Room Acoustics - Absorption Panels Behind ML's

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Norway84

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If you don't understand technical concepts, it's ok to just admit that and defer to those who do. Trying to make fun of science simply because you don't understand it just kind of makes you look pathetic. Especially on a forum like this where there are quite a few technically-savvy individuals.

I've got 16 years of experience working with and listening to over half a dozen models of ML speakers, experimenting with positioning them in multiple rooms and sound systems, and using bare walls, diffusion and absorption behind them. I'm offering the OP solid advice that is based in science and experience on how to deal with a well known property of ML speakers - the back wave of a dipolar speaker. You come into this thread with less than a dozen posts on the forum and and all you offer is: no one can say because they haven't heard the room.
I do understand I've been in the audio business for over twenty five years was co designer with Hales Design Group. All of what you are talking about is the inherent problem of a Dipolar/Panel speaker aweful off axis response vertical and horizontal. When you have a friend over he has to have the sweet spot to get the best sound. I have buddies over all the time I have a big room we never worry about where we sit we just listen to music and not play musical chairs. Having to deal with a back wave is a bitch. That is why I'm not a panel fan you turn your head slightly sound changes rolls off. Move up or down slightly sound changes. Not to mention the problem with dynamics. Panels are a one person speaker nothing wrong with that if you want to constantly fiddle with the speaker. and stay completely still like a zombie.
Do you and rur really enjoy music or is it just big words and terminology. I find it funny how a little joke got your panties all in a wad. And again being a speaker that you have to attend to the back wave of sound and room placement are more critical. I can remember when the ML rep came to my shop Audio Insight in Plano Tx and we had the Grand Utopias with the Levinson mono blocks the Logan's sounded way better in our room way out in the room. In the exact place we had the Utopias. When the rep wanted them closer to the wall but he agreed they did sound better out and away from the wall. Far away from the back reflection. After he spent i kid you not 3 hours of dicking around with placement another problem with panel speaker can't just put them down and get even decent sound. So my only point is numbers and physics are alway there your right. But it does not mean that it will work out that way. BECAUSE EVERY ROOM IS DIFFERENT SO IF YOU TELL PEOPLE ONE CERTAIN WAY YOU ARE GIVING THEM BAD ADVICE BECAUSE THEY WILL NEVER TRULY EXPERIMENT WITH ROOM PLACEMENT. YOU NEVER KNOW UNTIL YOU TRY!!!!! So get off the high horse help people. Sometimes the so called right way may not be the best way.
 
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Rich

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Congrats on improving your sound. I wouldn't state that you have found the "perfect" location for your speakers unless you spent a lot of time experimenting with various locations. Let's just say you have found a better position for your setup that works within your particular room's constraints. I would caution you against assuming that this positioning that works well with your Sources will be the optimum position for your Montis. They are a very different speaker in several respects. When you get the Montis and they are broken in, I would recommend starting the positioning process over again, experimenting with multiple positions in the room. Sometimes a few inches can make a huge difference. The Montis is a huge upgrade over the Source. You won't be disappointed.
 

Rich

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Do you and rur really enjoy music or is it just big words and terminology I find it funny how a little joke got your panties all in a wad.
And I find it funny that someone with "over twenty-five years" in the audio design business would dismiss out of hand the science of psycho-acoustics, a science that recording engineers rely on every day. I also find it funny that someone who posted in post #11 of this thread that they were "out of this conversation" is still here a dozen posts later, not to help the O.P. in any meaningful way, but rather for the sole purpose of agitation. Methinks thou art a troll and nothing more.
 

Norway84

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So you don't have somebody that agrees with you and you start to get mad and call me a troll. You need a time out you are a frustrated little boy. Just because I've only posted 11 wth does that have to do with my experience. You just have a hard time agreeing with anybody that disagrees with you. And the fact that I have a good point just makes you a unhappy little boy. And then you go back to psycho-acoustics I was first talking about rooms. I believe in psycho acoustics I just made a joke about it you are now putting words in my mouth because again you are hurt because somebody does not agree with you and has not made 3k post. That is the most asinine reason to think you know something about audio because you made a lot of post. Methinks you are frustrated!
OH I KNOW WHAT IT IS IM NOT A SUPER USER THATS IT LMAO!!
 
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stereoman

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On this quite Sunday I've decided to follow the suggestions in this and other similar threads to improve the setup in my challenging listening room. I don't have the depth needed for optimal distance from the back wall so I've placed them 40" from the wall and added Echo Buster diffusion panels directly behind the panels. I'm liking what I hear in the areas of clarity, sound stage and surprisingly, impact.
 

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Probi

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Hello, i'm a ML owner newbee, i write from Varese Italy and my name is Roberto.

