John Sayers’ Recording Studio Design ForumAn archive of johnlsayers.com, 2003–2022

Bass hanger orientation

Started by Rhino on 27 June 2011. 11 replies.

Originally posted at johnlsayers.com, topic 16346.

Rhino
It seems bass hangers are a bit of a black art, but I've been searching the forum to try and find some accepted guidelines. Here's what I've come up with: - Each hanger should be constructed with a sheet of softboard/homasote sandwiched between 2 fibreglass batts. - Although some (Knightfly, Barefoot) recommend using a "limp and dense" material like linoleum instead of the softboard / homasote. - Hangers should be kept 8" - 12" apart. - The longer the length of hanger (including length of hanging mechanism (chain, cord, pipe strapping, etc)) the lower the frequency affected. - Hangers should be placed so as best to interrupt the flow of sound, such as a herringbone pattern. - Or, John's preferred method is to place hangers on modal points (continually dividing the space in half and placing a hanger on each point, until there's no room left). I have two ceiling cavities in which to place bass hangers, one at the front of the control room, and one at the back. Right now I'm focusing on the back of the room.
Image not preserved: room profile.jpg
Image not preserved: room plan.jpg
I plan on the pinkbatt-softboard-pinkbatt approach. The slope of the ceiling dictates that each hanger panel will be a different height, presumably allowing for a range of frequencies to be affected. Question: What do you think is the best orientation for bass hangers at the back of the room? Are either of these ideas on the right track?
Image not preserved: rear hanger opt1.jpg
Image not preserved: rear hanger opt2.jpg
* slats, slots and diffusers are indicative only. Ceiling clouds and treatment at the front of the room not depicted. :)
Rhino
And another question. These hangers will be above an 'overhang', which is above the couch area. The underside of the overhang (the side you'll see if you look up while sitting on the couch) will be soft - insulation hidden by fabric. Should the topside be left open, or should I add some mass (plywood or plasterboard etc), effectively making a sealed cavity for the hangers with a narrow-ish opening at the front?
Image not preserved: rear wall.jpg
Here's a blank hanger cavity in case anyone would like to pick up a crayon and draw where they think the hangers should go..... :)
Image not preserved: hanger cavity.jpg
gullfo
option 1 is your better choice. are you considering making the vertical face in the front of the hanger cavity solid as well? you could make that out of Homasote board (since you buying a bunch anyways...).
Rhino
Thanks for the reply Glenn. :) Is option 1 better due to the way they're positioned, or because there's more of them? Yes making the front of the cavity solid is certainly possible. You're suggesting Homasote over plasterboard etc? What do you think about sealing the overhang as well? And if I've sealed the hangers on all sides, do I need to leave an opening somewhere for the sound to get in?
Rhino
Glenn, this link will show you roughly how I imagine the back of the room should be. I'd love to hear any thoughts you have, especially regarding the overhang (solid or not). http://www.youtube.com/watch?v=2DNexmoL__s The slats/slots and diffusers are just indicative, I'll measure the room at the appropriate stage to ascertain whether the slats/slots need to be tuned or broadband. I also need to get some advice on whether to seal some of those "bass trapping" areas into separate cavities.
gullfo
option 1 because they are breaking up the space better and there are more - consider a couple of ideas - different sizes to accommodate the slope of the ceiling, positioning on mode spots - corners, middle, 1/4, 1/3, 1/6, 1/8 etc and angled on 15-30 degrees. on the face (if there is one, or maybe that front trim sits against the ceiling) you can ignore me... i thought the room was rectangular. have you considered to the hangers in the front of the room as well?
Rhino
Thanks Glenn, I had a look at my recycled building materials supplier, it looks like I can get a stack of softboard ceiling tiles at 600x1200 for a fair price. 600mm is the width of a fibreglass batt, so that works out nicely, and I'll adjust the length of each hanger to follow the slope of the ceiling. I'll hang as many as I can fit at roughly 30 degree opposing angles similar to option 1 above, but with more consideration to modal points. Yes there is a cavity at the front of the room especially for hangers as well, almost mirroring the rear cavity. Actually that was an idea I gleaned from you in a different thread. I'll ask more about that once I have the rear hangers fully planned and understood. A few questions: 1. That softboard is pretty light stuff... is there any point in covering over the hanger cavity (vertical face) with it? Would it be just as effective to use fabric? Perhaps you were suggesting that in order to preserve high freqs? 2. Am I serving any purpose by lining the inside of the cavity with insulation batts or is this unnecessary? 3. The bottom of the hanger cavity (the overhang between the hangers and the couches), should this be solid or is it best left 'open'? Thanks a bunch!
gullfo
i prefer to line the hanger cavity with rigid insulation when its an option (space usually) but the softboard seems like it may be useful for making the hangers.
Rhino
I believe standard pink fluffy batts are recommended for the hangers themselves - pinkbatt|softboard|pinkbatt taped together. Is there any point in getting a few different thicknesses (different R ratings) and mixing it up a bit? I guess it's best just to make them all as thick as possible.
BriHar
I was under the impression the pink fluffy batting is only recommended because it's cheaper. Rigid I understand should work too - and looks neater - but costs more.