Active Room Treatment (ART) by Dirac

[kawauso]

It depends on you system i would say.

I have more or less all out active system and to ad active crossovers and amps is done in a jiffy
With it i also have peq and rephase capabilities.

It is not that i need more low end, but more low end will let ART have more to work with.
As is, surrounds only gives support between 100-150hz @ -10dB
I could offcourse swap them to some JBL floor stander but where is the fun in that
Peerless as you use your self or even Eminence Lab12 should do the jobb.
Small ported cab tuned to 20-30hz

From the perspective of efficient support, I would prioritize subwoofer channels first, but as a next step, reinforcing full-range speakers using methods such as a +1-way approach can also be effective.

Large JBL speakers work extremely well even at very high output levels with a 50–150 Hz support range.

In my Reference 1 Meta system, I use a much narrower 140–150 Hz support range for high-volume listening, and I am fully satisfied with the results.

I suspect the solid localization comes from having four subwoofers well balanced and evenly placed in the four corners of the room.

 

[Oddball]

Talking mac vs pc is very 90's.

Realy? Which one do you have or prefer? Think about REW setup as well if not anything else.

 

[kawauso]

Greetings Kawauso, with a double bow, we have been sourly missing you, but understand that there is life outside or the forum and hope you are getting the best of it.

Not my video - and I noted on the contrary.

I have some reservations and they are along the same lines as you note. While you could use the ART support in the surround/sub setup, that would have to be for every group so you don't loose on the sub impact, which will not at least theoretically be right for the surrounds that would need to support all the speaker groups. Filter limitations aside. But we don't have an idea of what he really did.

While anything is possible in a given room or setup, to be blunt, the guy is selling this little B 10" sub. A miracle just with a twist of B sub output. But that's not now ART works in general and no directional wonders will happen when you have full range speakers. They already do happen way before that. Happy to discuss in detail if any members are interested. But in the meantime, don't be buying the small subs for your bed channels just on the back of this video.

“Your video” came out a bit odd in my English — what I really meant was the video you shared. Thanks for bringing up a good topic.

ART does seem to have that quality where it can still sound good even with slightly unconventional settings. In my case, I’m already quite satisfied with just some light shelving adjustments.

 

[Oddball]

“Your video” came out a bit odd in my English — what I really meant was the video you shared. Thanks for bringing up a good topic.

ART does seem to have that quality where it can still sound good even with slightly unconventional settings. In my case, I’m already quite satisfied with just some light shelving adjustments.

Well the English level of the guy in video is at best medium rare . Somewhat because that his gestures and facial expressions don't have anything to do with that culture. So in all does not add up.

I completely agree with you that in large setups nothing more than shelves is really needed if you chose you support range and intensity up to your speakers capability. Large would be 4 subs at least to 20h, and beds to 50hz.

I find that ART is not really picking up my LCR at 50hz (even though they can go to 30hz F3 @85db), which is smart. Subs can do a much better job at that frequency. Taking about the "directional subs" in ART concept is really not possible. ART just won't go for it in traditional way. If the Mad guy has a Fran movie as reference, my reference is Masters of the Air. That one has 3D bass coded in all the speakers, including Atmos. And in my system they do follow the visual clue - go figure.

 

[Dj7675]

Taking about the "directional subs" in ART concept is really not possible.

This certainly could be true. There is some documentation and people using various support strategies for directional bass with ART. Here is one piece of info from Dirac..

How should one think in the case of wanting to set up directional bass? | Dirac Live Active Room Treatment

helpdesk.dirac.com

And here

https://www.avsforum.com/threads/dirac-live.3137722/page-1494

One user there, Lombardi9905 had this to say which I thought was interesting. I have not tried it myself, nor know if it works, or is a good idea. However it could be of interest…
“ And so .... if you separate the subs each into their own group, and separate speakers each into their own group, you can assign specific subs to support specific speakers over specific ranges. Essentially this directs ART on how to do bass management for the other speakers, effectively defining crossover points, and even allowing bass management to be in stereo if you wish. For example, if you have two subs in the front of the room left and right, you can have the left sub play left channel bass up to whatever crossover point you want ... 60-70-80Hz or whatever. And the right sub can play right channel bass. If you have small tops that only play down to 110Hz, then front speakers can play their bass - left and right - from 110 down to 80 and THEN cross to the left/right subs respectively .... if you want to do this, it works ...”

