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

[dlaloum]

ART lets the infra through "untouched"...

Meanwhile it is processing the rest of the frequency range, and messing with gain/amplitude...

If "in the raw" your audio signal has a relatively "flat" frequency respons through to infra, and with ART there is a higher level for the 20-20k range, than for below 20Hz, then Dirac has boosted the gain/level of the main frequency range - whereas the Infra has been left alone.

Messing with gain / levels might provide what you want - you need to get it to where Dirac is reducing rather than boosting your subs (roughly speaking) - that way the main sound level and your infra level will end up more or less on a par.

Right now there are no tools to help easily achieve this - it's all trial and error - I expect that over the next few months, the bass head members of our fraternity will work out a systematic means of achieving this!

It is clearly possible (demonstrably given some of the graphs shared in the various Dirac forums)... but at present it appears to be a bit of a pot luck situation.

 

[mityfang]

ART lets the infra through "untouched"...

Meanwhile it is processing the rest of the frequency range, and messing with gain/amplitude...

If "in the raw" your audio signal has a relatively "flat" frequency respons through to infra, and with ART there is a higher level for the 20-20k range, than for below 20Hz, then Dirac has boosted the gain/level of the main frequency range - whereas the Infra has been left alone.

Messing with gain / levels might provide what you want - you need to get it to where Dirac is reducing rather than boosting your subs (roughly speaking) - that way the main sound level and your infra level will end up more or less on a par.

Right now there are no tools to help easily achieve this - it's all trial and error - I expect that over the next few months, the bass head members of our fraternity will work out a systematic means of achieving this!

It is clearly possible (demonstrably given some of the graphs shared in the various Dirac forums)... but at present it appears to be a bit of a pot luck situation.

Thanks for this informative response. It makes a lot of sense. I guess this Thanksgiving I'll be cooped up messing with it trying to dial it in.

 

[srekal34]

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.

Sometimes movies still have them - as far as I remember The Dark Night has some scenes hitting 16Hz - these could only be able played at home, since no movie theatre goes that deep.

 

[dlaloum]

Sometimes movies still have them - as far as I remember The Dark Night has some scenes hitting 16Hz - these could only be able played at home, since no movie theatre goes that deep.

And there is no standard... so each movie, in terms of infrasonics, is its own individual lucky dip, which may or may not have anything there...

And that which is there, may be intentional or an accidental inclusion - which may or may not enhance the movie, and likely was not part of the mastering intention in most cases!!! (as the mastering setup is unlikely to have had subs with reach far beyond the standard... why would they!?)

 

[KenMasters]

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….

This sounds sounds similar to the bug I experienced my first time trying ART. No matter what I changed in the program, nothing actually seemed to change real world.

I reinstalled my AVR’s firmware (clearing out all previous Audyssey and Dirac cals) and ART is working properly now. Might be worth a try?

 

[ThELiZ]

I personally think I’m in a good position with my setup. I was getting flat response in my room down to 16Hz before Dirac ART. Obviously now I use ART I get roll off at 20Hz.

This has been fine for me, as I’m using a tactile transducer for anything under 30Hz, and this goes down to 10Hz. I have the best of both worlds, personally.

 

[mityfang]

This sounds sounds similar to the bug I experienced my first time trying ART. No matter what I changed in the program, nothing actually seemed to change real world.

I reinstalled my AVR’s firmware (clearing out all previous Audyssey and Dirac cals) and ART is working properly now. Might be worth a try?

Did you reinstall firmware through usb? Or factory reset the AVR from it's settings?

 

[KenMasters]

Did you reinstall firmware through usb? Or factory reset the AVR from it's settings?

I did a Factory Restore using the front face buttons (power+setup+dimmer).

 

[ThELiZ]

And there is no standard... so each movie, in terms of infrasonics, is its own individual lucky dip, which may or may not have anything there...

And that which is there, may be intentional or an accidental inclusion - which may or may not enhance the movie, and likely was not part of the mastering intention in most cases!!! (as the mastering setup is unlikely to have had subs with reach far beyond the standard... why would they!?)

This has been one of my issues with BassEQ… Are we restoring content that was never meant to be there?

This may be a misunderstanding on my part, but I’ve often watched films with BassEQ where I go “that seems a bit odd”. The bass thump (from my tactile device) doesn’t really tie up with what I’m seeing on screen.

I seem to only like having BassEQ when the movie has specifically been nerfed at 40Hz for the home audience. Master and Commander UHD being a good example!

 

[dlaloum]

I seem to only like having BassEQ when the movie has specifically been nerfed at 40Hz for the home audience. Master and Commander UHD being a good example!

What makes you think it was nerfed for the home audience?

Theatre/Cinema standards specify low end extension only to 32Hz...

A 40Hz limit for Mastering seems to make perfect sense for a theatre release!

