Quote:
Originally Posted by
chrismeraz
β‘οΈ
When you say "lots," are you talking like 25% coverage of the room? 50%?
Hi chrismeraz
I never calculated it and perhaps I would calc it wrong. Probably less than 50% if including ceiling and floor surfaces. Perhaps more than 50% if only considering walls.
When I finished absorber building a couple of years ago, posted a pictorial overview of the end result here on my website that time forgot--
http://errnum.com/html/new_office_overview.html
Last year I hobby-built some coax studio monitors and the most recent measurements are shown here after installing/tweaking the homemade monitors. The rest of the room and location of absorbers is the same as that earlier overview. Only the speakers and amps were changed.--
http://errnum.com/html/coax_speaker_build_3.html
The room has two always-open interior doors in the rear wall, an un-covered window on one side wall and an exterior door on the other side wall. The remaining worst null around 37 or 39 Hz is almost certainly caused by reflections between the side walls. I suppose that bass null could be improved by putting deep absorbers over the left-wall window and the right-wall exterior door, rendering the exterior door useless and blocking natural light from the window.
To get serious about it, I would need to move some furniture out of the room to allow more absorbers. The big thin absorbers in the pictures and the frame of the front "speaker enclosure" are 3" thick safe'n'sound brand rockwool. They seem to measure effective for highs and mids, and possibly a dB or two "total" improvement in bass. That is, all the thin absorbers added together might be responsible for leveling bass peaks and nulls by one or two dB. I doubt if they do more than a dB or two all together, in the low bass. But seem to work quite satisfactory in mids and highs.
The "speaker enclosure" is three inch thick safe'n'sound rockwool on both sides, back, and top. All surfaces open on both sides. All coverings are burlap.
The hanging ceiling absorbers and several other small absorbers are the same rockwool but thicker than 3".
The front-left corner is 2 foot X 9 inches safe'n'sound rockwool, as is the absorber seen sitting a foot in front of the right exterior door. Those two 6 foot X 2 foot X 9 inch rockwool absorbers were the first two I built when started experimenting with room treatment. Not knowing any better, I expected to measure better improvement than reality dictated. Placed in both front corners, the room decay time was measurably reduced but no useful change could be measured in frequency response. That was my first hint that maybe I needed to build a lot of absorbers to expect much improvement.
One corner is floor-to-ceiling 2 foot square of pink fluffy. Another corner is 2 foot X 3 foot floor to ceiling pink fluffy. The front left wall is 8" thick Pink Fluffy, and the absorbers sitting on-top of the rockwool speaker overhang up to the ceiling are 12" thick pink fluffy in the thinnest "top to bottom" dimension. They are about 3 foot X 2 foot X 1 foot pink fluffy.
All the absorbers are built "as open possible" to present to the room as much absorber surface possible. Most of the fluffy absorbers open on all four sides and the top, with thin wood frames holding them together.