Dirac ART on Marantz AV10

[peng]

OK, I think I see the 'improvement' in the DB lowering of equivalent time lines below 150 htz in the ART result. By the way, those JBLs may be small but their bass response is mighty!

I would agree, that part looks obvious. The table below does say it would do time-domain decay control.

 

[Paul McNeil]

Hello all, I've made a new set of measurements, comparing DLBC versus ART. This time I've made sure that all the amps are on (not just those for the L/R stereo pair) and that I actually was measuring activated ART (see TimoJ's remarks above).

Here are the results with the AV10 processor set to 'Dolby' (the center channel is the primary high frequency responder).

My thoughts:
1) TimoJ may have been right, not about 'weird settings' but about ART not having been engaged. My apologies for that possible mistake. Because now the sub 20 htz response is cut off by ART (see the DBL curve below), as he expected. I'm not sure I am happy with this, for sure! Is there any way to avoid this when using ART?
2) Now there is a big difference in the delay curves, thanks again TimoJ for suggesting these for comparison. Clearly below 50 htz (which is the domain the side and back surrounds operate in, set by default by ART) there is an improvement, well so this old fool thinks. And this corresponds to my subjective opinion that spoken dialogue is improved (and my wife who is not a native English speaker has not been asking for subtitles since ART implementation, so it's not only me!).
3) But below 50 htz I'm not sure this is an improvement indicated by the decay curves.
4) I haven't taken in all above comments but am wondering what to do next. I saw reference to 'banks' of speakers that I did not understand.

Thanks for all the help with this!

 

[Paul McNeil]

Another question for folks testing ART on D+M gear: Can you enable LFE Distribution on the AVP/AVR with ART enabled or is this feature locked out?

It's locked out.

 

[Paul McNeil]

Thank you for sharing the results. My understanding of ART is limited, based on the little understanding I do have, I never expected noticeable results with ART over DLBC though, as DLBC is really quite effective, compared to ARC G and Audyssey Sub EQ HT, at least for the two subwoofers, full range front row scenario. As others mentioned, your DLBC FR seems very good already, so how much better it can get would depend largely on how good your speaker's bass responses are relative to the sub's, as I am sure ART would not try to push the speakers too hard.

I suspect you might get more obvious results (visibly) if you lower the subwoofers output, and/or lower the bass response a couple dB, i.e. without using too much of a so called Harmon curve. I also think ART probably would do better for the non mmp position, whereas for the mmp, in you case, I really don't think you could expect much improvements on paper. Just one note, someone mentioned DLBC works in the freq domain and ART time domain, that I don't think is correct. As I understand, DL bass control works also in the time domain (ie both domains), it is obvious, as it's main function is to do phase optimization.

I'm not sure that I agree that the results are not noticeable, not now after my latest measurements, and further listening. Dialogue is to die for, with ART engaged...

 

[Paul McNeil]

Then ART isn't active in your system. No change compared to DLBC at 20 Hz proves that.

TimoJ, please see my new measurements above. No 'weird' ART setting used, just default provided by Dirac.

 

[ban25]

Pretty sure it's locked out. This is Audy only feature and only for speakers designated as large.

In theory, if you assign your low end capable bed channel speakers to support the subs, you would get ART version of the LFE distribution, which is obviously different - and all say better.

ART is just playing cancellation waves to reduce decay below 150 Hz through destructive interference. ART is not content. LFE is low-frequency content specifically mixed into a dedicated channel by the sound mixer (either during production in case of a DD track on a Blu-Ray or in real-time in the case of a game on a console). LFE Distribution takes that content destined for the ".1" channel and feeds it back into the other channels you specify (after being attenuated by a specified value). It has nothing to do with room correction beyond the fact that it's tied to Audyssey as an implementation detail. As I understand it, StormAudio has a similar capability (as described by Gene at Audioholics) that can run alongside Dirac.

 

[Paul McNeil]

ART is just playing cancellation waves to reduce decay below 150 Hz through destructive interference. ART is not content. LFE is low-frequency content specifically mixed into a dedicated channel by the sound mixer (either during production in case of a DD track on a Blu-Ray or in real-time in the case of a game on a console). LFE Distribution takes that content destined for the ".1" channel and feeds it back into the other channels you specify (after being attenuated by a specified value). It has nothing to do with room correction beyond the fact that it's tied to Audyssey as an implementation detail. As I understand it, StormAudio has a similar capability (as described by Gene at Audioholics) that can run alongside Dirac.

I think ART is modifying all low frequency content, by, as you say, destructive interference. And it does in my system, see latest measurements above. But not evenly, across the whole 150-20 htz spectrum, not in my system, at least. The question is how to get this full spectrum effect? 'Grouping' choices? Additional subwoofers?

 

[ban25]

I think ART is modifying all low frequency content, by, as you say, destructive interference. And it does in my system, see latest measurements above. But not evenly, across the whole 150-20 htz spectrum, not in my system, at least. The question is how to get this full spectrum effect? 'Grouping' choices? Additional subwoofers?

Make sure you click the Infrabass checkbox to get <20Hz content, though there have been reports that this feature is bugged and content below 20Hz is lost regardless.

 

[ban25]

I think ART is modifying all low frequency content, by, as you say, destructive interference. And it does in my system, see latest measurements above. But not evenly, across the whole 150-20 htz spectrum, not in my system, at least. The question is how to get this full spectrum effect? 'Grouping' choices? Additional subwoofers?

