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[Picture Inside] Will Putting 4 Inch Thick Acoustic Panels Here Noticeably (Non-Placebo) Improve Sound Quality?

SadMonster

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rockwoolpanels.jpg
 

Doodski

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What about behind the head? That dampens some reflections and improves imaging.
 

AnalogSteph

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Use a mirror or plain ol' geometry to identify wall reflection points - you are likely to find that the panels at the side walls need to go further towards the speakers for one. Also make sure the room doesn't go too dead altogether - you may prefer a diffuser on the ceiling.

Absorbers at the back wall in particular can be a double-edged sword - while a major step up in general, mine netted me a substantial midrange scoop as a result of (a) maximum absorption not kicking in until 500-600 Hz or so and (b) a speaker dispersion pattern with little in terms of highs towards the back. Two steps forward, one step back. I had to consult a microphone and manually tweak the resulting EQ. The response was reminiscent of some '90s Sennheiser headphones otherwise (e.g. HD590, HD540 II).
 

detlev24

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Yes, if the acoustic panels consist of the right material(s). By covering such a small area, you wouldn't have to worry about making the room sound "dead" at all.

There are different philosophies... In a room like yours I'd suggest the use of matching diffusers only on the back wall - to make the room sound bigger as it is. But you said it's not possible to apply room treatment there, right? Edit: No wall in close proximity behind your head is great news!

Have a look at RealTraps or GIK Acoustics room kits; and at their explanations on where to find the appropriate positions for absorption.
 
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tecnogadget

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Best advice is place something that could act as a panel like a spare thick matress or anything similar to those acoustic panel and measure with REW. Check how much RT60 and ETC changes/improves, plus ny change in frequency response. Then decide if its worth installing them by DIY of buying them.

It is a small room, biggest problem will be in the bass department, because the bookshelfs are literally against the corner (pressure maxima location) , and no bass trap will help without stealing Half of your available space.

4” is thick but still that will only absorb from bottom mids to highs. The same effect could be achieved by rugged maths, carpet, furniture,etc. But since your room is quite empty, the panels could be a good idea to compensate the lack of absorbing surfaces.

I don’t think placing some panels and diffusers where you want could make any harm. Give it a try and I hope you like the change (most likely you will). If not, you could always go back. Just don’t expect drastic changes or will get disappointed by results.
 

andreasmaaan

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It certainly looks like the room could do with a bit of absorption. 4" panels should do a reasonable job down to a couple of hundred Hz. In terms of placing them behind the speakers, try to make them reach from the corners through to (and past) the first reflection points, which looks like it will be on the wall somewhere between the speakers and the TV.

It's hard to see from the pic where your first sidewall reflection points are. Probably not where you've circled (the circles look too close to your listening position - hard to tell from the pic though).

Perhaps placing absorbers in these spots would be a better approach:

1601933511156.png


That will also (probably - you need to determine the first reflection points to know for sure) leave the first sidewall reflection from each speaker to its opposing wall intact, while catching the first reflection from the adjacent wall. The reflection from the opposing wall is likely to be delayed enough to add some spaciousness without significantly harming the perceived tonal balance.

Doing the ceiling sounds like a reasonable idea to me too. It looks relatively low, and it doesn't seem like you'd be overdamping the room given it already has so many hard surfaces.
 
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Daverz

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I'd definitely treat the corners (panels on immediate sides and front wall; bass traps should not be necessary). This is also a good speaker location for using digital room correction as DRC can flatten out the bass gain from the corners and is good at fixing any reflections close in time to the initial impulse. Speaker location close to the front and side also reduces Speaker Boundary Interference Response (SBIR). I'd also try panels on the side walls and ceiling, but don't be afraid to leave them bare if treatment dulls the sound.
 

FeddyLost

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Definitely it might improve sound, but barely will help in bass department.
Porous absorbers with 4 inch thickness without airgap usually work from ~200 Hz up depending on exact construction.
Something more sophisticated will be expensive.
 

Soniclife

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Have you tried moving the front speakers away from the sidewalls? You could put them on desktop stands on top of the subs (or a pile of books to get them the right height to test).
I agree, shoved into corners has never worked for me, if the speaker stands were swapped with the subs, and absorption placed where @andreasmaaan suggests above.
 

beagleman

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I would try moving them out of the corners. Usually that gives a boomy mid bass sound.

Out away from the walls, will improve imaging and clarity usually.
 
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