Added some treatment with no results

E

Endaar

Enthusiast
There is always a lot of talk of the importance of room treatment. I have a room that I would think is a prime candidate for it. It’s asymmetrical, with the viewing area skewed up against the left wall, and roughly another 6’ of room to the right. My left front speaker is basically in the corner, and my right front has 4’ open behind it and the aforementioned 6’ to the right.

I saw one of the Audioholics videos which said that if the room is asymmetrical, to treat the side closer to the wall so that acoustically it becomes as symmetrical as possible. I’ve tried to do so and I am seeing zero impact.

Untreated, and without any DSP, REW shows my LF has a significant peak at 250Hz and from 350Hz – 425Hz. Speakers are Axiom M60v2, which are almost exactly 4’ high.

I purchased (4) 4’ x 1’ panels from Acoustimac, with 2” OC 703 as the core. The 703 shows significant NRC at 250Hz and 500Hz, and higher.

I just tried essentially every possible position of the (4) panels, and REW shows virtually no change. What little variation I see is well within a margin of error. I tried behind the LF, on the wall next to the left front, both, various positions on the side wall, etc.

For the heck of it I also tried behind my center channel – no change.

I’m at a loss. I could understand if they didn’t work well and didn’t improve things, but I certainly expected some measurable difference.

Appreciate any feedback. Thanks.

Endaar
 
Pogre

Pogre

Audioholic Overlord
I wouldn't even attempt room treatments without A LOT of homework or even an in home consult with an acoustician. I don't know your level of knowledge but there's a lot of science to this and randomly placing panels around the room likely wouldn't do a whole lot. Did you have someone come to your house and have a look at your room? Provide sweep files so they could diagnose issues?
 
TLS Guy

TLS Guy

Audioholic Slumlord
There is always a lot of talk of the importance of room treatment. I have a room that I would think is a prime candidate for it. It’s asymmetrical, with the viewing area skewed up against the left wall, and roughly another 6’ of room to the right. My left front speaker is basically in the corner, and my right front has 4’ open behind it and the aforementioned 6’ to the right.

I saw one of the Audioholics videos which said that if the room is asymmetrical, to treat the side closer to the wall so that acoustically it becomes as symmetrical as possible. I’ve tried to do so and I am seeing zero impact.

Untreated, and without any DSP, REW shows my LF has a significant peak at 250Hz and from 350Hz – 425Hz. Speakers are Axiom M60v2, which are almost exactly 4’ high.

I purchased (4) 4’ x 1’ panels from Acoustimac, with 2” OC 703 as the core. The 703 shows significant NRC at 250Hz and 500Hz, and higher.

I just tried essentially every possible position of the (4) panels, and REW shows virtually no change. What little variation I see is well within a margin of error. I tried behind the LF, on the wall next to the left front, both, various positions on the side wall, etc.

For the heck of it I also tried behind my center channel – no change.

I’m at a loss. I could understand if they didn’t work well and didn’t improve things, but I certainly expected some measurable difference.

Appreciate any feedback. Thanks.

Endaar
Pictures of the room and the measured responses would be very helpful, in fact essential for any helpful comments. It could be you room is just not suitable for a sound system, a lot of rooms are not.
 
ryanosaur

ryanosaur

Audioholic Spartan
AH Drinking Game! Take a shot, folks! :D

Room treatments can be vital, but too many do not understand how to use and apply them, or why. You provide a great example in that your 2" think panels are not thick enough to work on frequencies that low. You really need to be using 4" panels to absorb attenuate below 500Hz.

Pictures and measurements are a bare minimum to be able for somebody to offer assistance.

I also recommend learning a little about acoustics. You don't have to be an expert, but reading something like this will help you be more educated in your choices:
 
lovinthehd

lovinthehd

Audioholic Jedi
That was my thought as well about the panel thicknesses. Also the expression you can't put lipstick on a pig could apply if the starting arrangement is poor.
 
T

Tachead7075

Audioholic
You also have to understand that there is far more to the picture then just what a SPL graph is giving you. People fall into this way of thinking when the SPL graph is only part of the picture. I would get the book recommendation above along with this one...


and read them before going any further. Also completely read Jerry's REW guide and learn how to take and understand the other types of measurements...
 
Trell

Trell

Audioholic Field Marshall
That was my thought as well about the panel thicknesses. Also the expression you can't put lipstick on a pig could apply if the starting arrangement is poor.
When I started out I too thought that a few panels would suffice, but the more I read the more it became clear that a lot of surface area had to covered by panels (including corners) and had to be fairly thick if you wanted to absorb bass.

In my office I have 2" panels with scatter plates but that is for improved recording during meetings where I use a headphone. Beside, the panels looks great in the background :)

In my living room (link in my signature) the panels are 4" thick but wish I had gone with 6": Lots of panels, though. It is also a living room so it has to look fairly nice and work with the room as it is. In essence, it's a compromise in that I can't build a proper room for this, but then I'm not looking 100% perfection either.
 
