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Room Treatment = Sonic Improvements!!!

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DTB300

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This weekend I addressed first reflection points (side walls and behind my seating position) with acoustic treatment. I posted this same information in another thread, reagarding treating my room, but I wanted to start another thead regarding room treatment. Our rooms are the most neglected part of our audio systems, usually due to ignorance on our part of how to resolve the issues. Through trial-and-error learning, I have treated my room using Auralex products and the results have been a very nice improvement in the overall sound.

Here is my post on the first reflection treatment:

Like I have stated previously, I have wanted to treat my first reflection points on the side walls and behind my seating position since installing the Auralex behind my speakers. I already have some of the Auralex behind my seating position, but I wanted to get more coverage there. (Previously I had used 6 of the remaining panels from the DST-36 package attached to some foam board and hung on the front of the bookcase. The bookcase sits approximately 5 ft behind my head.)

I looked at the ProPanels, but they are too much money for my budget. The GIK Acoustics look like a very nice product at a reasonable cost (three of the 242's I could afford), but the WAF was not happy with the size of these when I showed her the site.

So yesterday, I went out to my local Auralex dealer and picked up three 2' x 4' sheets of the 2" Wedges - Total cost <$50. I then attached these three pieces with two on the sidewalls and one behind me. The side wall placements were determined by a mirror. As before, I attached the pieces by use of "T-Pins" for ease of installation and de-installation.

The Results: Less congestion is the best way I can describe the change - like removing a slight veil from in front of the music. There is more detail between instruments and Vocals became clearer and more precise sounding. High end cleaned up and sounded much better, and with Bass - not much change as the 2" does not go low enough in its absorption properties. Also the placement of instruments and singers became better defined on the soundstage.

Once again, adressing room treatment has made a very nice change/improvment in the sound of my system. While there are better solutions for wider and improved frequency absorption, the Auralex product fit into my current budget and WAF, producing very nice improvments.

Dan
 

Joey_V

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You gotta post pics Dan.... I'm interested in room treatments also, but I'm a rolling stone, moving from dorm to dorm. Maybe in a couple of years.

Joey
 

DTB300

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Joey_V said:
You gotta post pics Dan.... I'm interested in room treatments also, but I'm a rolling stone, moving from dorm to dorm. Maybe in a couple of years.
You can put room treatment in without worry about them being "permanent". Many different options available for hanging or attaching to walls wihtout having to destroy a wall to install or de-install.

Pictures huh? I will see if I can post some...

Dan
 

Kruppy

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Reflection points.

Dan,
Pardon my ignorance here as I have very little knowledge of room acousitics, but how did you identify where the side wall reflection points are?

By the way, thank you and others like JonFo that have sparked my intrest in this topic.

As Joey pointed out, pictures would be helpful/nice.

Side topic: There are others that have spent a lot of time posting here that have not posted their systems yet, DTB300, Roberto and Socialxray in particular. It sure would be nice to see them on the site. I as I'm sure like others quite enjoy viewing everyone elses rigs and rooms.

Bob
 

SugarMedia

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every time I sit down to listen, I'm thinking how much I need room treatment; knowing it will make all the difference in the world. I'm uncertain though on which one to get, which one is less intrusive aesthetically, and which is less expensive while not sacraficing quality.

Here's some resources I've acquired over the past couple of months for those interested in further reading.

http://store.acousticsounds.com/browse_detail.cfm?Title_ID=13420

http://www.eighthnerve.com/products.html

http://www.rivesaudio.com/resources/listening_room/frame.html

http://www.geocities.com/jonrisch/a.htm
 

Reverb

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Kruppy said:
Dan,
Pardon my ignorance here as I have very little knowledge of room acousitics, but how did you identify where the side wall reflection points are?
A Mirror is an easy way to find the first reflection point.

