PSI Audio Avaa C20 experience

[aerochrome2]

I am afraid you are going to be disappointed, I tried one and then two and there was a small improvement but I would have needed at least four probably eight to really resolve the issue here.
You should discover the cause of the null before you any purchase anything.
Keith

We will see I guess. I have read other accounts and seen other measurements to the contrary but I appreciate your warning! At worst I can sell 'like new' without a huge loss (I got a good discount)

 

[Bjorn]

Here's a measurement with two Modex Edge standard bass traps vs none. Take note that front and subs hadn't been leveled matched here, so that's the reason for the drop above 180 Hz. There were no time alignment here either, so there's are room for further improvement of flatness with that included. The goal here was to reduce the the dip between 50 Hz and 60 Hz at first.

Blue it without and red is with two Modex Edge. The 50-60 Hz cancellation was almost completely removed with two of these.

 

[Justdafactsmaam]

Start with a three metre depth of rockwool on every surface and add as necessary from there.
Keith

Or use a tuned diaphragmatic bass trap.

 

[Purité Audio]

Yes I have three RPG ‘Modex’ panel absorbers and they do work, you just need a lot of them.
Keith

 

[Bjorn]

Yes I have three RPG ‘Modex’ panel absorbers and they do work, you just need a lot of them.
Keith

Depends on the room and frequency as well. For higher frequencies we can get away with less and if they are placed where the pressure is very high.

Like below where a 70 hz resonance was treated with two Modex plates and that was basically sufficient for that frequency. But a lot more would be needed to treat the 35 Hz resonance.

Before:

After (two Modex plates). It also effected some of the cancellations.

 

[Purité Audio]

They are good and take up a lot less space, we covered them with a smart fabric and they ‘almost’ disappear, but in a shared domestic room there is a limit, eq takes care of the rest.
Keith

 

[Bjorn]

Yeah. A lot better to build treatment into walls. I'm always surprised people don't do that, especially when they are building rooms from scratch.

Here's a customer who build slats in front of some Modex plates on the front wall.

 

[Purité Audio]

Completely agree but even amongst customers who have dedicated rooms I am struggling to recollect one who has made actual physical alterations to the structure of the room, in fact I see less and less dedicated rooms, less enthusiasm for the single listener isolated from their family, customers increasingly want to include their family/partner which seems eminently sensible.
Keith

 

[Justdafactsmaam]

Completely agree but even amongst customers who have dedicated rooms I am struggling to recollect one who has made actual physical alterations to the structure of the room, in fact I see less and less dedicated rooms, less enthusiasm for the single listener isolated from their family, customers increasingly want to include their family/partner which seems eminently sensible.
Keith

I am planning a rebuild of my dedicated listening room including the removal of the ceiling and turning the entire attic/ crawl space into a giant wide band bass trap.

 

[aerochrome2]

Here are my ARC genesis frequency curves with the AVAA on and off and the unit in the front left corner a few feet from the sub (I still plan to play a bit with positioning). It looks like it totally takes care of the null at 100hz, but makes the one at 50hz slightly worse, which I can't figure out. Also, I didn't expect it to help with the 200hz null, but that seems like it will be the next challenge,

WITH AVAA ON:

WITH AVAA OFF:

I still need to get REW up and running to so some more sophisticated measurements.

 

[Bjorn]

Kind of hard to see when you're using such low resolution on the y-axis.

 

[aerochrome2]

Kind of hard to see when you're using such low resolution on the y-axis.

That's all I can get from ARC. I've never used REW so that's going to be the next project.

 

[Justdafactsmaam]

Here are my ARC genesis frequency curves with the AVAA on and off and the unit in the front left corner a few feet from the sub (I still plan to play a bit with positioning). It looks like it totally takes care of the null at 100hz, but makes the one at 50hz slightly worse, which I can't figure out. Also, I didn't expect it to help with the 200hz null, but that seems like it will be the next challenge,

WITH AVAA ON:

View attachment 341262

WITH AVAA OFF:

View attachment 341263

I still need to get REW up and running to so some more sophisticated measurements.

How many are you using?

 

[aerochrome2]

How many are you using?

Starting with 1. I have a small room and a single nearfield listening position. I know they recommend at least 2.

 

[Justdafactsmaam]

Starting with 1. I have a small room and a single nearfield listening position. I know they recommend at least 2.

I have two and I’m thinking four might be the magic number. Which is extremely expensive!

State of the art bass management is a motherfu… “shut your mouth!” But I’m talkin bout bass management.

 

[aerochrome2]

I ended up taking off the high pass on my mains, removing the port bungs and messing with some other things and I think I got a better overall curve. Here it is now, with and without AVAA.

WITHOUT AVAA (large nulls at 100 and 200)

WITH AVAA (reduced nulls at 100 and 200, flattened peaks)

 

[holdingpants01]

I ended up taking off the high pass on my mains, removing the port bungs and messing with some other things and I think I got a better overall curve. Here it is now, with and without AVAA.

WITHOUT AVAA (large nulls at 100 and 200)

View attachment 341332
WITH AVAA (reduced nulls at 100 and 200, flattened peaks)
View attachment 341333

those aren't really nulls, they're still mostly above the target so simple EQ would flatten the response anyway, as you can see with green line in both instances the result is the same. The placement of the microphone was also probably different, as there's bigger difference in the 2-5kHz area than in the low end. What would show more meaningful difference is spectrogram and decay rate of low frequencies, but that can should be measured in REW

 

[holdingpants01]

BTW as I'm the OP I will add that I sold two of my three AVAAs. I worked more on the passive part of the treatment with additional tuned bass traps and also changed the directivity of my monitor system to cardioid and after that I couldn't find a place for 2 AVAAs to make any positive change. They were slightly blurring the impulse response anywhere I've put them. I kept one and it stayed above the door in a tight place, as it was helping there and couldn't be replaced with passive trap because of the small available area

 

[aerochrome2]

OK - back with my REW measurements. This is my first time using REW. I followed Amir's guide (and a few others I found online), but let me know if something seems obviously wrong, or if there is another graph that would be more useful to see (I did frequency, waterfalls and spectrograms).

I did 4 measurements --- the first one had neither room correction (ARC) nor the AVAA active; the second had just AVAA on, the third had just ARC, and the fourth had both AVAA and ARC.

I am curious how the waterfall/spectrograms look in particular since I have trouble reading those.

Two notes based on my very amateur detective work:

• Re: frequency response, the AVAA seems to make the null at 55hz a little worse, but does flatten out some of the other responses (at least a bit).
• Re: waterfall/spectrogram - the AVAA seems to both reduce decay time from about 40hz to 125hz fairly dramatically
• Re: ARC - it seems to have a very positive effect, but it does seem to significantly increase the decay SPL levels under 32HZ, and possibly cause some issues between 100hz and 130hz in the waterfall (I wonder if changing the ARC settings/targets could fix some of that?)

 

[Justdafactsmaam]

Looks like AVAA alone gave you the best overall results. But the results lets are definitely mixed.

Sorry about the edits but I mixed up the order on my initial response