Active Room Treatment (ART) by Dirac

[napfkuchen]

There are reports on the Storm forums of users having excellent results with stereo or 2.1 setups...

I would be thrilled if this were to prove true for me in practice. My front speakers can play down to 40 Hz, and the two subwoofers (also at the front) down to 20 Hz. All the other speakers don't have much to offer below 80-90 Hz.

 

[DutchJay]

Gents,

It's exactly like I said. Your fronts will rum full range and act as sources of bass to get the smoothest base in your room.

Pls see my questions to dirac helpdesk in italic and their answer in CAPITAL lettets.

Hello

“ART uses support speakers to cancel room modes. But does it also use all the bass capable speakers to get the smoothes bass frequency response?”

YES

“Does that mean your fronts will run as full range speakers and thus add to the bass by cancelling But ALSO DIRECTLY to get the flatest response?”

YES

“Or does it set crossovers and will the fronts only correct/support below the crossover?”

NO, there is no crossover.

You’ll find details in the attached document:

Dirac-MIMO-framework-for-active-room-treatment-and-Unison-.pdf

Thanks for your interest in Active Room Treatment, and kind regards!

Flavio

COPY FROM THE PDF:

ART and Dirac Unison enhance the concept of bass management by not only directing low frequencies to speakers capable of handling them but also by allowing speakers to share the same frequency ranges. This overlap helps even out sound variations throughout the listening area. The technology customizes bass playback for each speaker, considering the unique acoustics of the room, based on detailed measurements and advanced lters for low frequencies. While it's simple to present a smooth bass response using broad 1/3 octave frequency plots, this method can be misleading. It glosses over the complexities of bass reproduction. To truly understand and improve what happens in the bass region and how it's experienced by listeners, a much ner analysis is necessary.

 

[DutchJay]

It's even better than I imagined!! @Oddball

All speakers can support the LFE channel to create a super subwoofer!

From the pfd: With ART, all the other speakers in the system can assist our main speaker to perform better. They help extend its frequency range and achieve the desired collective sound response at every listening spot. Similarly, the Low-Frequency Eects (LFE) channel can be distributed among all speakers capable of handling bass frequencies, creating a powerful, room-lling "super subwoofer" eect through the optimized, combined output of the eight speakers. However, typical surround speakers, which usually don't reach deep into the bass spectrum, might not contribute to supporting the lower frequencies down to 20 Hz.

 

[OCA]

Just a heads up for those who care about their subs' below 20Hz output capabilities: ART applies a brickwall filter at 20Hz by default. If you want infra-bass coverage, you’ll have to pay extra and even then, it doesn’t seem to work properly and decays are not minimized (at least in the case of Storm).

 

[EWL5]

It's even better than I imagined!! @Oddball

All speakers can support the LFE channel to create a super subwoofer!

From the pfd: With ART, all the other speakers in the system can assist our main speaker to perform better. They help extend its frequency range and achieve the desired collective sound response at every listening spot. Similarly, the Low-Frequency Eects (LFE) channel can be distributed among all speakers capable of handling bass frequencies, creating a powerful, room-lling "super subwoofer" eect through the optimized, combined output of the eight speakers. However, typical surround speakers, which usually don't reach deep into the bass spectrum, might not contribute to supporting the lower frequencies down to 20 Hz.

I don't think anyone's arguing that all speakers can be "help speakers" but the more important thing is whether they should!

A 4-year old certainly can help w/the spackling and painting of a house but should they?!!!

 

[napfkuchen]

I don't think anyone's arguing that all speakers can be "help speakers" but the more important thing is whether they should!

There's a saying: "A lot (bass support) helps a lot." What is a lot depends on your own circumstances (room + audio devices) and requirements. You'll have to experiment for yourself to determine the settings offering you the best sound. The waterfall diagram after the calibration and your own listening experience will be helpful.
All my speakers are positioned approximately 2-2.5 meters from the listening position. Other users may have a significantly greater listening distance. And some users here want to have "maximum infrasonic impact". My neighbors, for example, certainly don't want any sound in the infrasound range to be played at all.

