Advice on non-intrusive room treatment for a living room

hopkins

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Sep 10, 2022
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I do not have a dedicated room, but would like to improve the acoustics in my living room.

My room is roughly 4 meters wide, and 11 meters long, ceiling is 2.5 meters high.

My listening spot is on one side of the room, my speakers are on the long wall. This setup is not perfect (not symmetrical), but I have tried every possible speaker placement and this is the best I have found.
My speakers are large (open baffle), but I do not feel they are "too large" and they play well at low listening volume. I have them on wheels, and store them in a corner of the living room when I am not using them.

Here is a sketch of my room:

Salon2.jpg

I have an acoustic curtain along the window behind the speakers. I have a coffee table in front of my couch, and slide it to another part of the living room when listening to my speakers. My couch is L shaped, and it gets in the way - but I plan on changing it. I change the angle of the TV when listening.

Here is an RT60 curve, taken from my listening spot:

RT60.jpg

The RT60 is relatively flat, but I feel that things could be improved.
Here is a spectogram between 200-10.000 Hz (lower frequencies are also an area of improvement, but I don't want to get into this here):

Spectogram.jpg

Even though I cannot permanently hang panels on my living room, I bought some for testing purposes, and have played around with absorption and diffusion at a number of places, including on the front wall (above my couch), but the difference is not really significant (both to my ears, and with measurements).

I feel that the main area of improvement are reflections on the ceiling & floor (low ceiling height, hard walls). I do have a carpet covering all the area between my speakers and the couch. From what I have read, carpets are not very effective, outside of high frequencies (if at all).

It is very hard to test panels on the ceiling. I have tried panels on the floor in front of the speakers (don't laugh), and feel they make a difference but this does not really correlate with significantly improved RT60.

Any advice ?
Are these measurements "good enough", or should I be targeting significantly lower measurements ?
 
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I do not have a dedicated room, but would like to improve the acoustics in my living room.

My room is roughly 4 meters wide, and 11 meters long, ceiling is 2.5 meters high.

My listening spot is on one side of the room, my speakers are on the long wall. This setup is not perfect (not symmetrical), but I have tried every possible speaker placement and this is the best I have found.
My speakers are large (open baffle), but I do not feel they are "too large" and they play well at low listening volume. I have them on wheels, and store them in a corner of the living room when I am not using them.

Here is a sketch of my room:

View attachment 108774

I have an acoustic curtain along the window behind the speakers. I have a coffee table in front of my couch, and slide it to another part of the living room when listening to my speakers. My couch is L shaped, and it gets in the way - but I plan on changing it. I change the angle of the TV when listening.

Here is an RT60 curve, taken from my listening spot:

View attachment 108775

The RT60 is relatively flat, but I feel that things could be improved.
Here is a spectogram between 200-10.000 Hz (lower frequencies are also an area of improvement, but I don't want to get into this here):

View attachment 108776

Even though I cannot permanently hang panels on my living room, I bought some for testing purposes, and have played around with absorption and diffusion at a number of places, including on the front wall (above my couch), but the difference is not really significant (both to my ears, and with measurements).

I feel that the main area of improvement are reflections on the ceiling & floor (low ceiling height, hard walls). I do have a carpet covering all the area between my speakers and the couch. From what I have read, carpets are not very effective, outside of high frequencies (if at all).

It is very hard to test panels on the ceiling. I have tried panels on the floor in front of the speakers (don't laugh), and feel they make a difference but this does not really correlate with significantly improved RT60.

Any advice ?
Are these measurements "good enough", or should I be targeting significantly lower measurements ?
I would highly recommend Franc Tchang Acoustic system resonators to be the most non intrusive, they are most effective, and very powerful,if you send him the enclosed layout you have shown, he will likely come back and advise where to place and purchase them. You could start with just three to begin with.
 
I would highly recommend Franc Tchang Acoustic system resonators to be the most non intrusive, they are most effective, and very powerful,if you send him the enclosed layout you have shown, he will likely come back and advise where to place and purchase them. You could start with just three to begin with.

