concrete room with window/air gap to be isolated/insulated

I previously made a topicabout this, but it's getting old and I hate to kick it up again :arrow: The setting: the room is on the first floor (the floor above ground level i mean), and has a big window, and an air gap to the ground level. http://users.pandora.be/plvl/ikke/drum/accoustics/setting.gif Complaints come mostly from the neighbour at the left. He can hear me drumming, but he can pretty much live with that, as long as he doesn't have too work or so, but when we rehearse with a band, he says the noise of the amps is really irritating. The other neighbours don't have much problems with it (but that doesn't mean i don't want to improve the situation) :arrow: My goals: a)improve the sound isolation (especially transmission attenuation towards the neighbour in red) b)improve the room accoustics: i don't know exactly how to describe it, but we have to turn guitar and bass amps really really loud, and pointed towards me (the drummer) in order to hear something from them. I don't know the exact problem but this is probably because of the high/many reflections, especially at the low end? If the amps don't need to be so screaming loud the leaked sound will also be less. :arrow: The room: http://users.pandora.be/plvl/ikke/drum/accoustics/map.gif http://users.pandora.be/plvl/ikke/drum/accoustics/A.jpg http://users.pandora.be/plvl/ikke/drum/accoustics/B.jpg http://users.pandora.be/plvl/ikke/drum/accoustics/C.jpg http://users.pandora.be/plvl/ikke/drum/accoustics/D.jpg I read most of this pages which gave me a pretty decent information :) :arrow: thanks to a buddy, i can make a pretty good deal I think: this panels (they are 4m² or so and cost me €10 each) The big window is double glassed btw, with a thicker glass at the inside (I don't know if they are angled though, but they are placed with the need for isolation in mind) :arrow: What should I do? I suspect the big window, the roller shutter in the small storage area, and the air gap towards the ground level to be the biggest air leaks, so Maybe i can make panels (with the gypsum panels) which fit nicely in the window, and in the air gap? Like the panel absorbers described here (and leave the little storage room with the window for what it is)? This should also be a good idea (better then just placing a piece of gypsum board in the window) i think?

Dieter, sorry for the delay; I should be getting caught up here in a day or two. Can you post a drawing that shows everything on one page? Need to know where the neighbor is with respect to your room layout, which floor neighbor is on, and if possible what type walls are between neighbor and your area. I'm suspecting flanking is the main culprit here; if so, a floated riser for drums and amps may help quite a bit. Need more info first though... Steve

everything on 1 page: (updated picture) http://users.pandora.be/plvl/ikke/drum/accoustics/setting.gif new picture: http://users.pandora.be/plvl/ikke/drum/accoustics/E.jpg I think that my neighbour "lives" (and works) on the same level as the rehearsal room, an that the level above that is only for his bedroom, but i'll ask it this evening or so when he's home. I have no idea what type of walls are used. My uncle says nowadays "fast-build" bricks are used in most homes (which are big bricks with air holes/gaps in it) for the internal walls, and for the external walls "fast-build" bricks at the inner side, air gap, and then a wall of "outside-bricks", but this is a pretty old house, my parents are on vacation so I don't know :) For the record, I also made some shots in the attic (the level above the rehearsel room) which might be interesting: http://users.pandora.be/plvl/ikke/drum/accoustics/attic1.jpg http://users.pandora.be/plvl/ikke/drum/accoustics/attic2.jpg http://users.pandora.be/plvl/ikke/drum/accoustics/attic3.jpg After some thinking, its probably the floor (or the ceiling if you are on the ground level) that does it, because its probably built out of 1 piece (for the whole house)

