Active Room Treatment (ART) by Dirac

[IngMishael]

From the descriptions by Dirac, I feel that the handles are likely to more gently adjust the speakers natural response, than the manual target curves, that more aggressively attempt to make the system comply...

I also may (time, and silent access to the house permitting) do some measurements of equivalent DL and DLBC configurations

Yes. Always should be a curve that follows the speakers natural tapering off in your space. After all you bought the speaker for its own identity so why discard that with aggressive manual curves

 

[R4pture]

Measurements are important, but I completely agree that listening should be the final judge.
It also makes sense that you switch between full-band correction and correction up to 300 Hz depending on the content.
Your setup with all four subs placed along the front wall sounds both unique and visually impressive.
I’m looking forward to reading more details tomorrow.

Hey Kawauso, sorry for the late response. Yes, it really does look visually impressive, atleast that is how I see it . I am currently away from home and this is the only photo I got on my phone showing all subwoofers. It does not show much but what you can see is how close each subwoofer is placed to each other. Dirac is handling every subwoofer individually.

I think before I start with the Follow-up on my current experience with ART I want to share why I have desperately waited for the ART release since I heard from it in 2023. In my last post I mentioned that ART has fixed the biggest issue in my room. This one has haunted me since the beginning of my little home theater journey.

What you can see in the waterfall plot [1] is the raw bass decay of two subwoofers working together along the front wall. The room is a concrete bunker in my basement and is heavily treated. If, for some reason, someone is interested in the decay plot without physical room-treatment, then please look at [2]. The microphone position on [1] compared to [2] is probably slightly different. Based on my knowledge about this awful room it is close enough. It is old data still saved somewhere in the cloud from 2023 but not much has changed aside from now having 4 subwoofers to work with. This is a big deal, but you can expect almost the same result if you put all subwoofers along the front wall. The main issues still remain.
We have a giant hill at 25hz, which is fine for movie content. Audyssey MultEQ X has done a great job taming this region. However, it was a problem for music content. I like soundtracks with deep bass and some tracks were unlistenable. The biggest offender is at around 76hz. Every single room in my basement has this problem and with a room height of just around 2.3 meters, there is little to do with physical room-treatment.

[1]

[2]

Let’s focus on the next graph:

Slight height variations of around 10-15 cm is enough to give you a different bass experience between 70-80hz. Extreme SPL can be measured near the ceiling and the ground even at moderate volumes. You can measure near perfect nulls at around half the room height anywhere in the room. Unfortunately, the SPL spike near the ground causes my couch to heavily vibrate even at lower volumes. It has often masked deep rumbling effects in movie content and many songs become simply unlistenable. Audyssey is not able to fix it. It was incredibly annoying to the point of almost giving up. I still had lots of great movie experiences but there is something about this issue I could not let go. Then I heard about ART and I have put my (last) hopes on an automatic active absorption solution.

A couple of months before the final release I knew which Denon receiver would get ART so I got two additional subwoofers and bought a new Denon receiver. I have placed the additional subwoofers near the back wall and switched from Audyssey to DLBC. I call it an expensive incremental improvement for my main issue. But other things have improved. I was impressed.

At this point I can refer to my initial experience with ART posted on October 2, 2025 (Dirac ART is now running on beta FW for Denon Xx800H AVRs! | Page 47 | Audio Science Review (ASR) Forum). In short: Highly impressed with the result for music content. My main issue I did not describe in the comment (I thought it was too specific) was fixed. Mixed feelings about movie content and a couple of issues with the audibility of the upper support frequency range on my surround speakers. Had some issues understanding how to apply a custom curve that sounds good compared to how I have done it with DLBC.
Focussing on movie content I have lost almost all of the rumbling effects I previously enjoyed. I have figured out it was not about infrasonic bass. In my case the important frequency range is between 20hz to maybe 35hz. I have already boosted this range by +10db. In retrospect I have felt undesirable ear pressure in my tests while missing the rumbling effects on my couch and clothes sometimes. It felt unbalanced while also looking almost perfect in the measurements.

