Active Room Treatment (ART) by Dirac

[dlaloum]

I have a 7.4.6 setup with 8 groups: 4 for the bed layer, 3 for the top speakers and 1 for the subwoofers. I tried to max out support assignment as close as possible to each related speaker to avoid channel bleeding fromt to back and vice versa. My ART system leans heavily on the 4 subs to preserve dynamic capabilities as all my speakers have a bottom support of 80Hz except the fronts which do 50Hz. And it clearly works as switching between DLBC and ART makes a huge difference. Yesterday I watched a movie with war scenes in-between the story and they felt amazingly real. Jump scares through sound are at least twice as intense even at slightly lower playback volume.

The removal of the decay exposes the fundamental dynamics much more...

 

[mmares056]

I thought I'd share my thoughts on how I've been getting on with Dirac ART. I've had it since it came out for my Denon x3800H. Before it I was running one of the versions of A1/MultEQ-X with the subs running MSO.

My system is 7.4.4 (Dirac sees 7.3.4 as my rear subs are connected via Y-splitter - I need sub out 4 from my AVR for tactile devices). All my speakers are in wall (Revel W553L, Revel W763) and my ceiling speaker are Kef (Ci130QR). My subs are Q Acoustics QB12, placed in each corner of the room. It is a very small, purpose built, cinema room in my garden. Measures 4.7m x 2.7m x 2.2m.

Before I used ART I had a very good sounding system, with just a niggle being bass could occasionally sound too loose and boomy at certain frequencies. This always puzzled me, as my frequency response looked pretty clean and flat. I've since learned it was showing it's head in other measurements that I was yet to full understand.

Here are my plots before ART (using A1/MSO):

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And here are my results with Dirac ART. I've been playing around with support speakers, levels, grouping etc, but things pretty much look the same on the graphs. What I have noticed in listening tests was that with the default settings, it was unenjoyable. It felt like the sensation I get with noise cancelling headphones. I was getting strange pressure sensations in my head. I pretty much go no higher in support than -12dB for support speakers. This made things better for me. The following data is with -6dB for the support speakers:

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I'm not great with deciphering the graphs, but things look much better now to me than pre-ART. As for listening impressions, things have really just gone to another level. The thing I've noticed most is drums now sound really impactful. I notice this most on Hans Zimmer's 'Mombasa' from Live in Prague. That blows my socks off every time! I've also noticed dialogue has become clearer. I can crank the volume higher than before and it just gets better!

So all in all, Dirac ART has been great in my little room!

Next I plan on getting it into my living room with my Audio Frist Cadentia 3 speakers. That's a bigger room, but no optimal MLP. My sofa is right against the back wall and the speakers are quite close to the front wall. Let's see how we get on there next!

Hope this helps someone.

Thank you for sharing these graphs. It's very helpful. The objective data clearly shows significant improvement. What self support levels did you use for your speakers groups?

 

[ThELiZ]

Looking at the decay around 100 ms, it’s clear that ART is working effectively. Although the bass already appears relatively tight, you mentioned that it feels significantly improved. It also seems that the default ART settings were a bit underwhelming. Did you reduce the number of assigned support speakers slightly?

The default settings seemed to make the system sound like it was a pair of massive noise cancelling headphones. It was a strange pressure sensation. It’s possible this is because I have a small room.

I think the best thing I did was remove my side surrounds as support. These are only 1.3m from my mlp.

At the moment I have support from all speaker groups (apart from surrounds and ceiling) and I set them to be -6dB.

 

[mmares056]

The default settings seemed to make the system sound like it was a pair of massive noise cancelling headphones. It was a strange pressure sensation. It’s possible this is because I have a small room.

I think the best thing I did was remove my side surrounds as support. These are only 1.3m from my mlp.

At the moment I have support from all speaker groups (apart from surrounds and ceiling) and I set them to be -6dB.

Do you have any of your bed layer speakers supporting your subs?

 

[GregBe]

Hi all, I'm new here, I have a question about target curves as it specifically relates to ART. I know in DLBC, the rule of thumb was to apply a target curve to all speaker groups. Is that still the same thought process for ART, or does messing with base levels for speaker groups other than the subwoofer group mess with how those speakers contribute to other speakers? Thanks in advance! Greg

 

[ThELiZ]

Do you have any of your bed layer speakers supporting your subs?

