Active Room Treatment (ART) by Dirac

[alvigg]

By good, I meant all the bells and whistles were explained. I didn't know what some of the checkboxes did etc. If I remember correctly he told you how to split subs not that it was a good idea.

 

[alvigg]

On AVS someone posted Dirac's guide which is what I was really looking for. https://media.dirac.com/sharing/fil...7xz9ah2DyxcO2myfwc_aem_-0gMn1tK5lP8aoK_nEFVmQ

 

[gorman]

If I remember correctly he told you how to split subs not that it was a good idea.

Problem is he provides wrong information about that, as I pointed out.

 

[theREALdotnet]

Problem is he provides wrong information about that, as I pointed out.

To be fair, with that Youtube video thumbnail he put up a reasonable content warning. To me it screamed: don't watch!

 

[smygolf]

To be fair, with that Youtube video thumbnail he put up a reasonable content warning. To me it screamed: don't watch!

I try to stay away from Youtubers that has this kind of content !
It is mostly false info or biased in some way.

Dirac and Storms manual says nearly all there is to know.
A couple of question got answered in here.

But i guess some are to lazy to RTFM.....

 

[AlArenal]

To be fair, with that Youtube video thumbnail he put up a reasonable content warning. To me it screamed: don't watch!

It also puts me off. But a part of being fair is realizing how YouTube's recommendation algorithm works. These days it is next to impossible to build a user base without using such titles and thumbnails. Even down to earth content creators I've been following for years do it these days. Not beacuse they like to shoot themselves making funny faces, but because they have to to stay relevant.

 

[dlaloum]

This is a feature of Denon and Marantz AV receivers.

View attachment 484427
Standard (Default):

“All subwoofers output LFE signals and bass below the crossover frequency of all the speakers.”

Directional:

“All subwoofers output LFE signals. In addition, each subwoofer outputs bass below the crossover frequency of speakers that are placed near them.”

I wasn’t aware that this feature becomes selectable with Dirac ART.

With Dirac Bass Control, the selection of Subwoofer Mode (Standard / Directional) is disabled, so I assumed it would always be inactive.

Some thoughts...

Properly delivered bass below 60Hz isn't localisable.
Having said that - the distortions, are at higher frequencies eg: 2nd harmonic of 60Hz is at 120Hz which IS localisable

And of course, many subs are being matched with bookshelves/satelites requiring the sub to cover a range reaching up to potentially as high as 200Hz

So if your main speakers (base layer) are full range (reaching down to 60hz and below), and your subs are low distortion, is there any point to setting up a "directional sub" setup?

I think in most case subs are localised due to their THD... (especially given that even high quality subs often have THD specs of 10%+)

 

[kawauso]

Some thoughts...

Properly delivered bass below 60Hz isn't localisable.
Having said that - the distortions, are at higher frequencies eg: 2nd harmonic of 60Hz is at 120Hz which IS localisable

And of course, many subs are being matched with bookshelves/satelites requiring the sub to cover a range reaching up to potentially as high as 200Hz

So if your main speakers (base layer) are full range (reaching down to 60hz and below), and your subs are low distortion, is there any point to setting up a "directional sub" setup?

I think in most case subs are localised due to their THD... (especially given that even high quality subs often have THD specs of 10%+)

I agree with your point.
In my case, Dirac ART seems to reduce distortion and smooth out the wave behavior, making the bass feel more natural and better integrated into the room.
It gives a sense of the whole space working together, while directionality where it should exist remains clear and stable.

 

[TimoJ]

Properly delivered bass below 60Hz isn't localisable.

In theory. But in practice there are vibrations near the subs and also in "extreme cases" pressure waves that will allow you to locate the sub.