Putting all four subwoofers along the front wall removes the pressure on my ears. I can add +12db peaking at 25hz without issues. All missing rumbling effects are restored compared to the 2Front-2Back-Configuration. The 4Front-Configuration sounds more front loaded and less “everywhere” in the room but that's okay. There is no subjective(!) loss in precision across all bass frequencies handled by ART. I initially thought it would have a detrimental effect on the bass response but there is nothing obvious to care about. That is why I have no measurements available at this time showing the differences between both configurations. For the first time in years it feels just right. I can even lie on the ground and enjoy the sound!

Aside from that I have noticed a couple of other things:

1. I think Dipole(potentially Bipole)-Surround-Speakers increases the audibility of the support sound. I have switched to a mixed Dipole + Front-Fire mode on my surround speakers. All my surround speakers now support up to 150hz without any issues.
2. Letting all speakers support each other in my 7.4 system while listening in Stereo-Mode creates a slight crosstalk effect (I think this is the right term?) in the upper ART range if leaving the Phantom-Center position. Can be fixed with a different support configuration.
3. I can’t get better results below 22hz. The infrasonic checkbox does not help. I have no problem with a cut-off at 19hz but please let me apply the boost of +10db at 20hz if I want to. I could boost +15 and still get a massive roll-off at 21hz, even worse at 20hz. I have seen many graphs from others showing the exact same roll-off pattern at high bass boosts. At this point it feels like something Dirac could change in future updates.

 

[kawauso]

Hey Kawauso, sorry for the late response. Yes, it really does look visually impressive, atleast that is how I see it . I am currently away from home and this is the only photo I got on my phone showing all subwoofers. It does not show much but what you can see is how close each subwoofer is placed to each other. Dirac is handling every subwoofer individually.

View attachment 497170


I think before I start with the Follow-up on my current experience with ART I want to share why I have desperately waited for the ART release since I heard from it in 2023. In my last post I mentioned that ART has fixed the biggest issue in my room. This one has haunted me since the beginning of my little home theater journey.

What you can see in the waterfall plot [1] is the raw bass decay of two subwoofers working together along the front wall. The room is a concrete bunker in my basement and is heavily treated. If, for some reason, someone is interested in the decay plot without physical room-treatment, then please look at [2]. The microphone position on [1] compared to [2] is probably slightly different. Based on my knowledge about this awful room it is close enough. It is old data still saved somewhere in the cloud from 2023 but not much has changed aside from now having 4 subwoofers to work with. This is a big deal, but you can expect almost the same result if you put all subwoofers along the front wall. The main issues still remain.
We have a giant hill at 25hz, which is fine for movie content. Audyssey MultEQ X has done a great job taming this region. However, it was a problem for music content. I like soundtracks with deep bass and some tracks were unlistenable. The biggest offender is at around 76hz. Every single room in my basement has this problem and with a room height of just around 2.3 meters, there is little to do with physical room-treatment.

[1]
View attachment 497172
[2]
View attachment 497173
Let’s focus on the next graph:

View attachment 497174
Slight height variations of around 10-15 cm is enough to give you a different bass experience between 70-80hz. Extreme SPL can be measured near the ceiling and the ground even at moderate volumes. You can measure near perfect nulls at around half the room height anywhere in the room. Unfortunately, the SPL spike near the ground causes my couch to heavily vibrate even at lower volumes. It has often masked deep rumbling effects in movie content and many songs become simply unlistenable. Audyssey is not able to fix it. It was incredibly annoying to the point of almost giving up. I still had lots of great movie experiences but there is something about this issue I could not let go. Then I heard about ART and I have put my (last) hopes on an automatic active absorption solution.

A couple of months before the final release I knew which Denon receiver would get ART so I got two additional subwoofers and bought a new Denon receiver. I have placed the additional subwoofers near the back wall and switched from Audyssey to DLBC. I call it an expensive incremental improvement for my main issue. But other things have improved. I was impressed.

