2. misc-audio
  3. 1075699247

Guidelines for treating cathedral ceilings

My listening room is 18' wide x 18.5' deep, with a cathedral ceiling symmetrically over the room.
I have done the 'standard' room treatments (absorption behind the speakers and listening seats, and absorption at the first reflection points on the side walls). Absorption is 2" thick Owens Corning 703 fiberglass.

However, I am still hearing a sharp slap echo when I clap my hands in the room. I am beginning to suspect some sort of ceiling or upper corner interaction. Is there any rule of thumb for where to first start with a treating a cathedral ceiling? I am a little bit surprised, since the ceiling is angled and does not present two parallel surfaces for sound to bounce off of.

The practical concern is some sibillance when playing certain CDs at high volumes (possibly exciting something in the room and exaggerating the treble?).

thanks in advance,
Bill

(I hope this drawing comes through OK- the A is the top of the ceiling, and the two S are the speakers).

.......................A
.................... /....\
................./.............\
............../...................\
.........../..........................\
...........|...........................|
...........|...........................|
...........|...........................|
...........|.....S...............S.....|
............ --------------------------
gnobber
mejames
986 posts
 
Michael Greene of roomtune fame has products which fix this problem the original corner tunes or the even better newer PZC controllers
newbee
4,093 posts
 
Dumb question time - Where are you standing when you slap your hands? If your not at your listening position it probably doesn't make a difference. Have someone stand where you have placed your speakers and clap their hands while you are seated in the listening position and see what happens.
flex
292 posts
 
I don't agree with Newbee. Flutter echo makes a difference anywhere in the room, since sound reflects from all of the surfaces and combines into what reaches your ears.

The source of flutter echo is usually easy to locate. If you walk carefully around clapping, you may pinpoint the exact place where it begins and ends. Open hallways, or reflections between ceiling edges and untreated hardwood floors are typical sources. You can check floor-ceiling bounces by putting thick towels or rugs down on the floor and see if that kills it.

In my setup, I've found that foams and absorbers on the ceiling can do too much absorbing. Diffusors at either reflection point work equally well and, in fact, better than absorbers. So you might experiment with RPG or other diffusors, as well as rugs, bookcases and the like when you identify the source.
More to discover