 

[Oddball]

This certainly could be true. There is some documentation and people using various support strategies for directional bass with ART. Here is one piece of info from Dirac..

How should one think in the case of wanting to set up directional bass? | Dirac Live Active Room Treatment

helpdesk.dirac.com

And here

https://www.avsforum.com/threads/dirac-live.3137722/page-1494

One user there, Lombardi9905 had this to say which I thought was interesting. I have not tried it myself, nor know if it works, or is a good idea. However it could be of interest…
“ And so .... if you separate the subs each into their own group, and separate speakers each into their own group, you can assign specific subs to support specific speakers over specific ranges. Essentially this directs ART on how to do bass management for the other speakers, effectively defining crossover points, and even allowing bass management to be in stereo if you wish. For example, if you have two subs in the front of the room left and right, you can have the left sub play left channel bass up to whatever crossover point you want ... 60-70-80Hz or whatever. And the right sub can play right channel bass. If you have small tops that only play down to 110Hz, then front speakers can play their bass - left and right - from 110 down to 80 and THEN cross to the left/right subs respectively .... if you want to do this, it works ...”

This appears to be correct. One could do that, provided sufficient filters. How would that impact the overall balance of the system is probably difficult to say as it is room and system dependent. But in general it is a terribly bad idea.

I can't really see a point of people pushing for the directional bass in ART. That just comes naturally without the need to invent it if you have speakers that are capable of providing those low end clues. 50hz is probably better than 80hz on your bed and Atmos, but even at the higher end of that range (probably even a bit higher, but don't have first experience with that) can't see that you would need to seek such drastic solutions. 2 or 4 subs will support each other and other groups way better than if you separate them.

This reminds me of Audy or Storm directional sub solutions. It was horrific if your room was for whatever reason not exception to that rule. Storm could tune that in better than Audy, but still was less than optimal.

At the higher level what comes to my mind is the Beautiful Mind movie and Mr. John Nash and his contributions to game theory. Play together not apart. ART has a great plan so no need to worry. Coming up with a better plan is going to be difficult.

 

[Dj7675]

This appears to be correct. One could do that, provided sufficient filters. How would that impact the overall balance of the system is probably difficult to say s it is room and system dependent. But in general it is a terribly bad idea.

I can't really see a point of people pushing for the directional bass in ART. That just comes naturally without the need to invent it if you have speakers that are capable of providing those low end clues. 50hz is probably better than 80hz on your bed and Atmos, but even at the higher end of that range (probably eiven a bit higher, but don't have first experience with that) can't see that you would need to seek such drastic solutions. 2 or 4 subs will support each other and other groups way better than if you separate them.

This reminds me of Audy or Storm directional sub solutions. It was horrific if your room was for whatever reason not exception to that rule. Storm could tune that in better than Audy, but still was less than optimal.

At the higher level what comes to my mind is the Beautiful Mind movie and Mr. John Nash and his contributions to game theory. Play together not apart.

It could be terrible. After I get my system up and get a configuration that I am happy with in a more standard way, I may attempt a variation of this in my room to compare with. LFE is mono so I don’t care about it because it is not directional in nature anyway. In theaters all LFE is behind the screen. However, in theaters, they generally have surrounds crossed to their own subs which create a full range channel. I believe more full range”ish” speakers are better because movie content is tied to channels (that is not LFE) and I do believe this can enhance the experience. When I changed from smaller surrounds to speakers that can do high output at 40-50hz, the experience is just better IMO. Having bass come from the area of the channel designated by the creator, is beneficial, just like having more capable speakers. Denon/Marantz directional bass I think are flawed as well IMO. However, ART is fundamentally different and it may still work with some directional bass setup and still provide the outcomes ART was designed to achieve. I think it is interesting to consider, test, and compare although it certainly may not work.

