UK Garage Mix Room Design, right track?

Thanks again Stuart. I now have insulation and vapour barrier installed, so next stop is the plasterboard-a-thon, whoop whoop!

Hi again folks, WOW, trying to build a home studio room whilst working and having a family REALLY takes a long time! I may have underestimated that this time last year :-) The good news is, I pretty much have a sealed room now, just need to get my door on and we're sealed. So on to the next phase, the treatment! I have a question about my back wall treatment, which I'd appreciate some thoughts on. I know I will have some hefty bass issues in this room, the dimensions aren't ideal (W 2.96m x L 5.07m x H 2.7m) but my plan was to maximise the volume I could get from a single garage and then treat treat treat. I plan to have 60cm superchunk treatment in the front corners, but there is still a question mark over my rear wall. I have planned to have a large corner trap of some description in one rear corner, as I am limited by the door entrance in the other corner. My question is, which type of bass treatment would be most effective use of this space? Would it be just to have a very large superchunk (cutting my 120 x 60cm earthwool slabs diagonally and stacking them) or would putting a few hangers in there be more effective? I have a quick question about the front wall also, I plan to have a reclaimed pallet wood wall between my two front superchunks, would this be best directly applied to the plasterboard or could I build a frame leaving room for 100mm mineral wool behind? Would I be stepping into dangerous "untuned slot resonator" territory if I did this?? I know some elements of the treatment can't be defined until I test the room, which I will do as soon as the door is on, but as I know there will be 200hz downwards issues I want to get cracking with my low end treatment. Thanks again!

WOW, trying to build a home studio room whilst working and having a family REALLY takes a long time! I may have underestimated that this time last year

That makes you a normal, typical., fully-qualified studio builder! :) It always takes longer, is more complex, and costs more than you ever imagined when you first started...

I have a question about my back wall treatment, which I'd appreciate some thoughts on. I know I will have some hefty bass issues in this room,

The very best thing you can do is to measure the acoustic response of your empty room BEFORE you put any treatment at all in it. You do that using the REW software package, which is free. That will tell you exactly what the issues are with your room, and based on that you'll be able to design the correct treatment.

I plan to have 60cm superchunk treatment in the front corners,

Is there any reason why you didn't want to flush-mount ("soffit-mount") your speakers? That would do several things for you, among them saving space in the room, but most importantly eliminating many of the problems, issues, and artifacts that come from having speakers in the room.

My question is, which type of bass treatment would be most effective use of this space? Would it be just to have a very large superchunk (cutting my 120 x 60cm earthwool slabs diagonally and stacking them) or would putting a few hangers in there be more effective?

Both would work fine, but you'll very likely need more than just that back there.

I plan to have a reclaimed pallet wood wall between my two front superchunks,

why? What acoustic purpose does that serve?

Would I be stepping into dangerous "untuned slot resonator" territory if I did this??

It would not be a slot resonator unless you sealed it air-tight, and even then it would likely not be tuned usefully (if at all): more likely it would be an unpredictable diffuser/reflector with unknown properties...

but as I know there will be 200hz downwards issues I want to get cracking with my low end treatment.

That's sort of like saying "I know I'll get sick at some point in my life, so I'll take a whole bunch of drugs now, randomly, in advance, and hope one of them works.... :) First, get the tests done to find out what "illness" your room really has, then treat only that. There's no point treating "illnesses" that it does not have, and in fact the treatment could make it even more "sick", in other ways... - Stuart -

The very best thing you can do is to measure the acoustic response of your empty room BEFORE you put any treatment at all in it. You do that using the REW software package, which is free. That will tell you exactly what the issues are with your room, and based on that you'll be able to design the correct treatment.

Once again you speak the wisest of words, I am in a battle between my impatience to get it finished and the desire to do it right :-) I will be getting a rig in there to do a REW test as soon as I can get the room dust free, and look forward to your help decoding the results!

Is there any reason why you didn't want to flush-mount ("soffit-mount") your speakers? That would do several things for you, among them saving space in the room, but most importantly eliminating many of the problems, issues, and artifacts that come from having speakers in the room.

I have being swaying between soffit mounts and not, and the main thing that has kept me from doing it at this stage is that as soon as I have paid of some construction costs my next big upgrade will be monitors. So I'd rather not create custom soffits for my currrent Mackie's when I know an upgrade is imminent. Secondly, I am currently eyeing up the Focal Twins, which is understand aren't ideal for soffit mount?

why? What acoustic purpose does that serve?

