• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). There are daily reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Room Acoustic Panel/Treatment

Martini

Active Member
Joined
Jun 13, 2020
Messages
138
Likes
160
I'm looking at getting a some acoustic panels for my size challenged listening room. I know bass modes are the biggest problem and I'm addressing them with Dirac EQ, for the time being. I was looking at the 2" thick panels from Acoustical Solutions, because they are local and can save the shipping cost. The speakers are Revel F328Be and I was originally thinking of starting with 3 panels; 2 for first reflection points and one directly behind my listening position which is only 36" from the rear wall. However, some have mentioned that Revel uses or benefits from the first reflection points. So, I am now wondering if the 2nd reflection points might be more important for me to address because: a) the 1st reflection point are equidistant from the L/R speakers and fairly early, about 39" from the speaker. b) the room widens before the listening position, so the 2nd reflection points are not equidistant L/R. Is this reasoning sound? Also, would you recommend absorption or diffusion for these locations (or which locations?)

Possible panels, but open to other recommendations:
https://acousticalsolutions.com/pro...ribute_pa_size=2-x-6&attribute_pa_thickness=2
https://acousticalsolutions.com/product/alphasorb-sound-diffuser/?attribute_pa_size=2-x-4
 

FeddyLost

Senior Member
Joined
May 24, 2020
Messages
453
Likes
320
It depends on your tastes, resources and possibilities.
Diffusion adds width and spatiality, good absorption makes better 3d and pinpoint imaging.
I don't know what do you prefer in music, but i'd like to remind, that these reflection points depend on speakers' placement, and you need to optimise it before applying any DRC.
Personally i like 3d imaging, so I vote for absorbers working down to your Schroeder frequency (but it will be more than 2" thick).
Quantity of absorbers will depend on their properties and your expected RT/decay time. If you have small room and a lot of absorption (in your case these panels might be 5' high and at least 2' wide, so first and second will make 8*5'*2' = 80 square feet of heavy absorption, and i don't mention ceiling and carpets) result might be dull and dry sound. Usually it's not what people want from expensive system.
If you prefer diffusion, keep in mind that diffusers require some distance from LP to form proper diffusion pattern. And usually they are much more expensive.
You can mix these technologies, but it's better to consult some pro about that for best bang for buck.
 

alex-z

Senior Member
Joined
Feb 19, 2021
Messages
427
Likes
700
Location
Canada
2" absorbers aren't effective at absorbing low frequencies. Even with a 2" air gap you can only expect performance down to 500Hz. Go with another company that offers thicker products or build yourself. Pretty easy to throw together some 2x4ft frames with a circular saw + drill.

You will need way more than 3 panels to properly treat a room. I would start with at least 4 for the ceiling, 4 for the rear wall, 3 for each side wall, and some extras to place around your speaker for reduced speaker boundary interference.

Even with thick panels, you will still need multiple subwoofers + EQ to deal with the problems below 100Hz. Porous absorption technology isn't well suited to that range.
 

FeddyLost

Senior Member
Joined
May 24, 2020
Messages
453
Likes
320
Even with thick panels, you will still need multiple subwoofers + EQ to deal with the problems below 100Hz. Porous absorption technology isn't well suited to that range.
Unless one can sacrifice around meter from room length and width ...
 

dasdoing

Major Contributor
Joined
May 20, 2020
Messages
2,454
Likes
1,334
Location
Salvador-Bahia-Brasil
size challenged listening room

you wanna look at 20cm+ for the rear wall....and as big as a gap, too. that's where you get results in the first mode that is terrible in small rooms. reflaction point ones can be thinner.
be sure you have no carpet, since else your room will be to dry afterwards.
 

dasdoing

Major Contributor
Joined
May 20, 2020
Messages
2,454
Likes
1,334
Location
Salvador-Bahia-Brasil
depending on how small the room is, it makes sense to extend the sidewall reflection panel all the way to the front wall. and than straddle the corners behind the speakers with panels, too (>=20cm or so called superchunks)
 

Hipper

Addicted to Fun and Learning
Joined
Jun 16, 2019
Messages
696
Likes
562
Location
Herts., England
Side wall reflections are, as FeddyLost points out, a matter of taste. I don't like them and bought two GIK 242 (600mm x 1200mm x 67mm) on feet to deal with the issue, placing them beside the outside of each speaker:

017a.JPG


My room is 420cm x 386cm and I tried quadratic diffusers and found I could hear them - I didn't have the space for them to work properly.

I also employ 'The Thirds' positioning, which is supposed to help with reflections and bass issues:

http://www.barrydiamentaudio.com/monitoring.htm
 

dasdoing

Major Contributor
Joined
May 20, 2020
Messages
2,454
Likes
1,334
Location
Salvador-Bahia-Brasil
Side wall reflections are, as FeddyLost points out, a matter of taste. I don't like them and bought two GIK 242 (600mm x 1200mm x 67mm) on feet to deal with the issue, placing them beside the outside of each speaker:

View attachment 142352

My room is 420cm x 386cm and I tried quadratic diffusers and found I could hear them - I didn't have the space for them to work properly.

I also employ 'The Thirds' positioning, which is supposed to help with reflections and bass issues:

http://www.barrydiamentaudio.com/monitoring.htm


very eficient sidewall solution. it will keep the room alive for later (multi-bounce) reflections
 
OP
Martini

Martini

Active Member
Joined
Jun 13, 2020
Messages
138
Likes
160
Thanks all for the feedback, especially on the need for thicker panels. I'll see what I can find in the 3-4" thick range and perhaps making them myself... Although, I have race car that seems to take all my free time & money. It's in the body shop at the moment due to my being a rusty driver :facepalm:, after loosing all last year because of the covid-lockdown. Anyway, the room I get to use for listening is medium sized bedroom and I don't have "free reign" on what I do. The room is carpeted, there are windows behind the speakers with wooden blinds and fairly heavy drapes. One corner has closet door adjecent to the speaker, which needs to be accessible. so I cannot do symmetric corner treatment. There is a ceiling fan that probably kills any treatment up there, maybe a hanging panel or two.
 
Top Bottom