Feedback asked acoustic improvements with Magnepan 20.1 + Velodyne DD12

In my new build house I have the luxury that I was able to build a dedicated listening room in the basement of the house. Dimensions are mentioned in the drawing of the room I did add.

In short my current audio system:
• Magnepan MG20.1 (fully modified, silver foil wiring, no internal crossover, all external with high quality components)
• 2x Velodyne DD12 (I am not using the bass panel of the MG20.1 because it has a negative influence on the mid panel and tweeter. The 2x DD12 replaces the bass panels and using the internal DSP I already improved the low level frequency domain in combination with my room.)
• Metrum Ambre source
• Metrum Adagio DAC (volume control normally not used)
• Audio Research LS26 (modified with ODAM caps)
• Magnepan active analog filter (crossover between bass and mid/high)
• Krell KSA 300S (upgraded version) and Audio Research VS115 (I use 1 of both to power the MG20.1. The Krell is better in controlling the mid panel and the VS115 creates a nicer and bigger soundstage with the big ribbon tweeter)
• Interlinks Transparent Balanced reference and speaker wires self made using Mundorf 44mm foil and Teflon isolator.
• PS Audio P5 Power Plant power line conditioner

The only acoustic treatment I have at the moment in this room is a sealing that is sprayed with a paper/ glue mixture (black) that works well above 250Hz.
Acoustic spraying: Acosorb seamless spray plasters - Acosorb
I contacted somebody living not that far from me who designs and produces acoustic treatment for studio’s and also listening rooms. He did create a 3D design based on my input which you can see in attached drawings. I am curious if you can provide me feedback on this design based on the room size and system I have. I am also busy doing some measurements with REW which I can share later.
 

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Hi JeroenD,

Implementation look like what i thoughts about diffusors.
I'm not sure about the bass trap but why not if they are located (and tuned) according to your measurements of room behavior.

You can't locate anything on front wall? I think it could bring something to have some diffusion in there too. But if not possible, it's not possible.

No Skyline diffusors above listening point?
 
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Hello krivium,
The amount of bass traps is something I need to experiment with.
I want to start with the diffusers.
I learned by reading form others experiences a room with Magepan speakers does not need much damping.
It mainly needs diffusion in the front and back side of the speakers mainly at the spot where the sound waves hit the wall for the first time.
I use a big part of the front wall as beamer screen (special paint on the wall).
So that is why more diffusers are applied besides the speakers and front wall where the waves hit the wall for the first time. I checked with a laser where the waves should hit the wall at the front and back wall.
The sealing has had a special acoustic treatment and is sprayed with acoustic material like you can see on this website Acoustic spraying: Acosorb seamless spray plasters - Acosorb .
At the moment I don’t know if a diffuser above the listening position will improve the acoustic even more.
I was planning to do first the diffusers at the speakers and back wall in combination with big bass traps in the back corners.
After that listen and measure bass energy again to check if more bass traps are required.
I the current design I need:
• 4x QRD N11 Diffuser 60x120cm
• 14x QRD N7 Diffuser 40x140cm (I can bay this set second hand for 4200,- Euro)
I discovered that this is about 6500,- Euro only for the diffusers. That is much more than I initially planned. So I am checking if it can be done cheaper.
 
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I agree with Allen.
VPR ( bass trap) could be used, they are effective ime. Limp mass absorbers can work too (in an higher range than VPR).

Anyway only measurements will tell at which frequency wrt their location the 'bass traps' could be of better efficiency.

For options about diffusors: if you know a good carpenter it may be possible to have the QRD built for less than what your acoustic furniture builder could offer.

But from a cosmetic point of view the one from a manufacturer will probably be very nice to look at. It was the case with the one i've seen/installed in studios.

But if you can withstand some painted one's it could be made cheaper (with less noble 'woods', even chipboard - they may end heavy though).

Do you have a link or spec of the diffusors ( numbers of wells, dimensions, eventually their range of effectiveness)?