Thanks for your reply, but to be blunt, that seems like "snake oil" to me and I may be wrong, but it is a "leap of faith" I am not willing to take...
 
Hello hopkins,

1) What sonic problem(s) do you feel you currently are experiencing? What is wrong with the sound you are getting now? What, sonically, are you not happy about?

2) Is there any chance of moving the buffet, swinging the couch 90° counter-clockwise to bisect the two rooms, so your back is to the large room and you are facing the wall on the right?
 
I would highly recommend Franc Tchang Acoustic system resonators to be the most non intrusive, they are most effective, and very powerful,if you send him the enclosed layout you have shown, he will likely come back and advise where to place and purchase them. You could start with just three to begin with.
The question is about non-artificial room treatment that may improve the speakers' sound. I have achieved huge improvements since moving into a new-build flat with difficult features, far worse than the OP’s. I'm no expert in room treatment or at using measurement devices such as REW. However, looking at the room plan, we're told there is carpeting between the speakers and listening position (probably essential) and curtains at the window behind the speakers.

I can only make 2 suggestions - one cheap and one costly! It may be worth hanging something soft on the wall behind the sofa. Anything to reduce sound reflection may help - but may not! Bookshelves perhaps?

More costly is to consider the best TYPE of speaker for your room. You are using open baffles at present. Is it worth re-evaluating their suitability? I’ve not used OPs since college days and always considered them more DIY jobs rather than serious high fidelity speakers, but perhaps they are the best choice for your room - or perhaps you built them yourself and can't bear the thought of moving them on!! I sympathise as I built Wharfedale Airedale copies decades ago and perhaps kept them for longer than I should - although they were very good after moving to KEF drivers and facing all the drivers forward. In my present own much more difficult room, I found that electrostatic panels were a serious disappointment and conventional boxes somewhat uninspiring, but horns seem to offer the best sound at my listening position, though not at other parts of the room. From a room acoustic point of view, I suspect horns are the most forgiving and perhaps can be more relied upon to deliver top quality sound if set up properly – and without the need for “room correction DSP”. The sweet spot is small , but perhaps much sweeter than OBs or many other types. It seems that the OP would be happy with a small sweet spot as he goes to some effort to set up his speakers and move furniture for each listening session. Another advantage of horns is that they are much less fussy about their proximity to side and rear walls, so perhaps wouldn't need to be pulled forward when listening - and getting rid of the wheels would help too of course!
 
Hello hopkins,

1) What sonic problem(s) do you feel you currently are experiencing? What is wrong with the sound you are getting now? What, sonically, are you not happy about?

2) Is there any chance of moving the buffet, swinging the couch 90° counter-clockwise to bisect the two rooms, so your back is to the large room and you are facing the wall on the right?

I just feel that the reverberation is too high, and that I hear too much "resonance", which I find distracting and somewhat degrades the clarity of the sound.

The frequency response curve is within a 10db range from 40hz to 10Khz, which is ok with me, but there are obviously peaks and dips (comb filtering). Above 10kHz, the response varies with small changes of the microphone placement, and below 40hz, my speakers roll-off significantly. That's another topic.

Obviously the scale of the curve below compresses the display, but the point is that the variations (psyachoustic smoothing) are contained within a fairly narrow bandwidth.

spl.jpg

I have spend hundreds of hours testing all possible speaker placements (listening and measuring). The configuration you mention is one that would seem "logical" given the room, and this is how I had my speakers for some time before switching to the current configuration. Why did it not work so well ? It may not be so obvious from my sketch, but I can place the speakers further apart now (a little less than 3 meters apart), and I prefer it that way. The bass response was not very satisfactory with the speakers in that initial placement. It may also not be so obvious from the sketch, but the room narrows significantly after the entrance, in the left side, so it is difficult to get the speakers spaced sufficiently apart from each other without having them smack against the side walls.

Modern constructions, with low ceilings and hard walls, are not ideal. I am afraid I may not be able to significantly reduce resonances without considering some form of absorption on the ceiling. I may order thick (>5cm) basotect foam to test them on the ceiling. I am at a bit of a loss. Maybe I should hire an "acoustician" to get a proper "diagnosis" and some recommendations ?
 