The pallet wall is purely a cosmetic idea, with perhaps some bonus minuscule diffusion due to irregularities??? I have a big and fairly pressing question at my current stage; my clouds are nearly complete (pics soon) and I am looking into the hard backing. I initially planned to use 18mm OSB, but the sheer weight of the stuff is scaring me, seen as these things will be above my head! Would 9mm OSB be suitable, or is that not massive enough to break any waves? Thanks again Stuart, you are truly an Acoustic Buddha!

I will be getting a rig in there to do a REW test as soon as I can get the room dust free, and look forward to your help decoding the results!

:thu: Set it up with the configuration being as close as possible to the way it will actually be once every last piece is finished. Speakers at the exact location, height, and angle, mic set up exactly where your mix position will be, in the middle of your future head. Then mark and measure those positions with great accuracy, so you can always get everything back to the same point. That's the only way to ensure that you can validly compare data later, after you start installing treatment. Particularly the mic: it is very important that you always get it back to that exact same spot for all future measurements, so measure carefully to points that wont be covered up and inaccessible later! Then calibrate REW carefully, following the instructions and using a good quality hand-held sound level meter to do the calibration. (not an iPhone app, nor a cheap Chinese "toy" meter!)

as soon as I have paid of some construction costs my next big upgrade will be monitors. So I'd rather not create custom soffits for my currrent Mackie's when I know an upgrade is imminent.

You don't have to custom fit them! You can have a soffit that allows for easy replacement of the speakers at any time in the future. Take a look at this thread: www.johnlsayers.com/phpBB2/viewtopic.php?f=2&t=20471 When I originally designed that room three years ago, the customer warned me that he would probably change his speakers later, but he didn't know what he would get. So I designed the soffits with slide-in "trays" that hold the monitor, and I made the tray bigger than the largest monitor he might want to use. Fast forward to early this year: he had to change his monitors as one of the old ones was getting "crackly". So he got the new monitors, which are very different from the old ones, slid out the old tray+monitor assembly, slid in the new ones, and we re-tuned the room to take care of the differences in response. Simple!

I am currently eyeing up the Focal Twins, which is understand aren't ideal for soffit mount?

You mean the 6Be model? No problem. They are front ported, and have the necessary rear panel controls for rolling off the low end. They can be soffit mounted. In fact, I've changed my views over the years: I use to think that most speakers could not be soffit mounted, with only some being suitable. Now I know better: pretty much any speaker can be soffit mounted, unless it has drivers on the sides, top or back, or has a very strange physical shape that would be too hard to fit into a baffle. Most speakers can be soffit mounted: In that room that I linked above, for example, the speakers are Eve SC-407's, which are in fact rear ported! Conventional wisdom says you can't soffit mount a rear-ported speaker. I spoke to the chief engineer at Eve (a very helpful guy), and he said there would be no problem doing that, and gave me some tips on things I should take into account. That speaker is also normally meant to be used horizontally, but I felt it would work better vertically in that room. We discussed that too, and he agreed. So I broke all the rules with that mount (with the manufacturers blessing), and it works fantastically, even though it is rear ported and mounted vertically. So long story short: Design your soffits with removable trays for your speakers, and mount your mackies in there now, then your Focal Twins later when you get them (or any other speaker that you might decide to get in the meant time...)

my clouds are nearly complete (pics soon)

B...B...B...But you can't mount them yet! You first have to run REW on the empty room! :) Priorities....

I initially planned to use 18mm OSB, but the sheer weight of the stuff is scaring me, seen as these things will be above my head!

So wear a crash helmet while you mix! Sheesh! What's the problem??? :) :shot: Don't worry: just kidding...

Would 9mm OSB be suitable, or is that not massive enough to break any waves?

Correct.... there's also the issue of flexibility: 9mm OSB is fairly flexible, and might have strange resonances... To mount your cloud, use chains, not wire or rope, and use proper rigging hardware to hang them: no S-hooks, for example: only links that lock. Use eye-bolts (not hooks) screwed into the joists, and use enough of them to spread the weight safely. All your hardware should be rated for ten times the weight of the cloud, for safety. So if for example your cloud weighs 30 kg, your hardware should be able to support 300 kg. Use at least six chains at different points on the cloud. Another point: you might not need to cover the entire cloud back with thick OSB. In that same room above, part of the cloud is hard-backed and part is not. You can see that it is in several sections, all hung independently, and there are two different angles involved there. You might want to do something similar, and split your cloud into two or more smaller sections, with hard backing only on the ones that need it. It also means that each individual section is lighter in weight, so it won't crack your skull so seriously if it falls! :) (Just kidding, again - I have a weird sens of humor... )

Thanks again Stuart, you are truly an Acoustic Buddha!