Along with standing waves, the reflections that distort sound the most are the loud reflections that bounce once off the side walls, ceiling and floor on the way to your listening/viewing spot. These strong reflections are called "early" reflections. Controlling the intensity of early reflections is crucial to achieving optimum sound.

So, how do you figure out exactly where these reflections are coming from?

An easy, accurate way to locate the precise points of sound reflectivity on your walls, ceiling and floor is to use a mirror. You'll need a friend or family member to act as an assistant. While seated in the listening position have your assistant slide a small mirror (8" x 10" works well) along the left wall at the height of the tweeter. Your assistant should start across from the left speaker and move slowly toward the listening position. As the mirror is moved toward you along the wall, you will at some point see a reflection of the left speaker in the mirror. Mark the spot on the wall where the tweeter reflection appears with a piece of tape.

As the mirror continues moving toward your listening position, you will next see a reflection of the right speaker. Mark the location of the right tweeter reflection spot on the wall with another piece of tape. Now repeat this procedure on the right wall to locate the corresponding two reflective positions there.

Early sound reflections from the points you located are adding significantly to the sound you hear at your listening position. They cause some sounds to be canceled out while others are amplified, resulting in smeared stereo images.
 

DTB300

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Zip3kx07 said:
A Mirror is an easy way to find the first reflection point.
Yeah...makes it a real no-brainer for 1st reflection placement. Don't forget about a wall behind you as a first reflection point too.

Early sound reflections from the points you located are adding significantly to the sound you hear at your listening position. They cause some sounds to be canceled out while others are amplified, resulting in smeared stereo images.
After side and rear installation, the music had more detail and imaging of the stage became better - I thought it sounded pretty good before the treatment :D. The installation has improved the sound with the cost far less than I originally thought.

Dan
 

SugarMedia

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DTB300 said:
Yeah...makes it a real no-brainer for 1st reflection placement. Don't forget about a wall behind you as a first reflection point too.


After side and rear installation, the music had more detail and imaging of the stage became better - I thought it sounded pretty good before the treatment :D. The installation has improved the sound with the cost far less than I originally thought.

Dan
Dan, how did you determine if you should use panels that absorb the reflection or a go with a panel that will diffuse it?
 

garmtz

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In smaller rooms, almost always absorption is the way to go. And I really recommend Auralex. It is relatively cheap, works very effectively and is easy to handle. The DTS36 package is a nice entry level product which will work magic in almost ANY room.

I am an Auralex dealer myself in The Netherlands.
 

DTB300

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SugarMedia said:
Dan, how did you determine if you should use panels that absorb the reflection or a go with a panel that will diffuse it?
Trial and error for me. I first used some "off the shelf" items to see what they would do. "Off the shelf" = what do I have laying around the house that could work as absortpion or diffusion. For me I used blankets/quilts and fake fiscus trees for some of my testing.

I also starting reading all the forums that are available to disucss acoustic treatment. Ethan Winer's, Rives Audio, etc.

I would also like to start to use items for Bass Trapping, but I think I have pushed the WAF to it's limits.

Dan
 
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twich54

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as always Mr "Dan", good solid advise ! BTW have you seen Stereophile recent review of the new Plinius refrence amp ? Drool, drool and more drool !!!
 

DTB300

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twich54 said:
as always Mr "Dan", good solid advise ! BTW have you seen Stereophile recent review of the new Plinius refrence amp ? Drool, drool and more drool !!!
No, I generally stay away from Stereophile. Read it for many years, then Atkinson arrived, and I cancelled my subscription about a year later.

I will look for the article next time I am at Tower.

Dan
 

DTB300

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garmtz said:
IThe DTS36 package is a nice entry level product which will work magic in almost ANY room.
This is the package I started with. Most of the application is behind the speakers. I then used the 2" wedge panels for 1st reflection points. All in all I have spent < $175 on all of it, with a benefit :D of better sound.

