Need some advice on using these as bass traps/broad bands

  • Thread starter Thread starter Capt Hair
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Capt Hair

Capt Hair

Jeff
Well I went to dinner to tonight at my local Outback Steak House and they had recently renovated the building and got all new everything and had all the old everything sitting out in pods in the parking lot.

Well I spotted these:

DSC02221.webpDSC02222.webp


The booth seats. Now, yes they are foam, but this isn't your standard "aurlex" type foam, it's very high density stuff. It can hold your average person up from hitting the wooden booth below them. They're 3 1/2" thick and the largest ones are 7 1/2' in length and the small ones are just under 3 1/2', I could almost fill the full corner with the large ones!

The question!
Now the thing I'm worried about and don't know about is the "leather/pleather/vinyl" wrapping them... Would this reflect the sound to some extent????:confused:

If so, I have more than enough cotton fabric left over to wrap them myself, but would rather leave them as is so I don't have to tear them apart.

thanks guys!
 
If you cant blow air through the fabric, it will reflect.
If you try to blow air through them, try it on the back of the seat instead of actual seat.
Nasty! :eek:
 
homestudioguy said:
If you cant blow air through the fabric, it will reflect.
If you try to blow air through them, try it on the back of the seat instead of actual seat.
Nasty! :eek:
Click to expand...

well there's wood on the back, and then a few open holes.

And I did disinfect the hell out of them lol.

I'll probably just rip one of the smaller ones open and try to wrap that one up before I try to tackle the larger ones.
 
Without knowing the exact construction, I can quickly approach a logical conclusion --

1) Cushion foam is freakishly inexpensive compared to OC703/705/Roxul/etc.

2) People still use 703/705/Roxul/etc.
 
Massive Master said:
Without knowing the exact construction, I can quickly approach a logical conclusion --

1) Cushion foam is freakishly inexpensive compared to OC703/705/Roxul/etc.

2) People still use 703/705/Roxul/etc.
Click to expand...

word, fair enough. Might just use a few and rig up some gobos, need to find some use for them.
 
I would agree that the vinyl is going to reflect, especially in the higher frequencies. And the foam inside will mostly only absorb at higher frequencies. So... they may have some limited benefit, but only if you change the fabric.

If I scored those, I would use some of them to build some cool bench seating for the studio!
 
Potsy24 said:
If I scored those, I would use some of them to build some cool bench seating for the studio!
Click to expand...
How 'bout it -- A big frame -- half the area could be for storage, half could be compressed bagged-glass which would actually help the low end...

That'd be cool -- A space for mic stands, one for cables & cans - the possibilities...
 
Potsy24 said:
I would agree that the vinyl is going to reflect, especially in the higher frequencies. And the foam inside will mostly only absorb at higher frequencies. So... they may have some limited benefit, but only if you change the fabric.

If I scored those, I would use some of them to build some cool bench seating for the studio!
Click to expand...

That's always a possibility^^^

I just want to find some use for these, some 2 in 1 seat/storage boxes would be cool. Any other ideas guys? I might just save a few and plop the others on craigslist and make a couple extra bucks.
 
Well I tracked down what the things are made of, took me two weeks:p, it's not traditional "foam", just wanted to see what ya'll would say. It's density is 6lbs/ft3, twice as dense as your standard OC/rockwool. I'm just finding it hard to believe that 4" thick pieces wouldn't effect the low end.

It's the "mutli/rebounded mixed foam at the very bottom of the page Same stuff they use to fill punching bags.
 
homestudioguy said:
You need to do some more research to find some definitive information about this materials sound absorbency coefficient.
SAE: Coefficient Chart
Scroll down to Fiberglass Board 4" thick
Scroll back up to Upholstered Foam Seats.

Acoustic Insulation - Order Online, Ships UPS
GIK Acoustics. Acoustic Panels and Bass Traps.

BG
Click to expand...

I know about the coefficients of the materials. This just isn't standard foam which is why I'm having trouble finding anything on it or conveying that it is abnormal to all of you, it hardly compresses at all, at first I thought it was just because of the plastic/leather outside, but upon ripping them open, it's still just as rigid. I can bend the stuff in half and rip what's in your normal couches/upholstered chairs, which is what I'm "assuming" the SAE chart is talking about. Can't say the same for this. Again, assuming, upholstered seats in the SAE chart are for 2" thick material. That's what it is for all other tests I can find. Something with double the thickness would then mean double the absorption, correct? Which would mean full absorption at 125hz.

In the mean time, I'm go to keep digging, maybe I'll find a chart on a similar material now that I know what it's called.

Edit: And is a density of a material going to be the same with another? 6lb/ft3 foam = 6lb/ft3 fiberglass??? Wouldn't it absorb a similar amount then?

Edit 2: After researching some other tests, including Auralex's bass traps, and few others, if a high density foam material of 2-3'' thick and only with a density of 1.7lb/ft3 can fully absorb low end. It at least gives me the confidence that a similar material an inch thicker and 3 times the density would have no problem absorbing at 125hz.
 
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It actually does sound like these cushions might function as a decent bass trap. The best way to test them is to... well, test them. What some people would do is set up some mics and play some sine waves at different frequencies and record the response of each at different points in the room (or something to the effect).

Here is what I would do: Go into the control room and listen to some music with heavier low end that you know well. Get a good feel for how it sounds in the room, and from all different points in the room. Then prop up the cushions across every possible corner (wall/wall as well as wall/floor). Then listen to the same song and see if it sounds different.

In general, you should be hearing more bass coming from your monitors. As you move around the room, stick your head in corners, and lay on the floor, you should hear a consistent sound. You should not find peaks and dips that are different all over the room. I was planning on buying new monitors before I treated my room. I actually had a buyer lined up to buy my old ones (I got lucky and he never showed up). After treatment, I immediately realized I did not need new monitors. It sounded that different. The bottom line is, if your cushions work as bass traps, you'll know.
 
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