Bass Hangers / Superchunks

I've been looking around a little to answer my question, however I havn't really found a definitive answer; not one that seems to meet my situation anyway. My room is currently under construction and its size will be: Width: ~3.16m Length: ~ 3.06m Height: ~2.60m Not perfect, but thats what it has to be. The main question for this thread is about bass trapping. I know there are issues with cube shape rooms due to modes etc but I have asked those questions in a different thread. Once the room is complete I'll compile all my threads for a diary:) Anyway. I have space for one corner trap at the back of the room. I'd like two but the door is in the corner as shown by my basic sketch of the layout. Question 1a: Would a Superchunk be more/less effective than a hanger design given the size available (illustrated)? Question 1b: Which of the hanger designs would prove most effective? Question 2: On the back wall/ceiling join I may have space for another bass trap. I assume this would be preferable to absorbsion just across the face of the rear wall. However, as shown, the join between the bass traps looks a little odd, so would it be better to lose some of the corner bass trap to enable the ceiling one to be added? Thanks for any replies, Gareth

i think the center drawing of the hanger traps would be more effective as its more like a broadband trap. you can put a 4" layer of 703 and cloth on the front as well - keep the hangers free - although it works on the principle of diffraction - so you get clear flow through the hangers. line the trap as well. overhead, i'd put in a superchunk style.

i think the center drawing of the hanger traps would be more effective as its more like a broadband trap. you can put a 4" layer of 703 and cloth on the front as well - keep the hangers free - although it works on the principle of diffraction - so you get clear flow through the hangers. line the trap as well.

Yeah, the center one was my guess too. I only did the other two because I saw on some posts it was good if the hangers were in a herringbone pattern, hence the left design trying to alter the angles a bit. The right design was just because I was wondering if turning the hangers so that more sound hit the "face" of them would be more effective.

overhead, i'd put in a superchunk style.

Hmm, I might be able to do that, but I think the cost might be a bit prohibitive. Maybe I could use superchunks in the "corners" and then have a few hangers in the middle of the trap. I'll have to cost that one out. If I do have the ceiling trap, I'll have to reduce the size of the corner trap, so that it would fit together. Here's a sketchup: Now I look at that, then maybe its still worth adding hangers, though they are rather small. Would a "Corner Trap" design be just as effective without as much effort? I'll read up on that recent thread combining chunks with hangers. Thanks for your continued support, I'd be screwed without it:D Gareth

Okay so I read the thread about combining hangers with superchunks, but it wasnt quite what I meant and it didnt really have a definitive answer. However, quoted from SAE:

Acoustic Hangers. This is a system of fibre board panels that are wrapped with insulation and are hung freely using wire or rope. The large hangers 1.8m x 500mm work in the low frequency range whilst the panels 1.2m x 300mm effect the low mid frequencies. It is common to have up to a 1.2m space at the rear of the control room with the large hangers whilst the smaller hangers are effective if suspended in the ceiling cavity created by a false ceiling.

By the looks of it, I'm not going to have enough space in the corner for "low absorbsion" hangers, unless I make the corner trap bigger, which I'd rather not as it wouldnt look very good. I can make the ceiling hangers 500mm wide, but obviously only about 500mm long too. Any ideas on that? I've been considering a "Limp Mass" absorber for the flat section on the back wall, and I'm doing a bit more research on that, but I've also found that the following type of Resonator might be a good idea: http://www.thomann.de/gb/the_takustik_sa2_ras_schallabsorber.htm On the german version of the site there's a bit more detail, and it says "Absorbtionsbereich über 60% bei 80-400Hz" which I believe roughly translates as 60% Absorbsion from 80-400 hz. Due to that being pretty small considering the frequency its absorbing, if I made something along the lines of that (or even bought that, depending on construction costs) then I could use the hangers to even out the lower mids? Okay so I suppose now the questions are: Question 1: Ceiling Absorber // Superchunks over the corners and hangers in the middle, or hangers all the way across? Depending on cost, I could superchunk the whole length, but I have a feeling its going to cost more than it will benefit? Question 2: Would hangers of the size shown in the latest sketch be worth using, or would it be better/cheaper to use a superchunk or corner trap idea? Again, the final design will probably come down to cost/benefit, but it would be nice to know what people think are "good ideas" at least. On the limp mass/"big slat" idea, I think that will be last in, so that I can tune that to any big bumps I get once I test the room. Sorry for going on a bit! Just like to get all my thoughts down and more importantly, have them checked over!! Thanks, Gareth

Mmmm, I like the look of this:

i'd go with the superchunk approach. its got good broadband performance and should be straight forward to construct.

Hello friends I´m new to this forum . I was looking at yours pictures and I wonder what´s the diference betwen filling a cavity whith fluffy fiber glass and hangers. Sorry about my english. I speak spanish. Thanks :(

you're actually using a dense fiberglass for the superchunk and using a lighter insulation on light density particle board, osb , or plywood for the hangers. generally the hangers need a proper cavity to sit in to be effective. superchunks can work in just a corner. another option is to use a polycylindrical diffuser across the corner lined with rigid fiberglass, and optionally perforated to add some additional absorption.

gullfo wrote:

you're actually using a dense fiberglass for the superchunk and using a lighter insulation on light density particle board, osb , or plywood for the hangers. generally the hangers need a proper cavity to sit in to be effective. superchunks can work in just a corner. another option is to use a polycylindrical diffuser across the corner lined with rigid fiberglass, and optionally perforated to add some additional absorption.

Thanks! Do you know about the absortion range or for which frecuencias it works the best? Top and boton must be sealed? Thanks!!

generally, polys diffuse above 500hz, and they absorb (depending on the cavity space) below 300hz. (Everest MHoA pg 204 or thereabouts). sealing top and bottom is good to improve the panel absorption characteristics and adding a layer or two of insulation inside the cavity is also good.

gullfo wrote:

i'd go with the superchunk approach. its got good broadband performance and should be straight forward to construct.

gullfo: What do you think of placing bales of unpacked rolled up fluffy fiberglass in the room corners, could it emulate a super chunk? Just leaving the bales rolled up in their original plastic wrappers. some thing like the images. Thanks!

give it a try - it works stacked in the corners so it should work up on the ceiling-wall corner - bearing in mind the vertical and tri-corners are the most concentrated bass locations. the rolled pack increases the density of the insulation making it better for bass trapping and the plastic preserves some of the higher frequencies by reflecting them.

Porous absorber calculator is your best friend.

Hannes_F wrote:

Porous absorber calculator is your best friend.

Thanks both, can you post a link for download the Porous absorber calculator thanks again!!

gareth.h.rees wrote:

Mmmm, I like the look of this:

Sorry Ican not translate to spañish, the word gobo, can you explain what Gobo is? Thanks!!

Here you'll find a gobo: http://www.johnlsayers.com/phpBB2/viewtopic.php?t=5928