These panels you can get for 10 euro; the pic isn't quite clear enough, is each panel 32mm compressed fiberglass bonded to 10mm gypsum? And, are they about 1200mm x 2400mm in size? If so, the first thing I'd do is make it plain to your neighbor (if you haven't already) that you want to solve this problem, but that you'll need his cooperation to do it; hopefully doing this will help keep the whole thing from turning into a "war" - generally people want to at least be acknowledged when they have a problem, and that's what you're doing at this stage. Next, if you have access to any kind of sound level meter this will help - first, it will let you actually MEASURE any differences you make in the sound levels at your neighbor's place, and second, it will (assuming you practice using the meter BEFORE you let your neighbor see you doing it :=) add an air of professionalism to the proceedings. Next, be sure you let your neighbor know what it is you're doing - you don't want him thinking you're making all that noise just to irritate him - Have one of your bandmates stand in whatever room of your neighbor's place is the loudest, and you play a solid beat on your drums - if you have access to the sound meter, set it on "C" weighting, slow response, and have your bandmate hold it in a place in the neighbor's room that can be duplicated later, EXACTLY - get readings of the levels in the neighbor's room while you're playing the drums AS THINGS ARE RIGHT NOW, with no changes whatever. Then, use two of those panels you pictured; lay them on the floor in the SAME PLACE your drums are now, then place two MORE panels of PLYWOOD or MDF on top of the other panels, with the seams running at right angles (so they don't wobble so much) - set up your drums ON TOP of this platform (be sure nothing touches the walls) and repeat the experiment, trying very hard to play at the SAME VOLUME (and the same pattern) you did before. Have your SAME bandmate (consistency is important here) check the sound meter at the SAME POSITION it was before, and make notes of the sound levels. Make sure the settings on the meter are the same as before- some meters, such as the Radio Shack Digital Sound level meter, default to specific settings on power-up. Mine sets itself to fast, "C" weighting. For this experiment you want "SLOW" response to get more of an average. Be sure to have your neighbor present at BOTH tests, so he can (a) see that you really care, and (b) see for himself whatever improvement was made. Once this test is done, we can tell more about where your sound leakage is coming from. One thing I would NOT, repeat NOT do, is to put a bunch of these fiberglass/gypsum panels up around your room just yet; chances are, unless you were to put them up with the fiberglass facing OUT into the room, you will create another leaf in your wall/ceiling structure, which would make low frequency isolation WORSE. It could, however, make the mid/high frequency isolation a bit BETTER, but this is probably NOT where the problem is. The next step in the room, as you mention, is making the sound more intelligible so you don't play your amps as loud. This will involve several absorbent panels placed across corners and on the ceiling. If you can find either some panels like the $10 ones WITHOUT the gypsum, or some mineral wool batts 75-100mm thick, these will work. We can get into that part after the "drum riser" tests... Steve

knightfly wrote:

These panels you can get for 10 euro; the pic isn't quite clear enough, is each panel 32mm compressed fiberglass bonded to 10mm gypsum? And, are they about 1200mm x 2400mm in size?

It's definatly 30mm "yellow stuff" on 10mm hard white "stuff". Thats all I am really sure of, sorry. I do think that the yellow stuff is indeed compressed fiberglass (it can loose particles which are bad for your health if you breathe it), and the white thing is probably gypsum yes. I've seen the panels, and yes, i think they must be something like 1200x2400 (If you want i'll go measure it) Don't worry. My relation with the neighbour is decent enough :) He certainly doesn't think i'm making noise to irritate him :wink: I will get hold of a sound level meter and do what you say, but I have some questions: a)Maybe it's a good idea do the same experiment with a Bass amp too? Because its also (or maybe even more) the "booming of the amps" (both guitar and bass) that ennoys him. b)I don't quite get what you mean with the "seams in the right angles", but If i make sure the construction is sturdy and doesn't wobble, its ok right? Does it matter if the gypsum panels are right next to each other or can i leave a gap between them? And then I would just place the mdf/plywood panels next to each other, sideways "over" the gypsum panels... (when you talk about 2 panels, you want them next to each other right?)

The drum tests were just an example; of course use whatever is the most irritating. And yes, you would put two of the "yellow stuff" panels down to make a square (fiberglass side DOWN) and then the plywood panels make a square on TOP of the other panels, but rotated 90 degrees so they "tie in" to make this "drum riser" more stable without having to nail anything. All you're doing here is making a temporary floated floor for your drums/amps, so you can tell whether your suspicions are correct about the continuous floor being one of your main problems... Steve Another thing; you might try turning UP the TREBLE and DOWN on the BASS tone controls on your bass amps, at least for practice; this generally will improve the note "definition", making it easier for others to hear without all the low frequency volume. This might let you turn the overall volume DOWN a bit and still hear what the bass is doing, and at the same time make less low frequency to travel to the neighbor...

Experiment done. My guitarist didnt have time, so the test was performed with the drumkit only (which was more then good enough) I asked my neighbour to measure it himself, and keep in mind to be consistent about place too stand etc; We used the AVM2050 Even on slow response this baby swings alot, C weighting was used; As it was hard too tell because the needle swinged a lot, the results are very clear imho: "between 70 - 80 dB" without any treatment, versus "between 65-70 dB" when the drum riser was used. So the difference is about 7,5dB; My neighbour also told me that, not only the sound was cleary more silent, also the differences in sound level are less subtle (10dB "swing" versus 5dB when treatment was used) Personally, when i was drumming on the riser, it also sounded like i was playing more quit , even when hitting as hard (maybe a little harder) as before. My neighbour also said that its ok now, if i use a drumriser, and make little platforms for the guitarists, he won't have nothing too complain :) But, it doesn't stop here for me. As said there is still work to do, because when we rehearsel i cannot here the guitarist, bassist, etc, so...on to step 2 :) And offcourse, i have some nice pictures for you guys :wink: The upper level wood is called 'OSB'.

