mean instead of one 1.20x0.60 panel, to make two 0.60x0.60, i mean i already have the wood for framing 16 panels, why waste them?
Soundman2020 wrote:Are you talking about putting the melamine across the front of your superchunks? If so, I'd wait a bit before doing that: you might need it, or you might not. Once the superchunks and all the other treatment is in place, then you can get your friend to test the room again, and see if you need it.
No i am not talking something like that. I found the melamine and i intend to use it like this
Superchunk.jpg
Soundman2020 wrote: What type of absorption can you get in Greece? Can you get Owens Corning 703? If so, then that would be great: buy lots of it! If not, then can you get some other type of semi-rigid fiberglass or mineral wool panels, similar to 703?
OC 703 no. Rock-wool is used mostly and lately this one is used instead of rock-wool 'cause it's eco/health-friendly, but unfortunately there are no acoustic specs for that. It is the same as rock-wool and it's density is around 40kg/m3
Soundman2020
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Re: Drum Room Construction

Post by Soundman2020 »

2.85 L, 2.45 W, 2.05 H.
OK, so your first three axial modes are at 60.4 Hz, 70.3 Hz, and 84 Hz. Then you have three tangential modes at 92.7 Hz., 103.5 Hz, and 109.5 Hz. And yes, those are all in the area where your kick drum might have a fundamental, depending on how you have it tuned. 70 Hz to 110 Hz, is common for kick tuning.

OK, want to see something interesting? Take a careful look at your the graphs that you posted earlier, and and see if you notice something happening those six frequencies I just mentioned... :)

All six of those are pretty clear on your results! Your room is doing exactly what theory predicts.

And here's some more interesting theory that matches your reality very well: According to theory, your room modes are dominant between 60 Hz and 180 Hz. In other words, that's the range of frequencies where simple standing waves (modes) are a big problem in your room. Then, from 180 Hz to 720 Hz, the biggest issues are diffraction and diffusion (not so much modes in that range). Above 720 Hz, you are into a pretty diffuse, even zone, where things aren't so bad any more. That's where you might need diffusion, but I doubt it. I think you'll be fine just with basic treatment, as this is only a rehearsal room, not a tracking room.

It's nice when reality matches theory so neatly! Your room is performing almost exactly as theory predicts, and even though your graphs aren't calibrated or accurate, the effects are obvious.

Fortunately, as it turns out, your room dimensions are not too bad at all. Your room ratio is 1 : 1.19 : 1.39, which is very close to a really good ratio, called Sepmeyer's ratio, which is 1 : 1.14 : 1.39. So you have a reasonably smooth distribution of modes. OK, it's a small room, so "smooth distribution" is relative! But your ratio is about as good as you could possibly expect. So you lucked out there! :) Finally, something good happened for you, by chance!
Damn, i thought so...how deep? 30-40cm would be OK?
Your superchunks are your main bass traps. Make them as wide across the front face as you can fit into your room reasonably. If you can make them about 80cm or so across the front, that would be good. They don't have to be equilateral triangles: If you want, you can stretch one side and make the other side fatter, if that would help. This is a rehearsal room, not a control room, so symmetry doesn't matter either: If you build one in each corner of the room, you can make them different sizes and different angles, if you feel like it. Or you can make them all the same, if that is easier.

I'd do those superchunks first, then measure the room again when they are finished, and we'll see how they are doing, before deciding on the next step.
Sorry...forgot to mention it. The classic panels with wooden frame, rock-wool covered with some type of fabric. Broadband absorbers, right?
OK, great. You'll need some of those, for sure! Yes, broadband absorbers is the right name.
OC 703 no. Rock-wool is used mostly and lately this one is used instead of rock-wool 'cause it's eco/health-friendly, but unfortunately there are no acoustic specs for that. It is the same as rock-wool and it's density is around 40kg/m3
That stuff should work just fine. They don't publish detailed acoustic specs, but there's one number they did give: the gas flow resistivity, which is important. It's a bit low, but plenty good enough for what you need. So that stuff should be good. Maybe you could call the manufacturer, and ask if they have more detailed acoustic specs that they can send you? They might have more data that isn't on the web site.