In any case, I'm optimistic that ART will improve my setup. If I see further potential for improvement, I might add two subwoofers to the rear speakers.

 

[Oddball]

It's even better than I imagined!! @Oddball

All speakers can support the LFE channel to create a super subwoofer!

From the pfd: With ART, all the other speakers in the system can assist our main speaker to perform better. They help extend its frequency range and achieve the desired collective sound response at every listening spot. Similarly, the Low-Frequency Eects (LFE) channel can be distributed among all speakers capable of handling bass frequencies, creating a powerful, room-lling "super subwoofer" eect through the optimized, combined output of the eight speakers. However, typical surround speakers, which usually don't reach deep into the bass spectrum, might not contribute to supporting the lower frequencies down to 20 Hz.

Well - I rest my case as Dirac claims it does it all. Thanks for doing the work and bringing it up Jay .

I still scratch my head though how exactly are they doing all this based on limited adjustments available. From what I gathered canceling sound needs to be quiet enough not to actually be heard, and if heard volume/support level should be turned down. Distributed LFE on the other hand should be audible, and preferably loud. But there is only one volume/support level setting for ART as far as I recall/see in videos?

Does that mean ART is distributing LFE without any user adjustments and volume/support level adjustment available is just for the cancelation signal? That would be a bit odd. From my experience, adjusting LFE distribution levels manually (as in D&M/Storm) is useful as different content has different levels of bass. This would also include any personal preferences as some like it hotter than the others.

 

[ltek]

I was told this by Storm... ART available in D&M products will be different than what Storm has. Each hardware manufacturer must make Dirac work on their own hardware, Dirac does not do that for them. Which means they must have engineers (not like there are a lot of Dirac firmware/software engineers roaming around). Storm has a multi-year head start on implementing Dirac properly on far more powerful hardware than the AVRs have. Storm adds their own IP to make it better and has an acoustic scientist and hardware designers on staff, full time.

I've been told the AVRs will have approx half the number of calibration points on the target curve that it can do. Will this make a difference for you?... if you have a high-end system in a dedicated room, why compromise the ability to get the most out of your speakers and room?

I get a Storm next week and will do a basic calibration in my 9.3.6 room with Theory speakers. Storm will do a full onsite calibration in a few months. I'll have more info for you then

 

[Curvature]

I don't think anyone's arguing that all speakers can be "help speakers" but the more important thing is whether they should!

A 4-year old certainly can help w/the spackling and painting of a house but should they?!!!

Remember that the support is fairly low in level and is used to cancel decays, not the signal. Speakers don't need to work as hard as subs normally would.

Right now there isn't much concrete guidance about how to optimally manage speakers. Users are experimenting for the best result. At some point we will have measurement-backed information.

 

[Daka]

so all in all - having capable speakers or subwoofers will result in better frequency response, not just better decay.

 

[Oddball]

Unfortunately users were experimenting for years and there is still nothing out there to make it complete. Look up the threads with thousands of post on various forums is the best way to deal with the issue apparently.

This is the best ART review that I found. But then not really indicative for most people as setup used is overboard for most budgets. Another interesting fact is that AVR was used for that extraordinary setup, apparently at no peril. Focal Astral 16, based on Storm Audio’s platform (200 WPC x 12 ALL CHANNELS DRIVEN!). Go figure, one power supply to rule them all I guess. Compression tests for SPL are not present though, but ART performance seems pretty flawless except beyond 20hz.

Focal 1000 Utopia IWLCR & IWSUB Speaker System Review

Focal's 1000 Utopia and Astral 16 deliver reference grade performance from an in-wall speaker. Check out our exclusive, in-depth, Focal 1000 Series Theater installation and a sneak peek at Dirac ART.

www.audioholics.com

 

[Daka]

Unfortunately users were experimenting for years and there is still nothing out there to make it complete. Look up the threads with thousands of post on various forums is the best way to deal with the issue apparently.

