Active Room Treatment (ART) by Dirac

[Oddball]

The bass differences look noticeable, but could just as well be within the margin of error. In any case, I prefer a 200 or 300 Hz curtain — I really don’t want Dirac to wreck the mids and highs.

When you say "wreck" - what would that be exactly? I do value your view so just a fair question.

I understand the over-correction issue but then there is in most rooms the under-correction issue as well. As you move up the FQ curve, the imbalances might just get too much in "bad" rooms (like mine). Perhaps too much of control freak, but I do like to have control over 4-9kz range where I have specific preference for sibilants.

I am about to embrace the curtain voyage with ART, but my experiences from the past do not point me to a curtain so low.

 

[levimax]

I understand the over-correction issue but then there is in most rooms the under-correction issue as well.

DSP can make the sound better or worse and often does both at the same time. My experience is over correction, especially with automatic apps and above Schroeder, is more common than under correction. Looking at the response of most untreated rooms you would think they would sound terrible and even having a conversation would be difficult, yet our brains, which have signal processing perfected over millions of years, manages just fine. I think humans ability to "hear through the room" is often underestimated.

 

[kawauso]

When you say "wreck" - what would that be exactly? I do value your view so just a fair question.

I understand the over-correction issue but then there is in most rooms the under-correction issue as well. As you move up the FQ curve, the imbalances might just get too much in "bad" rooms (like mine). Perhaps too much of control freak, but I do like to have control over 4-9kz range where I have specific preference for sibilants.

I am about to embrace the curtain voyage with ART, but my experiences from the past do not point me to a curtain so low.

It’s a subjective thing, really.
If the speaker’s directivity and tonal balance already match my taste, I prefer to keep the natural reflections and slight asymmetries in the mid/high range — they make the sound feel more realistic to me.
I used to enjoy full-band correction with Audyssey for years, but my view has changed over time.

 

[Audiofrog]

DSP can make the sound better or worse and often does both at the same time. My experience is over correction, especially with automatic apps and above Schroeder, is more common than under correction. Looking at the response of most untreated rooms you would think they would sound terrible and even having a conversation would be difficult, yet our brains, which have signal processing perfected over millions of years, manages just fine. I think humans ability to "hear through the room" is often underestimated.

I appreciate your perspective—it’s a nuanced and important point. As both a hobby musician and an engineer, I’ve spent a lot of time listening critically and experimenting with DSP ( managing 2 subwoofers ) , including now Dirac ART. My experience has shown me that DSP, when used judiciously, can significantly improve the accuracy and enjoyment of sound reproduction, especially in less-than-ideal listening environments.

You’re absolutely right that over-correction can be a pitfall, particularly with automatic systems that don’t account for the subtleties of human perception. Our brains are incredibly adept at adapting to acoustic environments, and sometimes, the pursuit of a "perfect" frequency response can strip away the natural character of music—something I’ve noticed when comparing heavily processed digital sound to the organic warmth of a well-mastered vinyl record.

That said, I’ve found that Dirac ART, when carefully configured, strikes a balance. It doesn’t just flatten the response for the sake of it; it helps mitigate the most problematic resonances and phase issues that can muddy the sound or cause listener fatigue. For me, the improvement in clarity, imaging, and bass control has been noticeable without sacrificing the "musicality" that makes listening enjoyable. It’s not about making the room sound like an anechoic chamber—it’s about reducing the distractions so the music can shine through more clearly.

I also think there’s a parallel to the analog world: just as a well-set-up turntable and cartridge can reveal details and emotions in a recording that a poorly configured digital system might miss, a thoughtfully applied DSP can help a system reveal the intent of the music without imposing its own artifacts. It’s all about finding that sweet spot where technology serves the music, rather than the other way around.

At the end of the day, I agree that the human ability to "hear through the room" is remarkable. But for those of us who love to tweak and optimize, tools like Dirac ART can be a valuable way to bridge the gap between the limitations of our listening spaces and the music we love—whether it’s coming from a vinyl groove or a digital file.

