XMC bass management

[LCSeminole]

Dan, I really like the "We control 100% of what's going on now" part!!!

[igorzep]

Jul 29, 2014 17:19:40 GMT -5 Dan Laufman said:

Hi all,
We've heard you loud and clear as it relates to dual mono bass management on the XMC-1.

Look for a firmware update by Friday, or Monday at the latest that will add this feature. We've got it running here now and are just banging on it to make sure it's rock solid.

You'll be able to dial in independent delay and EQ settings for each dual mono sub. All other bass management remains the same.

Hi Dan,

Thanks for updating us.

Please also make sure, when Dirac is out, it will be possible to set the delay/phase/level independently before the Dirac calibration and then let Dirac calibrate the combo as a whole (preserving the relation of the delay/phase/level), not each sub separately. This is a most important use-case for automatic EQ, I hope it is noted also, as doing EQ for each sub separately would be simply incorrect and waste headroom in this case.

[bootman]

Jul 29, 2014 18:36:22 GMT -5 igorzep said:

Jul 29, 2014 17:19:40 GMT -5 Dan Laufman said:

Hi all,
We've heard you loud and clear as it relates to dual mono bass management on the XMC-1.

Look for a firmware update by Friday, or Monday at the latest that will add this feature. We've got it running here now and are just banging on it to make sure it's rock solid.

You'll be able to dial in independent delay and EQ settings for each dual mono sub. All other bass management remains the same.

Hi Dan,

Thanks for updating us.

Please also make sure, when Dirac is out, it will be possible to set the delay/phase/level independently before the Dirac calibration and then let Dirac calibrate the combo as a whole (preserving the relation of the delay/phase/level), not each sub separately. This is a most important use-case for automatic EQ, I hope it is noted also, as doing EQ for each sub separately would be simply incorrect and waste headroom in this case.

Excellent point and I think this is more of a specific Dirac question that may be only answered by someone from Dirac Research.

To Emotiva:
Is there anyone from DR that could possibly answer this question?

Thanks!

[tknice]

Jul 29, 2014 17:19:40 GMT -5 Dan Laufman said:

Firmware release notes will be included with the package.

Dan the Man.. Any chance you could post the release notes here? Be your best friend.

Back on topic, I was hoping to use the separate subwoofer level to control the bass shakers in the seats. So in my case, the level could be much different than the sub.

[bootman]

Jul 29, 2014 18:59:33 GMT -5 tknice said:

Jul 29, 2014 17:19:40 GMT -5 Dan Laufman said:

Firmware release notes will be included with the package.

Dan the Man.. Any chance you could post the release notes here? Be your best friend.

Back on topic, I was hoping to use the separate subwoofer level to control the bass shakers in the seats. So in my case, the level could be much different than the sub.

+1 for the release notes.

And as far as your specific case, you should be able to do this easily.

[klinemj]

Dan - wow...awesome news! This really shows what Emotiva can do when it is in control. Great decision to take that control.

Mark

[hemster]

Jul 29, 2014 18:59:33 GMT -5 tknice said:

Jul 29, 2014 17:19:40 GMT -5 Dan Laufman said:

Firmware release notes will be included with the package.

Dan the Man.. Any chance you could post the release notes here? Be your best friend.

Back on topic, I was hoping to use the separate subwoofer level to control the bass shakers in the seats. So in my case, the level could be much different than the sub.

I agree on the release notes but only coinciding with the actual firmware release. 

Also, I do use a subwoofer out from my XMC-1 for well... sub duties and the other sub out for my Buttkicker. I am looking forward to be able to set them separately. 

[bluescale]

Jul 29, 2014 18:36:22 GMT -5 igorzep said:

Please also make sure, when Dirac is out, it will be possible to set the delay/phase/level independently before the Dirac calibration and then let Dirac calibrate the combo as a whole (preserving the relation of the delay/phase/level), not each sub separately. This is a most important use-case for automatic EQ, I hope it is noted also, as doing EQ for each sub separately would be simply incorrect and waste headroom in this case.

Not just Dirac, though...the PEQ also needs to allow people to manually EQ the summed output of the two subs.

[wizardofoz]

+ 10 on the release notes...well in anticipation of what normally is the "expected techie" release notes, nit the UMC versions hehehehe...