Dan
 

Joey_V

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twich54 said:
as always Mr "Dan", good solid advise ! BTW have you seen Stereophile recent review of the new Plinius refrence amp ? Drool, drool and more drool !!!
Upgraditis already Dave?
 

twich54

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Joey_V said:
Upgraditis already Dave?
Joey, I wouldn't steal your thunder !!! Honestly, thanks in a large part to Dan, I couldn't be happier than I am with my SA-102, trully the most listenable piece of SS amplification I have heard to date.
 

DTB300

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Update on Acoustic Room Treatments

As you have read before, I have treated behind my speakers and the first reflection points using some Auralex products with very nice results (read above :D)

This past weekend I purchased 8 Auralex LENRD Bass Traps. I was considering the GIK or Real Traps products, but I was able to get the Auralex at a price that was very hard to refuse. While I know the other products (GIK & RT) have better absorption ratings than the LENRD's, the Auralex product fit better into my room and also had a higher approval rating from the WAF. Also, while I would have liked to use the other products, doing something with acoustic treatments is better than nothing.

As everyone here may be aware of, I also use the Velodyne SMS-1 for Bass EQing in my setup/room. I have a Sumo 15" Passive Sub & a Sumo Polaris Amplifier (with a circuit designed/installed to run Stereo or Mono with the flick of a switch - very nice feature). The SMS-1 was a great addition to the system, helping to tame some of that room-boom by flattening out the low end response of the room from 20-150Hz to within +/- 3 dB (previous swings were in excess of 20dB's!!!!!) So knowing that EQing was only part of the equation, I wanted to do some Bass Traping in the room. Remember that my stereo room is also a Living Space first and foremost, so I always have to consider that when making changes, moving things around, etc. And in the past the wife has been very tolerant of me and my excessive hobby changes, and experiments!!!

BTW, I also replaced the Straightwire Speaker cable for the Sub with DH Lab Speaker Wire. Again, considering price versus performace, the DH Lab cables are a very nice solution both for IC's and Speaker Cables. Next time you are considering new cables, give them a try and see what you think. Before placing the LENRD's, I gave a listen to the DH Lab cable and liked the change (better bass response and detail) from the Straightwire.

As I installed the Auralex LENRD's in the corners behind the speakers, I watched the SMS-1 graphing in real time to see what differences they made. I tried many different configurations in lower corners, upper corners, across the wall up by the ceiling, etc. I finallly came to the setup where I had two of them stacked on top of one another in the lower corners and had one more in the upper corners, using 6 total LENRD's. The last two ended up on top of the bookcase (area where wall meets ceiling) that sits behind my seating position.

The initial graphing did not change too significantly, but if I could use more trapping throughout the entire room, then a significant change of the graph would occur. Bass Trapping should be done in all 4 corners (upper and lower tri-corners), and also along wall/ceiling points on the sidewalls for proper and efficient trapping. I ran the SMS-1 auto-EQ, then tweaked the settings even further until I had a very nice response of +/- 3dB from 20-150Hz. Now it was time to listen to some music and then tweak the SMS-1 settings further. Remember the graphing part is only a starting point, as listening is the true test and we each have our own preferences on bass amounts.

Results: While the SMS-1 had initially removed some of the Bass Boom I experienced with my system, the addition of the LENRD's reduced this Boom even further - the SMS-1 did a great job but with addition of the room treatments, the improvement was another step up.

At first listen, I thought the Bass levels were less than before, but it was the removal of the BOOM that I was hearing (or not hearing), not less bass. I did a few more adjustments with the SMS-1 particularly in the SubSonic Frequency setting and its slope, and now have better sounding, and a slightly deeper bass response then before.

Albums that sounded boomy (I thought it was a poor recording) now sounded better. I am hearing details in the low end that I have not heard before - subtle changes, but they are there. And at this point in my setup, the changes are not substantial anymore, just small incremental changes for the better.