2) Is there any chance of moving the buffet, swinging the couch 90° counter-clockwise to bisect the two rooms, so your back is to the large room and you are facing the wall on the right?
I would try that as well.
Much better symmetry for the speakers.
 
I can only make 2 suggestions - one cheap and one costly! It may be worth hanging something soft on the wall behind the sofa. Anything to reduce sound reflection may help - but may not! Bookshelves perhaps?

I tried hanging an acoustic curtain on the wall above the couch, and while my initial impressions were good, I found over time that it was not really worth the effort. The differences in measurements were pretty subtle. Perhaps I need to consider a more "multi-pronged" approach, having some kind of esthetically pleasing (and permanent) treatment on that wall AND something on the ceiling.

More costly is to consider the best TYPE of speaker for your room. You are using open baffles at present. Is it worth re-evaluating their suitability? I’ve not used OPs since college days and always considered them more DIY jobs rather than serious high fidelity speakers, but perhaps they are the best choice for your room - or perhaps you built them yourself and can't bear the thought of moving them on!! I sympathise as I built Wharfedale Airedale copies decades ago and perhaps kept them for longer than I should - although they were very good after moving to KEF drivers and facing all the drivers forward. In my present own much more difficult room, I found that electrostatic panels were a serious disappointment and conventional boxes somewhat uninspiring, but horns seem to offer the best sound at my listening position, though not at other parts of the room. From a room acoustic point of view, I suspect horns are the most forgiving and perhaps can be more relied upon to deliver top quality sound if set up properly – and without the need for “room correction DSP”. The sweet spot is small , but perhaps much sweeter than OBs or many other types. It seems that the OP would be happy with a small sweet spot as he goes to some effort to set up his speakers and move furniture for each listening session. Another advantage of horns is that they are much less fussy about their proximity to side and rear walls, so perhaps wouldn't need to be pulled forward when listening - and getting rid of the wheels would help too of course!

Good point. I do not want to embark, at this stage, on another speaker project - it is so complicated to find something I like, and listening at a dealers offers no guarantee that it will work in my room. I really like the sound of my speakers at my listening point, and they do fill the room nicely as well, but 90% of my listening is done from my couch, so I have no problem having a fairly narrow sweet spot. Horn speakers are on my radar, but I don't have the courage to embark on a completely different solution at this point. I've used two other speakers in that room: a small Davis acoustic tower speaker, and AudioNote speakers (that I still have, but plan on selling). In both cases, the acoustic issues were the same, and I really feel that the room is going to be an issue with many speakers (perhaps aside from horns).
 
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I would try that as well.
Much better symmetry for the speakers.

As mentioned above, I did try that, because it seemed like the obvious placement at first. I've gone back to it at times, just to check, and always return to my current placement.
 
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I appreciate all comments and suggestions, and don't want to seem like I am dismissing any. My current "issues" are not deal-breakers for me, I still enjoy listening to my system, but I would like to optimize the sound further, given that I spend so much time listening to music and do enjoy my system.

There may not be a magic bullet here. It seems to me that some guidelines can be followed for acoustic treatment, but that a lot of the solutions are specific to each room/speaker. As with anything else in audio, you can also read contradictory advice on room treatment, so that is confusing.

Maybe the best thing for me would be to get an expert (acoustician) to come over, listen and do some measurements, and see what can be "tested" at relatively low cost with removeable panels, for example, to confirm the validity of the recommendations.
 
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Even though I cannot permanently hang panels on my living room, I bought some for testing purposes, and have played around with absorption and diffusion at a number of places, including on the front wall (above my couch), but the difference is not really significant (both to my ears, and with measurements).
Hmm… Yeah, your room is quite resonant. I can hear it off my iPad playing your YouTube channel.

I think in these situations, you need a lot of panels to have an effect. How many did you try?
You could “minimize” the number of panels by just putting them at the first reflection points so right behind your ears, the left side wall and most importantly behind the open baffle speakers and possibly ceiling. You can identify where they are by using a mirror and a light/laser (just don’t blind yourself). But with so many panels, you’re definitely sacrificing the aesthetics a bit. Some panel companies allow you to put different designs on them so maybe that can improve the looks slightly.
 