 

[Talisman]

Personally, my brain has a hard time considering bass with little to no reverb to be satisfying. We've listened to music in untreated rooms for a lifetime, and we've associated some reverb and peaks with the power of the system. Some excessive vibrations, if kept at fairly low frequencies and not migrated to the mid-bass, provide a satisfying boost (for me).

Although my critical listening system consists of KEF R3s and four subwoofers controlled by Audissey, when I want to listen to music from the gut, I prefer my Klipsch RP 280Fs without any DSP in an untreated room. At certain frequencies, I can feel the sofa shaking brutally, and this makes me smile even if it's not technically correct.

 

[kawauso]

Personally, my brain has a hard time considering bass with little to no reverb to be satisfying. We've listened to music in untreated rooms for a lifetime, and we've associated some reverb and peaks with the power of the system. Some excessive vibrations, if kept at fairly low frequencies and not migrated to the mid-bass, provide a satisfying boost (for me).

Although my critical listening system consists of KEF R3s and four subwoofers controlled by Audissey, when I want to listen to music from the gut, I prefer my Klipsch RP 280Fs without any DSP in an untreated room. At certain frequencies, I can feel the sofa shaking brutally, and this makes me smile even if it's not technically correct.

Have you had a chance to experience ART?
Personally, I didn’t find its decay reduction that appealing at first — after all, some lingering bass reverberation is the natural state of things.
Instead, I was more interested in what ART’s MIMO processing could do for frequency linearity and distortion reduction.
Once I was able to use it properly in my setup, the bass turned out to be tight yet powerful — truly impressive.
Of course, preferences vary, but I’d definitely recommend giving it a try when you get the chance.

 

[masterhw]

Believe I saw some research that bass frequency reverb/decay time was one of the most important contributors to a sense of “space.” some live music venues add a bit for some performances, as a space can be too “dead” to suit certain genres.

 

[Oddball]

DSP can make the sound better or worse and often does both at the same time. My experience is over correction, especially with automatic apps and above Schroeder, is more common than under correction. Looking at the response of most untreated rooms you would think they would sound terrible and even having a conversation would be difficult, yet our brains, which have signal processing perfected over millions of years, manages just fine. I think humans ability to "hear through the room" is often underestimated.

I actually don't have a room. It's just a large area with lots of stuff in it (living/dining/kitchen/hallways) and some really odd shapes put together by some fancy architects...But that's best I have.

I must say that without going into curtain stuff, the level of separation between the channels and crispy sound I can hear from full room correction is, based on extensive prior experience, not making me want to dial back.

It’s a subjective thing, really.
If the speaker’s directivity and tonal balance already match my taste, I prefer to keep the natural reflections and slight asymmetries in the mid/high range — they make the sound feel more realistic to me.
I used to enjoy full-band correction with Audyssey for years, but my view has changed over time.

Many thanks - I will definitely try to dial back in time. And get the point - Audy is nothing remotely similar to ART so we do need to get back on the drawing board.

My speakers are not that similar as they came from different phases of my HT experience and the last choice - my LCR was really emotional. I don't regret it but yeah, they different is some ways than the rest of the gang. But if nothing else, they all look pretty good (at least I think so?).

Don't mind the bed - its just my preference and works pretty well in all aspects. My family has 2 other floors in that building so this is just an informal club where we do some loud family entertainment that would not be tolerated at more civilized (or regulated?) floors

 

[Audiofrog]

Have you had a chance to experience ART?
Personally, I didn’t find its decay reduction that appealing at first — after all, some lingering bass reverberation is the natural state of things.
Instead, I was more interested in what ART’s MIMO processing could do for frequency linearity and distortion reduction.
Once I was able to use it properly in my setup, the bass turned out to be tight yet powerful — truly impressive.
Of course, preferences vary, but I’d definitely recommend giving it a try when you get the chance.