At this point I can refer to my initial experience with ART posted on October 2, 2025 (Dirac ART is now running on beta FW for Denon Xx800H AVRs! | Page 47 | Audio Science Review (ASR) Forum). In short: Highly impressed with the result for music content. My main issue I did not describe in the comment (I thought it was too specific) was fixed. Mixed feelings about movie content and a couple of issues with the audibility of the upper support frequency range on my surround speakers. Had some issues understanding how to apply a custom curve that sounds good compared to how I have done it with DLBC.
Focussing on movie content I have lost almost all of the rumbling effects I previously enjoyed. I have figured out it was not about infrasonic bass. In my case the important frequency range is between 20hz to maybe 35hz. I have already boosted this range by +10db. In retrospect I have felt undesirable ear pressure in my tests while missing the rumbling effects on my couch and clothes sometimes. It felt unbalanced while also looking almost perfect in the measurements.

Putting all four subwoofers along the front wall removes the pressure on my ears. I can add +12db peaking at 25hz without issues. All missing rumbling effects are restored compared to the 2Front-2Back-Configuration. The 4Front-Configuration sounds more front loaded and less “everywhere” in the room but that's okay. There is no subjective(!) loss in precision across all bass frequencies handled by ART. I initially thought it would have a detrimental effect on the bass response but there is nothing obvious to care about. That is why I have no measurements available at this time showing the differences between both configurations. For the first time in years it feels just right. I can even lie on the ground and enjoy the sound!

Aside from that I have noticed a couple of other things:

1. I think Dipole(potentially Bipole)-Surround-Speakers increases the audibility of the support sound. I have switched to a mixed Dipole + Front-Fire mode on my surround speakers. All my surround speakers now support up to 150hz without any issues.
2. Letting all speakers support each other in my 7.4 system while listening in Stereo-Mode creates a slight crosstalk effect (I think this is the right term?) in the upper ART range if leaving the Phantom-Center position. Can be fixed with a different support configuration.
3. I can’t get better results below 22hz. The infrasonic checkbox does not help. I have no problem with a cut-off at 19hz but please let me apply the boost of +10db at 20hz if I want to. I could boost +15 and still get a massive roll-off at 21hz, even worse at 20hz. I have seen many graphs from others showing the exact same roll-off pattern at high bass boosts. At this point it feels like something Dirac could change in future updates.

So the main issue was really around 70–80 Hz.
It’s great that ART arrived at exactly the right time for this kind of problem.
It sounds like you can finally enjoy your system without constantly fighting the room anymore. The 4-front subwoofer configuration also seems to bring back a very satisfying physical experience.
Persistence, a bit of luck, and trusting your ears in the final tuning clearly paid off. That’s a really excellent result.

 

[dlaloum]

OK so here is my first (unimpressive) ART attempt... which did however result in noticeable audible improvements over the previous DL setup

Here is todays effort, after getting my 2nd sub out of storage, connecting it up, re-calibrating... sticking with default support levels and organisation -

Results for 5.2.4:

And here is the base Dirac Live (non ART) result :

Still a few issues there that could be improved on... was hoping that the 4 x full range base speakers would have sorted more of the nodes/nulls (and associated decay ridges) 55Hz and 130Hz are prominent...

reorganising speaker locations is not really an option... nor is adding more speakers/subs

But I do wonder what can be achieved with adjustments to support levels and groups...

I also have a feeling I can improve things in the 24Hz to 30Hz range...

The fronts and subs (which have matching woofer drivers) - can according to spec go down to 24Hz

 

[dlaloum]

I have seen a lot of very impressive before and after waterfall charts. How do you like the sound with ART?

Definitely better, cleaner and clearer than without ART - for comparison purposes I have presets set up using the same target curves, one with DL and the other with ART...

The differences are not "chalk and cheese" - but they are clearly audible.

 

[kawauso]

OK so here is my first (unimpressive) ART attempt... which did however result in noticeable audible improvements over the previous DL setup

View attachment 497199

Here is todays effort, after getting my 2nd sub out of storage, connecting it up, re-calibrating... sticking with default support levels and organisation -

Results for 5.2.4:

View attachment 497200

And here is the base Dirac Live (non ART) result :

View attachment 497201

Still a few issues there that could be improved on... was hoping that the 4 x full range base speakers would have sorted more of the nodes/nulls (and associated decay ridges) 55Hz and 130Hz are prominent...

reorganising speaker locations is not really an option... nor is adding more speakers/subs

But I do wonder what can be achieved with adjustments to support levels and groups...

