Treatment for small rental project studio

Hi all First Post! I've been lurking on and off for quite a while and finally am getting the guts up to make a start on the daunting task of treating my room! I've done a lot of reading but really want to some input from some people with experience so I spend my dollars in the right places! ha ha OVERVIEW: I want to assess my requirements and start building some free standing acoustic treatment for my project studio in our current rental unit. The treatment will be for monitoring purposes. To my ears I’m hearing a decent amount of flutter echo but the bass (to my novice ears) doesn't seem too bad – well at least not boomy. I work with low to moderate volumes and have good neighbours so I’m not concerned about soundproofing. I’ve positioned my desk so the back wall is actually the cupboards which I have OPEN to extend the room length and I get the added bonus absorption/diffusion from all of the clothes and junk in there. I must say when I close the cupboard doors the sound difference is very noticeable. I’ve included a basic layout diagram of the room, it has the wall behind the desk folded down so you can see the height and window dimensions. I’ve also included some tests from REW at the bottom of this post. I’ve yet to get my head around analysing these. As far as my gear I have KRK V8 mk II's on heavy sand filled metal stands. I believe I have them positioned correctly and my listening position is at the correct position for room length. I assume I'll need to make acoustic panels to catch the first reflection points and superchunk bass traps in the corners. With this room however I think the superchunks will only be possible in the front corners due to the cupboards spanning the back wall. Please note that due to being a rental property I won’t be able to treat the ceiling and the treatment will need to be freestanding. As far as construction of the current place I'm not 100% sure... All walls are plasterboard with I'd say brick outter on the left and front walls. Left wall is the neighbours place and right wall is a bathroom, back wall is the 1st bedroom and front wall (with the window) is the backyard. Door way goes to the hallway. Floor is pollished wood boards and this is a single level ground floor unit. BUDGET: Budget wise I’m hoping to be able to complete the treatment for well under $1000 AUD but I do see this as a long term investment that I can reuse so I’m flexible in this department. QUESTIONS: Can anyone give me some guidance regarding how many panels I would need, their placement and is there any suggestions for bass trapping in the back corners considering the layout described above? As far as materials for the acoustic panels I’m thinking of using Acoustisorb 3 (100mm thick): http://www.soundblock.com.au/pdf/tontine_accoustisorb_3.pdf From my initial calculations I can make 4 panels from one sheet. Each panel would be sized 1200 x 600 x 100 mm. There are 3 sheets per pack... so I think I'll need to get two packs to cover panel and bass trapping duties. For the bass traps, does 600mm x 600mm on the equal sides of the triangle sound like an adequate size? My REW calculations are below incase they're of any help. Two calculations are included, one with the cupbard doors open and one with the cupboard doors closed. I'm very new to REW so hopefully my calculations are correct. Thanks in advance for your time and help! Please let me know if I’ve missed any details that might be of use. Cheers Chris Cupboards open: Cupboards closed:

Hi "silverbeetle", and welcome! You don't seem to have very much treatment in that room at all! That seems to be the basic problem. It is mostly bare walls, doors and windows.

I assume I'll need to make acoustic panels to catch the first reflection points and superchunk bass traps in the corners.

Exactly! That would certainly be the first thing to do. I'd also go for absorption in front of the window (behind the desk and speakers), and on the door.

With this room however I think the superchunks will only be possible in the front corners due to the cupboards spanning the back wall.

What about the other ten corners? :) There are 12 corners in a room: people tend to only think of the 4 obvious vertical ones, but there are 8 others...

Please note that due to being a rental property I won’t be able to treat the ceiling and the treatment will need to be freestanding.

If you absolutely cannot get anything up there, not even supported on stands at the sides of the room, then your first reflections from up there are going to be a major problem. You can put a very thick rug on the floor to help with the flutter echo in the vertical plane, but that won't help the very large issue of first reflections form the ceiling. Why can't you put a couple of screws into the ceiling, to hang a piece of 703? If you leave, all you need to do is take out the screws, fill the holes and re-touch with a dab of paint. Worst case, you paint the entire ceiling. No big deal. Couple of hours with a roller, and you are done.

Can anyone give me some guidance regarding how many panels I would need, their placement ...

For your first reflection points, make large panels of 4" 703 (or similar) that you can just lean against the walls, worst case, or build gobo-type free-standing units that you can space a couple of inches away from the walls, for maximum effect. One panel on each side wall, two on the front wall (behind the speakers) and maybe a third in the middle, in front of the window. Plus the cloud, if you can figure a way of getting it up there.

and is there any suggestions for bass trapping in the back corners considering the layout described above?

There seems to be plenty of room ABOVE the closet: put a large superchunk horizontally in that wall-ceiling corner, across the entire width of the room.

As far as materials for the acoustic panels I’m thinking of using Acoustisorb 3 (100mm thick):

Compared to 703, that isn't very good: It's not bad, but 703 would be better for bass trapping, if you can get it. That "Acoustisorb" stuff seems to have peak absorption in the mids and a steep roll-off into the mow-mids, where 703 has better absorption. You can use that if you can't get 703, for sure, but the performance won't be the same. Perhaps you could make your devices thicker, to compensate.

