Active Room Treatment (ART) by Dirac

[Kal Rubinson]

Does you stating that you are beta testing mean it is close to be released to the masses, e.g. Denon Marantz?

I don't know of any connection but I wish it was so. I recently convinced my son-in-law to buy a Marantz AV10.

 

[pogo]

It's $299, in addition to the cost for Dirac Live and Bass Control.

Bass control is only necessary if you also use a subwoofer. Dirac is probably also considering a version without RC and BC.

 

[Kal Rubinson]

Dirac is probably also considering a version without RC and BC.

Without RC?

 

[pogo]

Yes, that's how I understood it at the time. Unfortunately, I can't find the source at the moment.

 

[Davide]

Has anyone by chance compared ART with HAF Room Shaper?
They seem similar products as they act on decay control, albeit with different approaches.
Room Shaper is not exactly clear how it works for me. From what I understand it intervenes selectively on late acoustic events (>250ms) up to 600Hz, with psychoacoustic option for treble also, but without exploiting the cooperation between drivers.
ART on the other hand seems to control the shape of the decay starting from the peak of energy, taking advantage of all the drivers, but only up to 150Hz (at the moment, but it can potentially go further).

 

[Magnus]

RC as in room correction? I've never heard of any DIRAC correction that didn't involve the base room correction, although having bass correction only to Schroeder isn't a bad idea, but it's kind of like admitting the room correction is worthless (I limit Audyssey to 3000Hz as the midrange and highs sound no better and often worse to my ears). Without Spinorama data, you're correcting the average room response of direct and reflected sound, not just the room and that can actually make the direct sound worse...a lot worse. My speakers are +/- 1.5dB direct. I'm not letting correction screw that up.

 

[Keith_W]

Has anyone by chance compared ART with HAF Room Shaper?
They seem similar products as they act on decay control, albeit with different approaches.
Room Shaper is not exactly clear how it works for me. From what I understand it intervenes selectively on late acoustic events (>250ms) up to 600Hz, with psychoacoustic option for treble also, but without exploiting the cooperation between drivers.

My understanding is that Room Shaper selectively shortens some bass frequencies to reduce ringing a those frequencies. Read this post.

 

[Davide]

My understanding is that Room Shaper selectively shortens some bass frequencies to reduce ringing a those frequencies. Read this post.

Yes, I had read that post, but it is still not clear to me how it works exactly and why it is different from what Audiolense/Acourate do with FIR to correct excess phase.

 

[Keith_W]

Acourate tackles two different types of excess phase. Firstly, the convolution of the linear phase XO with the inverted minimum-phase response of the loudspeaker will produce excess phase and apparent pre-ringing in the step response. This is the purpose of the EP correction in Macro 4 (if you use Acourate you will know what I am talking about). The second type of EP that Acourate corrects is introduced by the room. This is evident as a spike in the Group Delay graph that corresponds with a null in the frequency response. By introducing a high Q all-pass filter, the EP spike can be dealt with. Its purpose is to smooth out low frequency response.

Room Shaper works by analysing decay of certain bass tones. It then shortens the note to reduce the decay. Because of this, it has to work in real time which is why it is inserted as a VST in the DSP pipeline.

 

[Davide]

Firstly, the convolution of the linear phase XO with the inverted minimum-phase response of the loudspeaker will produce excess phase

Maybe you mean change instead of produce?
Otherwise I don't understand why...

 

[Davide]

Given my GD problem with BC I tried again to ask to Support for news about ART for PC/Mac, even in beta, but with no luck.
AVR is the priority

 

[pogo]

Dirac Live 3.13.2 // 2025-02-28​

Features​

• ART support range sliders now take precedence over the detected range of a speaker.
  • In cases where there is no subwoofer used as support speaker, ART filter designs could sometimes result in undesirable magnitude boosts at frequencies between the speaker’s detected low cut-off and the user’s selected low end of the ART support range.
  • The workaround has been to manually adjust the advanced target curve to not “ask for” more bass than the available supporting speakers can provide.
  • The updated functionality will instead use the selected low end of the ART support range to limit, or contain, the magnitude boost applied by the ART filter design. Therefore, it will not longer be necessary to adjust the advanced target curve to achieve a “reasonable” ART filter design.
• The LFE group in ART now uses a non-subwoofer speaker to define its time target.
  • ART utilizes the measured wavefront propagation of the main speaker in each microphone position to define the time target response for that channel.
  • For the LFE channel, ART utilized the first subwoofer in the LFE group as main speaker for the LFE channel. However, this has two drawbacks:
    • The main peak in a subwoofer’s impulse response can sometimes be difficult to detect. In cases where the detection has failed in one or more microphone positions, the resulting target may not represent a desired wavefront propagation.
    • When multiple subwoofers are used, then ART may “unfairly” assign too much power to the first subwoofer, due to its measured capability to contribute more effectively to attaining the target (which was defined by its measured response) than the other subwoofers.
  • The updated functionality will use a full-range speaker to define the time target for the LFE channel.
    • If there is a Center speaker, ART will try to identify it and use it as target.
    • If a Center speaker cannot be certainly identified, then ART will use either the Front Left or the Front Right speaker as target.
    • The advanced ART settings for the LFE channel group has a drop-down menu to let the user manually override the automatic selection.
• When Dirac is handling bass management (BM, BC, ART), the LFE channel will always have a low-pass filter applied at 120 Hz. This is to comply with LFE channel handling requirements and be consistent with the Dirac Live Bass Control (DLBC) behaviour.
• ART now supports the case where some speakers are excluded from supporting other speakers. However, they may still receive support from other speakers when they are enabled.
• Reduced the time it takes to export a filter to Onkyo/Integra/Pioneer devices.