Nah. My speakers are pretty small, so I leave the subs to support themselves.

 

[jhaider]

Well, I finally had time this weekend to finish up my system wiring in the new house and run a basic ART calibration on the HTP-1. I've done nothing yet except accept the ART default groupings and parameters so I could hear something, and I just did 9 measurements. I used a Neumann MA-1 microphone hooked up via an iRig Pre HD USB mic preamp. I anticipate doing a more full-blown measurement set, validations, and fine-grained tweaking over the next who-knows-how-long. But right now I just wanted to listen.

First impression is I am very impressed, honestly more than I thought I would be. For the last week or so we had been listening to a 3.0 setup with just the LCR. Because they're very good speakers with no apparent dynamic limits in this size space and they are fed stupid amounts of power, they were a very pleasant listen. But ART just transforms the upper bass. There's still a decent amount of tactility and punch, but room boom is just gone. The room sounds much larger than it is, which is just roughly 14' x 17' x 9', with 117" listening distance to L and R speakers. I'm sure over time and after a cycle of validation I'll find things to tweak, but right now I'm just enjoying finally having a real immersive system up and running again for the first time since mid-August.

For reference, the system is in a multipurpose family room with a 7.1.4h hybrid Auro/Atmos speaker layout with 4 subs*.
LCR: JBL LSR708i, Crown DCI8|600n (single wire configuration)
Sides/Rears: JBL CBT100, Crown DCI4|600n
Front/Rear Heights: JBL LSR705i, Crown DCT8|600n (single wire configuration)
Subs: 4x ~85L closed boxes, mounted in the four corners of the front wall (floor and ceiling). Floor subs are, respectively, 2x Aurasound NS15-992-4A and JBL 2288H (successor driver to the 2269H used in, inter alia, the Sub18). Height subs are each BMS 18n850. Amp and EQ for all subs is Crown DCI4|1250n.

*There's a 5th sub in the room, a Tymphany LAT-700 driver in a closed box of about 28L integrated into the media cabinet, but it is not currently hooked up. I am curious if having a bass source that's asymmetrically placed and bandwidth/level limited will make things even better. But that's something for another time...

Front of room image (from "aesthetic subs" thread):

One thing I do want to note: most consumer amplifiers are IMO inappropriate for most modern immersive systems. You really need to have level controls on each amp, because your height speakers are usually going to be both the least sensitive and the farthest away from the RSP. By dialing in the relative amp levels at Dirac's volume trim stage - i.e., adjusting the trims on the amps in Audio Architect to change the actual relative levels rather than adjusting the level slides in Dirac - I was able to keep just a 3.7dB level delta in the post-calibration channels, and save plenty of headroom for Dirac.

(Not sure why LS and RS are 0.1 ms off, lol.)

 

[dlaloum]

Hi all, I'm new here, I have a question about target curves as it specifically relates to ART. I know in DLBC, the rule of thumb was to apply a target curve to all speaker groups. Is that still the same thought process for ART, or does messing with base levels for speaker groups other than the subwoofer group mess with how those speakers contribute to other speakers? Thanks in advance! Greg

Basically think of ART as bass management - it handles the core interaction between the speakers/subs below 150Hz, and aims to achieve a neutral frequency response and treat nulls/nodes etc...

Then you have DL-RC also known as generic Dirac - that is where you do the Target curves - the Target curves are applied to the end result/output of ART

ART has substantial and fundamental impact on bass, so it is not unlikely that you may prefere a differing target curve once ART is in place...

 

[JRowland]

Hi all, I'm new here, I have a question about target curves as it specifically relates to ART. I know in DLBC, the rule of thumb was to apply a target curve to all speaker groups. Is that still the same thought process for ART, or does messing with base levels for speaker groups other than the subwoofer group mess with how those speakers contribute to other speakers? Thanks in advance! Greg

Once ART has a measurement it knows how every possible combination will interact. That’s why the “toon” has to be generated on their equipment and sent back to ours. I see a lot of chatter about target curves, ART figures out per speaker curves based on your in room response of each speaker. They’re all different for me but not different left and right sides. I’ve set them all the same and reset the Dirac default curves way too many times and I don’t believe the folks who say they have to be the same for this thing to work. I’m lucky in that I need to cut every speaker except my center so my default target curve is +5.3db L/R and +6db for my surrounds. It hits my center flat because of a dip around 100Hz, when I add a curve I see the filters fill that dip with boost (+0) if I add too much bass boost. +3db works but flat sounds the same to my ears. My subs have a bunch of boost at 20Hz but not a bunch above 100Hz so it defaults my LFE to +3.5db to get it to 120Hz where it defaults a curtain for me. TLDR I don’t hear a difference but I don’t mess with left and right differences, just “groups”. I do use different FS Low settings per speaker not caring about left or right just not target curves.