I don't think I've ever been called a "buddha" before! That's a first! :oops: :oops: And I'm still not all that much of an expert anyway. Acoustics is one of those things where the more you learn, you realize the more there is that you don't know! It's like one of those nightmares where you are running for the door to escape the monster, but the more you run, the further away the door recedes... - Stuart -

Hi Stuart, thanks for your quick and detailed reply! Although I really really don't want to be one of those guys that asks for advice and then doesn't take it, I'm having to make an executive decision and for now I'm going to leave the flush mount speaker option. I know it will be messier to do it down the line, but I'm hoping there'll be another point when I can afford new monitors at which I could look into it. Right now I've pretty much run out of money (after buying materials for acoustic treatment) and time, as I need to have this room at least basically operational by the time the kids start their summer school holiday, as I currrently have a temporary setup in my living room :? So, I've done a REW test to get the ball rolling, hopefully I followed the instructions carefully, I tried to read some other forum posts to see what mistakes us newbies were likely to make and hopefully avoid them (mains hum etc). On first look, to my novice eyes, the results look a little bizarre.... Perhaps I did do something wrong, but I thought I'd upload the file and perhaps you could give an unequivocal "yes you screwed up" or "you don't know what you're looking at" :-) Test was with an Avenson Audio STO-2 mic (flattest in my collection) into Mbox Pro. I cleared the room for the test, but unfortunately my cloud frames are too bloody big to put anywhere else, and the British weather isn't letting me put them outside! They don't have any insulation in yet, they are basically wooden frames with canvas (Camira Cara), and I put one at each side of the room against to wall to be as unobtrusive as possible. Perhaps they may have affected the results? https://www.dropbox.com/s/d20ol16cs4vr3xr/July%206th%20First%20Room%20REW%20Test.zip?dl=0

Although I really really don't want to be one of those guys that asks for advice and then doesn't take it, I'm having to make an executive decision and for now I'm going to leave the flush mount speaker option

No problem! We'll always try to give you the best advice, but often there are overriding reasons why you can't take it. "No money" is a very valid reason. If you can't do the soffits now, then by all means postpone them until you can.

So, I've done a REW test to get the ball rolling, hopefully I followed the instructions carefully, I tried to read some other forum posts to see what mistakes us newbies were likely to make and hopefully avoid them (mains hum etc). On first look, to my novice eyes, the results look a little bizarre....

It's a bit unusual, but nothing way out of the ordinary. It looks valid, and clearly the room was absolutely empty when you did that test, correct? Not one single shred of treatment of any kind in there?

Test was with an Avenson Audio STO-2 mic (flattest in my collection)

That's fine. Good choice for a measurement mic. They don't come much flatter than that! A couple of things about the way you did the test: first, you followed the REW instructions and did them at a level of 70 dB for each individual speaker, but I prefer to do calibrate and test at 80 dB for each speaker, which automatically gives you 86 dB with both of them on, and 85 dB just happens to be the "standard" level for calibrating studios and cinemas. It's also the level that many engineers like to mix at. And at that level, you are pretty much guaranteed of triggering all the modes that want to be triggered. So for all your tests from here on, please re-calibrate to get 80 dB for the "L" and "R" speakers individually. After you do that, do not adjust anything when you do the "LR" test. Second: You don't need to save each test as an individual file: you can save a whole bunch of tests inside one single MDAT file. Each time you hit "Start Measure", it adds a new measurement set to another tab down the left hand side of the screen. Just make sure to re-name each test as soon as it is done (text box at the top of each tab), so you don't forget which is which. You can get something like 20 or so tests into a single MDAT file, which makes it easy to compare things when you are analyzing.

and I put one at each side of the room against to wall to be as unobtrusive as possible. Perhaps they may have affected the results?