Emotiva could learn from the Oppo release notes format www.oppodigital.com/blu-ray-bdp-103/blu-ray-BDP-10x-Firmware.aspx

[sme]

Jul 29, 2014 18:36:22 GMT -5 igorzep said:

Hi Dan,

Thanks for updating us.

Please also make sure, when Dirac is out, it will be possible to set the delay/phase/level independently before the Dirac calibration and then let Dirac calibrate the combo as a whole (preserving the relation of the delay/phase/level), not each sub separately. This is a most important use-case for automatic EQ, I hope it is noted also, as doing EQ for each sub separately would be simply incorrect and waste headroom in this case.

EQing each sub uniquely is neither incorrect nor simple.  (I will explain my choice of word "unique" later.)  My current on-going experiments in this area confirm that a better result can be obtained by using different EQ curves for different subs.  This is especially true when optimizing for multiple seats.  Not only is it possible to obtain a much better frequency response using unique sub EQs, but it is also possible to actually increase headroom. For frequencies in which the sound from a single sub and its reflections arrives out-of-phase with the sound from another sub and its reflections, differentially EQing the subs can actually increase headroom.

Now let me clarify what I mean by "unique EQ" versus "separate EQ" or "independent EQ".  One cannot optimize EQ on multiple subs separately and expect their combined response to also be optimal.  Each sub's contribution is not independent of the others.  One must instead optimize the EQ for all of the subs simultaneously.  This is substantially harder than EQing a single sub is; hence, most automatic room correction systems don't try to do it.  That doesn't mean that having unique EQs is incorrect.  It just means the technology capability isn't readily available.

I am using a manual approach to optimize my 2 subs and 2 mid bass woofers.  I measured each source at each of 5 positions along my living room sofa.  I wrote custom software to simulate applications of various EQ/shelf/crossover filters on the combined response at each listening locations, and then spent a long time (several hours in fact) iteratively tweaking the filters and reviewing the responses until I achieved roughly +/- 3 dB response for all 5 positions from 15 to 120 Hz with minimal surrender of headroom.  I'm actually rather surprised that I achieved such a strong result, but it was all make-believe (as all computer simulations are) until I programmed the biquads into my MiniDSP earlier this week.

My first validation experiment confirmed that my methods are sound, and I have achieved a vastly superior result by using different EQs on each sub.  Subjectively, the bass is at least as good now with Audyssey MultEQ turned off as it was before the EQ settings but with Audyssey turned on.  Re-running Audyssey will likely improve things further by correcting peaks in the sub region in my mains output, but first I'm working on fixing addressing some unrelated gotchas with the MiniDSP that I hope to iron out in the next couple weeks.

[igorzep]

Jul 30, 2014 0:21:20 GMT -5 sme said:

EQing each sub uniquely is neither incorrect nor simple.  (I will explain my choice of word "unique" later.)  My current on-going experiments in this area confirm that a better result can be obtained by using different EQ curves for different subs.  This is especially true when optimizing for multiple seats.  Not only is it possible to obtain a much better frequency response using unique sub EQs, but it is also possible to actually increase headroom. For frequencies in which the sound from a single sub and its reflections arrives out-of-phase with the sound from another sub and its reflections, differentially EQing the subs can actually increase headroom.

Now let me clarify what I mean by "unique EQ" versus "separate EQ" or "independent EQ".  One cannot optimize EQ on multiple subs separately and expect their combined response to also be optimal.  Each sub's contribution is not independent of the others.  One must instead optimize the EQ for all of the subs simultaneously.  This is substantially harder than EQing a single sub is; hence, most automatic room correction systems don't try to do it.  That doesn't mean that having unique EQs is incorrect.  It just means the technology capability isn't readily available.

I am using a manual approach to optimize my 2 subs and 2 mid bass woofers.  I measured each source at each of 5 positions along my living room sofa.  I wrote custom software to simulate applications of various EQ/shelf/crossover filters on the combined response at each listening locations, and then spent a long time (several hours in fact) iteratively tweaking the filters and reviewing the responses until I achieved roughly +/- 3 dB response for all 5 positions from 15 to 120 Hz with minimal surrender of headroom.  I'm actually rather surprised that I achieved such a strong result, but it was all make-believe (as all computer simulations are) until I programmed the biquads into my MiniDSP earlier this week.

