Active Room Treatment (ART) by Dirac

[Fahzz]

How could I tell what it is?

Today I tried changing the position of the sub from the left front corner to almost the right front corner of my room and the problem is almost gone as you can see on the pictures... well, the audio problem is gone... as this right position is not nice visually (even for me, not talking about my wife) and makes the L/R speakers not by symmetric as there is a sidboard on the right side that takes up some space and make the whole worse... so I am guessing if ART would help solving the problem that could be solved by changing the sub position =) - maybe I contact Dirac and ask for their opinion or just try it out if I see a nice offer for an AVR and the ART license for Black Friday...

Anybody know what the Black Friday/Holiday discount was last time? They want a lot of moolah at full price for the whole kit and kaboodle bundle ...

 

[lessthanjoey]

Anybody know what the Black Friday/Holiday discount was last time? They want a lot of moolah at full price for the whole kit and kaboodle bundle ...

Last time looks like 20%, has been 30% in some earlier years.

 

[Dj7675]

Well, if I check the specifications on the web for my rears, they go down to 47Hz.
If I read my chart using Dirac live (standard) the corrected curve goes down to approx. 27 Hz. (see attached).

So it is a good question if they would be helpful if I buy a new AVR and the ART license... what would you guess? That would be awesome as I dont have much space in my living room for a second sub...

I would caution relying on that 47hz. Noted on your screenshot that is estimated in room. There are output considerations and distortion considerations for ART. My experience would be, you want want a very capable speaker to support down to 40-50hz. A typical 2 way surround I wouldln’t expect to set it to support any lower than 80hz. You can mitigate this some by lowering the level the speaker supports but still I would excercise some caution with small 2 way surround speakers. Support between 100-150hz though can still be quite useful though IME.

 

[fadetoblackbs]

@fadotoblackbs:
Is your room rectangular? If yes, have you tried simulating it in REW to get some ideas about where the subs would be positioned best?

Yes it is rectangular but L-Shaped on the back, you can see the beginning of the L-Shape on one of the pictures.
At the moment I use Dirac for measurements as it also shows me the curves... does REW has an advantage? Thanks

 

[Paul McNeil]

I'm wondering if there is any consensus on how to measure objectively the performance of Dirac ART, with REW? Compared for example to performance with no Dirac correction, or even better perfomance with Dirac Live with Bass Control, the level just below ART? Does on compare REW 'Delay' curves, or 'Waterfall' plots, or something else?

 

[masterhw]

Has anyone tried using ART to cancel the noise of projector fan and ventilation/HVAC? Would it work?

Curious to see if anyone tried taking measurements with them switched on to see if the noise level would drop taking those noises out.

I thought about this a bit longer, and while a compelling idea I don’t think it’s achievable. A number of things make that type of active noise cancellation much more difficult:
1) fan noise is ongoing, which is different to cancelling reverb
2) the fan noise is broadband, with components potentially in the kHz range
3) the directionality is a challenge, I don’t think it would be possible to actively cancel it for all locations in the room. only potentially right where you’re sat.
4) the noise is not constant, even a slight change in speed would meaningfully change the acoustic properties.

ANC like we enjoy with headphones and earbuds rely on inboard microphones for 3 and 4. Dirac only knows your room’s acoustic signature and the playback signal, it is not designed to actually incorporate ongoing feedback from your room (like from a microphone near your head). This would be cool tech, but we’re just not there.

 

[Oddball]

I'm wondering if there is any consensus on how to measure objectively the performance of Dirac ART, with REW? Compared for example to performance with no Dirac correction, or even better perfomance with Dirac Live with Bass Control, the level just below ART? Does on compare REW 'Delay' curves, or 'Waterfall' plots, or something else?

As you noted, you compare the measurements in absence of other relevant factors.

 

[fadetoblackbs]

I would caution relying on that 47hz. Noted on your screenshot that is estimated in room. There are output considerations and distortion considerations for ART. My experience would be, you want want a very capable speaker to support down to 40-50hz. A typical 2 way surround I wouldln’t expect to set it to support any lower than 80hz. You can mitigate this some by lowering the level the speaker supports but still I would excercise some caution with small 2 way surround speakers. Support between 100-150hz though can still be quite useful though IME.

Thank you for this valuable feedback.
I am not sure I understand it right though.

What would be the interpretation of this graphs created by Dirac Live?
The curve that goes until the low end at around 30Hz is just theoretical but will never be achieved? That is a bit confusing for beginners like me...
If so, what would be the lowest end where the speakers work using the Dirac filter? The datasheet frequency of 47Hz? Or as you say a reference value tipical for small rears of around 80Hz?

 

[jtatknox]

Thank you for this valuable feedback.
I am not sure I understand it right though.

What would be the interpretation of this graphs created by Dirac Live?
The curve that goes until the low end at around 30Hz is just theoretical but will never be achieved? That is a bit confusing for beginners like me...
If so, what would be the lowest end where the speakers work using the Dirac filter? The datasheet frequency of 47Hz? Or as you say a reference value tipical for small rears of around 80Hz?