T

Tachead7075

Audioholic
When I started out I too thought that a few panels would suffice, but the more I read the more it became clear that a lot of surface area had to covered by panels (including corners) and had to be fairly thick if you wanted to absorb bass.

In my office I have 2" panels with scatter plates but that is for improved recording during meetings where I use a headphone. Beside, the panels looks great in the background :)

In my living room (link in my signature) the panels are 4" thick but wish I had gone with 6": Lots of panels, though. It is also a living room so it has to look fairly nice and work with the room as it is. In essence, it's a compromise in that I can't build a proper room for this, but then I'm not looking 100% perfection either.
It's not just about thickness of panels. Ideally you want a mix of broadband absorption panels, diffusers, and bass traps(real ones and not just thick broadband panels) that are picked based on measurements. Their locations also need to picked based on room acoustics and user preferences. This is a very complex subject and a huge rabbit hole that can eat a ton of time. If I could go back I would have started by reading Floyd Toole's book. I suggest you do the same. Trying to fix something when you don't fully understand the basic theory is an effort of futility. It's like trying to rebuild an engine when you don't understand basic 2 and 4-stroke theory.
 
Trell

Trell

Audioholic Field Marshall
It's not just about thickness of panels. Ideally you want a mix of broadband absorption panels, diffusers, and bass traps(real ones and not just thick broadband panels) that are picked based on measurements. Their locations also need to picked based on room acoustics and user preferences. This is a very complex subject and a huge rabbit hole that can eat a ton of time. If I could go back I would have started by reading Floyd Toole's book. I suggest you do the same. Trying to fix something when you don't fully understand the basic theory is an effort of futility. It's like trying to rebuild an engine when you don't understand basic 2 and 4-stroke theory.
All my panels/bass traps have scatter plates on them to avoid over dampening the upper mids and highs, while at the same time be able to have enough panels to handle some bass. My HT room is small, so lots of bass issues, but that also means that having diffusers is not that straightforward as I likely would be too close to them.

That said, I have guidance from GIK Acoustics giving them REW measurements I've done.

From reading I think that one common mistake is to use too thin or inefficient room treatment leading to a dead room where the bass issues are not resolved properly.
 
ryanosaur

ryanosaur

Audioholic Spartan
@Tachead7075 , I really agree with what you are saying. I've said as much over several threads on this very topic. I have a couple chapters left in the Master Handbook, then I am on to Toole. :)
@Trell 's situation is a little unique. That he is using GIK for their recommendations and product is largely why I haven't commented on his room. IIRC, one side is pretty much all window, so he has limited placement opportunities. If he is noticing improvement and happy with it, then Hooray! :D
For most all other situations, though, one of the more interesting stand out points in the Master Handbook was that if you treat about 25% of all surfaces, properly, you will have a better impact than treating just one wall completely. Understanding which type of treatment to apply where, and why, is the trick; and no small feat!

Also completely read Jerry's REW guide and learn how to take and understand the other types of measurements...
Is this AustinJerry's guide you refer to? Available here for any interested:

I do wish there was better understanding of, and true interest in, proper room treatments by around 75% of the people that go on about it. ;) So much misinformation and lack of knowledge has led too many astray.
 
T

Tachead7075

Audioholic
All my panels/bass traps have scatter plates on them to avoid over dampening the upper mids and highs, while at the same time be able to have enough panels to handle some bass. My HT room is small, so lots of bass issues, but that also means that having diffusers is not that straightforward as I likely would be too close to them.

That said, I have guidance from GIK Acoustics giving them REW measurements I've done.

From reading I think that one common mistake is to use too thin or inefficient room treatment leading to a dead room where the bass issues are not resolved properly.
That can be good but, room liveliness should be based on your RT60 times.

Yes, diffusers aren't generally as effective at shorter distances but, I would still look into your options.

That is good but, you have to be careful getting your info from people looking to sell you stuff(especially when they specialize mainly in basic absorption options). If you have bass problems you should be looking into products more advanced then basic superchunk designs imo(ie: limp membrane, Helmholtz resonator, etc.).

Yes, too much absorption can be a problem. Again, you can measure this in REW...
 
T

Tachead7075

Audioholic
@Tachead7075 , I really agree with what you are saying. I've said as much over several threads on this very topic. I have a couple chapters left in the Master Handbook, then I am on to Toole. :)
@Trell 's situation is a little unique. That he is using GIK for their recommendations and product is largely why I haven't commented on his room. IIRC, one side is pretty much all window, so he has limited placement opportunities. If he is noticing improvement and happy with it, then Hooray! :D
For most all other situations, though, one of the more interesting stand out points in the Master Handbook was that if you treat about 25% of all surfaces, properly, you will have a better impact than treating just one wall completely. Understanding which type of treatment to apply where, and why, is the trick; and no small feat!


Is this AustinJerry's guide you refer to? Available here for any interested:

I do wish there was better understanding of, and true interest in, proper room treatments by around 75% of the people that go on about it. ;) So much misinformation and lack of knowledge has led too many astray.
I am gonna get the 7th Edition of the Master Handbook when it comes out as I haven't read it. I'm reading Toole now.

