Active Room Treatment (ART) by Dirac

[Oddball]

i am not done yet, still want to find the limits.
This is a focused measurement, 20cm between the points - makes the higher freq Very straight.
But you have to have your head in a vice.
Also it makes things easier for Dirac but it still shows the important bits.

I forgot to change the curtain on 1 measurement that is why the highs falls as a stone.


1: Left with CR + subs supporting (identical result to nr4)
2: LFE
3: L with CR support but no subs
4: L with only subs supporting (identical result to nr 1)
5: L with no support at all and no subs
View attachment 486126

GD/waterfall looks more or less the same, so in my case i do not really need LCR support.

1: Left with CR + subs supporting
View attachment 486127


4: L with only subs supporting
View attachment 486128

Some really pretty looking graphs .

 

[fzst]

That is an interesting thought. Subs with different drivers were previously somewhat difficult to integrate, but now we have ART so that problem could go away.

I feel like this could potentially be one of the biggest advantages of ART, it looks like with ART, it's almost irrelevant what kind of of subs and even speakers you are combining, ART should be able to properly integrate pretty much anything. And judging by the testimonials so far, it manages to do so very well and without limiting the performance of the more powerful subs in the system- achieving that was very hard before with manual tools. It was certainly way beyond may capabilities so I had to rely on Bass Control to integrate my SVS with my Arendals and even though I think it did a very good job, I never quite felt a 100% sure if the two could properly gel together... now with ART, any remaining doubt has pretty much vanished, they just "act as one" now.

Honestly, this works so good that I'm temped to try to through a ported sub in there just to see what ART would do with it

 

[smygolf]

Some really pretty looking graphs .

It all comes down to focused measurement, 20cm are the smallest distance in my experience.
For music it works really well and it also gives you a Very wide sound stage
Measurement in 1/6 smoothing

 

[Oddball]

I feel like this could potentially be one of the biggest advantages of ART, it looks like with ART, it's almost irrelevant what kind of of subs and even speakers you are combining, ART should be able to properly integrate pretty much anything. And judging by the testimonials so far, it manages to do so very well and without limiting the performance of the more powerful subs in the system- achieving that was very hard before with manual tools. It was certainly way beyond may capabilities so I had to rely on Bass Control to integrate my SVS with my Arendals and even though I think it did a very good job, I never quite felt a 100% sure if the two could properly gel together... now with ART, any remaining doubt has pretty much vanished, they just "act as one" now.

Honestly, this works so good that I'm temped to try to through a ported sub in there just to see what ART would do with it

Given that ART is still relatively new to me, I can't say that sometimes I don't get that feeling - where is my ribeye fat greasy bass steak. Find myself usually with +8 or 10dB bass curves and unfortunately craving more . But then quickly realize that new diet is so much better than the old one.

Also, think that ART finally made my system obsolete. I would not recommend to go with big speakers all around any more. I did some tests and not much difference if I roll off my 6 surrounds with 10" woofers at 50hz or 80hz. Pretty much the same thing. Number of subs is room dependent and seems that it is the best bang for the buck. I would also keep LCR beefy as they do most of the work.

 

[smygolf]

Given that ART is still relatively new to me, I can't say that sometimes I don't get that feeling - where is my ribeye fat greasy bass steak. Find myself usually with +8 or 10dB bass curves and unfortunately craving more . But then quickly realize that new diet is so much better than the old one.

Also, think that ART finally made my system obsolete. I would not recommend to go with big speakers all around any more. I did some tests and not much difference if I roll off my 6 surrounds with 10" woofers at 50hz or 80hz. Pretty much the same thing. Number of subs is room dependent and seems that it is the best bang for the buck. I would also keep LCR beefy as they do most of the work.

I got the question on a Swedish forum, will ART work with "normal" LCR that start to roll of at 80hz.
Simple answer, if you have a couple of subs - Yes.

 

[Frank207be]

I feel like this could potentially be one of the biggest advantages of ART, it looks like with ART, it's almost irrelevant what kind of of subs and even speakers you are combining, ART should be able to properly integrate pretty much anything. And judging by the testimonials so far, it manages to do so very well and without limiting the performance of the more powerful subs in the system- achieving that was very hard before with manual tools. It was certainly way beyond may capabilities so I had to rely on Bass Control to integrate my SVS with my Arendals and even though I think it did a very good job, I never quite felt a 100% sure if the two could properly gel together... now with ART, any remaining doubt has pretty much vanished, they just "act as one" now.