My first validation experiment confirmed that my methods are sound, and I have achieved a vastly superior result by using different EQs on each sub.  Subjectively, the bass is at least as good now with Audyssey MultEQ turned off as it was before the EQ settings but with Audyssey turned on.  Re-running Audyssey will likely improve things further by correcting peaks in the sub region in my mains output, but first I'm working on fixing addressing some unrelated gotchas with the MiniDSP that I hope to iron out in the next couple weeks.

If we talk about absolute optimum then yes. But usually you need no more than one or two biquads to do it. Although just with delay/phase/level adjustments AND placement of subs it can be done quite close to the optimum. And definitely a lot (and I mean really a lot lot) better in terms of headroom and frequency response uniformity than EQualizing each individual sub for flattest response and then sum it acoustically. Because in case of equalizing the sum we do optimize acoustically in the first place, but in the case of equalizing two subs separately - we don't at all! So, this is why it is incorrect considering the available features.

I would like to emphasize one more time the automatic EQ process with Dirac. As we (will) have a version of Dirac Live on the XMC-1, not something else like Dirac Unison, we cannot expect from it EQualizing the interaction between multiple bass sources. They can only equalize one logical unit at a time in isolation. So either they EQ two separate subs without considering about each-other or both as one logical unit. Giving the choice first is obviously not a dual sub bass management (same as with the "stereo sub" - it is a kind of bi-amping, not dual sub BM), as we can't optimize bass acoustically. The second one is a BM as it allows for acoustic optimization.

[clockwork33]

I also have a question about the Bass management. I own Velodyne DD15 sub with inbuild Digital Drive Room management. Will I still be needing this feature when I use the XMC’s Dirac or can I replace the Velo with a less expensive model.

[igorzep]

Jul 29, 2014 19:40:32 GMT -5 bluescale said:

Not just Dirac, though...the PEQ also needs to allow people to manually EQ the summed output of the two subs.

With PEQ there is at least an easy (but terribly inconvenient) workaround - just put the same parameters for both channels.

[igorzep]

Jul 30, 2014 3:07:11 GMT -5 clockwork33 said:

I also have a question about the Bass management. I own Velodyne DD15 sub with inbuild Digital Drive Room management. Will I still be needing this feature when I use the XMC’s Dirac or can I replace the Velo with a less expensive model.

Dirac should be not worse if not better in EQing it. Actually with 11 manual PEQ bands you are also quite flexible and can do it well if you don't mind configuring it by hand with a help of a mic and some third-party software such as REW.

[clockwork33]

Jul 30, 2014 3:27:18 GMT -5 igorzep said:

Jul 30, 2014 3:07:11 GMT -5 clockwork33 said:

I also have a question about the Bass management. I own Velodyne DD15 sub with inbuild Digital Drive Room management. Will I still be needing this feature when I use the XMC’s Dirac or can I replace the Velo with a less expensive model.

Dirac should be not worse if not better in EQing it. Actually with 11 manual PEQ bands you are also quite flexible and can do it well if you don't mind configuring it by hand with a help of a mic and some third-party software such as REW.

oke, thanks! I will wait until the XMC has arrived. I am really looking forward to try Dirac in my HT.

[igorzep]

PS! to Dual Sub Bass Management & Dirac. If, by any chance it will be possible for Emotiva to do it this way:
1) together with a delay/phase/level, allow a few points (just one or two biquads) of manual EQ before the automatic calibration
2) EQ both subs configured as above as a unit with automatic Dirac procedure

This would be an ideal and make XMC-1 unbeatable in BM. As Emotiva have 100% control on the XMC-1 this should be possible, I hope I personally don't expect this level of flexibility to happen, but will be pleasantly surprised if it is done that way. Also if Dirac will be able to take into account the phase/group delay distortion at the BM crossover region and also fix it with their excess phase filters it would be an ideal in just everything (AFAIK no processor is doing it today, but the only thing Dirac should know for this are the frequencies of BM xOvers).

[bootman]

Jul 30, 2014 3:48:43 GMT -5 igorzep said:

PS! to Dual Sub Bass Management & Dirac. If, by any chance it will be possible for Emotiva to do it this way:
1) together with a delay/phase/level, allow a few points (just one or two biquads) of manual EQ before the automatic calibration
2) EQ both subs configured as above as a unit with automatic Dirac procedure

This would be an ideal and make XMC-1 unbeatable in BM. As Emotiva have 100% control on the XMC-1 this should be possible, I hope I personally don't expect this level of flexibility to happen, but will be pleasantly surprised if it is done that way. Also if Dirac will be able to take into account the phase/group delay distortion at the BM crossover region and also fix it with their excess phase filters it would be an ideal in just everything (AFAIK no processor is doing it today, but the only thing Dirac should know for this are the frequencies of BM xOvers).