I also have a feeling I can improve things in the 24Hz to 30Hz range...

The fronts and subs (which have matching woofer drivers) - can according to spec go down to 24Hz

Have you tried turning off all support speakers except the subwoofers, and then adding them back one by one while checking the results in REW?

 

[dlaloum]

Have you tried turning off all support speakers except the subwoofers, and then adding them back one by one while checking the results in REW?

That is going to be a lengthy process... my experiments and critical listening were cut short by the "return of the space invaders" (cue ominous soundtrack)....

AKA: the rest of the family...

The up and downside of Dirac ART is the sheer number of potential permutations and combinations of settings...

Being time poor, I am starting with the Dirac ART defaults... and marginal tweaks to those.

Time allowing I will do further adjustments and measurements.

 

[kawauso]

That is going to be a lengthy process... my experiments and critical listening were cut short by the "return of the space invaders" (cue ominous soundtrack)....

AKA: the rest of the family...

The up and downside of Dirac ART is the sheer number of potential permutations and combinations of settings...

Being time poor, I am starting with the Dirac ART defaults... and marginal tweaks to those.

Time allowing I will do further adjustments and measurements.

ART has a lot of parameters you can tweak, but one of its strengths is that it already works very well with the default settings.
And dlaloum, you do enjoy dialing things in yourself, right?

If you’re short on time, you could also try my go-to setup like this:

Group 1 (L/R): support speakers = LR, subs
Group 2 (Center): support speakers = subs
Group 3 (Surround L/R): support speakers = SLR, subs
LFE group: support speakers = subs + L/R, or subs only

 

[OCA]

Beta of ART with Storm was up to 300hz. Not sure if they intend on going back to that or not. I used it up to 300hz and didn’t notice issues with it, but I would think that there could be issues with it.

The way mimo filters work, that would limit the smooth bass area in the room down to a 1.14m diameter circle. Storm was perhaps beta testing ART at and around MLP.

 

[JRowland]

Are you talking about self support here? Or support from other speakers? I can’t tell from the context and I’d like to try what you’re doing. Thanks.

The upper level the subs support the other speakers. I have all speakers supporting the LFE group up to 150hz including the subs but when the subs support the other speakers they only do so up to 70Hz.

 

[JRowland]

Just wanted to say thanks for posting this!

I changed my subs FSH from 150hz down to 80hz, and that really tightened up the sound for music. It seems to also gain clarity too. It never sounded bad at 150, but it’s even better at 80. I didn’t quite go to 70hz like you mentioned as I thought 80 would help keep the fullness to the sound that I enjoy.

Cheers!

That is what I hear as well. I also didn’t think it sounded bad before, seems hard to make a “major” improvement over what ART does by default. The curtain for me is probably the biggest change.

 

[JRowland]

As far as a finished product - they need to sort out infra.
Even if it means that all below 20hz are not being processed.

I turned infra off yesterday and compared the song Bass I Love You by Bassotronics and it is not the same with a 20Hz hard cut. I’ll vote no for the all below 20Hz not being processed at all. I get a hump at 20Hz, I tried to use the target curve to lessen it but it did very little for me. I can’t hear the hump so I don’t really care but I thought I’d try.

 

[JRowland]

OK so here is my first (unimpressive) ART attempt... which did however result in noticeable audible improvements over the previous DL setup

View attachment 497199

Here is todays effort, after getting my 2nd sub out of storage, connecting it up, re-calibrating... sticking with default support levels and organisation -

Results for 5.2.4:

View attachment 497200

And here is the base Dirac Live (non ART) result :

View attachment 497201

Still a few issues there that could be improved on... was hoping that the 4 x full range base speakers would have sorted more of the nodes/nulls (and associated decay ridges) 55Hz and 130Hz are prominent...

reorganising speaker locations is not really an option... nor is adding more speakers/subs

But I do wonder what can be achieved with adjustments to support levels and groups...