 

[smygolf]

Did some testing out of curiosity - how much support is added ?
Test on left ch
LCR support down to 50hz / -10dB
Subs support to 20hz / -18dB

*edit*
Dirac measurement with screen upp - this measurement is done with screen down - loosing a bit of top end, normaly it rolls of at 16K

Left with support from R-C + rear sub - no front subs.
Only left support, C-R and rear sub - no front subs
Only left support from C-R
Everything engaged

1/6 smoothing
Group delay

Dirac

 

[dlaloum]

In theory. But in practice there are vibrations near the subs and also in "extreme cases" pressure waves that will allow you to locate the sub.

Yes, resonances and other distortions which will commonly show up as harmonics... within the localisable frequency range

 

[Frank207be]

Yes, resonances and other distortions which will commonly show up as harmonics... within the localisable frequency range

That's where I think that very large subwoofers have a huge advantage: An 18" or larger cone has to travel much less compared to a 10-12" to give the same SPL and with more excursion comes more harmonics.

 

[dlaloum]

That's where I think that very large subwoofers have a huge advantage: An 18" or larger cone has to travel much less compared to a 10-12" to give the same SPL and with more excursion comes more harmonics.

Swings and roundabouts - higher THD at higher frequencies, lower THD at lower frequencies.... I think that is the general rule of thumb relating to driver size...

hence a 10" or 8" is better suited to the 150Hz end of the ART spectrum... but may not reach down to 20Hz... a 15" will reach down to 20Hz but may not be suited to over 60Hz... (or whatever it's distortion driven limit should be!)

Perhaps we are entering an era where we might see multi driver subs combining 8" and 15" to best cover both ends of the bass spectrum?

 

[Ciobi69]

Swings and roundabouts - higher THD at higher frequencies, lower THD at lower frequencies.... I think that is the general rule of thumb relating to driver size...

hence a 10" or 8" is better suited to the 150Hz end of the ART spectrum... but may not reach down to 20Hz... a 15" will reach down to 20Hz but may not be suited to over 60Hz... (or whatever it's distortion driven limit should be!)

Perhaps we are entering an era where we might see multi driver subs combining 8" and 15" to best cover both ends of the bass spectrum?

the bigger the better for subs, no problem over 60hz

 

[dlaloum]

the bigger the better for subs, no problem over 60hz

Here is an example of a well regarded 15" sub... (https://www.audioholics.com/subwoofer-reviews/descend-dn15)

It is interesting to note that the THD Minimum is at 40Hz... (3%) and rising substantially to 11% at 125Hz, and close to 13% at 20Hz. - That THD "sweetspot" will move up as the sub driver shrinks, and down as the sub driver expands... so how "good" a specific driver size is, may be related to how much THD you are willing to accept at certain frequencies.

Note that the reviewer considers 10% THD from a sub perfectly acceptable...

However once you are at over 1% THD - chances are the Harmonics will identify the sub location - even though the main signal won't (at non localisable frequencies, below 60Hz)

With issues such as sub localisation, as well as ART, I have a feeling (yeah gut feeling, no science...) - that low THD is going to become a lot more important than it has been the last 20 to 30 years.

The giveaway to a sub's location is almost always going to be resonances and THD.... and that THD is also going to compromise ART performance to some degree.

The ART paradigm shift is only getting started!

 

[Frank207be]

View attachment 486111

Here is an example of a well regarded 15" sub... (https://www.audioholics.com/subwoofer-reviews/descend-dn15)

It is interesting to note that the THD Minimum is at 40Hz... (3%) and rising substantially to 11% at 125Hz, and close to 13% at 20Hz. - That THD "sweetspot" will move up as the sub driver shrinks, and down as the sub driver expands... so how "good" a specific driver size is, may be related to how much THD you are willing to accept at certain frequencies.

Note that the reviewer considers 10% THD from a sub perfectly acceptable...

However once you are at over 1% THD - chances are the Harmonics will identify the sub location - even though the main signal won't (at non localisable frequencies, below 60Hz)

With issues such as sub localisation, as well as ART, I have a feeling (yeah gut feeling, no science...) - that low THD is going to become a lot more important than it has been the last 20 to 30 years.

