Cool, thanks for the info!! .14mm plastic. Off to do some testing.
T
mike0370 wrote:
John Sayers wrote:That BBC article doesn't even mention plastic. It's refering to something entirely different.
cheers
john
[/size[/img]
Hi John.... maybe I put the wrong link... this is the graph I was refering to, in the article , the call it polythene, but on the graph you can see they say plastic
knightfly wrote:Not familiar with any semi-serious documented test of the diff; although this would be much easier to do than MOST acoustic treatments - just put up all the rockwool you're gonna use, test without plastic, temporarily tack really thin (like painter's drop cloth) plastic up, test exactly the same way/place, tear that down, put up 1 mil, repeat, etc... Steve
Sorry for the delayed reaction, especially seing I posted right after your post that I now replying to.
Do you mean anything similar to fig 9 (pdf page 10) in BBC RD 1992-11?
i still think that removing the plastic would help, these traps can act as broadband absorbers too, unless you want them strictly for very low frequencies.
Has anyone actually ever measured the performance of these so called SuperChunks? Just curious - I mean its what you hear vs. doing the correct math or things by the book. But, I am curious as to documented results in relationship to other trap, any/all general bass type traps, tube trap type concepts etc.
I mean cutting em triangular to fit in the corner is more for ergo functional reasoning - not for anything else. So, why not just cut squares and stack em and get even more surface area and trapping potential? Like in these photos its not like a square is gonna use up any space that is functional i.e. the triangle cut isnt saving space you might otherwise use, though it probably gives perceived feeling like not so much floorspace is being up by traps.
But, if they perform so good, seems like it would be even easier to slice em once into squares and stack em and get more density etc.
Additionally, has anyone compared the triangled Superchunks vs. Square Superchunks (i.e. take a package of Rockwool bats 4' long and stack em two high in every corner)...?
I guess this concept is the easiest way to go, and know many of you are great advocates of em, and certainly in a basic shaped room (rectangle vs. angled walls) or bad rooms (square or cubes) - this sort of trap or really any deep type trap (John's corner traps or ASC or DIY Tube Traps) makes a heap of sense and is a requirement.
I guess scientific data or at least straight up shoot out between them would be nice detailed info to have...
I've been interested in that thread at studiotips.... were the superchunks they tested 24" wide, or 32"wide? I'm wondering how much mass there were in the tested units....
I was also surprised by the good performance of the MegaLENRDs, better than I expected... but then I didn't realize until recently just how huge (ie, lots of mass) those units actually are....
jwl wrote:I've been interested in that thread at studiotips.... were the superchunks they tested 24" wide, or 32"wide? I'm wondering how much mass there were in the tested units....
Uhh, I'm confused. Superchunks are by design 32" wide, and material filling the triangle. SCA's (Studiotips Corner Absorbers) (don't you just love proprietary trade names? and this is just a bunch of internet acoustic practitioners! ) are the batts vertically postioned, creating a space behind.
I'm referring to the two different cutting patterns on the superchunks site, one of which yields a 34" front (4 triangles from a single 2'x4' sheet), the other of which yields a 24" front (8 triangles from a sheet).
A compromise size versus efficiency cut pattern is shown in the cut pattern attached below, but of course bigger is better - so use whatever fits your room dimensions / budget.
So based on that I was just wondering which cut pattern was tested.
jwl wrote:I'm referring to the two different cutting patterns on the superchunks site, one of which yields a 34" front (4 triangles from a single 2'x4' sheet), the other of which yields a 24" front (8 triangles from a sheet).
A compromise size versus efficiency cut pattern is shown in the cut pattern attached below, but of course bigger is better - so use whatever fits your room dimensions / budget.
So based on that I was just wondering which cut pattern was tested.
I know this is pretty old but I remember testing super chunks vs straddled panel with loose fluffy in for low frequency and the latter performed better.
Purelythemusic wrote:I know this is pretty old but I remember testing super chunks vs straddled panel with loose fluffy in for low frequency and the latter performed better.
Do you have the test results from that? I'm assuming you'd have an MDAT file with the "before" measurements, then the "after" measurements for both cases separately? That would be convincing proof. It's rather had to believe that a couple of inches of pink fluffy would out-perform 30" of OC-703. I'd really like to see the proof of that.
Ah yes, I thought I might be able to find them, but it wasn't my computer and I can't find even the images of the mdat files from REW, let alone the jpegs to show it. Frustrating! It was a comparison between superchunks made from RWA45 rockwool and probably 6 inches or so more of loose fluffy with some old bbc panels in front... there are some photos on this very amateur website my Dad wanted made at the time:
From your comments at that time "Our current hanging loft insulation was much larger than the previous superchunks that we had installed in the corners," I would suspect that's the real reason for the better performance!
) are the batts vertically postioned, creating a space behind.
Steve