This is the best ART review that I found. But then not really indicative for most people as setup used is overboard for most budgets. Another interesting fact is that AVR was used for that extraordinary setup, apparently at no peril. Focal Astral 16, based on Storm Audio’s platform (200 WPC x 12 ALL CHANNELS DRIVEN!). Go figure, one power supply to rule them all I guess. Compression tests for SPL are not present though, but ART performance seems pretty flawless except beyond 20hz.

Focal 1000 Utopia IWLCR & IWSUB Speaker System Review

Focal's 1000 Utopia and Astral 16 deliver reference grade performance from an in-wall speaker. Check out our exclusive, in-depth, Focal 1000 Series Theater installation and a sneak peek at Dirac ART.

www.audioholics.com

it is surprising how little feedback there is indeed. It might be StromAudio is even more niche than Trinnov.
Those speakers are more for music than HT tbh and you pay for that fidelity over the top. You can get better ones for less so I wouldn't stress about it.
Nevertheless another confirmation of ART addressing room modes not only decay time.

 

[Oddball]

it is surprising how little feedback there is indeed. It might be StromAudio is even more niche than Trinnov.
Those speakers are more for music than HT tbh and you pay for that fidelity over the top. You can get better ones for less so I wouldn't stress about it.
Nevertheless another confirmation of ART addressing room modes not only decay time.

This system was designed to provide great frequency response. Decay times are the cherry on the top. I don't see any reference in the review as to any potential LFE distribution that Dirac claims it does. Not saying it does not do it - as Dirac says it does - but just making a note that this is not addressed.

 

[TimoJ]

This system was designed to provide great frequency response. Decay times are the cherry on the top. I don't see any reference in the review as to any potential LFE distribution that Dirac claims it does. Not saying it does not do it - as Dirac says it does - but just making a note that this is not addressed.

But in the same document Dirac also says this:
The LFE (Low-Frequency Efects) channel can be optimized by assigning one subwoofer as the main speaker, with the others (and possibly full-range speakers) supporting it.

 

[Oddball]

But in the same document Dirac also says this:
The LFE (Low-Frequency Efects) channel can be optimized by assigning one subwoofer as the main speaker, with the others (and possibly full-range speakers) supporting it.

If you don’t know after all these years then nobody knows. So rather than pointing to marketing material, your own view would be more appreciated.

I won’t be the one to contradict, but can’t say that it smells roses as it does not. The sentence you quoted is just saying as much as it doesn’t.

 

[TimoJ]

If you don’t know after all these years then nobody knows. So rather than pointing to marketing material, your own view would be more appreciated.

I won’t be the one to contradict, but can’t say that it smells roses as it does not. The sentence you quoted is just saying as much as it doesn’t.

Last time I used, LFE with ART worked like Dirac said. i.e. just one sub outputs real LFE and all other subs and selected speakers support it. I think Storm has added some setting that allows to assign more subs for LFE channel.

 

[ltek]

Last time I used, LFE with ART worked like Dirac said. i.e. just one sub outputs real LFE and all other subs and selected speakers support it. I think Storm has added some setting that allows to assign more subs for LFE channel.

Storm can according to when I spoke with Storm directly about this 2'ish weeks ago. We will test setting up 2x 18s (front) + 1x 15" (behind 2nd row riser). They told me I could get as many subs as I wanted for either LFE or as dedicated support, or dual use.

 

[Kal Rubinson]

Last time I used, LFE with ART worked like Dirac said. i.e. just one sub outputs real LFE and all other subs and selected speakers support it.

That is currently what I do.

I think Storm has added some setting that allows to assign more subs for LFE channel.

So does Jriver.

 

[Fidji]

Just a heads up for those who care about their subs' below 20Hz output capabilities: ART applies a brickwall filter at 20Hz by default. If you want infra-bass coverage, you’ll have to pay extra and even then, it doesn’t seem to work properly and decays are not minimized (at least in the case of Storm).