 

[middlemarch]

This question is not ART specific. But that's what I'm working on at the moment. I currently have four subs being driven by my A1H. Two of these are HSUs with built in amps. The other two are sealed units being driven directly from a Crown amp, which is driven by the A1H. The HSU units don't have built in DSP, but do have some form of processing that affect the frequency response (variable Q and possibly other filtering). The sealed subs are running "bare naked" so reflect the standard 12dB/octave slope of a sealed unit.

Dirac then measures and does it's magic based on what it measured. The target curve is being achieved, it seems with no complaints.

So my question. I have a couple of miniDSPs in a drawer doing nothing. Would there be any benefit to inserting one of them between the A1H and the Crown and putting in a low shelf to try to somewhat counteract the 12dB rolloff curve? Would Dirac somehow have more to work with in that case? Or is this totally redundant to what it's doing anyway and not worth thinking about?

 

[kawauso]

This question is not ART specific. But that's what I'm working on at the moment. I currently have four subs being driven by my A1H. Two of these are HSUs with built in amps. The other two are sealed units being driven directly from a Crown amp, which is driven by the A1H. The HSU units don't have built in DSP, but do have some form of processing that affect the frequency response (variable Q and possibly other filtering). The sealed subs are running "bare naked" so reflect the standard 12dB/octave slope of a sealed unit.

Dirac then measures and does it's magic based on what it measured. The target curve is being achieved, it seems with no complaints.

So my question. I have a couple of miniDSPs in a drawer doing nothing. Would there be any benefit to inserting one of them between the A1H and the Crown and putting in a low shelf to try to somewhat counteract the 12dB rolloff curve? Would Dirac somehow have more to work with in that case? Or is this totally redundant to what it's doing anyway and not worth thinking about?

Using DSP can make it possible to extend the usable low-frequency range of sealed subwoofers. However, if Dirac correction alone already reaches the target frequency response, I don’t think pre-processing with a miniDSP is strictly necessary.

That said, if you happen to have a spare miniDSP, I would recommend using an LPF to limit the high-frequency content sent to a passive woofer, as this can help reduce residual noise.

 

[middlemarch]

Using DSP can make it possible to extend the usable low-frequency range of sealed subwoofers. However, if Dirac correction alone already reaches the target frequency response, I don’t think pre-processing with a miniDSP is strictly necessary.

That said, if you happen to have a spare miniDSP, I would recommend using an LPF to limit the high-frequency content sent to a passive woofer, as this can help reduce residual noise.

Wouldn't the A1H sub output channels already limit the higher frequency content? I know the LFE channel rolls off after 120Hz, but don't know about the rest of the bass, since ART doesn't use crossovers per se.

 

[smygolf]

Using DSP can make it possible to extend the usable low-frequency range of sealed subwoofers. However, if Dirac correction alone already reaches the target frequency response, I don’t think pre-processing with a miniDSP is strictly necessary.

That said, if you happen to have a spare miniDSP, I would recommend using an LPF to limit the high-frequency content sent to a passive woofer, as this can help reduce residual noise.

Thing with ART is that you do not really know how it will handle the subs
If you can safely push a sub with a minidsp, go for it but do not take for granted that ART will use the added low end

 

[seashell]

Why would one need an external LPF with ART? Put any subs you want to LPF in a group and set F-support high to a low frequency for that group in any channels it is supporting. That will LPF all the data from those channels to those subs. If you also want to LPF the LFE channel itself you can do that with a target curve on the LFE group. You'd only need to do that if the sub you want to LPF is the one in the LFE group.

 

[middlemarch]

Why would one need an external LPF with ART? Put any subs you want to LPF in a group and set F-support high to a low frequency for that group in any channels it is supporting. That will LPF all the data from those channels to those subs. If you also want to LPF the LFE channel itself you can do that with a target curve on the LFE group. You'd only need to do that if the sub you want to LPF is the one in the LFE group.

I suppose kind of by definition the fact ART FSH is max 150Hz implies that is pretty much the low pass upper limit. Of course that's the max frequency ART will use in support of another. Still very confusing to me what signal, other than support, each speaker will produce. It seems there is the support task, and the "play your channel" task.