Probably having some effect, but very minor compared to the huge undamped room response,which is thousands of times bigger. Sort of like comparing a speed-bump to Mount Everest... :). At this point in the game, that just isn't relevant. OK, about the actual data: You need new speakers! Or at least a sub. Those things have no low end at all. Below about 38 Hz, they die real fast. Amazingly fast: by 33 Hz, there's nothing left at all! :shock: As long as you don't need low bass, you'd probably be sort of OK with that, but if you ever need to mix a 6-string bass, grand piano, church organ, 10-octave keyboards, or anything else that hits the bottom octave of the musical scale, then you really do need something to fill in a bit down there. Second, your modal response is crystal clear: 67.9, 73.2, 94.4, 104.9, 117.4, 132.3, 137.4, 151, 169, 191, 206. I bet if you plug your room dimensions into a mode calculator, that graph would match your data very handily. I also bet your room is close to square... several of those seem to be occur in pairs that are very close together... What are the final interior dimensions of your room? The other thing that is crystal clear is the SBIR dip at around 79 Hz, and other smaller ones at around 96, 121, 158 and 213. I could do the math and figure out which dimension each of those relates to, but I'm lazy right now, and in a bit of a hurry, as I have deadlines to meet on a couple of projects I'm working on. But you can do the math: the 1/4 of each of those will be directly related to the distance between the speaker and one of the walls, referenced to the location of the mic. I'm betting that the huge dips around 79 Hz are related to the rear wall... So what does all this mean? 1. Major treatment on the rear wall! Superchunks or hangers, for sure, plus whatever else you can throw at that wall. It needs to be killed. But you will also need something in front of those bass traps to keep the highs in the room: probably plastic will do the trick. 2. Large bass traps in several other corners. The front vertical corners, definitely, but perhaps also the wall-ceiling corners? I'd go for superchunks there too, at at least corner absorbers. 3. Cloud: It definitely needs to be hard-backed, and hung at as steep an angle as you can get within reason. And it needs thick insulation both below and above the hardback. I'd go for OC-703 below, and maybe on top as well, or at least thick "pink fluffy" on top. Here too I'd put thin plastic below the bottom absorber before you put the fabric on. Not so much for returning highs here, but more for preventing the insulation fibers from sifting down all over your gear over time... nasty stuff... 4. More treatment! But let's get to that later. First do the above, in any order you like, but do another set of three REW tests at each stage, as soon as you have it finished, so you can check that it is working as planned. Do the test BEFORE you put the final covering on, if you can, so that do any modifications that might be needed before covering. Why all this treatment? The target RT-60 time (or more accurately "decay time") for a room that size is probably around 200 ms (I'll figure it more accurately once I know the dimensions). Right now it is well over 1200 ms! :ahh: It's a boomy, screamy, clangy, shrill, roaring, hellish monster in there right now! And that's putting it mildly. It's BIG monster, so it's gonna need some serious taming. You have to get it down to a soft, dull whimper... That needs a lot of taming. The GOOD news here, is that the overall frequency response isn't that bad at all, and there's definitely hope that it can become a really good room. But you have your work cut out for you! :) - Stuart -

Thanks again for the speedy reply!

It's a bit unusual, but nothing way out of the ordinary. It looks valid, and clearly the room was absolutely empty when you did that test, correct? Not one single shred of treatment of any kind in there?

Yup, just computer, speakers and clouds in there, not a shred of treatment! I'm actually impressed with the length of the verb in here, it's like a cathedral!

I prefer to do calibrate and test at 80 dB for each speaker, which automatically gives you 86 dB with both of them on, and 85 dB just happens to be the "standard" level for calibrating studios and cinemas. It's also the level that many engineers like to mix at. And at that level, you are pretty much guaranteed of triggering all the modes that want to be triggered. So for all your tests from here on, please re-calibrate to get 80 dB for the "L" and "R" speakers individually. After you do that, do not adjust anything when you do the "LR" test.

Got it, thanks! Will do future tests at those levels, and save multiple runs in the same file.

Sort of like comparing a speed-bump to Mount Everest...

Haha! I like it :-)

You need new speakers! Or at least a sub. Those things have no low end at all.

Yeah... they are Mackie hr624's, so not a whole load of bottom end thump. A sub will probably be on the cards, new speaker choice dependent. If I rob a bank and end up with some MicroMains..... :-)

What are the final interior dimensions of your room?

The back end of the room is slightly odd, so I've added a quick sketch with dimensions, room height is 2.55m:

The other thing that is crystal clear is the SBIR dip at around 79 Hz, and other smaller ones at around 96, 121, 158 and 213. I could do the math and figure out which dimension each of those relates to, but I'm lazy right now, and in a bit of a hurry, as I have deadlines to meet on a couple of projects I'm working on.