In most of the rooms 20Hz will be well below first modal frequency, so no standing waves/ringing/resonances that you need to correct. You are good just with simple EQ filter to get you desired infrasonic output [or in case of dedicated infra sub with proper phase alignment with normal subs] Below 20 Hz your issue to solve is power leakage out of the room and having enough woofage to get the proper output.
In most of the commercial subs you will hit limiter settings much sooner than Dirac 20Hz brickwall if you want to get anywhere near reference levels.

It's even better than I imagined!! @Oddball

All speakers can support the LFE channel to create a super subwoofer!

From the pfd: With ART, all the other speakers in the system can assist our main speaker to perform better. They help extend its frequency range and achieve the desired collective sound response at every listening spot. Similarly, the Low-Frequency Eects (LFE) channel can be distributed among all speakers capable of handling bass frequencies, creating a powerful, room-lling "super subwoofer" eect through the optimized, combined output of the eight speakers. However, typical surround speakers, which usually don't reach deep into the bass spectrum, might not contribute to supporting the lower frequencies down to 20 Hz.

ART will still not bend physics and output will be limited by cone area, excursion and available power of amps. Short and uniform decay will do great things in terms of clarity and quality of bass perception, but the trade off is that you will need significantly more power to get to same bass levels. Think of it as an equivalent of very lively vs damped room in treble region, where short decay sounds dull and treble seems to be missing.

So the idea that somehow miraculously bunch of 6.5 or 8in woofers willl create some “super sub” is more of an illusion. If anything ART will unmask limits of the woofer’s output and instead of room resonances you will start to notice compression and distortion in lower frequencies.

I had a chance to hear two ART installations - and it was useful to understand the advantages, but also the drawbacks. It definitely does what it promises in terms of controlling the decay times.

 

[Daka]

In most of the rooms 20Hz will be well below first modal frequency, so no standing waves/ringing/resonances that you need to correct. You are good just with simple EQ filter to get you desired infrasonic output [or in case of dedicated infra sub with proper phase alignment with normal subs] Below 20 Hz your issue to solve is power leakage out of the room and having enough woofage to get the proper output.
In most of the commercial subs you will hit limiter settings much sooner than Dirac 20Hz brickwall if you want to get anywhere near reference levels.



ART will still not bend physics and output will be limited by cone area, excursion and available power of amps. Short and uniform decay will do great things in terms of clarity and quality of bass perception, but the trade off is that you will need significantly more power to get to same bass levels. Think of it as an equivalent of very lively vs damped room in treble region, where short decay sounds dull and treble seems to be missing.

So the idea that somehow miraculously bunch of 6.5 or 8in woofers willl create some “super sub” is more of an illusion. If anything ART will unmask limits of the woofer’s output and instead of room resonances you will start to notice compression and distortion in lower frequencies.

I had a chance to hear two ART installations - and it was useful to understand the advantages, but also the drawbacks. It definitely does what it promises in terms of controlling the decay times.

No one is saying all speakers combined will result in more dBs in room - I think what we're trying to say is a single sub supported with other speakers will result with no nulls and flat response.

Mind that cancelation waves are done at lower SPL - so your towers don't need same woofer area as your sub - math says to achieve 20dB cancelation wave (max ART can do if not mistaken) for a signal of 100dB you would need signal at 94dB (6dB lower for 20dB of cancelation) - most towers can do that albeit at higher distortion.

Math:

For a 20 dB reduction from the original 100 dB signal, you want the final result to be 80 dB SPL.

Using the formula for combining sound levels with destructive interference: L_total = L1 + 10 × log₁₀(1 - 10^((L2-L1)/10))

Where:

• L1 = 100 dB (original speaker level)
• L2 = X dB (canceling speaker)
• L_total = 80 dB (desired result)

Solving this equation: 80 = 100 + 10 × log₁₀(1 - 10^((X-100)/10))

This gives us: X ≈ 94 dB SPL