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Looking for room treatment advice

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Sep 7, 2020
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#1
Just moved into a new place, and have my stereo system set up in the loft. I have put three 4'x2'x4" ROCKWOOL in the rectangle space behind speakers, as well as applied DIRAC DRC, to reduce the standing wave. They do improve the sound quality by killing the spike around 80 and 200 Hz.

One remaining issue is about the echo. In current listening space, the RT60 Topt @200 Hz is ~500ms, and it is rising with frequency to ~ 800ms. In my previous listening room the RT60 Topt was ~350ms @ frequency >200 Hz, so I am totally unsatisfied with the clarity of sound. I am planing to apply my remaining 7 pieces of Auralex 2"x12"x12" studiofoam, and also to have more room treatment, in order to reduce the echo. But I have no idea where / which (absorption or diffusion) would be more effective. I would like to seek for any thoughts and advice. Thanks a lot!

I am also attaching the RT60, some pics of the listening space, and the REW measurement.
RT60.jpg

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detlev24

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#3
I would strongly suggest you go for absorption of early reflections, as the room offers plenty of big surfaces (incl. the angled ones) that naturally would continue to diffuse sound. Even the spaces between absorbers will contribute to diffusion.

The area(s) on the ceiling to cover would be exactly half way between each of your loudspeakers and the listening position(s). Same concept applies to a thick rug on the floor.

The easiest way to identify the correct spots on the side walls is with help of another person. This person would hold a mirror close to the concerning wall at about midrange/tweeter height, "move it around" and mark the areas on the wall, where you - sitting at your listening position - can see the mirror imagining of each loudspeaker separately. You would repeat the process from each listening position, in case there are several to be covered. [Watch this video.]

Should your listening position(s) be close to a rear wall: I would suggest to apply absorption behind the listener/-s' head(s), as well.

====
Generally, it would also be beneficial to apply bass trapping in as many of the (close to) 90° angles between surfaces, as you are willing to cover. :D
 
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Joined
Dec 13, 2020
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#6
In line with the recommendations above, mirror point damping and maybe a very practical and scaleable way is to add several heavy curtains (not necessarily on window surfaces only). This would enable you to either or close them while doing measurements and testing. Your room does have angles that many would like to have, so a very good aspect to get things in place.
In my room I got RT60 below 600ms and from there I am experimenting with diffusers in front between the loudspeakers and some damping (pillows) behind my head/listening spots. This flattens out the bump around 1kHz. Still stuck with a room 40Hz bump but I will not try to solve it since I want to maintain a good marriage ;-). BUT, if I could go ahead with that, I would start with stuffing all corners (bass-trap triangles) since treating the corners seem to have the first/big effect. Next, stuffing vertical corners and if that didn't get met there the horizontal corner traps.
On this track, be aware of over damping since it kills a lot of the musicality. I can imagine that going extremes on demping (RT60 <300ms)) can be a first step to flatten the RT60 and next trying to get the reflections back in a controlled way by adding reflectors/diffusors. For measuring, I mention RT60, but do read about the backgrounds of this since RT60 seems to be for large rooms and for smaller rooms other parameters might help you better getting into the direction you want (Topt in REW etc)
 
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#7
Oh, and check with REW where your reflection peaks are since this will tell you more on the distances of reflecting surfaces (that might require some treatments)
 

detlev24

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#8
relatively affordable ...
Well, I am not aware of any other company that would offer comparably affordable products - that also do work(!) as advertised. // For a more refined finish, that adds to the cost, there would be RealTraps [but they, unfortunately, don't have any distributors outside of the US].

Certainly, one could DIY; which is rather time-consuming: Preferably use fiberglass material (quite inexpensive but there's no better material for the job!). A minimum of 5 cm [~2 in.] thickness for early reflection points and a minimum of 10 cm [~4 in.] for bass absorbers [which would go, e.g., behind the head(s) and straddling the corners]. If one leaves an air gap [~2 cm would already do; much better up to ~8 cm where possible] to the flat surface behind any absorber, even better, as efficiency increases while sound waves pass the absorber(s) twice.


Anyways, I am not sure @k900733 is following his thread anymore...
 
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JohnnyHonda

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#9
Well, I am not aware of any other company that would offer comparably affordable products - that also do work(!) as advertised. // For a more refined finish, that adds to the cost, there would be RealTraps [but they, unfortunately, don't have any distributors outside of the US].

Certainly, one could DIY; which is rather time-consuming: Preferably use fiberglass material (quite inexpensive but there's no better material for the job!). A minimum of 5 cm [~2 in.] thickness for early reflection points and a minimum of 10 cm [~4 in.] for bass absorbers [which would go, e.g., behind the head(s) and straddling the corners]. If one leaves an air gap [~2 cm would already do; much better up to ~8 cm where possible] to the flat surface behind any absorber, even better, as efficiency increases while sound waves pass the absorber(s) twice.


Anyways, I am not sure @k900733 is following his thread anymore...
In addition to the GIK and ATS Acoustic panels in the high visibility areas, I have DIY with interior wall Corning fiberglass from Home Depot and wrapped it with acoustic fabric and placed this in lower visibility areas. I also made a pillow from non-fiberglass acoustic material to absorb some early reflections from my couch. I would like to start measuring my room, do you have any preferable links to measuring the room (since there are so many)?
 

Harmonie

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#10
I would also rather start with furniture, curtains, carpets and moving around things before investing real money.
 

Duke

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#11
If you have the option of re-orienting, in my (limited) experience rooms with a peaked ceiling may work better when the peak runs up and down the centerline of the room, sort of like in a church.
 

detlev24

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#12
[...] I would like to start measuring my room, do you have any preferable links to measuring the room (since there are so many)?
No, the REW help files should explain anything in detail. :p

Although it might not be updated to the latest software revisions, I like the following description: Everything you need to measure a room [easier setup: using a calibrated USB measurement microphone] // and if you wanted to know how good your absorbers work, this description.

A comparison of your room measurements before & after would certainly be great!
 
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