Wow! :shock: I'm surprised the results were that good! It's not exactly perfect testing conditions, but very interesting and worth more investigation I think! 8)

Great thread, guys... For those that are following this thread, a drumkit "decoupling" effect is just what I'm after in this related thread: http://www.johnlsayers.com/phpBB2/viewt ... d47dd225f1 Fyi, I've long been curious about what sorts of positive acoustic effects might be possible by simply & inexpensively floating certain instruments (like the drumset, or a bass amp). It's very cool that Dieter is able to decrease sound transmission over to his neighbor's location - but I'm also interested in testing other possible positive effects (like reducing structure borne transmission between different instrument mics when recording an entire band in the same recording room). I'll let you all know what happens when I try this out myself (likely this weekend.) Adam

Good job, now you know about how much of your transmission is due to flanking - another test you can do (if you're into it) is to play a fairly loud sine wave thru your speakers, and adjust the frequency down while holding your hand on the riser's OSB layers; note the frequency of the sine wave when it vibrates your hand the most, and you may be able to improve things even more by adding another layer of OSB to lower the resonant frequency. If you don't have a way of generating sine waves, try this http://www.moonaudio.com/softwar5.htm IF you're on a Mac, sorry; no links for that... Steve

knightfly wrote:

another test you can do (if you're into it)

I don't think this is very important to me right now. Maybe when rehearsing or practicing we will feel the need for it , if/when it will resonate :wink: (btw i'm on linux :) but i have a windows too :wink: ) I would like to go on with this part :)

knightfly wrote:

The next step in the room, as you mention, is making the sound more intelligible so you don't play your amps as loud. This will involve several absorbent panels placed across corners and on the ceiling. If you can find either some panels like the $10 ones WITHOUT the gypsum, or some mineral wool batts 75-100mm thick, these will work. We can get into that part after the "drum riser" tests... Steve

Dieter@be wrote:

knightfly wrote:

another test you can do (if you're into it)

I don't think this is very important to me right now. Maybe when rehearsing or practicing we will feel the need for it , if/when it will resonate :wink: (btw i'm on linux :) but i have a windows too :wink: ) I would like to go on with this part :)

knightfly wrote:

The next step in the room, as you mention, is making the sound more intelligible so you don't play your amps as loud. This will involve several absorbent panels placed across corners and on the ceiling. If you can find either some panels like the $10 ones WITHOUT the gypsum, or some mineral wool batts 75-100mm thick, these will work. We can get into that part after the "drum riser" tests... Steve

Hi. I got sent here from another forum, on the topic of drum riser construction. When you want to go on reading about acoustic treatment of the room, there are heaps of good information on this page: linky Flaat.

Flaat wrote:

When you want to go on reading about acoustic treatment of the room, there are heaps of good information on this page: linky Flaat.

I did it :) wow, great article, I learned a lot of it (the cool thing is that it explains you the "why's" and the "how's" of all kinds of things, whereas the SAE documents mainly focus on a brief "do this and you should that" without much "because") So, let's see... i should make some bass traps, prefferably in the corners but i dont have much space there, I do have some large empty walls , but probably i could also use some wooden deflectors on there.. I also have these cheap (or so I think) panels that I could use, but for making bass traps the gypsum part shouldnt be there, and the panels should maybe be thicker. So I guess I will need to look out where I can buy material that fits my needs more properly This is hard, i kinda know pretty much about it, but i couldnt tell for sure what i need to do exactly (considering sizes, placement,...) :o I'm sure the mods here can give me some great advice? :) Knightfly? John? sharward? :)

Dieter@be wrote:

I'm sure the mods here can give me some great advice? :) Knightfly? John? sharward? :)

Whoah! :shock: I'm flattered to be in such esteemed company! 8) However, in the spirit of full disclosure...

