Can I convert this couch into a giant bass trap??

[Lights]

I have an old, ugly, but very comfortable couch (goose down pillows) in my basement studio that appears to be the location of a 43Hz frequency hotspot.

(You can read all about my adventures in bass trapping my basement studio by looking at this thread.)

Here's a picture of the couch:



My first instinct was to toss the comfy couch and ask the woodworking friend of mine who built all of my other bass trap contraptions to build a giant box of Owens Corning Ecotouch to replace it.

But then I would lose my comfy couch. Yes, it's ugly... but this is my basement we're talking about...

So I started to wonder... what if my comfy couch could become a bass trap?? I need the experts to weigh in on this before i attempt it.

First off, I flipped the couch on its back and found that it's largely hollow.

Here's a picture of the underside where there's about a 5.5ft x 2.5ft x 7" hollow box that the cushions sit on, which sits off the floor about 3" on wooden feet:


On the front, back, and sides, this box is surrounded with .5" thick plywood, but it's open to the bottom (save the fabric you see pulled back in the image above) and on the top (save the padding, springs, and fabric you can see in the image above).

There's an additional hollow space that runs up the back of the couch and appears to be about 6" at the bottom and narrows a bit at the top so it's roughly 5.5ft x 6in x 2ft.



All told, that's more than 13 cubic feet of open space that is easily accessible by pulling back the fabric on the underside as pictured above.

A few questions:

1. Would stuffing this full of Owens Corning Ecotouch make it an effective bass trap?

2. Will the fact that the main cavity is surrounded on four sides with solid wood impede its effectiveness? Because the top and bottom represent roughly 36sqft of surface area and the front and sides represent roughly 6sqft, I wasn't sure how much of a difference they would make.

2a. If you said yes to #2, would drilling a series of large holes in the wood surrounding the cavity mitigate that problem? How much of the wood needs to go away to make it effective? I have a hand drill 1" wood drill bit and drilled one test hole succesfully just to test that it could be done, and it was rather hard wood... I might burn out my drill if I tried to turn the front panel into swiss cheese.

3. Do the goose down pillows that cover the "open" top make it less effective? They are about 6" thick and relatively dense.

Thanks for your thoughts on this!!

[Aqualung]

I'm no expert, but I personally wouldn't put fiberglass in an area where it would be subject to motion from people using the couch. It's not the same as when it's undisturbed in wall/corner/ceiling panels. If you want to put something in the hollow spaces, I'd use layers of cotton quilt batting.

[feelKlang]

My answer is (unfortunatelly) NO. It should be entirly off foam, like my couch elements:

[JoRillo]

Semi related question - I have a mattress - *roughly* 1 1/2' deep 4' wide and 6 1/2' long - it has no springs, just whatever material it is made out of (comfortable as can be). Would this thing act as a good bass trap - or is it more likely to do damage then to help? I have a door right at one of my room corners - so intention is to bass trap the other three corners then throw this up in the door corner whenever I feel it necessary.

[erikdrink]

It would have been cool thoug, a couch on the wall!

[daillman]

I'm no expert but it seems like it should have some effect on the frequencies running around. It might be what ur looking for but I think t would be of some benifit plus I would love to see pics.

[Lights]

A couple of thoughts:

1. Is cotton batting as effective at super-low room modes (40-50Hz)? It seems like the only success has been with R-30 fiberglass. See: 40Hz, go to hell!

2. The new Owens Corning Ecotouch seems to be really different from common fiberglass like the 703. While still made of glass it seems to be made in such a way that the fibers don't break off and get into the air or your skin. I'm not sure what they do to get it like that. Perhaps some sort of binder. It's also free of formaldehyde and other nasty chemicals from what I can tell.

3. Regardless of what material I use... I'm still looking for thoughs on whether the couch itself is an effective enough container for the material:

Originally Posted by Lights

A few questions:

1. Would stuffing this full of Owens Corning Ecotouch make it an effective bass trap?

2. Will the fact that the main cavity is surrounded on four sides with solid wood impede its effectiveness? Because the top and bottom represent roughly 36sqft of surface area and the front and sides represent roughly 6sqft, I wasn't sure how much of a difference they would make.