I also have a feeling I can improve things in the 24Hz to 30Hz range...

The fronts and subs (which have matching woofer drivers) - can according to spec go down to 24Hz

I lowered the low support of my R7s yesterday to 30 Hz. At normal volumes it was an improvement. I believe you have said loud isn’t your thing, I however like it. I always hold the remote in my hand and watch my woofers when I do the first “high speed” run on a tune, I bottomed a woofer cone briefly at only -10. When I removed the fronts from support duty I could get back to -10 without that sound but I didn’t push as I want the fronts for support, instead I just moved the lower support back to the recommended 50Hz and made it to plus 5 before it got uncomfortable with no issue. Just suggesting you crank it up and make sure it’s good or set a volume limit. It’s not that the speakers alone can’t do the range, it’s what else they’re being asked to do behind the scenes I think that taxes them.

 

[smygolf]

I turned infra off yesterday and compared the song Bass I Love You by Bassotronics and it is not the same with a 20Hz hard cut. I’ll vote no for the all below 20Hz not being processed at all. I get a hump at 20Hz, I tried to use the target curve to lessen it but it did very little for me. I can’t hear the hump so I don’t really care but I thought I’d try

As long as you can adjust your target curve it should not be any problem.
For them that can reach 10-15hz it is a lottery if they even will have respons at 18hz

Let ART do what it does today but also have the option to not do anything below 20hz

 

[OverTheAir]

Just a suggestion but it might be useful for those providing feedback on ART to detail their speakers and subs in their signature in order to give context to their comments/suggestions/feedback on ART and its settings. Especially when discussing support frequency ranges. If readers are interested then they can then look up those speaker characteristics/specs/claims and reviews if they exist on ASR or elsewhere. Equipment might be listed by room for those with ART in multiple systems. Up to you guys of course but it would make your comments more valuable IMHO and save readers having to mentally track what equipment may or may not have been mentioned previously.

As examples:
Member FZST includes the following as part of their signature:
Front: 3x XTZ M6 Surrounds: 2x Monitor Audio Silver FX dipole Bass: 2x Arendal 1723 1S, 2x SVS SB13U

Oddball provides a very detailed signature which I've edited down to just show the audio chain but the room size/description also provides useful context:
Slovak HT: 9.4.4 system in 6000+cft loft / Marantz AV-10 processor / Bryston 4B SST powering 2x Heco La Diva LR towers @300Wpc into 8ohm / Bryston 4B SST @300W into 8 ohm powering Revel C426BE centre / 5x Rotel RB 1070 @130Wpc into 8 ohm powering 6x Gallo Reference 3.1 towers SLR, FWLR, SBLR and 4x GoldenEar AON 3 front and back LR Atmos wall mounted bookshelves / LFE powered subs 2x SVS PC 4000 front LR and 2x Arendal 1723 2V back

 

[Frank207be]

As long as you can adjust your target curve it should not be any problem.
For them that can reach 10-15hz it is a lottery if they even will have respons at 18hz

Let ART do what it does today but also have the option to not do anything below 20hz

Is this a lottery? I have significant extension to 15Hz with 4 sealed subs. Mind you that the best extension is reached with the least amount of boost. A Harman Curve only starts rising at 20Hz so infrasonics get neglected.

Subwoofer 1 is located in front of the room and contains 4x Dayton sealed MX15-22. This sub also works the hardest when looking at the power meters of my Crown amps. OK they're the least sensitive of the pack and the furthest away from the MLP but with DLBC the amp load seemed to be more balanced.

2026 will hopefully/finally be the year that I'll start building my LCR speakers. I'm also considering of converting the front subs to ported LLT with a 12Hz tuning but I'm not sure it's worth the effort. Once built this choice is pretty definitive...

 

[smygolf]

Is this a lottery? I have significant extension to 15Hz with 4 sealed subs. Mind you that the best extension is reached with the least amount of boost. A Harman Curve only starts rising at 20Hz so infrasonics get neglected.

