Hello,

I have a 23L X 16W X 9'H studio over my garage. I've built several QRD's and soft panel absorbers, but hadn't done any proper bass management. Since the BBC testing seemed to reveal promising results, and I had almost everything needed to build them from my renovation days, I build 64 SF of them. I'm posting this here to hopefully help others to see what they do in a real world situation, since most of the information I can find is just talk and theory.

The panels:
-All backs/sides constructed with either 3/4" plywood, or 3/4" MDF, depending on what I had.
-Front is standard 1/8" hardboard.
-All joints are glued and then caulked inside to be as air tight as possible.
-The BBC stuffed 8" into a 6" deep box, so there was presumably some tension on the front panel, so I did the same with standard fiberglas pink. It would appear that it's important for the insulation to touch the front to dampen the vibrations, but i'll let others speak to that.
-24SF of 2X2' panels are 6" thick - inside dimensions - as the BBC ones.
-40 Sf are 5 1/4" thick. A past REW I'd done indicated that my problems were above the 63Hz their boxes supposedly are tuned to. I figured instead of concentrating all my efforts on one frequency, i'd spread them out a bit. Very unscientific of me.

The green waterfall is mix position without any a10's in the room.
The purple waterfall is in the same position with all 62 SF of A10's in the corners of the room.

It seems to me to have flattened the room from about 200Hz down, which is a pretty pleasing result, since they supposedly target that 63Hz spot so directly. Ultimately it should be good enough for an amateur like me.

FYI I don't have a speaker that I know kicks out even signal from 20-20K, so I used a Yorkville 550W powered one for live gigs. Probably why it doesn't go much below 40Hz. I also don't have a measurement mic, so I used an SM 51, which should be flatter than any room. The important thing for me was to see the *difference* with the A10's.

I intend to do some 1' thick soft panels for the corners not caught by these ones.

Baby steps.

Can you post the actual REW mdat you measured?

Also you should scale the waterfall it so the top end is about 75db and bottom is 15db-25db.
It would be easier to see the decay and modal ringing.

Hi there,

Sorry, I don't really understand the terms you're using. My REW skills are rudimentary at best. As you can see, I had to post a screen shot. However, I think this is what you mean by scaling them up.

By the way, mic placement and all other aspects were the same. I even sat in the same spot in the room. The only difference was the panels.

The BBC did 100 SF with their tests. Might more need to be built to see dramatic changes?

Red is no A10's
Green is all A10's in the corners.

Cheers

Sorry what i meant if you can attach the actual REW measurement mdat so anyone can download an analyze.

It still difficult to tell by your waterfall. It would need to be scaled even more with a longer decay times and a different X axis to be viewed better.

But you are right in that its brought down some of the 49-50hz peak, but its also caused 70 hz to ring out where it wasn't before( which is your 0-2-0 width mode).

63hz won't really target your 2-0-0 mode or your 1-0-0 or 0-1-0 mode which is what you really want to be going after if you are targeting the corner spots.

Congratulations on the results!

Unfortunately what you built has at least 2 significant differences from an A10. A10s are 7" deep and yours are 6". The back and sides are 3/8" and 3/4" is what you used. In addition I can not how similar your insulation is to Supawrap 600.

The only material I found with the name Supawrap was this one and I am not even sure it is equivalent to the one in the paper from 1992 !

https://www.promat.com.au/en/product...aseal-supawrap

https://www.gumtree.com/p/building-i...ion/1325620988

https://www.youtube.com/watch?v=cBWO2FDzzLM

It was made by Pilkington.

Thanks for letting me know

Is there any equivalent in today's market?

It seems like a low density mineral wool

Pilkington was purchased by Owens Corning years ago(1994?) and at the time they were the world's biggest glass maker, so my guess its your standard pink attic insulation.

I think afterwards they called it Pilkington Pink Panther insulation which is on the Owens Corning logo for years.

In todays Owens Corning catalog probably R-40 and up.

Why is this “unfortunate.”

Maybe I wasn’t clear. My side walls are 6” PLUS the back and front, so pretty similar to the bbc.

Also, 40 SF of it was only 5-1/4 deep (side walls, plus front and back, for approx 6” total) yet overall the room seems to have improved.

As for thickness of the wood, As I understand it, it’s paramount that that back and sides are very rigid, and that they have high mass, so how could it be “unfortunate” that I used wood of double the thickness(more mass, more rigid) that what the bbc used?

As for not using sup a wrap, how could this matter? I suspect modern Fiberglas insulation is the same as 1992 UK Fiberglas. And even if not, there is no reason to believe it would function any less effectively.