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I tried hanging an acoustic curtain on the wall above the couch, and while my initial impressions were good, I found over time that it was not really worth the effort. The differences in measurements were pretty subtle. Perhaps I need to consider a more "multi-pronged" approach, having some kind of esthetically pleasing (and permanent) treatment on that wall AND something on the ceiling.



Good point. I do not want to embark, at this stage, on another speaker project - it is so complicated to find something I like, and listening at a dealers offers no guarantee that it will work in my room. I really like the sound of my speakers at my listening point, and they do fill the room nicely as well, but 90% of my listening is done from my couch, so I have no problem having a fairly narrow sweet spot. Horn speakers are on my radar, but I don't have the courage to embark on a completely different solution at this point. I've used two other speakers in that room: a small Davis acoustic tower speaker, and AudioNote speakers (that I still have, but plan on selling). In both cases, the acoustic issues were the same, and I really feel that the room is going to be an issue with many speakers (perhaps aside from horns).
Generally dipole is the most room friendly speaker .. I am sure you have read linkwitz on this
If possible I would try something like the attached to get left speaker out into more open space and add a diffusive shape that reflects away from sitting position. Amray have a neat ray trace program to look at reflections.
Have you heard your speaker design in larger spaces ... that wobble above 3k is odd as most speakers start beaming and give pretty good in room response in that area
Cheers
PhilScreenshot_20230503-215707_Chrome.jpg
 
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I do not have a dedicated room, but would like to improve the acoustics in my living room.

My room is roughly 4 meters wide, and 11 meters long, ceiling is 2.5 meters high.

My listening spot is on one side of the room, my speakers are on the long wall. This setup is not perfect (not symmetrical), but I have tried every possible speaker placement and this is the best I have found.
My speakers are large (open baffle), but I do not feel they are "too large" and they play well at low listening volume. I have them on wheels, and store them in a corner of the living room when I am not using them.

Here is a sketch of my room:

View attachment 108774

I have an acoustic curtain along the window behind the speakers. I have a coffee table in front of my couch, and slide it to another part of the living room when listening to my speakers. My couch is L shaped, and it gets in the way - but I plan on changing it. I change the angle of the TV when listening.

Here is an RT60 curve, taken from my listening spot:

View attachment 108775

The RT60 is relatively flat, but I feel that things could be improved.
Here is a spectogram between 200-10.000 Hz (lower frequencies are also an area of improvement, but I don't want to get into this here):

View attachment 108776

Even though I cannot permanently hang panels on my living room, I bought some for testing purposes, and have played around with absorption and diffusion at a number of places, including on the front wall (above my couch), but the difference is not really significant (both to my ears, and with measurements).

I feel that the main area of improvement are reflections on the ceiling & floor (low ceiling height, hard walls). I do have a carpet covering all the area between my speakers and the couch. From what I have read, carpets are not very effective, outside of high frequencies (if at all).

It is very hard to test panels on the ceiling. I have tried panels on the floor in front of the speakers (don't laugh), and feel they make a difference but this does not really correlate with significantly improved RT60.

Any advice ?
Are these measurements "good enough", or should I be targeting significantly lower measurements ?
ASI "Sugar Cubes" are at least as effective as panels on the ceiling in my experience, are cheap, unobtrusive, and easy to experiment with - so unobtrusive in fact that they may go unnoticed thereby mitigating the risk that someone might think you were playing around with "snake oil".
 

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ASI "Sugar Cubes" are at least as effective as panels on the ceiling in my experience, are cheap, unobtrusive, and easy to experiment with - so unobtrusive in fact that they may go unnoticed thereby mitigating the risk that someone might think you were playing around with "snake oil".
If you can hang art on your walls then the other thing to consider is the unique DHDI ZR Acoustics panels which I have deployed in my dedicated listening room - in place of the absorber and diffuser you have in your sketch. The "Sample Rate Panels" are 1" thick and some people find them attractive (see photo). They are superior to conventional room treatments, and because they affect all frequencies they improve bass response as well.