Honestly, this works so good that I'm temped to try to through a ported sub in there just to see what ART would do with it

I'm also thinking of making my stacked front sub 2-way with 4x Dayton Audio MX15-22 ported EBS6 between 10-12 Hz and crossing them around 30-35Hz to 2x Faital Pro 18XL1800. I would use 2x Crown XLS2502 for this purpose. I'm only doubting because of the infrasonic behaviour of ART as adding a boost curve only starts from 20Hz.

 

[Oddball]

I got the question on a Swedish forum, will ART work with "normal" LCR that start to roll of at 80hz.
Simple answer, if you have a couple of subs - Yes.

Right - of course it will. So no real need to go big - except see below.

My point was just that LCR really work hard in HT so I don't think it's unwise to spend more for the beefier speakers, especially if one wants to crank it up a bit. Handling 100dB SPL (aka peaks with -5dB reference) is tricky and even if support is limited to 80hz, that will still require some size from the speaker to pull it off at low distortion. So pretty much just SPL and distortion play, not really sub support play.

 

[Frank207be]

Now that's some serious fire-power. Not sure if ART rabbit hole is that deep though. At least in my system it seems that parameter adjustments (like support levels, even grouping to some extent) don't really produce any significant effect. IMO the biggest impact is the shelf/curve. I am not complaining - I actually prefer it this way. More listening, less tweaking.

Good luck tweaking .

Thanks! Rest assured that I also prefer listening over tweaking

 

[Flak]

While ART is often believed to shine only in large multichannel systems, it can also optimize room wave behavior in a simple 2.0 setup:

『Dirac ART Field Report: JBL Room in 2.0 Mode』

Table of Contents Overview Effect in 2.0 Configuration Spectrum Changes Subwoof…

ameblo.jp

 

[fzst]

Given that ART is still relatively new to me, I can't say that sometimes I don't get that feeling - where is my ribeye fat greasy bass steak. Find myself usually with +8 or 10dB bass curves and unfortunately craving more . But then quickly realize that new diet is so much better than the old one.

I'm kinda in the same boat in that regard, I didn't find a target curve that gives me the same deep bass pressure/rumble that BC provided with all four subs playing unisono but it definitely sounds cleaner with ART. I didn't find my golden settings either yet but I didn't have that much time tinkering with it.

Also, think that ART finally made my system obsolete. I would not recommend to go with big speakers all around any more. I did some tests and not much difference if I roll off my 6 surrounds with 10" woofers at 50hz or 80hz. Pretty much the same thing. Number of subs is room dependent and seems that it is the best bang for the buck. I would also keep LCR beefy as they do most of the work.

That's actually reassuring to hear since I only have some tini tiny rear surround speakers that can't really provide much to ART and I am wondering if I am missing out because of this...

 

[smygolf]

Right - of course it will. So no real need to go big - except see below.

My point was just that LCR really work hard in HT so I don't think it's unwise to spend more for the beefier speakers, especially if one wants to crank it up a bit. Handling 100dB SPL (aka peaks with -5dB reference) is tricky and even if support is limited to 80hz, that will still require some size from the speaker to pull it off at low distortion. So pretty much just SPL and distortion play, not really sub support play.

i hear ya !
My own LCR, well they are not small !
Upper horn are not active, JBL Pro all over.

 

[Oddball]

i hear ya !
My own LCR, well they are not small !
Upper horn are not active, JBL Pro all over.
View attachment 486161

Front line looking like it can do some serious damage

 

[smygolf]

Front line looking like it can do some serious damage

Yeps !
But that is more like a bonus or side effect.

All the transducers are from JBL:s upper line.
So low distorsion and high sensitivty.

2216ND (m2) woofers in 140L sealed boxes
2453SL with JBL PRX waveguide, M2 has to wide dispersion for my ears
And two 4645C in the bafflewall and one at the rear wall.

 

[kawauso]

Yeps !
But that is more like a bonus or side effect.

All the transducers are from JBL:s upper line.
So low distorsion and high sensitivty.

2216ND (m2) woofers in 140L sealed boxes
2453SL with JBL PRX waveguide, M2 has to wide dispersion for my ears
And two 4645C in the bafflewall and one at the rear wall.

That system looks destructive in the best possible way.
Yet the choice of drivers and waveguides shows remarkable precision and quality.

Personally, I find the slightly narrower dispersion and subtle imperfection of the K2 more natural and pleasant than the near-perfect dispersion of the M2.