Bug fixes

• Fixing a few issues related to measurements taken while an AVR was on an older firmware and using them for filter design and filter export to the same AVR with an upgraded firmware:
  • Dirac Live could crash when clicking the Bass Management filter design option.
  • Bass Control filter design could fail with a message “Malformed request”.
  • Filter export could fail with an error message “Failed filter export”.
• Fixed an issue where Dirac Live could crash when calculating a Bass Control filter with a narrowband subwoofer.
• Fixed an issue where Dirac Live could crash at the end of ART preprocessing for a 2.1 system.
• Fixed an issue where Dirac Live could silently fail to load an older ART project, showing no measurements in the filter design page.
• Fixed an issue where loading a stored Dirac Live filter design snapshot would put the filter design in a wrong state - as if it had a completed filter design, which it didn’t. An attempt to export that filter design to the device would fail.
• Fixed an issue where an offer to upgrade a license to ART wasn’t shown when connected to a device supporting ART.
• Adjusted the LFE low-pass filter cut-off frequency in Bass Control to be -3dB at 120Hz. It was previously erroneously set to -6dB at 120Hz.
• Fixed an issue where the Bass Control subwoofer impulse response plots were not properly scaled, almost appearing as having zero amplitude (flat).
• Fixed an issue in the Filter Export page where the text input box for the filter name would sometimes lose focus while typing.
• Missing/wrong signing for the previous beta releases has been fixed.
• Other minor bug fixes and under-the-hood stabilizations.

Known Issues

• The animations in the Dirac Live UI during measurements have been temporarily disabled. This is because we have found that the animations cause high CPU load on some computers, both PCs and Macs, resulting in audio buffer loss in the measurements. The measurement progress can be followed in the progress percentage, which is still displayed.
• Processing progress percentage can in some situations jump backwards. This doesn’t indicate that there is a problem with the processing itself. It is only the calculation of the progress that needs fixing.

 

[napfkuchen]

Updating firmware & software and convincing Dirac to save 9 measurements without crashing or losing connection to the usb-microphone? I'll leave this "experience" to the masochists out there until ART is supported by my receiver.

 

[tjcinnamon]

Hahaha! So true!

I got excited when I saw this hit my inbox! I was hoping it came out in Beta for Denon and Marantz!

 

[juliangst]

I hope 'Dirac ART for Marantz and Denon' won’t become the next 'Spotify Lossless coming soon'.

 

[tjcinnamon]

I hope 'Dirac ART for Marantz and Denon' won’t become the next 'Spotify Lossless coming soon'.

I think it will. Some insiders at AVNirvana heard rumblings that consumer AVRs would no longer be in scope

 

[alvigg]

I am not sure why this is hard. The same measurements apply to DL, DLBC, and DLART - at least I think so. Dirac then sends a curve to the processor. Seems like the processor should care how Dirac calculated that curve. Maybe there are some timings?

 

[tjcinnamon]

AVR receives a filter not a curve. ART is a completely different animal. It involves routing LFE/crossed over bass signals to speakers which normally wouldn’t receive them

 

[Magnus]

ART for the Monoprice HTP-1 has been in beta for 1000 years now.... DTS:X Pro was supposed to come shortly after. I feel sorry for the fools that bought this buggy POS clear back on 2019. When customers have to fix the bugs for you, it's BAD. I had hopes for it and at least the worst bugs are fixed (by customers) now.

I had a chance to get one for $2700 and almost bought it. I'm glad I didn't. I knew the promises of ART (let alone DTS:X Pro) were horse shi$. No one buys a product and expects the promised DTS:X Pro to take over SIX YEARS!!! Ridiculous.

Monoprice crapped their pants on this. They could have had the best AVP for the price, but this is right up there with Emotiva. And yet Masimo is looking to sell very reliable Drnon & Marantz to someone so there may soon be very few good options for 15+ AVPs/AVRs.

 

[GXAlan]

ART for the Monoprice HTP-1 has been in beta for 1000 years now...

When customers have to fix the bugs for you, it's BAD. I had hopes for it and at least the worst bugs are fixed (by customers) now.

Monoprice crapped their pants on this. They could have had the best AVP for the price

I’m sure at least in the realm of home theater, this is probably akin to Blockbuster video choosing not to acquire Netflix when they had the chance and money to do so.

Except for the 1000 years comment, everything you say is 100% accurate. All of the major bugs were fixed by customers so in its current state, its reliable as long as the existing feature set is all you care about.

They had a made in USA 16 channel processor with very high performance SINAD at good profit margins even when selling B-stock at $3200 or less which is still pretty good today 6 years later.

As inflation has kicked in, other companies have escalated prices, it’s the high end that is most resilient against market forces. They could have set the stage for a HTP-2 or Trinnov like upgrade program. Now, with the incoming tariffs and Monoprice’s heavily imported inventory, their ability to pivot toward AV electronics is compromised based upon their track record.

If the HTP-2 comes out, even HTP-1 owners are going to be skeptical no matter how good or cheap it is. The price of the HTP-2 would simply reflect the product itself, as opposed to the price that Denon or Marantz can charge based upon track record…