2a. If you said yes to #2, would drilling a series of large holes in the wood surrounding the cavity mitigate that problem? How much of the wood needs to go away to make it effective? I have a hand drill 1" wood drill bit and drilled one test hole succesfully just to test that it could be done, and it was rather hard wood... I might burn out my drill if I tried to turn the front panel into swiss cheese.

3. Do the goose down pillows that cover the "open" top make it less effective? They are about 6" thick and relatively dense.

4.

Originally Posted by erikdrink

It would have been cool thoug, a couch on the wall!

What?

[feelKlang]

Originally Posted by JoRillo

Semi related question - I have a mattress - *roughly* 1 1/2' deep 4' wide and 6 1/2' long - it has no springs, just whatever material it is made out of (comfortable as can be). Would this thing act as a good bass trap - or is it more likely to do damage then to help? I have a door right at one of my room corners - so intention is to bass trap the other three corners then throw this up in the door corner whenever I feel it necessary.

different materials have different absorbing center frequencys. in my case the 100 Hz couch plays together with my other room treatment

[vocom]

Originally Posted by Aqualung

I'm no expert, but I personally wouldn't put fiberglass in an area where it would be subject to motion from people using the couch. It's not the same as when it's undisturbed in wall/corner/ceiling panels. If you want to put something in the hollow spaces, I'd use layers of cotton quilt batting.

I would think if the fiberglass material is wrapped or enclosed by fabric that this shouldn't be a worry.

[Lights]

So you mean wrap it in fabric before stuffing it in the couch? Even though the couch is wrapped in fabric already?

[vocom]

Originally Posted by Lights

So you mean wrap it in fabric before stuffing it in the couch? Even though the couch is wrapped in fabric already?

My post got a little garbled by auto correct, ive edited for clarity. And the previous commentator worried about fibers breaking loose into the air with people sitting on the couch - moving, "stressing" the "trap". So just like wrapping a trap with fabric, make sure the fiberglass is enclosed like you would if making a hanging trap. That was my point.

[Lights]

Ah yes it makes much more sense un-autocorrected

Yes I think the couch itself would be a good enough fabric wrapper. At one point in its life it was a high-end custom-made couch. 11 years and 2 kids later and it's no longer pretty but still in great shape. I could make sure the bottom fabric is replaced and sealed around the bottom of the frame. I just wonder how much work I need to do to it to make it effective as a trap. Will the heavy goose down pillows on top reduce it's absorbency? Do I need to turn the frame on the front and sides into Swiss cheese or leave them intact?

[vocom]

I will leave the deep, technical answer to others. But it seems an inexpensive DIY experiment. It certainly won't hurt, I'd think. Lay off the drill and work your way toward a solution & answers.

[spiderman]

Definitely not fiber glass. I think you could use mineral wool though. Buy this and stuff your couch to the brim. It would definitely increase it's absorption property.

Scrap Mineral Wool

[Lights]

Isn't mineral wool the same thing as fiberglass?

Mineral wool - Wikipedia, the free encyclopedia

[vocom]

Originally Posted by Lights

Isn't mineral wool the same thing as fiberglass?

Mineral wool - Wikipedia, the free encyclopedia

I think the idea is mineral wool vs pink fluffy.

[Lights]

Have you guys played with the new Owens Corning Ecotouch? It's cheap and somehow it doesn't break up or get into the air or make you itchy. And it's a subclass of mineral wool. Regular mineral wool would do both of those things.

[jwl]

Originally Posted by Lights

Isn't mineral wool the same thing as fiberglass?

Mineral wool - Wikipedia, the free encyclopedia

Definitely not the same material, but they do provide similar results given similar sizes and densities. Generally if appearance is a factor I prefer to work with fiberglass as it is a more coherent material and holds its form/shape over time without degradation.