Still, when I build a new JBL room in the future, I’m planning to add a pair of M2s.
They’ll be placed outside the K2s so I can switch between them and enjoy two completely different JBL characters.
I also plan to use the M2s as luxurious front wides.

 

[smygolf]

That system looks destructive in the best possible way.
Yet the choice of drivers and waveguides shows remarkable precision and quality.

Personally, I find the slightly narrower dispersion and subtle imperfection of the K2 more natural and pleasant than the near-perfect dispersion of the M2.

Still, when I build a new JBL room in the future, I’m planning to add a pair of M2s.
They’ll be placed outside the K2s so I can switch between them and enjoy two completely different JBL characters.
I also plan to use the M2s as luxurious front wides.

Thank You

I was in a group buy for M2 and i sat for hours if i should go for M2.

Have listend for them a couple of times in both large and small rooms, mine is only 25m2 and ~3,6met wide.
And in smaller room the wide dispersion made it sound, strange and with little focus.
My room it self acts as a giant panel absorber and with a RT60 below 20ms.
But there is still reflective surfaces so i did not dare.

And i had read about AVS forum member Notnyt who built with Prs wave guide and 2453SL.
So i talked with him and decided to do the same, i can still use M2 wave guide if i want to.

Before this setup i used 2226 in the same kind of boxes, it also worked Really good.
Do not see any point of have ported system but have a crossover several octaves above the tuning.


You have not thought of M2 as MTM ?

 

[kawauso]

Thank You

I was in a group buy for M2 and i sat for hours if i should go for M2.

Have listend for them a couple of times in both large and small rooms, mine is only 25m2 and ~3,6met wide.
And in smaller room the wide dispersion made it sound, strange and with little focus.
My room it self acts as a giant panel absorber and with a RT60 below 20ms.
But there is still reflective surfaces so i did not dare.

And i had read about AVS forum member Notnyt who built with Prs wave guide and 2453SL.
So i talked with him and decided to do the same, i can still use M2 wave guide if i want to.

Before this setup i used 2226 in the same kind of boxes, it also worked Really good.
Do not see any point of have ported system but have a crossover several octaves above the tuning.


You have not thought of M2 as MTM ?

In Japan, there’s no place to listen to the M2, so I’ve only been able to imagine its sound from measurements — I’m a bit jealous that you’ve actually heard it!
As for the idea of using the M2 in an MTM configuration, I’m not really sure what the advantage would be.
I plan to simply copy the network settings into my miniDSP and use it in the standard way.

The K2 S9900 sounds excellent even to ears used to KEF speakers — I only use a -1 dB high-shelf EQ on the top end.
I actually prefer it over the 4367.

 

[smygolf]

It is not easy to compare K2 to M2, it is two different animals.
K2, Greg Timbers build made of Superb transducers is more hifi then monitors.
Made primarely for Asia so it lacks the bottom end of M2.

M2 needs a bit more distance to sound coherent and has a straighter respons - can sound a bit "boring"
Tranducers comes from the Pro division, can play Really loud without compression and with low distorsion.
It is a tool made work as main monitor more so then 4367 that are made to look as the vintage monitors.

All is imho

And sorry for the off topic, back to ART

 

[AudioJester]

One question - why is ART limited to 150Hz. Would it not be advantageous to go up to the room transition point?
Are cancellation waves a problem/audible >150Hz?

 

[theREALdotnet]

View attachment 486111

Here is an example of a well regarded 15" sub... (https://www.audioholics.com/subwoofer-reviews/descend-dn15)

It is interesting to note that the THD Minimum is at 40Hz... (3%) and rising substantially to 11% at 125Hz, and close to 13% at 20Hz. - That THD "sweetspot" will move up as the sub driver shrinks, and down as the sub driver expands... so how "good" a specific driver size is, may be related to how much THD you are willing to accept at certain frequencies.

I don't think the table shows that at all. According to the article, it is meant to "show the subwoofer’s clean peak SPL before heavy distortion sets in". Had the SPL been held constant at, say, 83dB, we would likely see a precipitous drop in distortion as the frequency goes up. There may still be sweet spots with lower distortion, but we would likely see an overall drop.

 

[Oddball]

I don't think the table shows that at all. According to the article, it is meant to "show the subwoofer’s clean peak SPL before heavy distortion sets in". Had the SPL been held constant at, say, 83dB, we would likely see a precipitous drop in distortion as the frequency goes up. There may still be sweet spots with lower distortion, but we would likely see an overall drop.

Not sure I follow your points. And speculation is well, what we do here, but then some speculations are more convincing then the others.