ETA I run a 250Hz curtain and only listen to music so take anything I say about target curves through that lens please.

 

[jhaider]

@Mr. Widget - carried over from your post on the "aesthetic subs" thread, where you reasonably wondered about the impact of having the front heights relatively close to the height subs. With the caveat that I haven't separately validated, here's what Dirac reports to be the average listening area response of the front JBL 705i's:

Not much different from the side/rearish 705i's, which have basically open wall or doorway on either side, and are much closer to the RSP.

 

[gepgep]

Is anyone else having problems getting ART to hit a high bass curve?

For example if I use the sliders and move the low end up to max (12Db) ART predicts it'll fall a couple of Db short at some frequencies.

I've tried varying the sub gain when taking measurements but Dirac seems to neutralise that, always setting the sub gain well below 0Db and then applying max (10Db) boost filters!

 

[EngineerNate]

Haven’t run into that, my trims in ART are near 0db.

 

[Vaporizer3644]

Is anyone else having problems getting ART to hit a high bass curve?

For example if I use the sliders and move the low end up to max (12Db) ART predicts it'll fall a couple of Db short at some frequencies.

I've tried varying the sub gain when taking measurements but Dirac seems to neutralise that, always setting the sub gain well below 0Db and then applying max (10Db) boost filters!

What does your f3 low in your groups look like?
I keep my f3 low at 80hz in all speaker groups and let subwoofer group do all the work with support level at -24db in all the speaker groups.

 

[TimoJ]

Dirac Live ART now available on Monoprice Monolith HTP-1

https://www.dirac.com/press/Monoprice-Monolith-ART

 

[EngineerNate]

Yep! It's what I'm running it on.

 

[jhaider]

Dirac Live ART now available on Monoprice Monolith HTP-1

https://www.dirac.com/press/Monoprice-Monolith-ART

So grateful to folks like you, Tom, Chuck, Markus, and of course Hobie, for staying the course and making this reality.

 

[IngMishael]

Dirac Live ART now available on Monoprice Monolith HTP-1

https://www.dirac.com/press/Monoprice-Monolith-ART

That's awesome

 

[mmares056]

Is anyone else having problems getting ART to hit a high bass curve?

For example if I use the sliders and move the low end up to max (12Db) ART predicts it'll fall a couple of Db short at some frequencies.

I've tried varying the sub gain when taking measurements but Dirac seems to neutralise that, always setting the sub gain well below 0Db and then applying max (10Db) boost filters!

Not me. ART nails the target in the bass region. I'm a benefactor of good room gain but still use f3 +20Hz for FSL on my LCR and let the subs handle the load on the low end. I use a +8dB boosted bass target curve.

 

[gepgep]

Not me. ART nails the target in the bass region. I'm a benefactor of good room gain but still use f3 +20Hz for FSL on my LCR and let the subs handle the load on the low end. I use a +8dB boosted bass target curve.

I can hit 8db, it hits the 10db curve at some points but comes up short at hitting 12db
Subs are only supported by Front L/R FSL 50hz Level -18db
Out of interest what does Dirac set your sub gain levels at when using the 8db level?

 

[mmares056]

I can hit 8db, it hits the 10db curve at some points but comes up short at hitting 12db
Subs are only supported by Front L/R FSL 50hz Level -18db
Out of interest what does Dirac set your sub gain levels at when using the 8db level?

I've tried a +10dB target and ART nails it too. Haven't tried a +12dB target though so not sure if ART will nail that one too. I have subs supported by LR/Surrounds FSL 70Hz, -5dB and Tops FLS 100Hz -4dB. Trims set by Dirac using the +8dB boosted target, Sub1 -4dB, Sub2 -3dB, Sub3 -5dB, Sub4 -3.5dB.