For the bass traps, does 600mm x 600mm on the equal sides of the triangle sound like an adequate size?

Yes, that's fine. Bigger if you can, but that's already a good size. You room actually has pretty good dimensions: the ratio is very close to Sepmeyer 1. The graphs are very useful, and seem to reveal some modal issues. You can see clearly how that changes when you close the doors: the 50 Hz problem moves up to 60 Hz, since the room is now shorter! In fact, you can see that many of the modal issues slide up the scale with the doors closed, indicating that they are related to the longitudinal axes of the room. With the doors closed, you also have new stuff going on in the 100-150 Hz region, too: Hence, the recommendation for absorption on the front window, and above the closet. I'd start with your basic plan of absorption in the first reflection points, super chunk on the rear wall above the door, and in the front corners too, if you can, plus absorption in front of the window, then measure again with REW to see what changed. Make sure that you have your measurement mic and the speakers in teh exact same location for the second measurement. - Stuart -

Hi Stuart Thanks for the awesome reply! I'm happy to run with your suggestion of three panels across the front (window side), two panels left and right, a cloud and bass trapping in the front two corners and above the cupboards. For the panels I’ll be building the frames wrapped in burlap with stands. These will be spaced away from the wall the equal depth of the insulation which I plan on being 4" thick. For the bass traps i was thinking superchunk style triangular insulation with a cosmetic burlap frame standing in front to hide the insulation. Does this sound correct? I've been doing a bit of browsing of the forums to find out more about clouds and came across this comment from you in another post:

Make it thick absorption, and hard-backed, then angle it at least 12° (maybe more, as needed), and spaced away from the ceiling. That should help with both your modal response, and your flutter echo, hopefully.

I assume these details apply to me as well and that the cloud would be angled towards the back of the room. So essentially the cloud would be made the same style as the panel I described above backed with a sheet of MDF/plywood? Am I correct in saying it should be positioned over my head in the mix position? If so the cloud would be going where the celing light is which sits flush with the ceiling... I guess there's no way around this and I'll have to just roll with alternate lighting in the room. I’ll most likely have to work out a non-permanent way to get the cloud in place (screwing them up wasn't well received :p) so I’m a little concerned how this will work weight wise. It's probably a very long shot but maybe several 3kg 3M removable hooks maybe be able to pull this off... somehow :p As for insulation choice for my panels and bass traps I’m feeling very overwhelmed/confused by the data and information flying around. 703 isn’t an option in Australia and I've not seen a clear choice of an alternative. I’ve seen John recommend the following, I’m not sure if these are applicable to my scenario though:

mate - try Higgins Sound Batt type HSB 3 - http://www.higginsinsulation.com.au/ind ... &Itemid=57 or Fletchers F132 50mm semi-rigid black faced fibreglass. http://www.eurekainsulation.com.au/spec ... aSheet.pdf

I've had a look at the Higgins website and I can't see clear info regarding weight... and then there's choice of wool, polyester or earthwool... I'm just getting really confused/overwhelmed with what to choose... can anyone help?!!

I've been doing a bit of browsing of the forums to find out more about clouds and came across this comment from you in another post: Quote: Make it thick absorption, and hard-backed, then angle it at least 12° (maybe more, as needed), and spaced away from the ceiling. That should help with both your modal response, and your flutter echo, hopefully. I assume these details apply to me as well and that the cloud would be angled towards the back of the room.

Most of that is applicable, but you might not need the hard backing: that was for a specific case of a vertical modal issue. If you don't have that, you don't need it.

Am I correct in saying it should be positioned over my head in the mix position?

It should be at the first reflection point on the ceiling. Get someone to hold a mirror up against the ceiling and move it around, while you are seated at the mix position: any place where you can see the speakers reflected in the mirror is a first reflection point and needs treatment. Normally, that will be right over the desk, not over your head, so the light might still survive! :)

It's probably a very long shot but maybe several 3kg 3M removable hooks maybe be able to pull this off

:shock: Ummmm.... :!: I wouldn't do that, no. If your cloud has a hard back, it will be HEAVY, and even without one it won't exactly be featherweight... To find out what kind of mountings you need, hold a few 1x6 planks and a large bag of mineral wool about 1.5 meters above your chair, and allow them to fall on your head: The amount of pain you feel is directly proportional to the quality and strength of mounting you will need! :) :!: :lol: :roll: :shot: (OK, just kidding about that! The point is, you need solid, safe mounts.)

As for insulation choice for my panels and bass traps I’m feeling very overwhelmed/confused by the data and information flying around.

Ordinary pink fluffy fiberglass is fine: look for stuff that weighs about 30 kg per cubic meter, more or less. Mineral wool is fine too: look for stuff that weighs about 50 kg per cubic meter, more or less.

I’ve seen John recommend the following, I’m not sure if these are applicable to my scenario though:

I just tool a look at the data for the "FI32 SEMI-RIGID ROLLS & SHEETS", and it looks great for what you need.

