Ron,
How did that work out with the new panels.. it sounds very lively but to me a little prominent in upper registers of piano and a bit recessed in the mid bass ( after all the band leader is on bass) .. maybe I am too baised by those plots you did .. its certainly not as reverbarent as you might expect looking at the room
I still suspect you could get a lot better balance with some big moves rather than fussing with panels but I presume that may come
Ron,
it sounds very lively but to me a little prominent in upper registers of piano and a bit recessed in the mid bass ( after all the band leader is on bass) ..
I can't make comments on the sound as I listen on a MacBook and the speakers are, well, you know. Non head phone owner.
What difference do you notice in the thickness changes? Are you keeping the panels in exactly the same place?
Can you make a simple bracket to let them hang from the horizontal walnut piece of trim? An equal space behind them would help their functioning from my understanding of absorption.
I only played one track, and the last time I play this track was three or four weeks ago, so I don't know there's any specific difference. If I had to guess, I think it sounds a little bit more alive than it sounded before.
I feel like I overshot the mark with the 1 inch panels. In theory, at least, replacing the 1 inch panels with half panels, and replacing the 2 inch panels with 1 inch panels, and minimizing the gap between the panels and the walls, will minimize absorption below 1000 Hz which nudges my frequency response in the correct direction.
The panels have "Z clips" attached to the backsides. I am very reluctant to put anything permanent on that front walnut wall, as who knows if I will change my mind or want to try some other arrangement.
You are correct. Ideally I would hang them on the wall to eliminate the air gap between the panels and the wall, and thus minimize absorption below 1000Hz.
Thanks for the reply Ron.
For my DIY diffusion panels I have small pieces of wood that come up the back and turns 90 degrees so they hang from top of the absorption panels. Easy to move left or right and leave no marks on the absorption panels.
I agree, not doing anything to leave any type of mark on the walnut is important.
all this talk about wall diffusion panels and gaps behind them reminds me of my room tuning experiences. in my very live room, i found that mostly i did not need more diffusion or absorption. what i needed was a cloth surface treatment to knock down reflective hash, but not rob energy or change tonality. and it worked perfectly. the cloth can be anything and thumb tacks make it easy to try. almost a free trial kinda thing. even works on ceilings easily.
i tried hanging side curtains with an air gap behind, it deadened the music energy.
there was one spot where i did add diffusion with the hallow Auralex T Fusors, a spot opposite my bass tower sides where i had distortion caused by sound bouncing between the wall and massive speaker cabinet.
all this talk about wall diffusion panels and gaps behind them reminds me of my room tuning experiences. in my very live room, i found that mostly i did not need more diffusion or absorption. what i needed was a cloth surface treatment to knock down reflective hash, but not rob energy or change tonality. and it worked perfectly. the cloth can be anything and thumb tacks make it easy to try. almost a free trial kinda thing. even works on ceilings easily.
Yes, and your experience guided me to a nice result in my own room. While I did need ASC diffusing/ absorbing panels on the ceiling in the middle between speakers and listening seat (fantastic improvement), I followed your suggestion and draped the remainder of the ceiling just with light cloth, because I didn't want to dampen my room further. It works wonderfully, so thanks, Mike!
all this talk about wall diffusion panels and gaps behind them reminds me of my room tuning experiences. in my very live room, i found that mostly i did not need more diffusion or absorption. what i needed was a cloth surface treatment to knock down reflective hash, but not rob energy or change tonality. and it worked perfectly.
Yes, most acoustic panels/absorbers/diffusers/traps change the tone and kill the sound. I do not try to fight with surfaces.
When I see a room filled by lots of acoustic panels then I think that room is awful
You are correct. Ideally I would hang them on the wall to eliminate the air gap between the panels and the wall, and thus minimize absorption below 1000Hz.
Any of the 3M Command products are typically safe on a clean surface. Short term install and reinstall multiple times is feasible with a single adhesive backing.
The room is always a significant part of the sound. Only part of what you hear comes directly from the speakers, and the rest is the reverberant field of the room. The sound characteristic of the reverberant field is dictated first by the 'off-axis' behaviour of the speaker, and then by the dimensions and materials that the room is made of and its' contents. There is a complicated science to this - almost unfathomably complicated so an academic approach is best left to professional acousticians - and in my experience they usually revert to the best approach which is intuition with trial and error. Experience obviously helps.
