Why Dirac ART has no infrasonic vs DLBC? My room measurements

[mityfang]

My setup is 5.3 system. 2 VTF TN1's in opposite corners and an SVS SB16 Ultra in another corner. All fed through an X4800H in a small 13'x14' room. My MLP is about 1/3 from the back wall. Speakers are Kef R7 Meta, R6 Meta, and Q Concerto. Measurements taken on a Umik 1. Room has extensive acoustic treatment (4 inch rockwool panels I DIY'd) and some amazon foam wedges.

I did check the infrasonic box on my sub group in ART and set my support speakers appropriately (Center removed from support). All subs grouped together. Set my FS Low and FS High per speaker based on their capabilities and tuned it extensively this past weekend. I'm pleased with the results for movies. But DLBC has much more infrasonic extension as measured at my MLP in REW. And I can hear this too in scenes like the opening to Edge of Tomorrow. Has this been your experience? ART is green, DLBC is Red. No smoothing applied. I've attached the zipped .MDAT file as well. Repeated ART measurement 5 times.

 

[smygolf]

It is the way ART works

 

[mityfang]

That's unfortunate. ART was intended for movie theaters and movies are where you would primarily get infrasonic LFE. The technology works great, my home theater is the closest it's ever been to an actual movie theater. I really like it but what a miss. I wonder if its a limitation of the technology or something the engineers can just update to allow. I can imagine making subs do double duty to cancel infrasonic frequencies is asking quite a lot from them.

 

[srekal34]

There is no infrasonic in cinema though, even imax steeply rolls off after 35Hz

 

[TimoJ]

ART was intended for movie theaters

No it wasn't. Originally it was for cars, now later for home audio.

 

[staticV3]

@mityfang See here:

How-to: Infra-bass bypass in ART | Dirac Live Active Room Treatment

Problem formulationDirac Live ART implicitly enforces a steep high-pass filter at 20 Hz, with the consequence that any content below 20 Hz present in a recording would not make its way out to any of the speakers, including infra bass-capable subwoofers. For reference, neither Dirac Live Room...

helpdesk.dirac.com

 

[smygolf]

If there was an option to have a curtain at the low end it might help those who can reach below 20hz


*edit*
Also dotted target curve that forces the respons up might also help.

 

[mityfang]

No it wasn't. Originally it was for cars, now later for home audio.

I thought ART was intended for home cinema? I know Dirac Live is popular in the car audio but didn't realize ART was used for it too. Kinda cool though I'm not sure how effective it would be in such a noisy environment.

 

[mityfang]

@mityfang See here:

How-to: Infra-bass bypass in ART | Dirac Live Active Room Treatment

Problem formulationDirac Live ART implicitly enforces a steep high-pass filter at 20 Hz, with the consequence that any content below 20 Hz present in a recording would not make its way out to any of the speakers, including infra bass-capable subwoofers. For reference, neither Dirac Live Room...

helpdesk.dirac.com

I did check the infrasonic box. I measured and wasn't getting much below 20hz. So I ran Dirac calibration again. And again. And again. After rerunning the calibration 5 times and checking the infrasonic box every time, I'm still not getting much below 20hz. So I came here to see if it's just an ART thing. I realized there's another thread about ART that's actually pretty active so will sift through and see if I can find something.

 

[TimoJ]

I thought ART was intended for home cinema?

Yes, for home cinema and home audio. But you said movie theaters, so I thought you meant commercial movie theaters.

 

[smygolf]

I did check the infrasonic box. I measured and wasn't getting much below 20hz. So I ran Dirac calibration again. And again. And again. After rerunning the calibration 5 times and checking the infrasonic box every time, I'm still not getting much below 20hz. So I came here to see if it's just an ART thing. I realized there's another thread about ART that's actually pretty active so will sift through and see if I can find something.

How much infra do you have before calibration ?
Not sure but i guess that if Dirac sense the measurement does not reach hz infra is no go.

DLBC do like to ad infra, even a bit to happy.
My subs drops as a rock at 20-22hz but with DLBC i can reach 15hz.
That wold kill them above 95dB

 

[staticV3]

I did check the infrasonic box. I measured and wasn't getting much below 20hz. So I ran Dirac calibration again. And again. And again. After rerunning the calibration 5 times and checking the infrasonic box every time, I'm still not getting much below 20hz. So I came here to see if it's just an ART thing. I realized there's another thread about ART that's actually pretty active so will sift through and see if I can find something.

The blog post shows an REW measurement with ART extending to about 14Hz.

If yours drops off at 20Hz no matter what, the chances are the bypass is not configured correctly.

 

[mityfang]

The blog post shows an REW measurement with ART extending to about 14Hz.

If yours drops off at 20Hz no matter what, the chances are the bypass is not configured correctly.

I saw in the other thread that someone does have usable infrasonic in their REW measurement using ART. I know I've checked the bypass. Here's a photo of my Dirac ART calibration for my sub group. Maybe it's a bug. Or maybe my subs just aren't capable enough. Not sure really.