Fully appreciated! Any time spent replying to me is time spent not earning on other tasks, so thanks again for your replies.

1. Major treatment on the rear wall! Superchunks or hangers, for sure, plus whatever else you can throw at that wall. It needs to be killed. But you will also need something in front of those bass traps to keep the highs in the room: probably plastic will do the trick.

I'm hoping I can do both, although it will be more heavily on one side of the room as I have an awkward rear wall door. I am currently thinking of trying to fit as many hangers as I can perhaps with superchunks above and below. Then perhaps also superchunk at wall-ceiling boundary. I also was thinking of putting some pallet wood (bit of a theme) planks widely spaced over rear wall treatment, hopefully this might help with the highs?

2. Large bass traps in several other corners. The front vertical corners, definitely, but perhaps also the wall-ceiling corners? I'd go for superchunks there too, at at least corner absorbers.

Definitely going with front corner superchunks, I may also do the wall-ceiling corners if more is needed.

3. Cloud: It definitely needs to be hard-backed, and hung at as steep an angle as you can get within reason. And it needs thick insulation both below and above the hardback. I'd go for OC-703 below, and maybe on top as well, or at least thick "pink fluffy" on top. Here too I'd put thin plastic below the bottom absorber before you put the fabric on. Not so much for returning highs here, but more for preventing the insulation fibers from sifting down all over your gear over time... nasty stuff...

Roger that! Noted.

t's a boomy, screamy, clangy, shrill, roaring, hellish monster in there right now! And that's putting it mildly. It's BIG monster, so it's gonna need some serious taming. You have to get it down to a soft, dull whimper... That needs a lot of taming. The GOOD news here, is that the overall frequency response isn't that bad at all, and there's definitely hope that it can become a really good room. But you have your work cut out for you! :)

Yup, that pretty much sums up the sound right now!! haha The good news is that I've had a chance to give some music a blast in here today too, and the isolation seems to be really good, certainly enough for my needs here! Feels like I've just about crossed the first hurdle. It's getting very exciting at this stage, and thanks again for your amazing input. As a local saying goes; You're one of the good ones! :D Adam.

The back end of the room is slightly odd, so I've added a quick sketch with dimensions, room height is 2.55m:

That's fine. There's still space for some bass trapping. Make it deeeeeep!

I'm hoping I can do both, although it will be more heavily on one side of the room as I have an awkward rear wall door. I am currently thinking of trying to fit as many hangers as I can perhaps with superchunks above and below. Then perhaps also superchunk at wall-ceiling boundary.

It's OK to have asymmetric treatment for the low end, bu you you still should keep it symmetrical for high frequencies.

I also was thinking of putting some pallet wood (bit of a theme) planks widely spaced over rear wall treatment, hopefully this might help with the highs?

Yeah, you could do that on the rear wall. As long as they are widely spaced, and not tuned. (You love pallets, don't you? maybe you could call your studio "The Pallet Box"... :!: :shot: :) 8) )

thanks again for your amazing input. As a local saying goes; You're one of the good ones!

:oops: :oops: :oops: - Stuart -

Hello again! So progress was quite slow over the summer with family holiday and the kids being off school, but I managed to make a little bit of headway. I now have clouds up, so lights are in and also sockets are all fitted. I have also put in my front end superchunks, so it's starting to look a bit studio-like at that end! I've done another REW test, perhaps if you get some time Stuart you'd kindly look over the results again? It looks a little odd to me still, especially the fact that the L and R speaker results don't seem to be the same, maybe you could shed some light?? https://www.dropbox.com/s/pe6rfri15kmao86/Sep%2009%20Room%20with%20Clouds%20and%20Front%20Chunks.mdat?dl=0 The test positions of the mic and speakers are the same, although you'll notice that I now have a temporary desk in with my iMac on. The iMac is currently in front of the speakers by about half a meter and is probably having a detrimental affect, I plan to make a stand and put the screen as close to the front wall as possible in the long run. I've attached a picture of the front end during testing. Look forward to your response and any advice you can give about further treatment. Next stop; back wall bass madness! P.S. Have you got any reserved rights on the name "The Pallet Box" Stuart?? :-) Thanks, Adam