A common mistake is to attack the situation with purely absorptive, deadening room treatment. These invariably operate over a wide bandwidth so that whilst they subdue your target problematic frequency range, they also subdue everything else as well and kill the life and space and freedom in the sound-world.
Sound can be absorbed, reflected, or diffused…the latter two usually bring the results you seek.
Bass traps in the corners can be useful 'IF' there is a bass / standing wave problem. I have heard them make some rooms worse, tread cautiously and make one step at a time.
Put them in and then take them out and see how this feels. Back corners are as effective as front corners, you do not necessarily need to treat all of them. Dealing with mid and HF emphasis or confusion is best done using scattering and diffusion. This is why when we do an exhibition in an unknown room, we like to get there a day or so early to let the system settle down and then we can pay attention to how the room behaves with scattering and diffusion.
Your room has the first reflected wave off the floor damped by a rug. This is usually my first listening experiment and only rarely have I thought it detracted. Usually everything improves.
The glass between and behind the speakers is a nice thing to have. In rooms with heavy drapes, I usually find much better spatial coherence with the drapes left open. It is probably good to experiment with some scattering and absorption at the back of the room as well as in the back corners. Not bass traps but reflective and 'scattery' surfaces angled across the corners such as book cases, LP and CD storage. Acoustic phase arrays that are relatively deeply pocketed…deeper than the phase arrays that you see at the sides of rooms can be very useful and look nice. Inexpensive as well.
Yes, known since long. The main question is the response of the panel versus frequency, and in small/medium rooms its variation with the angle of incidence. Also diffusion needs significant distance between source and panels.
Most panels have dips and strong variation in their response - they many solve a problem, but will create many others. They many be acceptable for studio work, that take little care of envelopment and apparent source width.
Yes, known since long. The main question is the response of the panel versus frequency, and in small/medium rooms its variation with the angle of incidence. Also diffusion needs significant distance between source and panels.
Most panels have dips and strong variation in their response - they many solve a problem, but will create many others. They many be acceptable for studio work, that take little care of envelopment and apparent source width.
I think this subject is more complex than looking to frequency response of acoustic panels.
Like other questions in high end audio the objective measurements (like frequency response) do not have a good answer to these questions.
Objective measurements (the full list, not just the frequency response, as you are assuming) will help people to built a proper room using the adequate treatment. But they will not tell us how to treat the room. Used with discernment they are a powerful diagnostic tool.
I only played one track, and the last time I play this track was three or four weeks ago, so I don't know there's any specific difference. If I had to guess, I think it sounds a little bit more alive than it sounded before.
I feel like I overshot the absorption mark with the 1 inch panels. In theory, at least, replacing the 1 inch panels with half panels, and replacing the 2 inch panels with 1 inch panels, and minimizing the gap between the panels and the walls, will minimize absorption below 1000 Hz which nudges my frequency response in the correct direction.
I think these thinner and narrower panels are probably a good compromise. I am happy with the tonal balance.
Ron
My bellow comment is not about your audio system and your judgments is well regarded, this is just an example about why audiophiles have different ideas about acoustic panels or AC filters or ground controls.
Imagine there is a low efficiency dynamic driver loudspeaker with plastic cone midrange driver and complex crossover, there is also an high feedback high power complex Solidstate amplifier in the room. Imagine This audio system connected to complex multi-stage AC filtering and all cables have great shields. I will expect to hear dead sound from this system and If you add absorber panels to the room then you will not detect the awful effects of absorber panels. You may also enjoy more after adding absorber panel because of better silence and blacker background and better soundstage.
When the audio system filter/remove liveness, beauty, micro dynamics and kill harmonics then there is no way to detect what absorber panel do with harmonics, micro dynamics and ...
many audiophiles have good ears but their audio system is dead sounding and they can not detect the awful effects of acoustic panels or AC filters.
Finally I always say proper judgment needs high performance audio system.
.. its certainly not as reverbarent as you might expect looking at the room 