Yes ( and extensively since October 1st and release on Denon you can see my other posts with some REW measurements and yes at I do agree with your analysis on the bass and overall sound experience ( comparing with no Dirac , and bass control )

 

[Talisman]

Have you had a chance to experience ART?
Personally, I didn’t find its decay reduction that appealing at first — after all, some lingering bass reverberation is the natural state of things.
Instead, I was more interested in what ART’s MIMO processing could do for frequency linearity and distortion reduction.
Once I was able to use it properly in my setup, the bass turned out to be tight yet powerful — truly impressive.
Of course, preferences vary, but I’d definitely recommend giving it a try when you get the chance.

I'm extremely tempted, but the complete package comes to around €700 without the option of a free trial. Considering that for the same amount I bought my Denon AVC X3800H, including the Audissey, it's an expense I need to think carefully about, and if, like Ken, I don't find an advantage in the end, I risk having wasted €700. I'm considering...

 

[kawauso]

I actually don't have a room. It's just a large area with lots of stuff in it (living/dining/kitchen/hallways) and some really odd shapes put together by some fancy architects...But that's best I have.

I must say that without going into curtain stuff, the level of separation between the channels and crispy sound I can hear from full room correction is, based on extensive prior experience, not making me want to dial back.

Many thanks - I will definitely try to dial back in time. And get the point - Audy is nothing remotely similar to ART so we do need to get back on the drawing board.

My speakers are not that similar as they came from different phases of my HT experience and the last choice - my LCR was really emotional. I don't regret it but yeah, they different is some ways than the rest of the gang. But if nothing else, they all look pretty good (at least I think so?).

View attachment 487873View attachment 487874

Don't mind the bed - its just my preference and works pretty well in all aspects. My family has 2 other floors in that building so this is just an informal club where we do some loud family entertainment that would not be tolerated at more civilized (or regulated?) floors

The Heco La Diva has such an elegant design. And this Anthony Gallo setup looks like a cute little snail — really charming. I’d love to just relax on that bed-like sofa with you, dog and otter style.

 

[kawauso]

I'm extremely tempted, but the complete package comes to around €700 without the option of a free trial. Considering that for the same amount I bought my Denon AVC X3800H, including the Audissey, it's an expense I need to think carefully about, and if, like Ken, I don't find an advantage in the end, I risk having wasted €700. I'm considering...

I’ve upgraded all four of my Denon AVRs from Bass Control to ART, and I can definitely recommend it.
The improvement was consistent across every setup.
Here’s my blog post about it: https://ameblo.jp/kawauso9991/entry-12940948855.html

 

[Audiofrog]

I’ve been experimenting with Dirac ART on my Denon AVR-X4800H and wanted to share some observations and measurements for feedback from more experienced users.



Room details:

• Dimensions: 4.65 × 4.65 × 2.5 m + small alcove 1.7 × 0.7 × 2.5 m
• Topt (RT60): 0.288 s
• Estimated volume: ≈ 57 m³
• Calculated Schroeder frequency: ≈ 142 Hz

Based on this, I initially assumed the room behaves modally below ~140 Hz and diffusely above that — so I compared different Dirac ART correction ranges to see how that theory translates in practice.

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Dirac ART Correction Range Comparisons​

I tested several limits: 200 Hz, 800 Hz, 7 kHz, and 20 kHz.

My expectation was that restricting correction to the low end would deliver the tightest bass by concentrating filter resolution where room modes dominate.

The results, however, were more interesting than expected:

• 200 Hz correction: Good low-end control, but slightly rounder and less defined bass than ideal.
• 800 Hz correction: Noticeable improvement in bass articulation and integration; smoother transition through the lower midrange, with vocals sounding more grounded.
• 7 kHz correction: Further improvement in bass tightness and overall coherence — likely from better phase alignment across a broader spectrum.
• 20 kHz correction: Preserved the gains from previous runs and refined the tonal balance even more, giving the most consistent presentation overall.