I realize that you are around the opposite side of the world from me, but there's really no need to post your picture upside down! :) I'm getting a really sore neck just trying to look at it... :? I'm downloading the REW data now... I'll let you know what I see... - Stuart -

Haha yeah I thought I post the photograph geographically correct (from your perspective).... :roll: Not sure why it did that. Thanks for downloading my test, look forward to any thoughts you have. Cheers, Adam

Hi Stuart, don't wish to hassle a busy man like yourself, but just wondering if you noticed anything particular from my REW? I'm hoping to tackle my bass traps in the next couple of weeks, so any wisdom you can impart would be much appreciated! :D Ad

Adam, I'm not sure how I missed your thread for so long! :oops: I looked at your new REW data, but I couldn't find the original empty-room data to compare against. So that's sad! But the new data looks good, valid, and shows some improvement with regard to what I recall form the original. However, there's a big difference in response between the left and right channels. Not quite sure why, but possibly related in part to the rear wall that has no treatment yet. The big conclusion I draw from this data is that you need a lot of bass trapping! :) - Stuart -

Hi Stuart, thanks for the reply and sorry for my slow response! Been busy here with the festive season and family, and progress has been relatively slow in the studio, partly due to actually doing some work in here! :shot: My back wall still isn't finished, that's the next big push, so in the meantime I've put all my Auralex Maxwall panels in the back corner and the room sounds actually pretty darn nice :D I'll have to do another test to see where I'm at, and also I'd like to look into making some side wall diffusers, so will need to check out the data for that. If I want to put side wall diffusers mid-way down my room to control flutter, would I need to do a REW test from that point in the room to determine which frequency range to design my diffuser around? I'm currently thinking a Skyline style or in the style of the Multifuser. The big recent progress was building a custom desk for the room. I'm still a joinery novice but quite pleased with my efforts, it's made of reclaimed Scaffold boards and pallet wood (of course!!) :roll: It had to be now the studio is officially going to be called The Pallet Box haha! Do you get a cut for the name Stuart?? Thanks again for all your help so far on this long but rewarding project! Ad

This looks very much like what I am looking to achieve. Very nice marked for later reading!

Update:: I've had another big push and found time/money to get on with my rear wall bass trapping etc. I've made the frame and temporarily just stuffed it with the Auralex Max Wall which has been freestanding (and aesthetically annoying the hell out of me!) for about 6 months. I've also made the canvassed frames which will slot over the top of the trap for the cosmetic finish, which has made the room finally feel like an almost finished studio!! This buys me a little bit of time to consider the "guts" of the bass trap. My thoughts are currently: ::OPTION A:: A super duper mega chunk, stuffing the whole thing with layer upon layer of low density insulation. In which case, do you think this Earthwool Loft Roll 44would be suitable? http://www.knaufinsulation.co.uk/products/glass-mineral-wool-rolls/loft-insulation-rolls/earthwool-loft-roll-44 Does the density of the material have an exact correlation to it's effectiveness at specific frequencies? I know (now, cheers Stuart!) that in general that lower density is better for the low frequencies, just wondered how specific that is. i.e. should I wait until I've done a room test and know the specifics before even thinking bout ordering any insulation? ::OPTION B:: A combination of stuffing the frame with some slabs of low density stuff (like above) but also making some hangers to hang ceiling to floor in the frame. It's a relatively small space, but I reckon if I put some thought into angling the hangers I could maybe squeeze about 4 in there. I am slightly concerned that as it's a relatively small trap space that the hangers wouldn't be as effective as just stuffing the whole space with insulation. Any input at this stage would be greatly appreciated! I will be doing another REW test as soon as possible, just need a nice enough day to clear out all the drum kit etc and put it outside for a few hours :D :shot: Thanks! Ad.

. . . with layer upon layer of low density insulation. In which case, do you think this Earthwool Loft Roll 44would be suitable?

Looks like it might be OK, but what's the actual density? I could not find that in the specs you linked to. It just says "low density", but without specifying a number....

Does the density of the material have an exact correlation to it's effectiveness at specific frequencies?

Not a perfect linear curve marked precisely on a graph, no. There's lots of factors that come into play, and the curve is more bell-shaped than straight line: There's a point where lower density stops being better, and starts getting worse again. Very low density is as bad as high density. In other words, there's an optimum density for each application and each product type. However, it's a fairly gentle curve, so as long as you are "in the ball park", as the Yanks say, you should be OK. I would look for something around 40-50 kg/m3 if you are using mineral wool. As long as you don't go with 20 kg/m3 or 70 kg/m3, you should be fine. There's no need to be finessing the density to find the perfect point.

should I wait until I've done a room test and know the specifics before even thinking bout ordering any insulation?