What happens when a speaker that's given a support range of 80 to 150Hz, let's say, is sent a signal at 40Hz? In the old way that 40Hz is routed to the subs by the crossover, but ART doesn't exactly use crossovers. But there must still be bass routing going on as well. Very confusing to me still...

 

[Frank207be]

I have a 106Hz 24dB/oct LPF on all my Crown XLS2502. This removes residual ground loop hum, avoids midrange bleeding into my back subs and removes a bit of the midrange efficiency of my subs to favor low extension. Works great for me although i might experiment with higher LPF later on.

First I need to tear apart all electrical connections in my set to trace down the source of the hum.

 

[kawauso]

I suppose kind of by definition the fact ART FSH is max 150Hz implies that is pretty much the low pass upper limit. Of course that's the max frequency ART will use in support of another. Still very confusing to me what signal, other than support, each speaker will produce. It seems there is the support task, and the "play your channel" task.

What happens when a speaker that's given a support range of 80 to 150Hz, let's say, is sent a signal at 40Hz? In the old way that 40Hz is routed to the subs by the crossover, but ART doesn't exactly use crossovers. But there must still be bass routing going on as well. Very confusing to me still...

The fact that ART only operates up to 150 Hz does not make it equivalent to an LPF.

Why not actually check for noise and see what happens in practice?

 

[seashell]

What happens when a speaker that's given a support range of 80 to 150Hz, let's say, is sent a signal at 40Hz? In the old way that 40Hz is routed to the subs by the crossover, but ART doesn't exactly use crossovers. But there must still be bass routing going on as well. Very confusing to me still...

If a channel's self support is 80 to 150 Hz, that channel will be high pass filtered at 80 Hz to all speakers in that channel's group. So a signal at 40 Hz would be severely attenuated. If there are other speakers supporting that channel with support lower than 80 Hz they will play the 40 Hz content. This is the classic subs supporting small speakers situation, except in art each sub gets a unique filter for each speaker it supports as opposed to a singular cross over. Hopefully there's more than one sub (or other bass capable speaker) supporting each small speaker so you get the MIMO equalizer benefit.

If there are no other speakers with lower support for that channel the 40 Hz content would be effectively lost. I know this because ART decided not to use my subs as support for any channel when I tried it on the Marantz AV10 and since all the non-sub groups were set to the default 50 Hz all the content below 50 Hz was gone and it sounded bad.

You can see what ART is doing if you turn on the filter view. For a given channel you can see the filters to every speaker involved in the channel, both the ones in the channel's group and all the supports from other groups.

 

[Oddball]

It could be terrible. After I get my system up and get a configuration that I am happy with in a more standard way, I may attempt a variation of this in my room to compare with. LFE is mono so I don’t care about it because it is not directional in nature anyway. In theaters all LFE is behind the screen. However, in theaters, they generally have surrounds crossed to their own subs which create a full range channel. I believe more full range”ish” speakers are better because movie content is tied to channels (that is not LFE) and I do believe this can enhance the experience. When I changed from smaller surrounds to speakers that can do high output at 40-50hz, the experience is just better IMO. Having bass come from the area of the channel designated by the creator, is beneficial, just like having more capable speakers. Denon/Marantz directional bass I think are flawed as well IMO. However, ART is fundamentally different and it may still work with some directional bass setup and still provide the outcomes ART was designed to achieve. I think it is interesting to consider, test, and compare although it certainly may not work.

Looking forward to your experience. Couple of points.

Movie releases are different than home releases - or at least supposed to be. From a master movie soundtrack studios do theatrical audio to match Dolby spec (e.g. cutoff at 31.5hz for front subs, roll of of HF at some 5kh or so, etc.) and separately do home release. How much effort they put in home release mix and what actually ends up there is widely different. Streaming productions tend to do a good job in big releases, although some are just mixed for TVs and at best soundbars. My reference for directional bass as I noted is Masters of the Air. Air battles and explosions are actually 3D, including Atmos.

