Acoustic room treatment - part 2!

Hi all,
 
Well I've made my traps! Apologies for the dodgy cameraphone pics!
 
I made the frames from light pine -
 

 
Then filled them with 60mm of high density insulation. I finished the backs off by stapling cotton to them and then finished the front by glueing acoustic foam tiles on.
 
The finished articles -
 

 
I have a mirrored set up on the other side of the room.
 
I've only finished 4 but I intend to make a couple more to treat the other corners. I can hear the difference immediately - the bass sounds the same no matter what part of the room you stand in. They really do make quite a difference.
 
Thanks for looking and thanks to everyone here who helped me on my way 
 

Those frames would be way way way better served it you stuffed corning's 703 or 705 in them and then wrapped them in burlap (in a color of your choice). Using 703 or 705 is 10 times better than using studio foam. Your obviously taking the time to build nice frames. Why not do it right by using the right stuff for inside the frames.

Just an idea

Cj

They look great, Jamie!

Just beware that with all that foam, your reverberation times are going to shorten. You might want to use Bob Damiano's RT60 measurement tool or the Home Theater Shack's Room EQ Wizard to check those times after treatment.

The consequence of low RT60's (less than half a second) is that you may find that you're suddenly more heavy-handed with reverb. You won't notice it in your studio because you'll be subconsciously compensating for the deadness of the room. But play it in the car and you'll wonder what you were thinking with all that reverb!

At least that was my initial experience.

Hi Folks,

Yes, the frames are filled with high density insulation (around 45kgm3) from Wickes here in the UK. There's a depth of 60mm in each.

The foam tiles are there to complete the look and also hopefully tame some mids and highs.

@ Bit - thanks for the tips and the links, I try not to be too heavy with the reverb but its always worth thinking about

@ Mike - yes, I definitely need to make a start on the other corners in the room, unfortunately the room behind my mixing position is in an L shape and has a door so I'll have to get creative with the size and position of my next traps.

bitflipper

Two inches of 703FRK has a coefficient of 0.63, meaning it absorbs 63% of the sound energy that hits it.

Depending on the test used, I think this is actually incorrect. I will have to check through my notes (I did a uni subject on this last year) but I believe it's unfortunately not as simple as that. It is true that 1 does mean 100%, but I don't think it's actually linear, so the numbers don't necessarily represent the actual percentage absorbed. OR, I'm thinking of the impedance tube method where these values do not represent the actual percentage absorbed. But I believe the impedance tube method does actually give the actual percentages as it works very well for low frequencies. You CANNOT compare impedance tube results with that from a reverberation room, due to the coefficients actually being different things. They are different coefficients. Of course it is true that higher values mean more absorption though. I think the accuracy of reverberation room tests were really only to something like a tenth, not one hundredth that is always stated. So 0.56 vs 0.64 is likely to be pretty much the same. I'll have to double check that one too.

The fact that you can get 1.15 coefficients in high frequencies tells you something about all this. 1.15 is theoretically impossible, so clearly the results aren't really that accurate.

But now I'm just getting much more technical then this needs to be Still got to double check all this with my notes though!