10-15 Hz over F3 is what people have been trying. You might try 60 Hz to make it a round number.

 

[Curvature]

Has anyone tried using ART to cancel the noise of projector fan and ventilation/HVAC? Would it work?

Curious to see if anyone tried taking measurements with them switched on to see if the noise level would drop taking those noises out.

You can cancel the low frequency components to a certain using the Psi Audio active absorbers. You'll need at least two, if not more, depending on the size of your room. https://www.psiaudio.swiss/avaa-c214-active-bass-trap/

 

[Keith_W]

You can cancel the low frequency components to a certain using the Psi Audio active absorbers. You'll need at least two, if not more, depending on the size of your room. https://www.psiaudio.swiss/avaa-c214-active-bass-trap/

Those things are a waste of time. They can't absorb sound, they EMIT sound. It's a bass cancellation scheme. It wouldn't be so bad if it was reasonably priced, but over here they cost AUD$6000 (USD$3900) each. At that price, you are better off with two subwoofers. A friend bought two of those for his massive room (6m x 11m, or 20ft x 36ft) and they did not make any measurable difference whatsoever.

 

[Kal Rubinson]

Those things are a waste of time. They can't absorb sound, they EMIT sound.

I think you are confusing them with other, earlier devices. The only time they emit sounds is when you mishandle them.

 

[jtatknox]

I think you are confusing them with other, earlier devices. The only time they emit sounds is when you mishandle them.

If you own one of these and like it I'm not going to tell you not to like it but they don't seem to do much in objective testing:

Fresh From the Bench: PSI Audio AVAA C214 Digital Active Bass Absorber

This article is a detailed review of the intriguing AVAA C214 Digital Active Bass Absorber from Swiss studio monitor and high-end speaker specialist PSI Audio. The concept is more or less the same as the AVAA C20, which PSI launched in 2017. the first commercially available analog active bass...

audioxpress.com

If you have measurements with the thing on an off that are different please share.

 

[Dj7675]

Well, if I check the specifications on the web for my rears, they go down to 47Hz.
If I read my chart using Dirac live (standard) the corrected curve goes down to approx. 27 Hz. (see attached).

So it is a good question if they would be helpful if I buy a new AVR and the ART license... what would you guess? That would be awesome as I dont have much space in my living room for a second sub...

I can relate… There are times that adding more subs just isn’t possible in a given room I don’t know what speakers you are using as surrounds just by the specs and Dirac in room measurements. Just that they are 2 way, in room spec is 47hz. But also note the port tune is 58hz. My understanding is you really never want to boost below a speakers port tune either. The general rule I have seen is +20hz over F3 anechoic to be safe. What the Dirac in room measurements don’t give you a clue about is how loud they can play without unacceptable distortion. You could do some tests with REW to figure this out to see where the speaker starts to stress or you could just be safe and do around 70-80hz. If you want to go lower, you can also mitigate things by lowering the support level as well, so maybe 60hz would be fine as well. From using ART for a couple years, my opinion is it can absolutely help a great deal with the use of sub(s) and with the speakers people already own. It is fairly attainable too with something like a Denon X3800. I am guessing there will be a Black Friday deal deal as well of 20-30% off as well if history is a good guide.

 

[Kal Rubinson]

If you have measurements with the thing on an off that are different please share.

https://www.stereophile.com/content/psi-audio-avaa-c214-active-bass-trap

 

[dlaloum]

I would caution relying on that 47hz. Noted on your screenshot that is estimated in room. There are output considerations and distortion considerations for ART. My experience would be, you want want a very capable speaker to support down to 40-50hz. A typical 2 way surround I wouldln’t expect to set it to support any lower than 80hz. You can mitigate this some by lowering the level the speaker supports but still I would excercise some caution with small 2 way surround speakers. Support between 100-150hz though can still be quite useful though IME.

I would guess that it would also depend on the level of support... if you ask it to provide 5db it might be fine, where if you ask 18db of it, it might struggle...

I do wonder whether ART (like many EQ / Room Correction systems) provides best results with a "light touch".... rather than trying a sledgehammer approach! - it may not provide the perfect textbook correction desired, but the reduction in distortion might provide a countervailing benefit which combined with ART improvements might perhaps result in a better total outcome...

 

[smygolf]

It might be mentioned in the thread, with a 5.3 setup - is there any reason to have 1 of the fronts as LFE ref instead of one of the subs ?
Using 1 of the subs right now and everything sounds and measures ok

 

[jtatknox]

It might be mentioned in the thread, with a 5.3 setup - is there any reason to have 1 of the fronts as LFE ref instead of one of the subs ?
Using 1 of the subs right now and everything sounds and measures ok

Are you talking about LFE group or the LFE reference dropdown?

 

[smygolf]

The LFE reference dropdown in sub group

 

[Flak]

I'm wondering if there is any consensus on how to measure objectively the performance of Dirac ART, with REW? Compared for example to performance with no Dirac correction, or even better perfomance with Dirac Live with Bass Control, the level just below ART? Does on compare REW 'Delay' curves, or 'Waterfall' plots, or something else?

REW will show the improvement with waterfalls (before and after)