Bass below 80hz (even above that to some extent, this is individual) is hardly localizable. What could be localized is the sound pressure (different than sound wave itself) and direction where it comes from. This is best felt in smaller rooms with high powered sub. In my second setup I added another Arendal 1728 2V for that reason. One was clearly localizable and moving air / creating pressure at some 2.5m distance to MLP. Adding another one fixed that as both were placed symmetrically at the positions that front wides would have.

Now, while it could be beneficial to experience the direction of the pressure coming from a distinct channel strapped with a separate sub, that leads back to directional bass problems which is lack of SPL and uniformity of bass response as well as in ART concept lack of decay control. Just to be clear this would be a situation where you don't support your e.g. surrounds with dedicated subs with other subs. Once you engage other subs as support this directional pressure will be gone for sure.

So what to do? Hmm, couple things come to my mind. First is to try just pure directional bass sans any support from other subs or speakers (likely not optimal in most rooms). Second, try to support the surrounds and dedicated surround subs with other capable speakers to even out FQ response and reduce decay to the extent possible - but not engage subs. This would likely work better that first option in a system capable of decent support. Third, just include subs to support the surrounds with dedicated subs.

For the third option the hope would be that ART assigns more heavy duty low end to the surrounds and dedicated surround subs so that they become more localizable. I noted hope, as I don't know what would be a way to force ART to do so. It will likely not provide the sound pressure effect, but might (or not) help with further localization clues. Might be an interesting feature though if one could have another box to check with ART - prefer the source channel?

There is a big thread on AVS forum on directional bass so the ones interested in it can check it out. Last time I was there was pre D&M ART and most of it was using different techniques. REL was also always big on strapping on the subs to all speakers to make them full range, so that is another area to explore for information purposes.

 

[mmares056]

I'm as happy as can be as well and have a 3rd subwoofer on its way to support my surrounds

That's awesome. A third sub will definitely give ART more options to work with and do its magic. By now, It is a well known fact that the more speakers with lower extension capability the better ART can perform. I'm lucky in a sense that I get good room gain and I can get away with setting the FSL at either, 50Hz or 60Hz for my bed layer speakers. I wasn't taking advantage of the room gain and I had been a little conservative going with F3 +20Hz to avoid speaker damage. But after further experimentation and watching a few more videos where Joss confidently answers questions regarding room gain and FSL I decided to use lower support if it is there. I'm not leaving anything on the table as far as room gain goes.

With that said, currently I'm switching back and forth between two configs. For one config I use FSL of 50Hz for bed layers 70Hz Tops, everything supports everything at -18dB support level except Tops. Tops don't support subs. For the other config, I use FSL 60Hz bed layers, and 80Hz Tops, -18dB support level and everything supports everything too except Tops. So, when I listen at higher volumes I select FLS 60Hz config and FSL 50hz config when listening at lower volume levels. When I say lower volume levels I'm talking about -30 MV. and -26 MV for higher volume levels. I haven't noticed any distortion issues at these volume levels and corresponding group FSL and support levels. I also use REW to check distortion for a peace of mind.

 

[JRowland]

That's awesome. A third sub will definitely give ART more options to work with and do its magic. By now, It is a well known fact that the more speakers with lower extension capability the better ART can perform. I'm lucky in a sense that I get good room gain and I can get away with setting the FSL at either, 50Hz or 60Hz for my bed layer speakers. I wasn't taking advantage of the room gain and I had been a little conservative going with F3 +20Hz to avoid speaker damage. But after further experimentation and watching a few more videos where Joss confidently answers questions regarding room gain and FSL I decided to use lower support if it is there. I'm not leaving anything on the table as far as room gain goes.

With that said, currently I'm switching back and forth between two configs. For one config I use FSL of 50Hz for bed layers 70Hz Tops, everything supports everything at 18dB support level except Tops. Tops don't support subs. For the other config, I use FSL 60Hz bed layers, and 80Hz Tops, 18dB support level and everything supports everything too except Tops. So, when I listen at higher volumes I select FLS 60Hz config and FSL 50hz config when listening at lower volume levels. When I say lower volume levels I'm talking about -30 MV. and -26 MV for higher volume levels. I haven't noticed any distortion issues at these volume levels and corresponding group FSL and support levels. I also use REW to check distortion for a peace of mind.

