Looking for advice on panel/hanger treatment

Hi. I'm currently trying to tame a small control room. It's dimensions are 3.4 by 3.5 metres (awful, I know) with a 2.7m ceiling. The walls are VJ timber (tongue and groove). It's actually a spare room in my house, so I'm restricted from doing any permanent construction, wall changes, slot resonators etc. I'm also on a real tight budget. I've built four panel absorbers (for the corners) based on Ethan's DIY designs but portable, and am considering hangers as well. I don't mind hanging them anywhere and don't care if they're visible. So...would the hangers be excessive? Would I be fine with the panel absorbers in the corners and mid/high treatment on the walls? The other thing that concerns me are the parallel surfaces as the room is a rectangular prism. Standing waves and flutter echoes will presumably present problems, so is mid/treatment on the walls sufficient to counter these? Or maybe angled hangers all over the place? As you can see I'm a novice at this stuff. The other thing possibly worth mentioning is that I have access to loads of acoustic foam... enough to plaster the walls with it 4 or 6 inches deep if I needed to, but of course I'm wary of sucking all the highs and high mids out of the room. Hope all this scattered info is intelligible, and any help someone could lend to this struggling bedroom enthusiast would be hugely appreciated. Cheers. Bill. p.s. Found this stuff on the web, and comparing it's absorption co-efficients to the fibreglass panel figures at the SAE site it looks...well...comparable. Any thoughts?

Firstly you could create some ceiling clouds to break up the floor ceiling parallels. Maybe some book shelves, equipment racks or something to break up the wall reflections. Have you checked out this page?? http://johnlsayers.com/HR/index1.htm cheers john

Thanks for the quick response John. And thanks for the site to. I just have a few more questions though. Do I take that to mean you recommend against hangers John? I had looked at the page you recommended, but given the small amount of space to begin with, and the reasonably high ceilings (for a house at least) I thought about the hangers. Drops between 1 and 1.5 metres would still give me some room on the floor for gear/shelves/storage which I will need. Wouldn't hangers address (to some degree) the parallel surface between ceiling and floor as well? And I'm curious to know from anyone who has had experience with the polyester blanket I mentioned in the link above. My wife gets asthma really bad and I'd prefer to avoid fibreglass if possible. I know it shouldn't be a problem if handled correctly but there wouldn't be any such issues at all with polyester. Cheers. Bill.

Yeah I look at the polyester Bill - It's similar to the stuff we used at Left Bank but it has the foil cover which as you can see reduces the High end absorption. May you can just turn it around, does it have foil on both sides. Yes hangers in the ceiling are really effective and probably the way to go in such a small room. cheers john

Thanks John. You mention fibreboard in the SAE reference on hangers. I'm not familiar with that term and noticed in another thread you said it wasn't masonite. What other name might it go by in Australia? I presume it's not MDF or chipboard or the like. And what thickness should I be aiming at. Bill.

Bill wrote:

Thanks John. What other name might it go by in Australia? Bill.

Canite. (I think)

and thickness?

Yeah - what Michael said - Canite - it comes 12mm thick. cheers john

Like a pin board, yeah?

You've got it :) painted white on one side here in OZ for notice boards. cheers john

Great. Thanks for the assistance. I'll post the end results when I'm done. Bill.

I have a quick follow up question. Just wondering if canite is necessary for hangers because of its particular acoustic characteristics, or is it just used because it's light and easy to work with. The reason I ask is I already have a large amount of 3mm plywood lengths, between 300 and 500 mm wide, and 1200 to 2400 long. I'd barely have to cut them if they were a satisfactory substitute. Any opinions? TIA Bill.

I have a quick follow up question. Just wondering if canite is necessary for hangers because of its particular acoustic characteristics, or is it just used because it's light and easy to work with. The reason I ask is I already have a large amount of 3mm plywood lengths, between 300 and 500 mm wide, and 1200 to 2400 long. I'd barely have to cut them if they were a satisfactory substitute. Any opinions? TIA Bill.

For me the canite is important. It's mass is about right for the job. Remember - they are the hangers - the insulation is only there to stop their resonance. cheers john

So....if a substitute material had similar mass and size it should be ok? What do you think?

So....if a substitute material had similar mass and size it should be ok? What do you think?

I don't why not Bill :) cheers john

John, pardon me but I LIKE the smell of long-dead horses being flogged - Are you saying that because hangers are not rigidly mounted, that it's not necessary for the CORE of the hanger to also be absorbent? I would have thought otherwise, but you've built/used them... Steve

Anyone know where I can get absorbtion coefficients of Owens Corning Foamular 150 2" Rigid Foam Board??? Especially the Low, low mid figures Bryan Giles

Hello Brian, Do you have a link? If this is hard foam (closed or pseudo closed cells) than there is no absorption (isignificant). However such boards can be used as membranes (panels). But than it depends entirely on how thos boards are used not the absorption property of the boards itself. If you put something like that in a drywall, you DESTRUCT the acoustic properties of the drywall. If soft open cell foam please provide link Regards Eric

http://www.owenscorning.com/around/insu ... amular.asp I am trying to decide how or what materials (Inside the cavity) of the Slat rear and side walls. I have decided to hold off till Firday to build this wall and finish a few other walls 1st (Waiting on my 16pair Bulk WIre to arrive) Any help would be appreciated. Trying to be done by next Thursday. I am doing a wall a day and have 4 to go. :) My rear Resonator wall is 4'5" wide (each side. I posted a pic on another post) by 8'5" tall. John recommended not slating the whole wall, I am waiting till daylight in Aussie town for his followup. SO between you two guys I can figure out which way I shall go. Thanks in advance Erik. Bryan

Hello brian, I don't find directly technical info but: This is clearly NOT the material to use. As described in previous message. This is closed cell hard foam, probably polyurethane foam. No use in acoustics. Absorption. Think fiberglass, rock wool or comparable. Types: Don't know which ones you have over there. John or others will advise you. But you should find that in the forum somewhere. Regards Eric

Thanks for your help eric. I was just making sure. I will go ahead and use the Fibrex SAFB I found for these walls. God Bless. Bryan Giles