---

REW Observations​

Attached are REW waterfalls , group delay and RT60 plots at:

200 Hz, 800 Hz, 7000 Hz, and 20 000 Hz correction limits.



Subjective summary:

• Bass: The 20 kHz correction maintains the improvements from earlier settings, delivering tight, well-controlled bass with excellent definition.
• Midrange: Clear and linear across all cases, with the 800 Hz and higher corrections improving coherence through the vocal range.
• Treble: The 20 kHz correction provides the most refined top end so far — smooth, natural roll-off, reduced fatigue, and cleaner high-frequency detail.
• RT60 models:

200 Hz
RT60 is longer (~600–800 ms), especially below 100 Hz.
Can cause boomy or muddy bass. Room modes are likely dominant here.
800 Hz
RT60 is more controlled (~300–500 ms).
Midrange clarity is decent, but some decay may still affect speech intelligibility.
7 kHz
RT60 is shorter (~200–400 ms), closer to ideal.
High frequencies are well-controlled, reducing harshness.
20 kHz
RT60 is very short (~100–300 ms).
Highest frequencies decay quickly, which is typical and reduces sibilance.

---

Takeaway​

Even though my Schroeder frequency is around 142 Hz, limiting Dirac ART strictly below that range didn’t yield the best overall result.

Broadening the correction range to 800 Hz, 7 kHz, and finally 20 kHz consistently improved both objective and subjective performance — especially in terms of bass control, time alignment, and top-end smoothness.



It seems that in my setup, allowing ART to operate full-range enhances global phase and timing coherence, which indirectly benefits the perception of bass tightness and clarity.



I’d be very interested to hear how others have approached correction-range selection with ART on similar systems — especially regarding where you found the best balance between precision and natural tonality.

---

To keep my speaker natural voicing, I am choosing so far the 7 kHz correction in Dirac ART which strikes the best balance:
Controlled bass(tames room modes)
Exceptional midrange clarity (vocals/instruments shine)
Natural treble (avoids over-processing) ( despite better REW results in the 20kHz graphs)

 

[Oddball]

The Heco La Diva has such an elegant design. And this Anthony Gallo setup looks like a cute little snail — really charming. I’d love to just relax on that bed-like sofa with you, dog and otter style.

Many thanks for the compliments as always. The Gallos are actually much bigger in output than they seem. They did so well over the years that I would really be devastated if they don't last for much more years to come...

Some of the photos where they were born.

We can continue other things via PM. That will be the first but you never know if it will be the last

 

[kawauso]

Many thanks for the compliments as always. The Gallos are actually much bigger in output than they seem. They did so well over the years that I would really be devastated if they don't last for much more years to come...

Some of the photos where they were born.

We can continue other things via PM. That will be the first but you never know if it will be the last

View attachment 487893View attachment 487894

What a beautiful home — so European, with a real sense of history and timeless charm.
That table looks incredibly expensive! The snail-shaped speakers fit the room perfectly.
It would be heartbreaking if they ever stopped working.

 

[ooheadsoo]

I also felt the bass was too lean art default settings, and bumping the curve on the subwoofer to +10db did not improve things. The effect wasn't impressive. What did help was applying that more moderate +6db curve that I posted a few pages back to basically all of my speakers. This increased bass evenly across the board, and movies shake the home. If I had time, I might create a +3 or +4db profile, but I'm already pleased and not in a rush.

 

[TimoJ]

I also felt the bass was too lean art default settings, and bumping the curve on the subwoofer to +10db did not improve things.

That's because the subwoofer curve actually adjusts only LFE channel's response. Denon/Marantz is missing the correct labeling.

 

[alvigg]

Several people report problem with bass too thin. Could this be a common problem?

 

[kawauso]

Several people report problem with bass too thin. Could this be a common problem?

My bass sounds quite dry, but I actually feel it has more body now. Probably because the small dips have been smoothed out. I even reduced my low-end target from +3 dB to +2 dB compared to Bass Control. Even when I increase it to +6 dB, it still sounds clean and controlled, so it feels full yet pleasant.

 

[smygolf]

Several people report problem with bass too thin. Could this be a common problem?

Most of us that have measured can see that the respons is the same with different version of Dirac.

And ART does what it is supposed to, lowers the decay in the bass = your ears think you have less bass then before.