It could turn out a no brainer, if somebody here we trust could do a review. There is a studio/mixing guy, who really raves about them on YouTube👍🏼
GO ON Thomas, sod the stand for now and borrow a pair 
!!
I will need to do a weekend paper run for a while, if somebody here rates them highly 
. ATB Peter
I mentioned reading a review. This isn’t it, however over the years I have found Sound on Sound to be a good and reliable resource re semi-pro audio matters:
https://www.soundonsound.com/reviews/psi-audio-avaa-c20
If I recall were I saw the original review I mentioned I’ll post it.
Of course the value of any review - this or by a forum member - would depend on the room and speaker setup and any similarity with the reader’s, as well as the competence and neutrality of the reviewer.
The effect of the room is so drastic to the point I retired my Naim gear in my previous house as the room was triple height with mostly glass windows and it just sounded horrible.
I guess since most of us are not dedicating a hifi room during the design and construction phase of the house, we have to make the most of what we have.
Hi Peter,
I’ll most certainly try one or two of those PSI AVAA C20.
But I won’t do it in the near future.
We still have to decide about the Soulution 760 and Soulution 711 combo.
My wife was less impressed by the 711 than she was the last time she heard it. Perhaps due to the fact she got used to the huge amount of acoustic treatment we have now.
The room makes such an enormous difference…
That said, our plan is:
- decide on the Soulution electronics
- build a new rack
- take another set of serious room measurements
- design a completely new room treatment, based on the measurements, and include a room separation.
- take other set measurements and decide about the PSI AVAAs
This room separation made out of 30 cm thick absorbing material sounds like a brilliant idea.
I’ll have a “separate” room, completely controlled down to 80 Hz. And, at the same time, the big volume of the original open plane for the lower frequencies to expend.
Below 60Hz the wall won’t do much. Under 40 Hz it’ll become nearly transparent.
Of course, before doing that, I’ll ask/pay for some advice. As much as I now know about room acoustics (and I read a lot about the subject), it’s all theoretical. One important thing I’ve learned is that acoustics isn’t an exact science. We can make some predictions, but that’s all. A few readings can’t replace the practical experience of a real acoustician 
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God yes, compared to proper room treatment, the value of the best rack available is like the limit of 1/x when x tends to infinity 
At this point of need for room measurement, there should be no controversy.
In my experience,
A room treated with passive acoustics, without precise measurements, will not sound, like a measured room.
A human ear, can only make an assessment of the “sound of the room”. Accurate measurement gives us the overall picture and along the way, also saves us, unnecessary expense …
…but even an ageing human ear and a near dead brain can evaluate at what point vocals and instruments sound just right 
Enjoy Peter
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As always, there is no definitive answer.
It very much depends on the goals one wishes to achieve.
One can achieve a pleasant room treatment down to 350 Hz without any measurements and without spending much money (using absorbing material up to 10 cm thick).
Of course, the lower spectrum remains untreated, and that’s precisely where lie the bigger problems.
But… treating down to 350Hz brings impressive gains: clarity, better stereo image, details popping up, etc.
Of course, if one wants to attend to problems below 100 Hz, then measuring is mandatory. And the reason is pretty simple: the treatment needed to treat those problems usually has a narrow efficiency band. We need to know/see our target to hit it.
So do we need measurements to treat a room?
As said above, it depends 
Hi Thomas,
Obviously we are not dealing here, with pure mathematics …
but,
For my personal taste, someone who buys a Naim system for tens / hundreds, thousands of euros, and does not properly take care of his listening space, misses the wonderful potential it has to offer …
Putting acoustic panels, according to the eye / ear / management satisfaction, without measuring the space in depth, seems to me a blatant waste of money, on black boxes …
But as you mentioned, above, it depends on the personal will of each one … 
Clearly Peter,
but,
The old ear and the stale brain from old age, can be wrong, occasionally …
Well Ditton, you shall be most welcome to come for a listen, and be the judge of whether you feel I’ve wasted my money and my terrier like persistence with my room 
ATB Peter
Having measured my room before, during and after treatment with that cheap little mic, I came to the conclusion I could have done the treatment without it.
That’s my experience in my room.
Of course, my experience is limited to my own room (meaning I’m well aware I have no experience).
But I believe that with some readings and understanding of what acoustic problems are, and with some basic physics knowledge, one can achieve excellent results without measuring ones room.
It mostly depends on the goals one wishes to achieve.
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Hi Thomas, exactly the belief I maintained throughout my 18 months venture with my room.
My 80-90 Hz oblique stacking of modes was actually very obvious to hear, but obviously threw 2nd/3rd harmonies up into the midrange. Deep earth shaking bass did strangely work greatly in my room from the outset with no clouding of frequencies above or boom for that matter.
My latest scoop was in fact getting rid of the leather sofa replacing it with a single fabric upholstered 50s retro chair and treating the lower back wall as per your suggestion with Monsters. This has also now led me to play my Fact 12s on a flat bass setting (they have got helpful pots to tweak both woofers and tweeters) and not hearing anything to fault. Oh the journeys……
Best Peter
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UMIK-1 is that? It may be cheap, but it does have plenty good enough performance for the task!
I found REW (with a measuring mic - not the UMIK I already had a different one) made speaker and listening position assessment in a problematic room far quicker as well as more accurate than by ear. It had tge added benefit of enabling direct comparison even with placement from previous days. It also provided a lot of other information such as decay time at different frequencies, very useful for assessment of what needs treatment to improve.
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Same here, just at 50Hz, and as REW explained to me it’s a room mode. Looks like n-lot has one around 35Hz. I dampened it a little with 1 DIY mineral wool bass trap (2 simply don’t fit in my small room) but also a little bit by re-positioning and tuning the phase of my subwoofer, but that was quite a painstaking effort.
My room treatment so far has reduced the 64hz peak by around 3 to 4 dB … but more importantly the decay time in this area is far superior. I will need some dsp … I have measured with rew … and hopefully most of my issues … will be reduced at the expense of reducing the overall level by about 6dB…I have yet to test this…my pmc’s were around 84dB and the S12’s are around 87dB…so hopefully I am only looking at around 3dB level loss…its a case of suck it and see…I am having some issues trying to get Roon to accept the wav files I need more time…will report back.
Audioholics share some videos of the Anthony Grimani lectures on this subject on youtube -tip: use the search function and may want to start with the 101.
(no affiliation)
Yes that’s the one I have.
It’s the one recommended on the REW website. It costed ~60 USD.
I started all this room treatment adventure in 2018.
The first steps (see below) made such a HUGE difference that I decided to stop changing or upgrading my system until the room was somewhat correctly treated.
→ The Listening Room Reality - #48 by Thomas
I’ve done those few first steps without any measurements.
Of course, the low end was still a mess, but it made such a massive difference down to 250Hz that I realised the acoustic treatment was probably the best part of my audio system.
The BEST spent few thousand euros ever!
Taking the room out of the equation, or at least minimising a bit its effect, was such an epiphany!
I was so happy with the fantastic results
Then came REW, the mic, the measurements and the harsh reality of the waterfall graph…
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Peter ,
do not challenge me, 
I will come to visit and I am sure I will enjoy what I hear at your place
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Room Treatment - Treated versus untreated
While a bit on the promotional side, this video is an excellent illustration of how a room can deteriorate, and colour, the sound.
The funny thing is that I could well imagine getting used to the non treated room and once treated finding something is missing
So what’s best?
The music actually recorded and coming out of the speaker?
Or the music coming out of the speaker + distortion caused by room reflection?
→ Hear the difference: Untreated Vs Treated Room Acoustics - YouTube
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