 

[Dj7675]

What makes you think it was nerfed for the home audience?

Theatre/Cinema standards specify low end extension only to 32Hz...

A 40Hz limit for Mastering seems to make perfect sense for a theatre release!

These are pretty different in regards to bass when comparing the origninal DTS MA 5.1 track and the Atmos track. They should not be doing this.

 

[dlaloum]

View attachment 493100View attachment 493101
These are pretty different in regards to bass when comparing the origninal DTS MA 5.1 track and the Atmos track. They should not be doing this.

Yep, two quite different masterings!

But it might be best to assume that the DTS MA track was mastered for Videophile home use - as there is a far higher likelihood of a Videophiles home having subs capable of infrasonic performance, as opposed to a cinema/theatre, which is typically limited to 32Hz.

And yeah - no way of knowing which track will be recorded with (or without) infrasonics, without getting it and measuring it!! - No standards, no reference point - we are dependent on individual viewers reviews of soundtracks to uncover infrasonic "gems"

And you also have to watch out for unintended infrasonics - in many cases the mastering suite won't have infrasonic capabilities, and noise or undesired effects could be present.... which would detract from rather than enhance immersion.

It is a tangled web!

 

[Dj7675]

Yep, two quite different masterings!

But it might be best to assume that the DTS MA track was mastered for Videophile home use - as there is a far higher likelihood of a Videophiles home having subs capable of infrasonic performance, as opposed to a cinema/theatre, which is typically limited to 32Hz.

And yeah - no way of knowing which track will be recorded with (or without) infrasonics, without getting it and measuring it!! - No standards, no reference point - we are dependent on individual viewers reviews of soundtracks to uncover infrasonic "gems"

And you also have to watch out for unintended infrasonics - in many cases the mastering suite won't have infrasonic capabilities, and noise or undesired effects could be present.... which would detract from rather than enhance immersion.

It is a tangled web!

There is no valid reason, IMO, for bass in a movie to be reduced in that manner. Showing previously released movies then done in 4k/Atmos What’s next? Removed frequencies over 10khz

shows what they are doing. Here is another…

 

[dlaloum]

There is no valid reason, IMO, for bass in a movie to be reduced in that manner. Showing previously released movies then done in 4k/Atmos What’s next? Removed frequencies over 10khz

shows what they are doing. Here is another…View attachment 493106View attachment 493107

What are the tracks you are showing?

and Yes - Cinema/Theatre spec only requires F/R to 15kHz.... the 15Khz to 20Khz range might well be discarded in mastering!! (so not 10K, but 15K...)

 

[Dj7675]

Top is DTS MA 5.1/Bottom is the newer Atmos 4K release. I don’t really care about under 20hz much, but I do think they should not mess with the audible band of 20hz-20k.

 

[dlaloum]

Top is DTS MA 5.1/Bottom is the newer Atmos 4K release. I don’t really care about under 20hz much, but I do think they should not mess with the audible band of 20hz-20k.

I agree... my setup has its -3db point at around 24Hz... but uses sealed subs and sealed full range speakers, so has a gentle slope with performance still present down at 20Hz and below.

would be nice to know that whatever the "best" mastering is, all the tracks have the same extension range...

But sadly it simply isn't the case

And coming from a background of being happy with a version of whatever was released at the cinema, and not expecting the home release to have more, my expectations are lower, due to having read the cinema specifications for Dolby Atmos... I must track down the DTS cinema specs and see whether they require more!

 

[Dj7675]

I agree... my setup has its -3db point at around 24Hz... but uses sealed subs and sealed full range speakers, so has a gentle slope with performance still present down at 20Hz and below.

would be nice to know that whatever the "best" mastering is, all the tracks have the same extension range...

But sadly it simply isn't the case

And coming from a background of being happy with a version of whatever was released at the cinema, and not expecting the home release to have more, my expectations are lower, due to having read the cinema specifications for Dolby Atmos... I must track down the DTS cinema specs and see whether they require more!

The 32hz spec is really a function of the venue. It is incredibly difficult to get to 20hz in large spaces like that. Some theaters, such as IMAX appear to shoot for better (seems to be around 23/24hz from what I see). Content has been there through many many movies, even from the laser disk/dvd days. And reproducing down to 20hz of the audible range is very doeable in the home with the smaller spaces. All to common with 4K/Atmos releases is a 35-40hz filter. Not sure when they are doing it but it is quite intentional, and not appreciated by many.

 

[Descartes]

There is no valid reason, IMO, for bass in a movie to be reduced in that manner. Showing previously released movies then done in 4k/Atmos What’s next? Removed frequencies over 10khz

shows what they are doing. Here is another…View attachment 493106View attachment 493107

Interesting that the audio was better on DVD that on 4K with ATMOS why do they do that!