How much infra do you have before calibration ?
Not sure but i guess that if Dirac sense the measurement does not reach hz infra is no go.

DLBC do like to ad infra, even a bit to happy.
My subs drops as a rock at 20-22hz but with DLBC i can reach 15hz.
That wold kill them above 95dB

I'm not sure but HSU's VTF-TN1 port tuning is 15hz in extended mode (which is what i have them setup as). Audioholics measured them and they hit 16 hz anechoically so I figured with room gain I could dig even a bit deeper. My Dirac calibration results above show all my subs seem capable enough. Not sure what's going on. Maybe I messed something up.

 

[staticV3]

I saw in the other thread that someone does have usable infrasonic in their REW measurement using ART. I know I've checked the bypass.

Do you get a different result with ART+Bypass On vs ART+Bypass Off?
If not, then the issue lies with Dirac (programming or configuration).

Or maybe my subs just aren't capable enough. Not sure really.

Doesn't this prove that they are?

 

[smygolf]

Only thing i can think of is to use the sub that plays furthest down should be LFE, rest working as support. (purple in the measurement)
-24dB on support offcourse, i would also try values in the other end just for the sake of it, like -5dB

 

[mityfang]

Do you get a different result with ART+Bypass On vs ART+Bypass Off?
If not, then the issue lies with Dirac (programming or configuration).


Doesn't this prove that they are?
View attachment 492841

I think they are sufficient especially in my relatively small room. With DLBC they can play low enough with minimal distortion validated through REW. When I get home I'll test with the bypass unchecked and see if that makes a difference. Never did that actually. As it stands I still really enjoy ART. Most content doesn't have infrasonic so it doesn't really bother me. And even if it does it's not horrible. Just wanted to see if others had similar experience and rule out if it's a setup error or something within ART. Thanks for the help!

Only thing i can think of is to use the sub that plays furthest down should be LFE, rest working as support. (purple in the measurement)
-24dB on support offcourse, i would also try values in the other end just for the sake of it, like -5dB

I'll try this as well. I did run a calibration with two subs (left the SB16 Ultra out since it was the least capable) and again, DLBC had much lower extension whereas ART rolls off at 20hz. With only 2 subs it was a lot less even so elected to keep all 3. But I'll play with ungrouping and the level of support. Appreciate the tip.

 

[mityfang]

There is no infrasonic in cinema though, even imax steeply rolls off after 35Hz

Wow, I never knew that. I always figured there’d be some kind of payoff at the end of this rabbit hole. Guess I’m chasing infrasonics purely for the love of the game at this point.

 

[staticV3]

Wow, I never knew that. I always figured there’d be some kind of payoff at the end of this rabbit hole. Guess I’m chasing infrasonics purely for the love of the game at this point.

You can restore(ish) infrasonics to soundtracks using BassEQ.

If you have a capable system and forgiving neighbors, then it's a no-brainer.

 

[mityfang]

Welp, I tried infrasonic bypass on and off. Ran REW just now and the bass sweep looks identical. I tried ungrouping my SB16 Ultra and ticked infrasonic only on my VTF TN1's and bass sweep looks identical. Added a 6dB harmon curve and the frequency response looks identical except +6dB. Tried decreasing intra-subwoofer support and looks identical. I cannot replicate Dirac's Infrasonic REW measurements no matter what i do. In fact, my measurements barely change unless I change the target curve. I'm thinking its a bug in the software or the combination of software and components I'm using. That or I did something wrong but I can't imagine what. Thanks for all the suggestions and help. Not really upset since I have an essentially flat response down to 20hz. Just posting to share my results in case future members come across it.

Red: ART Infra Bypass unchecked
Green: ART Infra Bypass checked

Blue: Harmon +6
Teal: sB16 Ungrouped, Harmon +6

 

[dlaloum]

That's unfortunate. ART was intended for movie theaters and movies are where you would primarily get infrasonic LFE. The technology works great, my home theater is the closest it's ever been to an actual movie theater. I really like it but what a miss. I wonder if its a limitation of the technology or something the engineers can just update to allow. I can imagine making subs do double duty to cancel infrasonic frequencies is asking quite a lot from them.

If you look up the standards for Dolby Cinema's you will find that the LFE requirements only extend to 32Hz.... yeah it does not even require 20Hz, let alone infrasonics.

Mastering for cinema's is based on the standards... so any infrasonic content is basically a "bonus" - obviously some cinemas may have audio systems that have capabilities that extend beyond the minimum standard for Dolby / DTS / THX certifications....

But the certifications and the audio mastering that is based on them, doesn't include infrasonics.

Also in terms of intent - I don't believe I have seen any mention of ART focusing on the cinema/theatre marketplace - it appears focused on enabling cinema equivalent performance within smaller, more difficult, compromised spaces...ie: Home and Cars