Dirac Live Bass Management?

[markus]

Well, I provided the explantion for term "boundary reinforcement" , which btw is very well known to anyone dealing with the acoustics, but I certainly cannot force you to understand it and accept it. Judging by what you said that it is related to rays and not to audio waves I believe it's time we agree that we disagree as I have nothing more to add to what I have already said.

Yep, you're beating a dead horse. Geddes summarized it better than I ever can at diyaudio.com.

 

[QMuse]

Yep, you're beating a dead horse. Geddes summarized it better than I ever can at diyaudio.com.

I have a better read about boundary effects for you, this one is with detailed explanations and with pictures and measurements so you should be able to get it.

 

[markus]

I have a better read about boundary effects for you, this one is with detailed explanations and with pictures and measurements so you should be able to get it.

Thanks but I don't have questions about that.

 

[QMuse]

Thanks but I don't have questions about that.

Well you should, because that proofs that your statement about wavelength and room dimension is meaningless in the context of adjacent boundary effect.

Not to mention that explanation you offered for your statement was even more meaningless ("I said this because at LF the behavior is best described in terms of sound waves, not rays").

 

[RichB]

From the Dirac Live Bass Control User Guide:

Generalized Low-frequency Support Since full-range speakers can produce frequencies below 100 Hz, we can contribute to the optimization by including them into the bass control design. As seen in section Handling of multiple subwoofers, by adjusting levels, delays, and phase responses of the individual subwoofers, it is possible to minimize the variation between the measurement points and get a more unified listening area. Correspondingly, it is a planned Bass Control feature that the user will have the ability to include their full-range speakers into the Bass Control optimization. From the optimization design perspective, a full-range speaker will be seen as both a small-range speaker and a subwoofer.

I'll be upgrading my rears Studio2's to Salon2's. The ability to use the bass capability in bass optimization is an intriguing feature.
There is simply no option to go beyond 2 subs in my room but better bass handling, especially for music makes better use of my system.

I am hoping that Emotiva supports DLBM but not interested enough to jump ship to Storm Audio.

- Rich

 

[markus]

Well you should, because that proofs that your statement about wavelength and room dimension is meaningless in the context of adjacent boundary effect.

Not to mention that explanation you offered for your statement was even more meaningless ("I said this because at LF the behavior is best described in terms of sound waves, not rays").

Sorry if it sounds meaningless to you. Get familiar with the wave equation. A good start might be to follow the discussion on diyaudio.com I've linked earlier. Then everything will come together.

 

[QMuse]

Sorry if it sounds meaningless to you. Get familiar with the wave equation. First start might be to follow the discussion on diyaudio.com I've linked earlier. Then everything will come together.

As an EE I assure you I'm pretty familiar with different kinds of waves. On the other hand you seem to be unable to explain your own thoughts in more detail than one sentence that doesn't contain any meaningfull information at all.

 

[Music1969]

Hi @Flak

I saw in the Dirac Bass Control guide, the below picture.

What current Dirac Live hardware supports 4 independent subwoofer outputs and supports Bass Control?

I am interested in such hardware.

http://diracdocs.com/Bass Control in Live.pdf

 

[Flak]

Hi @Music1969

the original photo is from the Dirac Live Processor set up with Bass Control (not released to the public yet)...
but you could do the same with a StormAudio unit. Some of the new Harman Luxury Audio products also support up to five subwoofers.

Flavio

 

[Pultzar]

I am curious about the "Full bass optimization" mode in which fullrange main speakers are considered for low frequencies. I have fullrange main speakers with linear output down to about 20hz. However, their output at 20hz pales in comparison to the dedicated subwoofers. Would my system output be limited by these main speakers? It's not clear how they are going to be weighted compared to the subs...

 

[Flak]

I am curious about the "Full bass optimization" mode in which fullrange main speakers are considered for low frequencies. I have fullrange main speakers with linear output down to about 20hz. However, their output at 20hz pales in comparison to the dedicated subwoofers. Would my system output be limited by these main speakers? It's not clear how they are going to be weighted compared to the subs...