The giveaway to a sub's location is almost always going to be resonances and THD.... and that THD is also going to compromise ART performance to some degree.

The ART paradigm shift is only getting started!

Low THD indeed is very important. I can't give distortion numbers of my overdimensioned subs but front and back give support up to 116Hz and none of them are localizable. Only at reference level they start vibrating the seats through acoustic pressure but that's obviously what I want.

 

[Oddball]

Swings and roundabouts - higher THD at higher frequencies, lower THD at lower frequencies.... I think that is the general rule of thumb relating to driver size...

hence a 10" or 8" is better suited to the 150Hz end of the ART spectrum... but may not reach down to 20Hz... a 15" will reach down to 20Hz but may not be suited to over 60Hz... (or whatever it's distortion driven limit should be!)

Perhaps we are entering an era where we might see multi driver subs combining 8" and 15" to best cover both ends of the bass spectrum?

That is an interesting thought. Subs with different drivers were previously somewhat difficult to integrate, but now we have ART so that problem could go away. Not a good person to try that as have 6 x 13.8" drivers .

 

[Frank207be]

I also want to add that I once bought a Klipsch SW-115 as a second subwoofer in the back of the room. A fantastic subwoofer for the price but it didn't work for me. I never succeeded to integrate it in my set and improve the bass evenness and quality. Despite it's proximity to the back seat it simply couldn't keep up with my 4x 15" DIY front sub. As soon as I cranked up the SPL I could localize it and when I turned it down a bit it went MIA.

Soon after I built dual B&C 21SW152 and with the arrival of my Denon I added dual SBA NERO 21SW1100D and dual Faital Pro 18XL1800. I'm extremely happy with them and and how they melt together with ART.

Also curious how a new 21pt measurement will improve ART. At the moment our house is getting a much needed and significant insulation upgrade that'll be ready in a few weeks so I'm already very happy that the older measurements gives such good results. When all works are done I can finally focus on making a new measurement jig (boom stand replacement) and take a deep dive into the Dirac rabbithole

 

[Oddball]

I also want to add that I once bought a Klipsch SW-115 as a second subwoofer in the back of the room. A fantastic subwoofer for the price but it didn't work for me. I never succeeded to integrate it in my set and improve the bass evenness and quality. Despite it's proximity to the back seat it simply couldn't keep up with my 4x 15" DIY front sub. As soon as I cranked up the SPL I could localize it and when I turned it down a bit it went MIA.

Soon after I built dual B&C 21SW152 and with the arrival of my Denon I added dual SBA NERO 21SW1100D and dual Faital Pro 18XL1800. I'm extremely happy with them and and how they melt together with ART.

Also curious how a new 21pt measurement will improve ART. At the moment our house is getting a much needed and significant insulation upgrade that'll be ready in a few weeks so I'm already very happy that the older measurements gives such good results. When all works are done I can finally focus on making a new measurement jig (boom stand replacement) and take a deep dive into the Dirac rabbithole

Now that's some serious fire-power. Not sure if ART rabbit hole is that deep though. At least in my system it seems that parameter adjustments (like support levels, even grouping to some extent) don't really produce any significant effect. IMO the biggest impact is the shelf/curve. I am not complaining - I actually prefer it this way. More listening, less tweaking.

Good luck tweaking .

 

[smygolf]

i am not done yet, still want to find the limits.
This is a focused measurement, 20cm between the points - makes the higher freq Very straight.
But you have to have your head in a vice.
Also it makes things easier for Dirac but it still shows the important bits.

I forgot to change the curtain on 1 measurement that is why the highs falls as a stone.


1: Left with CR + subs supporting (identical result to nr4)
2: LFE
3: L with CR support but no subs
4: L with only subs supporting (identical result to nr 1)
5: L with no support at all and no subs

GD/waterfall looks more or less the same, so in my case i do not really need LCR support.

1: Left with CR + subs supporting

4: L with only subs supporting