I'm thinking that we may just have this. (or very close)

1) One would manually adjust phase, level and use the 11 band PEQ individually for each sub.
2) One could then run Dirac which would treat the sub as one unit. (I haven't read anywhere about Dirac able to EQ stereo or dual subs independently in any available literature)

This could work because the filters Dirac calculates are independent of the built in PEQs.
(again from everything I have been able to gather so far)

So the XMC may be closer than you think now with this latest change.

Now if someone from Dirac could further explain to confirm or correct our assumptions as their software interfaces with the XMC's bass management in this regard that would be of great benefit.

I'm also curious how Dirac would treat the subs if a user wishes just to go the full AUTO route which I'm speculating would be the majority of the case.
We need to be honest here and those of us willing to get this unheard of level of adjustability and actually use it to be a small (but vocal) minority.

But like in most tech, those on the edge tend to drive innovation.

[KeithL]

Their room correction feature does indeed do pretty much the same thing as Dirac (but only for their sub). As such, you won't be needing it. However, odds are that there are other (audible) benefits of having a "better model" of sub - it would be surprising if that was the ONLY difference between the model you have and "lower" models.

When buying any piece of equipment, it usually makes sense to try to avoid buying expensive features you don't need or plan to use, but it rarely makes sense to sell off a piece of equipment and replace it with a lower model only because you ended up not using one or two features. Generally "better models" have several areas where they are at least slightly better - and the cost/performance analysis is different when you're talking about the added cost of buying a more expensive model, and the amount of money you'll actually pocket by selling it and then buying the lower model to replace it.

Jul 30, 2014 3:07:11 GMT -5 clockwork33 said:

I also have a question about the Bass management. I own Velodyne DD15 sub with inbuild Digital Drive Room management. Will I still be needing this feature when I use the XMC’s Dirac or can I replace the Velo with a less expensive model.

[bluescale]

Jul 30, 2014 6:56:36 GMT -5 bootman said:

I'm thinking that we may just have this. (or very close)

1) One would manually adjust phase, level and use the 11 band PEQ individually for each sub.
2) One could then run Dirac which would treat the sub as one unit. (I haven't read anywhere about Dirac able to EQ stereo or dual subs independently in any available literature)

This could work because the filters Dirac calculates are independent of the built in PEQs.
(again from everything I have been able to gather so far)

If you engage Dirac, doesn't it completely bypass the PEQ? In other words, my impression is that it works off of a flat EQ as its base. Filters upon filters seems like wasted headroom in most cases, and much more work for Dirac than necessary.

Jul 30, 2014 6:56:36 GMT -5 bootman said:

We need to be honest here and those of us willing to get this unheard of level of adjustability and actually use it to be a small (but vocal) minority.

But like in most tech, those on the edge tend to drive innovation.

I think most people with dual subs will know enough to configure it correctly if the options are available to do so. That said, it is good for all of us to keep in mind that we're asking Emotiva for features that will be used by a small percentage of the population. I liked Igor's statement that he's not necessarily expecting the ideal state he mentioned, but would be very pleasantly surprised if it happened. We should all have that mindset.

[bootman]

Jul 30, 2014 10:36:14 GMT -5 bluescale said:

...it is good for all of us to keep in mind that we're asking Emotiva for features that will be used by a small percentage of the population. I liked Igor's statement that he's not necessarily expecting the ideal state he mentioned, but would be very pleasantly surprised if it happened. We should all have that mindset.

I can't agree more.


This last series of events with us presenting a point of view and then having the manufacturer respond in kind is exactly what this place was at the very beginning.

I hope we can continue these lines of communications open going forward and have a better product for all, be the end result.
Can we have everything?
No, it is unreasonable to expect that, but this last exchange should serve notice to those that had the mindset that this company has moved away from listening to its customers.

It is these exchanges that make me want to invest in one (or more) of their products.

We should all work hard to keep this going.
It really benefits us all.