Yes, this is a crazy complicated subject and definitely no small feat! (I am far from an expert myself but, am learning every day).

Yes, it's not the most complete guide but, a start.

I agree way too much misinformation and/or just partial understanding of the theories(including myself). This is why I have taken a step back and am really working to learn the theory to really understand things so that I can get the best results. It is making a difference and I am achieving better sound every day in my listening rooms...
 
ryanosaur

ryanosaur

Audioholic Spartan
I am gonna get the 7th Edition of the Master Handbook when it comes out as I haven't read it.
I had no clue! :)
August 2021!

Their explanations of Absorption, Diffusion, etc are very informative, including some How To... What really brought it together was some of the final chapters about actually setting up a small listening room/HT room. Even more interesting in some ways are the chapters on studio design. Good stuff!
 
Trell

Trell

Audioholic Field Marshall
@Trell 's situation is a little unique. That he is using GIK for their recommendations and product is largely why I haven't commented on his room. IIRC, one side is pretty much all window, so he has limited placement opportunities. If he is noticing improvement and happy with it, then Hooray! :D
For most all other situations, though, one of the more interesting stand out points in the Master Handbook was that if you treat about 25% of all surfaces, properly, you will have a better impact than treating just one wall completely. Understanding which type of treatment to apply where, and why, is the trick; and no small feat!
My living room is, unfortunately, far less than optimal as a HT room while still being a living room, but that does not mean I should not try to improve :) Front and back wall is covered about 25% and currently very little on the ceiling apart from the wall/ceiling traps.

And, as you and I wrote, a lot of surface has to be treated, and that is invasive with respect to look and feel in a living room. I think this is an underappreciated aspect of room treatments.

All in all, this will make a bigger change (for good or bad) than replacing my Denon AVR-X4200W with the Denon flagship AVR and cheaper as well.
 
Pogre

Pogre

Audioholic Overlord
I hate it when folks post a thread like this, offer no feedback whatsoever and just stop replying...
 
ryanosaur

ryanosaur

Audioholic Spartan
My living room is, unfortunately, far less than optimal as a HT room while still being a living room, but that does not mean I should not try to improve :) Front and back wall is covered about 25% and currently very little on the ceiling apart from the wall/ceiling traps.

And, as you and I wrote, a lot of surface has to be treated, and that is invasive with respect to look and feel in a living room. I think this is an underappreciated aspect of room treatments.

All in all, this will make a bigger change (for good or bad) than replacing my Denon AVR-X4200W with the Denon flagship AVR and cheaper as well.
I get it. :) I've said before: most of us have less than ideal conditions and have to make the best of it! My room is no different.
The only thing that may have a bigger impact on how your system sounds than it does today may be upgrading to something with Dirac rather than stepping up in Denon or Marantz. I think most of us regular participants agree that chasing improvements through electronics is a foolish path.
So ya, what you have done/are doing, that it seems to meet a balance with your partner: kudos!
 
T

Tachead7075

Audioholic
I totally get it too. It's all a game of compromises in most combo rooms especially when dealing with a significant other that cares more about aesthetics then sound lol. All one can do is hopefully pick the compromises that least affect the sound quality really. That and ease into it as I find personally that acoustic treatment's looks grow on most so in time one can add more. There are also a lot of ways to incorporate AT into a room that isn't so obvious. Paintable panels are a good example of this and can look just like a high end print if done right. Bass traps and broadband absorption built into walls is another discrete way to add more treatment(albeit more work).

As for digital solutions, they definitely have their place. But, I think room correction should be used as a last resort to just get that final refinement. The bulk of the work should be done with targeted acoustic treatment and more importantly speaker and MLP placement. Too much EQ definitely degrades sound imo and can cause headspace issues as well.

Edit: more added.
 
Trell

Trell

Audioholic Field Marshall
That can be good but, room liveliness should be based on your RT60 times.

Yes, diffusers aren't generally as effective at shorter distances but, I would still look into your options.

That is good but, you have to be careful getting your info from people looking to sell you stuff(especially when they specialize mainly in basic absorption options). If you have bass problems you should be looking into products more advanced then basic superchunk designs imo(ie: limp membrane, Helmholtz resonator, etc.).

Yes, too much absorption can be a problem. Again, you can measure this in REW...
You can have a look at my living room and there are some REW measurements at the end of the thread. Link is in my signature.

With diffusers like the one in the middle of the speakers in the picture below, is that if you are too close you can hear distortion due to the different wells. For me I can't have them behind me on the back wall (too close), on the ceiling I'm uncertain what they will offer as they work from mids and above while bass is still a problem. The side walls are occupied either by bookshelves or windows. :(

I'm also a little perplexed as to why people put large diffusers behind front speakers in a stereo system as after a few hundred Hz the speaker will radiate toward the front and not much back. I have scatter plates on my panels on front wall mostly because they look nice :)

 

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