In the next week (during 16 of august... tic toc tic toc... :meditate: ) i will receive a couple of ML Montis and have the same question of Bikerneil with the only difference that i have at home a couple of this http://www.acusticaapplicata.com/volcano.php?lang=ita and i'm thinking to put them in the rear of the Montis.

Do you think may be a good idea?

Thank you
Rob
 

JonFo

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Hello, i'm a ML owner newbee, i write from Varese Italy and my name is Roberto.

In the next week (during 16 of august... tic toc tic toc... :meditate: ) i will receive a couple of ML Montis and have the same question of Bikerneil with the only difference that i have at home a couple of this http://www.acusticaapplicata.com/volcano.php?lang=ita and i'm thinking to put them in the rear of the Montis.

Do you think may be a good idea?

Thank you
Rob
Hi Rob, that's an interesting device, looks more like a resonator than an absorber/diffuser. So no, I would not recommend putting those behind a dipole like the Montis.
What you want is an absorber that covers ~250Hz to 15Khz. Not sure what's available in Italy, but there must be some EU acoustics products similar to the RealTraps products.

Oh, and bienvenuto to the club.
 

Andrew Perry

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frequency response (DIRAC eqaliz. on).jpg
20171128_195115.jpg

Here are my ML with Oudimmo Akupan panels (5 cm thickness, 60x120 cm - 2"x 23.6"x 47.2").

Distance Akupan panels - wall: 5 cm (2").
Distance electrostatic panels - front wall: 1 m (about 39").

The graphic shows the difference between before/after panels positioning (blue = with panels).
The system is equalized with DIRAC LIVE digital room correction, and target curves are different (above 1 kHz) in red/blue measurements.
Green line: interpolating line, showing average 1 dB/octave slope of blue graphic response.
 
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JonFo

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Nice job there Andrew, thanks for sharing. You can see the significant improvement in the mid-bass and midrange with the panel, a good bit more output and cleaner. I bet an unsmoothed graph would really show the decrease in comb filtering and cancellations.
 

Andrew Perry

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Nice job there Andrew, thanks for sharing. You can see the significant improvement in the mid-bass and midrange with the panel, a good bit more output and cleaner. I bet an unsmoothed graph would really show the decrease in comb filtering and cancellations.
You're right about the effect of the panels on comb filtering.
Here are the frequency responses without smoothing (1 kHz to 22 kHz), blue is with panels. :D

Comb effect - With panels (1 - 22k).jpg
Comb effect - No panels (1 - 22k).jpg
 
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JonFo

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Thanks Andrew, that's indeed mucho better.

One can see the impact of the panel at 1.1Khz, where before you had a significant dip and with the panel, it's much flatter. And the whole region of 5K to 10Khz is way better now.
 

captain-m

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To bikerneil; I am not sure on how much it costs, but ask an installation professional, and have them assess your listening area. From there they can give you acoustic treatment options and budget options. Like Rich posted just a few hundred bucks can go a long way.
 

bikerneil

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I am working with Real Traps to explore options and products. I sent them facts and am waiting to hear their recommendations.
 

davidwat

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A little late, but I wonder if some experimenting with something cheap like toweling or layered blankets below might be the best bet before expending real dollars for the final wife approved setup.

<https://m.youtube.com/watch?v=pABvTWSxOes>

Search YouTube “How to Make High Performance Sound Absorption Panels for $5” ? The forum apparently doesn’t like me posting a link.
 
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timm

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A little late, but I wonder if some experimenting with something cheap like toweling or layered blankets below might be the best bet before expending real dollars for the final wife approved setup.

<https://m.youtube.com/watch?v=pABvTWSxOes>

Search YouTube “How to Make High Performance Sound Absorption Panels for $5” ? The forum apparently doesn’t like me posting a link.
I did exactly that. Put a huge blanket up on my wall. Just tucked it in w the suspended ceiling. This gave me a feel for the direction absorption would take it. Now if someone could give me an idea for diffusion like that I would appreciate it. I have no fake plants to try out.
 

kach22i

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http://www.martinloganowners.com/forum/attachment.php?attachmentid=18515&d=1460914059

Just my opinion, and I might be in the minority here, but diffusion or nothing at all behind the speakers, and as much absorption as the wife will allow in between the speakers.

As a guy with a fireplace filled with batt and foam insulation and DIY absorber above that, I feel I know that first image well.

As a guy that lived with a 31" CRT Tube TV on a stand for a decade or more between his speakers, that second image pains me to know end. I had a ritual of draping a heavy wool blanket over the TV (similar in size to that dresser) and strategic pillow placement that in retrospect was a little obsessive.

I'm saying you have it all wrong, sorry that's my opinion.

Now you have a variety of opinions which to do your own testing from, no offense intended.

From my member system entry.

http://www.martinloganowners.com/forum/showthread.php?531-System-42-(Aerius)/page3
ACO-BROAD_zps1172e190.jpg
 
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