If a given speaker is playing content at a given frequency, it can't simultaneously be playing a cancellation wave at or near that same frequency, at least that's my intuition. Therefore it would make sense to add additional support speakers, preferably subwoofers since it's operating below 150 Hz. I think if you had 4 subwoofers and used them exclusively as supports (e.g. don't have the mains support other speakers), that would be optimal. Perhaps this is why ART plays LFE content only on a single subwoofer while the others (up to 3 of them) play cancellation waves.

 

[Paul McNeil]

Make sure you click the Infrabass checkbox to get <20Hz content, though there have been reports that this feature is bugged and content below 20Hz is lost regardless.

Hmm, don't see that!

 

[Oddball]

ART is just playing cancellation waves to reduce decay below 150 Hz through destructive interference. ART is not content. LFE is low-frequency content specifically mixed into a dedicated channel by the sound mixer (either during production in case of a DD track on a Blu-Ray or in real-time in the case of a game on a console). LFE Distribution takes that content destined for the ".1" channel and feeds it back into the other channels you specify (after being attenuated by a specified value). It has nothing to do with room correction beyond the fact that it's tied to Audyssey as an implementation detail. As I understand it, StormAudio has a similar capability (as described by Gene at Audioholics) that can run alongside Dirac.

First, we know very little how exactly ART reproduces LFE. So below is just guessing and brain-storming, not the actual statement how it really works. I have posted in multiple ART threads that I am really interested to understand this, but nobody seems to know. The fact remains that most users experienced benefit to a smaller or larger extent from using ART.

My best guess is ART does not operate just by destructive interference, or if so, then it builds up on what DLBC has already corrected. While there could be other solutions, it for sure needs some constructive additions along the way, otherwise people with 4 subs would not be getting the SPL that they are apparently getting.

So if the subs in support group contribute positively (not just by destructive interference) to the main sub, I don't see why other large speakers would not be doing the same. Might be wrong but above makes sense at least to me.

As far as LFE distribution, there will also be constructive and destructive impact, albeit we know for sure that all distributed speakers will play the same LFE signal, not just part of it. Not all speakers will be fully in phase with each other or the subs. I have been using this for 2 years - ever since I got AV-10. I use it on 8 bed channels with -6dB or -8dB intensity depending on speaker/positioning.

The bigger problem that LFE distribution introduces is that it works only for speakers designed as large so you get into LFE+main game unless your LFE distribution speakers are really monstrous and can do full sub gig.

Therefore, would not really recommend this setup as really complicated to implement and at the end will also depend greatly on setup and room, so might actually end up being worse than standard 80hz crossover setup.

 

[TimoJ]

TimoJ, please see my new measurements above. No 'weird' ART setting used, just default provided by Dirac.

Yes, now ART is working. But around 45Hz it doesn't look good. If possible, you should move your other sub to the back of the room.

 

[peng]

I'm not sure that I agree that the results are not noticeable, not now after my latest measurements, and further listening. Dialogue is to die for, with ART engaged...

It wasn’t noticeable from your earlier graphs, but it is from the graphs you just posted.

 

[Paul McNeil]

If a given speaker is playing content at a given frequency, it can't simultaneously be playing a cancellation wave at or near that same frequency, at least that's my intuition. Therefore it would make sense to add additional support speakers, preferably subwoofers since it's operating below 150 Hz. I think if you had 4 subwoofers and used them exclusively as supports (e.g. don't have the mains support other speakers), that would be optimal. Perhaps this is why ART plays LFE content only on a single subwoofer while the others (up to 3 of them) play cancellation waves.

This makes sense, that I can implement since I can deploy 4 subwoofers. Thanks.

 

[Paul McNeil]

Yes, now ART is working. But around 45Hz it doesn't look good. If possible, you should move your other sub to the back of the room.

Yes, I have another sub (sitting unused under a pool table and am going to move it to a back location). Now, will ART recognize it as another 'Group' or lump it with the other subs? ART can tell where the sub is located, after all, or so I think!

 

[Paul McNeil]

Yes, now ART is working. But around 45Hz it doesn't look good. If possible, you should move your other sub to the back of the room.

One more question, you and another mentioned and 'infrabass' setting. I don't see this option on my Dirac app running on a MacBook. Help please!

 

[Paul McNeil]

First, we know very little how exactly ART reproduces LFE

Yes, or how best to monitor it's effects quantitatively (objectively) with REW. Nor does Dirac offer any concrete suggestions based on common hypothetical systems. Nor, as I mentioned earlier, does Dirac offer a before and after measurement that would reflect ART's benefit, and allow one to experiment objectively!!!

 

[Paul McNeil]

It wasn’t noticeable from your earlier graphs, but it is from the graphs you just posted.

Yes, probably that was my mistake on the earlier graphs. But I'd swear in subjective heaven that the dialogue clarity and realism, the spoken human voice is amazing with ART implemented, even if, in my case, not fully yet.

 

[Geertidow]

If I understand this correctly, ART is really meant to implement multiple subwoofers that are preferably not situated near the main speakers?

So far I really like listening to music coming from the front in my 2.2 setup (KEF R3M with SVS2000 all in the front) but so far I'm reading the more speakers the better.

Cool to see a new development in hifi.

 

[Paul McNeil]

If I understand this correctly, ART is really meant to implement multiple subwoofers that are preferably not situated near the main speakers?

This seems to be a theme, that at least one subwoofer should be in at the opposite end of the room as the mains and other subwoofer(s). But I don't understand the physics involved (it's not a matter of lines with arrows, as represented at the Dirac site). One subwoofer can interfere with another output no matter where the two are located in the room!!