[sameal]

the thing that i pick up from all the acoustic articles and such i have read over time is, that a couch should be considered only if there is no other option.

that couches performance over something actually designed to do the job will probably not match up.

if it's all you got, it's all you have. and maybe it will work, who knows right? experimenting first and seeing the result with good measuring equipment is a better idea then taking forum advice from of all people myself. so by all means try it, test it and see what you get.

but substituting a couch for a bass trap is like cutting butter with a fork. it might work sure, but a butter knife is probably going to do the job nicer and cleaner.

[Lights]

I'm not talking about substituting a couch for a bass trap. The couch is already there... and not working as a bass trap. However, the question is could I make the frame porus enough and fill it with the same material that a REAL bass trap has.

[sameal]

Originally Posted by Lights

I'm not talking about substituting a couch for a bass trap. The couch is already there... and not working as a bass trap. However, the question is could I make the frame porus enough and fill it with the same material that a REAL bass trap has.

i understand that part. but i feel it won't work as well honest. but there's only one way to find out really.

try it out and measure it.


i guess it's more of a dropping a engine in a 300,000 mile frame analogy. but honestly you won't know for sure until you experiment.

(i'm no acoustic expert either, so take what advice i give with that grain of salt in hand)

[mutetourettes]

i was about to post this exact question too - i have two big couches in my room, and they're nice, but similar questions and structure etc..

the couches are staying, it's just a question of whether that volume can be put to use for bass trapping? and nicely disguised stealth bass trapping at that.. (never mind that there'll be a ton of very obvious trapping around the room too!)

pretty much every surface is upholstered wood apart from the underside and the area that supports the sit-on cushions. But some of those wood surfaces could be perforated for better absorbtion.

what i like is that they stand 4" off the floor. nice 4" gap that.......

[ears2thesky]

Can couches be bass traps? YES.
Can you tune the couch to your room's specific needs? DOUBTFUL.
Can it help? MAYBE.
Can it hurt? POSSIBLY.

Measure the response of the room with and without the couch and see what it's doing.

[mutetourettes]

ah. ok. so i was under the impression that more bass trapping is better. generally, in my simplistic first shot at treatment, in what cases is that wrong? this is smallish normal brick built house room, so i reckon as much trapping as i can fit in will still not be 'perfect'.. these couches are both at two-boundary intersections (floor/wall) where there's going to be lots of bass farting about no?

even if i pt holes in just the top half of the vertical front-under-leg surface, and lay 4" of 703 or equivalent across the whole bottom of the couches, that's effectively a very large (24sqft?), but somewhat obstructed (by cushions) wall panel with a 4" gap, only the 'wall' happens to be the floor.. is that daft?

[mutetourettes]

ah now i've read lights' other thread, I see he's trying to tune out the last nulls for one speaker... I wasn't thinking tuning yet, just brioad strokes..

I'd really love to see if a couch full of pink fluffy helps. Also, any point actually stuffing the cushions with that (assuming the fibres can be kept in reliably)? or is that too uncomfortable? is the cushion cover material too thick?

[Lights]

Don't forget that I'm talking about making the frame porous and filling it with bass trapping material.

I am probably less than a week away from testing this idea out so I'll try it and report back.

[Lights]

Originally Posted by ears2thesky

Can couches be bass traps? YES.
Can you tune the couch to your room's specific needs? DOUBTFUL.
Can it help? MAYBE.
Can it hurt? POSSIBLY.

Measure the response of the room with and without the couch and see what it's doing.

Just to clarify, how could additional bass trapping hurt? I've heard many times (from acousticians) that you can't overdo bass trapping.

[Lights]

I think I may have to abort this exercise before it even started. Today I pulled the couch out and replaced it with a stack of fiberglass just sitting there on a sheet of plastic. It was probably about a couch-full of fiberglass. And it had no effect on the 43Hz null in the left speaker.

So while I bet that the couch would make a decent soffit bass trap if stuffed with fiberglass (or mineral wool), I am pretty certain that it wouldn't mitigate my 43Hz problem.

I tried several alternative positions for the fiberglass and saw no change at 43Hz.

I'm not sure there's enough volume in the room to do much more... it's already loaded with 2 giant pink fluffy soffit traps and 10 standard OC703-equivalent 4" bass traps spaced 4" from the walls, and straddled across various corners. I'm running out of space to put insulation.