[DeanSheen]

Looking to add some additional treatments to my room. I already have 2 JRisch 6' panels up on the walls at first reflection points but wanted to treat the ceiling and corners.

1.) How do you measure the size and placement of ceiling first reflection treatments?  I plan on using some burlap covered 2" Rockwool for these and am trying to determine how many pieces I will need.  Should I just move a mirror around on the ceiling to figure this out?

2.) I keep reading about how great treating the corners are but have yet to find any DIY plans for these.  The retail solutions I have found are way to pricey for my budget so any links to plans for triangle treatments  of this type would be greatly appreciated.

I am also considering constructing some triangle bass absorbers for the rear of the room.  The only problem there is I would have to make 3 pieces as the one wall has a window halfway up it.  Any links to plans for those would be great also.

~DS

[Rob Babcock]

I have some rigid fiberglass that I'm thinking of using for just such a project...if I ever end up having time.   Right now I'm doing full time school and full time work.

[Big Red Machine]

Early in this thread see photos of what not to do and later photos, plus my gallery of what works:

http://www.audiocircle.com/index.php?topic=44734.0

Cut the triangles at 24" on the hypotenuse and you can get 8 pieces from every 2x4' piece of 703 or 705.

Rock wool may be too limp for ceiling work.  The stiffer 703 or 705 needs less support to stay up.  Mine has frames around them with 3" nails power nailed into the sides to keep them in the frames.  I screwed the frames to the ceiling with angle brackets.  Used full sheets after the mirror technique.

Bass trap the front first then see if the bass builds up in the back in a way that bothers you.  No bass build up in my front corners now with full floor to ceiling triangles in place of 703.  I am putting more traps in back corners now, but smaller.

[bpape]

To find the points on the ceiling:

If your speaker height and head height are approx the same, you can simply map points directly between your head and the speaker and transfer that straight up onto the ceiling.

Bryan