So to finalize this long-winded post :D :D, Room treatment once again showed me that it is a major component into improvements in the overall sound of our systems and it is something everyone should consider doing to some degree or another. While I would like to have some more Bass Trapping in my room, it will probably have to wait for a bit while the current changes settle into the WAF!!!

Dan
 
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Darrylp

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DTB300 said:
(side walls and behind my seating position) with acoustic treatment.
Dan
I've done similar Dan with great results but but I've treated the front wall too as I was advised to leave the back wall untreated as apparently THX recommend a live back wall with treated front and side walls.

Have you an opinion on this?

Thanks

Darryl
 

Reverb

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Darrylp said:
I've done similar Dan with great results but but I've treated the front wall too as I was advised to leave the back wall untreated as apparently THX recommend a live back wall with treated front and side walls.

Have you an opinion on this?

Thanks

Darryl
Keep in mind that THX and most other acoustic specifications are designed with cone box speakers in mind. Our speakers are unique that they are natural dipoles, but that also means our speakers interact with the acoustics of our room differently then that of a cone speaker.

If you were to add absorbers to the front of your wall you would minimize the back wave of your ESL’s and increase they’re imaging but at the sacrifice of the back wave. I prefer to use diffusers on the front wall to minimize the back wave but not defeat it like absorbers would. I like to use absorbers on the sidewalls at reflection points, your first reflection points won’t be as critical as that of cone speakers because of how directional our speakers are but it does still matter and you will want to address them. The back wall of the room I like to use absorbers directly behind the listener, it seams to focus the sound and increase the dynamics and imaging.

These are some of the techniques that have worked for me, but they wont work for everyone, every system and room is different and each require their own different types of treatments to achieve there very best. If I could give a tip to anyone looking to try acoustic treatments it would be to be careful with absorbing panels that you don’t over treat the room and kill it. If you over absorb it, the room can go flat and loose all that magic your looking for.

Take care,
 

DTB300

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Zip3kx07 said:
If you were to add absorbers to the front of your wall you would minimize the back wave of your ESL’s and increase they’re imaging but at the sacrifice of the back wave.
I tried them, many and few, in both places and after many days of trial and error, I prefered more of them on the wall behind my speakers, and then a large 2x4 panel behind my seating position.

Points about my room: Behind me is a large bookcase that creates a pseudo-diffusor, the room is small, and has very low drop ceilings. It is an odd shaped room which helps, but it is also a living area, and our main TV and movie viewing room. All of this limits me for ultimate placement of speakers, TV in the middle of the speakers, main seating position too far back in the room, other chairs, coffe tables, etc. etc. And due to these limitations, the room treatments have helped my overall sound considerably. I realize that the removal of TV, moving the couch forward more (37%), etc. would greatly improve my sound, but I have to live with the room and setup I have.

I prefer to use diffusers on the front wall to minimize the back wave but not defeat it like absorbers would. I like to use absorbers on the sidewalls at reflection points, your first reflection points won’t be as critical as that of cone speakers because of how directional our speakers are but it does still matter and you will want to address them. The back wall of the room I like to use absorbers directly behind the listener, it seams to focus the sound and increase the dynamics and imaging.
The first reflection points due to directionality is a good point Joe, but with the CLS panels and their curves there is some horizontal dispearsion, so depending on the amount of toe-in or not, some may have first reflections off side walls close by. Even if not close by finding those reflection points as you state make a difference.

With the absorbers behind my speakers, I too was afraid of getting things too dull, but after much experimenting with location and amount, I believe I have found a great middle ground.


These are some of the techniques that have worked for me, but they wont work for everyone, every system and room is different and each require their own different types of treatments to achieve there very best. If I could give a tip to anyone looking to try acoustic treatments it would be to be careful with absorbing panels that you don’t over treat the room and kill it. If you over absorb it, the room can go flat and loose all that magic your looking for.
Excactly...just like purchasing our components and setting up our systems, each is different, and what we do may help as a starting point, but should not be viewed as the absolute.

Dan
 
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