Subwoofer 1 is located in front of the room and contains 4x Dayton sealed MX15-22. This sub also works the hardest when looking at the power meters of my Crown amps. OK they're the least sensitive of the pack and the furthest away from the MLP but with DLBC the amp load seemed to be more balanced.

2026 will hopefully/finally be the year that I'll start building my LCR speakers. I'm also considering of converting the front subs to ported LLT with a 12Hz tuning but I'm not sure it's worth the effort. Once built this choice is pretty definitive...

There are several users ink my self that loose respons below 20hz so yes it is.
2 friends has systems that are reaching 10hz @ 110dB without ART.
With ART and infra they reach 18hz then the respons drops as a stone.

In my case i do not really care but ART still has a hard stop ~20 - 25hz
DLBC - vs ART

 

[fzst]

I changed my subs FSH from 150hz down to 80hz, and that really tightened up the sound for music. It seems to also gain clarity too. It never sounded bad at 150, but it’s even better at 80. I didn’t quite go to 70hz like you mentioned as I thought 80 would help keep the fullness to the sound that I enjoy.

Interesting, that's something I haven't tried yet. Maybe I'll give this a try as well would be interesting to see what happens to the region between 120 - 200 Hz where I have problems with big nulls (maybe due the height of my room?). ART does a way better job there, which I suspect is because it can use the subs up to 150Hz compared to BC, which has to make do with the mains only above the 80Hz crossover. Actually, I suspect that the filling of this null makes up a big part of the differences I hear between ART and BC - in the "punch-region" it's just not even fair to compare ART with BC, it's like BC doesn't have any punch at all when I switch back and forth, whereas in the actual "subwoofer- frequency- range" I feel like the differences are more subtle (because in my room, the decay times in the deep bass are already pretty good with BC). I could try out a BC filter with a crossover of 150Hz to see how that compares to ART but frankly, I currently don't have time for such shenanigans

This is only my current filter though, strangely my previous "favorite" BC filter did a little bit better here:

So either this is a phase issue and different Dirac filters get me different outcomes or the mic wasn't at exactly the same position for these two measurements (although I keep it fairly consistent, when I take measurements, I measure the mic's position against the side- and back wall as well as the height above the seat (this on is the least consistent metric)).

I would probably have to take a few different measurements in the "MLP- area" and sum them together to get a better picture of what's actually happening.

I did use the Storm Audio TC "max" filter for the last few weeks, which uses the highest support range (-24dB for the LFE-group, which consists of all 4 subs, for self support and to support the other speaker groups. It's not night and day but compared to my previous filter with -18dB I can definitely hear a difference. The max settings gives me more bass pressure feeling and I'd describe it as the infamous "wetter" bass we were discussing here earlier. The sound does get closer to how BC sounds, still tighter though and definitely punchier.

Is this a lottery? I have significant extension to 15Hz with 4 sealed subs. Mind you that the best extension is reached with the least amount of boost. A Harman Curve only starts rising at 20Hz so infrasonics get neglected.

Unfortunately yes, you either get lucky or not - most seem to loose quite a bit <20Hz even with the infrabox checked (me included). It seems to be dependent on what filters/phase Dirac is applying in the region just above the HPF @20Hz..?

 

[mmares056]

Just wanted to say thanks for posting this!

I changed my subs FSH from 150hz down to 80hz, and that really tightened up the sound for music. It seems to also gain clarity too. It never sounded bad at 150, but it’s even better at 80. I didn’t quite go to 70hz like you mentioned as I thought 80 would help keep the fullness to the sound that I enjoy.

Cheers!

Did you by any chance check the spread to see if there is any effect lowering the FSH?

 

[Denon545]

Did you by any chance check the spread to see if there is any effect lowering the FSH?

It is a very slight difference between the two when viewing the spread. With the subs set at a FSH of 80hz, the spread is actually a little tighter from 60hz-90hz, verses the spread with the subs FSH at 150hz actually being a little wider.

With ART, I've found that changing the settings only resulted in variations of good sound. Doesn't ever go from good to bad.