I'm just getting really confused/overwhelmed with what to choose... can anyone help?!!

I'd go with the 75mm stuff "FI32" stuff. It will work fine what you need. Alternatively, you could use the 50mm stuff, but then double it up for the cloud and first reflection point absorbers (to make 100mm thick). - Stuart -

Hi again and thanks again Stuart for your great replies. I've got some great news, I got permission from my landlord to hang the cloud with hooks in the ceiling :) Would one panel sized 1200 x 600 x 100mm be sufficient for the job? FYI I’ll have enough insulation to build 8 panels total... so that would be 3 front wall, 2 side walls... so there’s potential for up to 3 on the ceiling... Based on my graphs in my original post should the cloud be hard backed? In your last post you mentioned that that would only be required if I had a specific vertical modal issue... can you tell if I have one? Or would I be better off making this decision after all the other treatment is in place and new measurements are taken? Regarding the Pink Batts for bass trapping, do these sound OK?: Sono batts (Pink batts) R3.0 x 580 sized 1160 x 580 100mm thick And finally for the bass trapping above the cupboards I'll be limited to 500mm where the other bass traps in the room would be 580mm... Would this be enough to be worthwhile doing? Frame building begins this weekend!!

Hard to tell from your graphs, but it doesn't seem that you have axial modal issues in the vertical plane. So I don't think you need a back on your cloud, and you could always add one later it if tursn out that you do.

I got permission from my landlord to hang the cloud with hooks in the ceiling

:) Excellent!

Would one panel sized 1200 x 600 x 100mm be sufficient for the job?

I think I'd go for two, to start with, and see how that works out.

Regarding the Pink Batts for bass trapping, do these sound OK?: Sono batts (Pink batts) R3.0 x 580 sized 1160 x 580 100mm thick

Sound good to me!

And finally for the bass trapping above the cupboards I'll be limited to 500mm where the other bass traps in the room would be 580mm... Would this be enough to be worthwhile doing?

Anything is better than nothing! And 50 isn't too bad. I'd go for it.

Frame building begins this weekend!!

We have a saying around here: "Photos!!!! No photos means it didn't happen!"... :) - Stuart -

Awesome Stuart, so excited to get this rolling! I bought enough wood to make a single panel, will do a trial run before buying and getting the rest of the wood cut. If time is on my side I should have them all built this weekend. And yes, I'll definitely be posting photos! I've been giving the superchunk bass traps a bit of thought as to how I'll implement them. I've read that there is the danger of the insulation toppling over if they're not secured in place. Since I'm trying to minimise my use of screws into walls I thought about making a sack for the insulation which is tied back with a 3M removable hook. In my mind this would just be supporting forward movement so the weight wouldn't be so much of an issue and will keep the insulation neat/safe. What do you think is this overkill? In addition I'd have a burlap wrapped frame in front of this - would the thickness of the frame cloth followed by the cloth bag have a negative effect? I wouldn't think so on the bass frequencies but perhaps a negative impact on the mid to high frequencies? Then there's the horizontal superchunk above the cupboards on the back wall. I'm still researching but finding it hard to get good information on how to put these in place... At the moment I'm thinking of using that idea of the sack (perhaps two in this case to make it easier to put the insulation in place) with the frame held up by screw hooks to support and hold the insulation up. I really need to give this more thought, I might have troubles with the frame and the cornice too. *scratches head* Out of interest would I be losing much in the way of effectiveness of bass trapping if I didn't span the entire width of the wall (ie stop where the side cornices start)? All of the insulation is ordered and arrives on Tuesday! It cost me $666 ;) If that's not a pretty rockin' omen for a great sounding room I don't know what is ;)

Ok I'm back! Have been busy building and it's gone really well... There was a phenomenal difference getting the first for panels in the room (2x front wall + 1 per side wall). They are roughly positioned at this point in time as I've yet to get the stands made for them. Over the last couple of days I put two bass traps in (front wall)... I wish I did some measurements before I put them in but I didn't... I had a two panel sized cloud laying on the floor roughly below where it would be positioned once it's been hung and I've noticed a pretty bad ringing echo when I clap in the room. I took a few moments tonight to do a few measurements with REW with a few different scenarios. All of the measurements have the two bass traps and 4 panels with variations of cupboard doors open and closed and the 'cloud' positioned on the floor or standing up against the cupboard doors. I'd love to get some feedback on the results which I found interesting, especially referring to my original graphs in an earlier post. Based on this data I have a few questions: 1) Is there anything I should consider before hanging the cloud? 2) I had originally planned to have 3 panels across the front wall (where the window is) but I must have originally measured wrong as there's not enough room... would it be worth while making a cut down panel to fill the space? 3) Which is looking as the preferred option - open or closed cupboard doors? 4) Finally I had planned on doing a 3rd bass trap across the top of the cupboards, is this still worth while? I'm still trying to get my head around how to actually put this in place ;) Thanks for your on going support in my project!