Not necessary for bass traps, no. Just get reasonably good stuff, and pack it in thick. That said, it's important to do a complete set of REW tests before you put it in, so that you have "before" data, showing the room response in all its ugly detail, then do another test as soon as the insulation is in, before you put the face on, to check how it is working, what it did right, and what it did wrong. You will very likely find that it is sucking too much of the highs out of the room, and you need to cover at least part of it with some type of plastic or other reflective surface, to get the highs back again. The "before" and "after" tests will reveal that to you, showing you what highs need to be brought back, and how much they need to be brought back, so you can decide on the thickness of the plastic and % coverage that you will need to control that.

A combination of stuffing the frame with some slabs of low density stuff (like above) but also making some hangers to hang ceiling to floor in the frame.

I would just stuff the frame full of it. There's not really enough space in there to get a good set of deep hangers.

I will be doing another REW test as soon as possible,

:thu: - Stuart -

Wow, thanks for the quick reply Stuart! Stuffed corner of itch-wool it is then! I'll aim for 40kg/m3 and see what the best option is. I was planning on using some left over damp-proof membrane to keep the highs, though wondered whether it would be a little too thick, it's the 1000 gauge green stuff. As you say, it's all speculation until I get a REW done, so I'll report back with that ASAP. Thanks! Ad

So, another progress report. I went with the Knauf Earthwool rs45 Slabs, 150mm thick as the store had a bit of spare stock and I got a good price. I've got all the insulation in, and I put on that spare damp proof membrane on over the top, though I suspect from the sound of the high end at the back of the room now that I may need to take some off or all and replace with a thinner plastic. I've taken REW test at each stage, including with the fabric fascia back on, however I made one rookie error! (hopefully just one). In my haste to get chopping insulation, I forgot to to individual Left and Right speakers tests......doh. I can see that the mammoth canyon I had at about 73hz is now a mere trough, but other than that I could do with a hand unpicking some of the specifics if possible? Here is the REW file: https://www.dropbox.com/s/w336p2cppul9vo5/Bass%20Trap%20Measurements.mdat?dl=0 and here are the process pics: Note - when I did the Partial Membrane REW test I only had the left side covered, I just forgot to take a pic like that! https://www.dropbox.com/s/w336p2cppul9v ... .mdat?dl=0

Hi Adam Good looking build and it's nice to see another UK member on here. Could you share the fan you purchased? I'm struggling to find a good one over here for my slightly smaller build than yours. Also, I note you haven't gone for a mini-split unit. How are you heating the room? I've been musing over this for my build which will be in the ground floor of our 3 storey town house. It's currently heated with central heating radiator but it's always cold and I doubt I'll ever need to use anything to cool the air in there. Thanks Gareth

Hi Gareth, I went for a Soler and Palau TD Silent fan: https://www.tlc-direct.co.uk/Products/SLTD800SILENT.html?ad_position=1o3&source=adwords&ad_id=45425533757&placement=&kw=&network=g&matchtype=&ad_type=pla&product_id=SLTD800SILENT&product_partition_id=174056535907&test=finalurl_v2&gclid=CInQ_IDmvNMCFegK0wodYCAIGQ They do a range of sizes/power so you should find something suitable. Note that the fan itself is not silent though! I wouldn't want it in the same room, i have it in a separate partition. I currently don't have any heating in the studio, I wondered about an electric heater when it started to get colder over winter, but I actually just changed my cloud lightbulbs to Halogens instead of LED and the place is so well insulated that the heat off them is enough! If my budget would have allowed a mini-split that would have been the ideal option, but what I have ended up with is certainly workable. Ad

adamthedrummerboy wrote:

They do a range of sizes/power so you should find something suitable. Note that the fan itself is not silent though! I wouldn't want it in the same room, i have it in a separate partition. I currently don't have any heating in the studio, I wondered about an electric heater when it started to get colder over winter, but I actually just changed my cloud lightbulbs to Halogens instead of LED and the place is so well insulated that the heat off them is enough! If my budget would have allowed a mini-split that would have been the ideal option, but what I have ended up with is certainly workable. Ad

hi Adam do you have have any detail of how you rigged it up? i want to put mime in the garage loft space