- Stuart -
beeros05
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Re: Drum Room Construction

Post by beeros05 »

Soundman2020 wrote:OK, so your first three axial modes are at 60.4 Hz, 70.3 Hz, and 84 Hz. Then you have three tangential modes at 92.7 Hz., 103.5 Hz, and 109.5 Hz. And yes, those are all in the area where your kick drum might have a fundamental, depending on how you have it tuned. 70 Hz to 110 Hz, is common for kick tuning.
I tune all of my drum-heads in medium-low tension
Soundman2020 wrote:That's where you might need diffusion, but I doubt it. I think you'll be fine just with basic treatment, as this is only a rehearsal room, not a tracking room.
I did this room mostly for practicing and rehearsing but in the near future i will do drum tracking as well IF i have the possibility acoustic-wise to do so. But i will no do real professional-sounding recordings. All the recordings we do with my band are DiY, we dont go to pro studios 'cause usually we don't have the proper budget for a pro-studio and engineers.

These are the panels:
IMG_1259.JPG
Soundman2020 wrote:OK, want to see something interesting? Take a careful look at your the graphs that you posted earlier, and and see if you notice something happening those six frequencies I just mentioned... :)
All six of those are pretty clear on your results! Your room is doing exactly what theory predicts.
Soundman2020 wrote:And here's some more interesting theory that matches your reality very well: According to theory, your room modes are dominant between 60 Hz and 180 Hz. In other words, that's the range of frequencies where simple standing waves (modes) are a big problem in your room. Then, from 180 Hz to 720 Hz, the biggest issues are diffraction and diffusion (not so much modes in that range). Above 720 Hz, you are into a pretty diffuse, even zone, where things aren't so bad any more.
Soundman2020 wrote:Fortunately, as it turns out, your room dimensions are not too bad at all. Your room ratio is 1 : 1.19 : 1.39, which is very close to a really good ratio, called Sepmeyer's ratio, which is 1 : 1.14 : 1.39. So you have a reasonably smooth distribution of modes. OK, it's a small room, so "smooth distribution" is relative!
I will take a closer look at the above posts with my friend who is helping me out with the measurements, he will able to explain me these theoretical parts since i am not familiar with some terms. I will do some research by myself until that 'cause it is bloody interesting.
Soundman2020 wrote: It's nice when reality matches theory so neatly! Your room is performing almost exactly as theory predicts, and even though your graphs aren't calibrated or accurate, the effects are obvious.
Soundman2020 wrote: But your ratio is about as good as you could possibly expect. So you lucked out there! :) Finally, something good happened for you, by chance!
This is REALLY GOOD NEWS! It is the second good thing happening basically. The first thing is that the room insulation-wise is working even though i have not installed doors yet!
Soundman2020 wrote:Your superchunks are your main bass traps. Make them as wide across the front face as you can fit into your room reasonably. If you can make them about 80cm or so across the front, that would be good. They don't have to be equilateral triangles: If you want, you can stretch one side and make the other side fatter, if that would help. This is a rehearsal room, not a control room, so symmetry doesn't matter either: If you build one in each corner of the room, you can make them different sizes and different angles, if you feel like it. Or you can make them all the same, if that is easier.
I will make the all the same just for the easiness of it
Soundman2020 wrote:That stuff should work just fine. They don't publish detailed acoustic specs, but there's one number they did give: the gas flow resistivity, which is important. It's a bit low, but plenty good enough for what you need. So that stuff should be good. Maybe you could call the manufacturer, and ask if they have more detailed acoustic specs that they can send you? They might have more data that isn't on the web site.
OK I'll try to get in contact with them, is there some other type of material you recommend like the classic rock-wool for bass trapping? And if there is what is the best density for bass trapping?