Note by the way that diffusers need lots of space to work properly. You would not get any benefit from a diffuser directly behind the listening position, and it may degrade the sound. An acoustician/room acoustics consultant would typically recommend 7-10 feet minimum space behind the listening position for optimal diffusser performance.

FYI: https://www.whatsbestforum.com/threads/trying-the-zr-acoustics-panels.31846/page-12#post-871291
 

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Generally dipole is the most room friendly speaker .. I am sure you have read linkwitz on this
If possible I would try something like the attached to get left speaker out into more open space and add a diffusive shape that reflects away from sitting position. Amray have a neat ray trace program to look at reflections.
Have you heard your speaker design in larger spaces ... that wobble above 3k is odd as most speakers start beaming and give pretty good in room response in that area
Cheers
PhilView attachment 108778
I have not listened to my speakers in a larger space.

I did try that, and both measurements and listening did not conclude to significant differences.
 
I made some more tests and measurements this afternoon, and placed an acoustic curtain on the window to the right of the right speaker. Miraculously, I get a noticeably lower RT60. I did not expect that absorption at that location would have an effect.

RT60 v2.jpg

Overlay of two measurements (with and without curtain on that window):

RT60 comparison.jpg

I tried a variety of panels and diffusors behind the couch and oddly enough, there is no significant change in measurements. Listening comparisons are sometimes positivie, sometimes inconclusive.
 
Very often the corners where the walls and ceiling meet are the problem areas.My former home had a layout similar to yours.I bought some insulation panels from a big box store and tried them every which way.The most effective ended up being one in the corner ceiling juncture in the other section of the L and absorption behind the listening position. Back then I made my own triangular "pillow" for the ceiling,plus a tapestry over the panel over the couch framed in wood. If I were still there I would have the large panel customized with artwork, like what G.I.K. offers.You might want to experiment with treatments in the upper corners if you already haven't.
 
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Very often the corners where the walls and ceiling meet are the problem areas.My former home had a layout similar to yours.I bought some insulation panels from a big box store and tried them every which way.The most effective ended up being one in the corner ceiling juncture in the other section of the L and absorption behind the listening position. Back then I made my own triangular "pillow" for the ceiling,plus a tapestry over the panel over the couch framed in wood. If I were still there I would have the large panel customized with artwork, like what G.I.K. offers.You might want to experiment with treatments in the upper corners if you already haven't.

Interesting - thanks. I have not experimented with treatments in the upper corners, and will do that (tomorrow).
Over my couch, I have a glass frame, and surprisingly, putting an acoustic blanket on it had little effect. Perhaps because I already have a long acoustic curtain on the window facing the wall (between the two speakers). I have to experiment more...
 
Very often the corners where the walls and ceiling meet are the problem areas.My former home had a layout similar to yours.I bought some insulation panels from a big box store and tried them every which way.The most effective ended up being one in the corner ceiling juncture in the other section of the L and absorption behind the listening position. Back then I made my own triangular "pillow" for the ceiling,plus a tapestry over the panel over the couch framed in wood. If I were still there I would have the large panel customized with artwork, like what G.I.K. offers.You might want to experiment with treatments in the upper corners if you already haven't.
Note that I have done head to head comparative listening tests between two different brands of these triangular corner "pillows" and a single ASI Sugar cube in room ceiling corners and found the Sugar Cubes to outperform the "pillows" by a significant margin.

FYI: https://positive-feedback.com/Issue54/asi.htm
 

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Interesting - thanks. I have not experimented with treatments in the upper corners, and will do that (tomorrow).
Over my couch, I have a glass frame, and surprisingly, putting an acoustic blanket on it had little effect. Perhaps because I already have a long acoustic curtain on the window facing the wall (between the two speakers). I have to experiment more...
Note also that while I have not tried the full grid of ASI Sugar Cubes (in lieu of panels) on the wall behind my speakers, you might want to consider doing so since you are looking for unobtrusive solutions (on glass surfaces as well even if they are behind curtains).

FYI: https://6moons.com/audioreviews/acousticsystem4/sugar.html
 

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