Excellent question Pultzar
Generalized low frequency support isn’t in the actual product today, maybe this feature will be in some kind of “advanced mode” so that the user will have to decide for himself how to use the fullrange speakers... too early to comment about its final implementation

 

[QMuse]

Excellent question Pultzar
Generalized low frequency support isn’t in the actual product today, maybe this feature will be in some kind of “advanced mode” so that the user will have to decide for himself how to use the fullrange speakers... too early to comment about its final implementation

If I may siggest a feature: in that context I believe it would be interesting to implement not a single XO point to high-pass mains and low-pass subs but instead to implement different limits for both of them so that (for example) subs work in 20-80Hz range while mains work in 50-20.000 Hz. According to research from Geddes that may help in taming the room modes.

 

[markus]

If I may siggest a feature: in that context I believe it would be interesting to implement not a single XO point to high-pass mains and low-pass subs but instead to implement different limits for both of them so that (for example) subs work in 20-80Hz range while mains work in 50-20.000 Hz. According to research from Geddes that may help in taming the room modes.

I'm pretty confident that Dirac will get this implemented right now that they can control speaker filters and bass management. Unison goes beyond what Earl suggested. See Brännmark, Controlling the impulse responses and the spatial variability in digital loudspeaker-room correction, ISEAT 2015

 

[Neddy]

Excellent question Pultzar
Generalized low frequency support isn’t in the actual product today, maybe this feature will be in some kind of “advanced mode” so that the user will have to decide for himself how to use the fullrange speakers... too early to comment about its final implementation

'm in this same situation; mains go cleanly to 20hz, as does the sub, but it's just 'different' and definitely adds 'value', so need to get them to play well with each other (not horrible with just generalized EQ today, but....).
As I'm in the 'almost certain to go the Dirac route' I'll be very interested in how you address this in future....
and Thanks so much for sharing 'sneak peaks' like this!

 

[andyc56]

If I may siggest a feature: in that context I believe it would be interesting to implement not a single XO point to high-pass mains and low-pass subs but instead to implement different limits for both of them so that (for example) subs work in 20-80Hz range while mains work in 50-20.000 Hz. According to research from Geddes that may help in taming the room modes.

You do realize that Geddes' own speakers have an anechoic LF cutoff of about 80Hz, according to his own website, right?

And which "research" of Earl Geddes leads to these findings?

 

[andyc56]

I'm pretty confident that Dirac will get this implemented right now that they can control speaker filters and bass management. Unison goes beyond what Earl suggested. See Brännmark, Controlling the impulse responses and the spatial variability in digital loudspeaker-room correction, ISEAT 2015

Remind me which platforms Unison is available on?

 

[andyc56]

It can be seen from this capture of Earl's data of one of his customers that, in an electroacoustic sense, there is indeed a crossover (something he doesn't like to admit) at around 80 Hz. If there is overlap between mains and subs, and they're both flat in that overlap region, there will be a peak in the combined response in the overlap region. This peak needs to be suppressed by EQ, and when you do, you end up with a textbook crossover response in the electroacoustic sense.

 

[QMuse]

You do realize that Geddes' own speakers have an anechoic LF cutoff of about 80Hz, according to his own website, right?

And which "research" of Earl Geddes leads to these findings?

Dr. Earl Geddes, "Why Multiple Subs" (2011)

Dr. Earl Geddes, "Setting Up Multiple Subs" (2011)

The idea here is to use mains to act as additional subs down to whichever frequency they can handle. Dr. Geddes also advocates approach where not all subs should share the same frequency range.

P.S. Although I don't understand it I like the term "anechoic LF cutoff" - it sounds very scientific.

 

[andyc56]

Dr. Earl Geddes, "Why Multiple Subs" (2011)

Dr. Earl Geddes, "Setting Up Multiple Subs" (2011)

The idea here is to use mains to act as additional subs down to whichever frequency they can handle. Dr. Geddes also advocates approach where not all subs should share the same frequency range.

These articles don't actually show reduction in seat-to-seat variation in frequency response due to the recommended techniques.

P.S. Although I don't understand it I like the term "anechoic LF cutoff" - it sounds very scientific.

What do you think the Thiele-Small parameters are all about, then?

 

[QMuse]

These articles don't actually show reduction in seat-to-seat variation in frequency response due to the recommended techniques.

They don't show it, they explain how to achieve it.

What do you think the Thiele-Small parameters are all about, then?

I have yet to see precise anechoic measurement showing true LF cutoff.