THANK YOU!!! :shot:
Soundman2020
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Re: Drum Room Construction

Post by Soundman2020 »

I did this room mostly for practicing and rehearsing but in the near future i will do drum tracking as well IF i have the possibility acoustic-wise to do so.
OK, it's good that you mentioned that, as there are some things that you can do to make it a bit better for tracking. It won't be fantastic for tracking drums, due to the very low ceiling, but it can still be reasonably good.
It is the second good thing happening basically.
Actually, I think it it's the THIRD good thing: The first one, was when you found us here on this forum... :) Imagine where you would be right now if you had not found the forum!
is there some other type of material you recommend like the classic rock-wool for bass trapping? And if there is what is the best density for bass trapping?
Actually, that stuff that you linked to really is rock-wool! It just uses a different binder, that's more eco-friendly, but the basic material is the same. To be more correct "Rockwool" is a brand name: the right generic name is "mineral wool". If you use mineral wool, then you should look for stuff with a density of around 50 kg/m3, very roughly. But if you use fiberglass insulation, then you should look for 30 kg/m3. The reasons for the difference is rather complex to explain, but basically it's not the density that is important: it's something called "gas flow resistivity". But it turns out that, for each type of material (mineral wool, fiberglass, cellulose, etc.) there is a certain density where the gas flow resistivity is optimum . Mineral wool needs to be denser to reach the right gas flow resistivity, while fiberglass needs to be less dense in order to get to the same optimum gas flow resistivity. So basically that's what you should look for: mineral wool = 50 kg/m3, and fiberglass = 30 kg/m3. The numbers are not rigid: just somewhere in that area. So if you find mineral wool that is 43 kg/m3, or 57 kg/m3, that's fine too.


- Stuart -
beeros05
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Re: Drum Room Construction

Post by beeros05 »

Soundman2020 wrote:OK, it's good that you mentioned that, as there are some things that you can do to make it a bit better for tracking.
Things like what? Or it's too early to talk about these stuff?
Soundman2020 wrote:It won't be fantastic for tracking drums, due to the very low ceiling, but it can still be reasonably good.
No one in the band is a "perfect" musician. NO-ONE! We are Motorhead-style band and it is going to stay that way so we do not care that for "scientific quality" recordings. We like "old-school" stuff!
Soundman2020 wrote:Actually, I think it it's the THIRD good thing: The first one, was when you found us here on this forum... :) Imagine where you would be right now if you had not found the forum!
Hahahaha! No, i don't wanna imagine!

Soundman2020 wrote:Actually, that stuff that you linked to really is rock-wool! It just uses a different binder, that's more eco-friendly, but the basic material is the same.
Yes it is an eco-based, non chemical processed mineral-wool
Soundman2020 wrote:So if you find mineral wool that is 43 kg/m3, or 57 kg/m3, that's fine too.
OK, so a 40-60kg/m3 is fine. More dense that, should be avoided in order to avoid flanking effects right?
Ronnie LeBlanc
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Re: Drum Room Construction

Post by Ronnie LeBlanc »

These are the panels:
IMG_1259.JPG
Have you finished the? Any pics?
If they can't hear you, SING LOUDER!
beeros05
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Re: Drum Room Construction

Post by beeros05 »

No man, i haven't. I need fabric
beeros05
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Re: Drum Room Construction

Post by beeros05 »

beeros05 wrote: 2.85 L, 2.45 W, 2.05 H.
Soundman2020 wrote:2.85 L, 2.45 W, 2.05 H.
Fortunately, as it turns out, your room dimensions are not too bad at all. Your room ratio is 1 : 1.19 : 1.39, which is very close to a really good ratio, called Sepmeyer's ratio, which is 1 : 1.14 : 1.39. So you have a reasonably smooth distribution of modes. OK, it's a small room, so "smooth distribution" is relative! But your ratio is about as good as you could possibly expect. So you lucked out there! :) Finally, something good happened for you, by chance!
Stuart! I made a mistake...i hope it is not a huge one!

The dimensions of the room are 3.85 L x 2.45 W x 2.05 H.

Hence, the room ratios change...hence i might not be near of having a really good room ratio, i might not be lucky...Does this one meter in length changes drastically the room ratio?