I am not a moderator of this forum. I am a "mere mortal." You can learn how I achieved that official title in this thread. I am not an acoustics expert or soundproofing expert. I'm "just a guy like you" who made some fundamentally flawed assumptions at the beginning of my own project, and I was fortunate to be turned around by some very knowledgeable people here and elsewhere. In fact, I continue to make fundamentally flawed assumptions about my project as recently as yesterday! :? I do feel compelled to help those who are earlier on their path to Soundproofing Enlightenment, for altruistic reasons (i.e., "I've been there and I feel your pain"), as well as for selfish reasons (i.e., "The more I can offer help to those in need, the more help I'll be able to get by the 'real experts here' when I need it"). ;)

I am, again, flattered to be held in such high regard -- but I can't accept that honor without the requisite amount of self-deprecation that is warranted! ;) Now, lest you think I was ignoring your question -- I can honestly say that you probably know more about "acoustic treatments" than I do. Right now I'm so focused on getting my own room construction started that I've been turning a blind eye to anything truly "treatment" related. I'll get to that part of my schooling soon enough, but I expect it won't be a huge concern of mine (since I'm not recording in my space). Thanks for the compliment. :)

I knew you are not a mod, but you reply pretty actively to my posts and you seemed like a good help, so... :lol:

Not only that, but our "mere mortal" makes REALLY pretty drawings... :wink: Bass trapping - if your vertical corners are "all used up", consider diagonal absorbent across some (or all) your wall-to-ceiling corners. 4" mineral wool in 3-4 PCF (multiply by 16 for kg/m^3) figures) is probably the best "bang for buck" for this... Steve

How low would the lowest frequencies be? (those from the bass amp, and maybe from my kick drum too?) because i did a little calculation: speed of air (approx): 343,5m/s Frequency =x, so 343/4x = needed insulation thickness (including air gap) like explained here now i just need an idea of the lowest frequencys but the result depends quite a lot: for x=150Hz: 343/600 = 57cm thickness ? :? for x=100Hz: 343/400 = 85cm thickness ? :o for x=50Hz: 343/200 = 1,7m thickness ? :o :cry:

Dieter@be wrote:

Flaat wrote:

When you want to go on reading about acoustic treatment of the room, there are heaps of good information on this page: linky Flaat.

I did it :) wow, great article, I learned a lot of it (the cool thing is that it explains you the "why's" and the "how's" of all kinds of things, whereas the SAE documents mainly focus on a brief "do this and you should that" without much "because") So, let's see... i should make some bass traps, prefferably in the corners but i dont have much space there, I do have some large empty walls , but probably i could also use some wooden deflectors on there.. I also have these cheap (or so I think) panels that I could use, but for making bass traps the gypsum part shouldnt be there, and the panels should maybe be thicker. So I guess I will need to look out where I can buy material that fits my needs more properly This is hard, i kinda know pretty much about it, but i couldnt tell for sure what i need to do exactly (considering sizes, placement,...) :o I'm sure the mods here can give me some great advice? :) Knightfly? John? sharward? :)

What about the horizontal corners ( wall meets ceiling ) ? Surely you have lotsa space up there? Paul :)

Steve could you please do me a favor? I have a good understanding of the basic theories behind bass traps and other stuff, but i have absolutely no idea where exactly to place what kind of things(bass trap, deflector, whatever,...) , regarding my room So here are the pics again http://users.pandora.be/plvl/ikke/drum/accoustics/map.gif http://users.pandora.be/plvl/ikke/drum/accoustics/A.jpg (the stereo is gone) http://users.pandora.be/plvl/ikke/drum/accoustics/B.jpg http://users.pandora.be/plvl/ikke/drum/accoustics/C.jpg http://users.pandora.be/plvl/ikke/drum/accoustics/D.jpg You know what i want right? the isolation towards the neighbour is decent enough if i use my drum riser (and i will probably build little risers for guitar amps too), so now i want to make the accoustics in the room better. I want to hear the guitar and bass amps clearly even when i'm hitting hard :) (now i only hear myself and not the amps even if they are very loud) also there is a lot of (i think mostly, but not limited to, lowlevel) noise in the room which should be damped and i want you to tell me what kinds of things i should place at which positions. :) (also, i would appreciate your comment on bass trap thickness, as described 2 posts above)

Sort of follow-up to my previous post, i've been reading and thinking some more. How can i know what my problem is? (can you guess it?), -> me not hearing guitars when playing drums.... At first i kind of assumed it would be fixed by using bass traps for the bass guitar, but after thinking a little further... Maybe after applying ceiling insulation to cover mid/high frequencys i will get rid of my echo/ring and thus create enough "headroom" for the other sounds to come to me? Because in theory it would be really nice, having bass traps, diffusors and all... but bass traps require a lot of space, and i'm the only one complaining about not hearing bass. So what would you say if i would just try to use damping of my drums at first, and maybe then we'll see if bass traps are neccesary?