I currently can’t keep left and right subs without them supporting each other, I mean I can but it’s not as good. I’ve finally fallen in love with a tight spread/low decay. Hoping the 3rd sub right behind me can triangulate support so I can experiment more with sub left and right separation as well as experimenting with the front/rear more. I’m thinking I’ll add a 4th and go sidewall on either side of my chair eventually, it’s fun and my wife doesn’t hate me for it


It’s funny you mention the videos, I watched the one with the Phil guy again recently and I fired up groups again for fun. Doing a switch between my preferred and groups it was immediate the difference. I don’t prefer my left main or right main helping each other is what it boiled down to after playing around trying to figure out what the difference was. Feels more expansive without the mains supporting each other vs. more congested with them helping each other. I don’t need them to help each other so it’s not a big deal either way luckily. It’s fun messing around, I’m always listening to music so now I just do it with a laptop on my lap sometimes. I played with F Support low as well, I’ve been and still am taking 25Hz for my left main, 27Hz for my right, 37Hz left rear, 40Hz right, 50Hz center. Since I’m all music I work my center hard as a support too, have you listened up close to what the “off” speakers are doing by chance? It’s pretty neat. The filters don’t show the speakers being driven anywhere near the low end measured response so I’m not at all concerned and it sounds good, spread is real tight. I get a lot of free room gain on everything except my center. I did move them each up 5Hz each and kept it for a too loud for long pre-set. In that Phil video Joss was talking using the -3 point of measured in room, conditions permitting like everything with ART. I gave up on full correction too, I’m back to 250Hz. Back to back it always wins for me, I gave the full thing a few weeks and tweaks this time too.

 

[mmares056]

I currently can’t keep left and right subs without them supporting each other, I mean I can but it’s not as good. I’ve finally fallen in love with a tight spread/low decay. Hoping the 3rd sub right behind me can triangulate support so I can experiment more with sub left and right separation as well as experimenting with the front/rear more. I’m thinking I’ll add a 4th and go sidewall on either side of my chair eventually, it’s fun and my wife doesn’t hate me for it


It’s funny you mention the videos, I watched the one with the Phil guy again recently and I fired up groups again for fun. Doing a switch between my preferred and groups it was immediate the difference. I don’t prefer my left main or right main helping each other is what it boiled down to after playing around trying to figure out what the difference was. Feels more expansive without the mains supporting each other vs. more congested with them helping each other. I don’t need them to help each other so it’s not a big deal either way luckily. It’s fun messing around, I’m always listening to music so now I just do it with a laptop on my lap sometimes. I played with F Support low as well, I’ve been and still am taking 25Hz for my left main, 27Hz for my right, 37Hz left rear, 40Hz right, 50Hz center. Since I’m all music I work my center hard as a support too, have you listened up close to what the “off” speakers are doing by chance? It’s pretty neat. The filters don’t show the speakers being driven anywhere near the low end measured response so I’m not at all concerned and it sounds good, spread is real tight. I get a lot of free room gain on everything except my center. I did move them each up 5Hz each and kept it for a too loud for long pre-set. In that Phil video Joss was talking using the -3 point of measured in room, conditions permitting like everything with ART. I gave up on full correction too, I’m back to 250Hz. Back to back it always wins for me, I gave the full thing a few weeks and tweaks this time too.

You have a good strategy for sure and it sounds like you got everything dialed in with ART. With ART, experimentation is key and I agree that experimenting with ART is a lot of fun. Definitely, we gotta take all available free room gain. Yeah, I've listened up close to speakers that are not supposed to be playing and I can barely hear they are playing something but when I go seat on the sofa I can't hear it anymore. Joss also mentions this on the Joe N Tell video. Next on my upgrade list is to get beefy 3-way mains and surrounds. I will look for speakers that have excellent directivity and excellent in-room response. The ART experimentation continues.