According to this online room mode calc my ratios are 1 : 1.19 : 1.87
Last edited by beeros05 on Sat Jul 07, 2012 12:40 pm, edited 1 time in total.
Soundman2020
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Re: Drum Room Construction

Post by Soundman2020 »

Yes, the 1 m DOES drastically change the ratio! Even a few cm can make a difference. So your ratio now gets far away from the good one you had. But fortunately, it gets close to another good one. :)
According to this online room mode calc my ratios are 1 : 1.19 : 1.87.
Yes, that's one of the best calculators I know of. It gives you lots of very useful information, much more than just the ratio. And your new ratio isn't too bad either: Close to Louden's #2, which is Eric Desart's #6. The modal distribution looks reasonably good, with one exception: You have two modes right on top of each other at around 84 Hz, which is very likely to be associated with the issue you were mentioning, of not being able to hear your kick drum properly. So you might need some type of tuned trap to deal with that, but let's see how it goes after you measure more accurately and get your basic treatment in.


- Stuart -
beeros05
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Re: Drum Room Construction

Post by beeros05 »

Some friends proposed me to install "Hormann" Doors.

Hormann is a company that makes garage doors and industrial doors.

Their industrial doors are soundproof rated and fire rated.
The model they installed was T60.

It's a fire rated model but it is also rated for 42db insulation

Its is also not such massive and heavy. It felt like an iron construction with insulation inside.
It is not one solid piece of metal. The thickness is 6cm.
It seals air-tight.

The price including installation for two doors is not more than 900€

Here are some pics, these are my friend's doors, the installation is not 100% finished
IMG_1357.JPG
IMG_1358.JPG
IMG_1359.JPG
IMG_1360.JPG
IMG_1351.JPG
IMG_1362.JPG
IMG_1363.JPG
What do you think Stuart?
beeros05
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Re: Drum Room Construction

Post by beeros05 »

Hey guys, long time...

I made some bass traps and installed some panels here are some pics
IMG_2041.JPG
IMG_2038.JPG
IMG_2042.JPG
IMG_2045.JPG
IMG_2046.JPG
I have to make the last corner bass trap and bass traps in the corners of ceiling/walls

My bass drums sound a bit better but its clear that i need more bass trapping.

The toms sound much much better and the cymbals sound better but they still pierce my ears!
Soundman2020
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Re: Drum Room Construction

Post by Soundman2020 »

Good to see you back again! :)

There's a program called "REW" ("Room Eq Wizard") that you can download for free, and use to run a complete acoustic analysis on your room. If you post the resulting data file here, then we can analyze it and see what the problems are, and maybe offer some suggestions for fixing that. But just from looking at the photos, you are going to need a LOT more absorption in that room, both bass trapping and other types. It might also be a good idea to do a slat wall in front of one of your walls.

But the REW data will help a lot to understand the problems.

By the way, how is the isolation? Is it satisfactory, and as you expected?



- Stuart -
beeros05
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Re: Drum Room Construction

Post by beeros05 »

Soundman2020 wrote:Good to see you back again! :)

There's a program called "REW" ("Room Eq Wizard") that you can download for free, and use to run a complete acoustic analysis on your room. If you post the resulting data file here, then we can analyze it and see what the problems are, and maybe offer some suggestions for fixing that. But just from looking at the photos, you are going to need a LOT more absorption in that room, both bass trapping and other types. It might also be a good idea to do a slat wall in front of one of your walls.

But the REW data will help a lot to understand the problems.

By the way, how is the isolation? Is it satisfactory, and as you expected?



- Stuart -
Good to find you back here bro!

I know the program, i had done some tests remember? But we didn't have omnidirectional mic.
I dont know if i will run the tests again, we couldnt find a good omni mic (well we found from studios but they were not even renting it...)

Im gonna make 10 more wall panels and bass-traps in all corners. By the way, I don't know why and how but the room looks bigger now!

The isolation as far as the structural noise is very ok. The "floating" floor and the pads did a very good job. Obvious results!
As i told you there still is the bass energy through my parent's wall but I have not installed the doors yet!

What is slat wall? And why do something like that?
exit2studios
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Re: Drum Room Construction

Post by exit2studios »

I feel like I just read a novel and someone tore the last page out of the book.

What ever happened with this saga??
beeros05
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Re: Drum Room Construction

Post by beeros05 »

exit2studios wrote:I feel like I just read a novel and someone tore the last page out of the book.

What ever happened with this saga??
Im gonna install electrics, ventilation and doors in the next two months
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