Distributed Mode Loudspeakers?

[RobL]

Was reading about DLM (distribted mode loudspeakers) transducers and thinking they might make great rear surrounds. I have watched a few video like this one below and have heard them claim more than once that this type of speaker creates a diffuse sound field that causes NO reflections…umm, is that correct or even possible?

 

[NTK]

Interesting. Not intended for high fidelity home audio. (Link to spec sheet: https://tectonicproaudio.com/wp-content/uploads/2022/05/DML500-Rev-07-Jan-22.pdf )

 

[McFly]

Yes, very useful indeed. I would speculate the distortion would be, ugly, at best. That's why they don't target the home market.

Pretty much the same thing as this:

 

[RobL]

Yes, very useful indeed. I would speculate the distortion would be, ugly, at best.

The above is taken from HERE.

 

[RobL]

Polar of a DML. High frequencies are almost omni.
(From Newell and Holland, Loudspeakers for Recording and Reproduction)

 

[mwmkravchenko]

If you have listened to these panels you would not be impressed with the fidelity of the sound. I listened, and happily walked away from the Tectonic system.

 

[Sedge]

Was reading about DLM (distribted mode loudspeakers) transducers and thinking they might make great rear surrounds. I have watched a few video like this one below and have heard them claim more than once that this type of speaker creates a diffuse sound field that causes NO reflections…umm, is that correct or even possible?

The commentator in the video was getting a little carried away, when he says there are no reflections.
He probably ment to say that there are less destructive reflections ( cancellations and peaks).
I am uploading some of my old panels , small and large DML panels.
This is the latest one I have posted.
Please listen on headphones for best experience.

 

[Martinvb]

A few years ago I built my own DMLs, based on simple 20w exciters and 20mm PCB foam: they sounded incredibly well for acoustical music at low listening levels. A sub was required for more dynamic music, but overall my idea on how reproduced music should sound has changed since.

 

[Sedge]

The exciters are only 10watts and the digital amp amp is also only 10watts max.
It was only at almost half volume on the volume nob, half volume was too loud for me.
My small 6inch x 9inch panels can also fill a room with sound, as shown in my youtube posts.
How did your tasts change and why?
Steve.

 

[fineMen]

Interesting. Not intended for high fidelity home audio. (Link to spec sheet: https://tectonicproaudio.com/wp-content/uploads/2022/05/DML500-Rev-07-Jan-22.pdf )

Wow, the Fane Mini Pro resurrected, and rightly so. A great speaker system with, in contrast to what other say, tremendously LOW distortion sub 0,1% from about 300Hz on ... very wide dispersion ... free of feedback due to phase magic ... extreme far penetration without bothering people nearby.

Needless to say I'm an owner of the predecessor and happy with it. Did a garden party with a pair of Mini Pros (plus subs), 200pax not only dancing the walz.

Thanks for sharing!

 

[Sedge]

View attachment 255735
Polar of a DML. High frequencies are almost omni.
(From Newell and Holland, Loudspeakers for Recording and Reproduction)

When they first demonstrate the podiums at an audio show , they turned one panel around while playing music , it made little difference to the sound, very impressive.
Wherever you site in a room you get the full sound stage, a 3D holographic sound stage ,you can even walk through the centre to behind the panels and it still sounds perfect.
No real sweet spot which you have to clamp your head in
I love them.
Steve.

 

[fineMen]

I'm tempted to reiterate another idea, closely related to the DML.

People are talking so much about (a) perfect on axis frequency response and (b) still perfect off axis response, the latter as to fill up the room with (again) perfect sound because the rooms is assumed to be perfect.

Two tasks for the same speaker pair, which doesn't make too much sense.

Let the two stereo main speakers be of narrow dispersion. Narrow because listening too far off-axis will turn the otherwise highly applauded stereo-effect to a nightmare anyway. Neglect to some degree the off axis response other than it shall be minimized within reason. In consequence the direct on-axis sound can be deliberately equalized without disturbing the indirect, reverberant soundfiled in room.

This arrangement is supplemented by one or more DML speakers with inherently uncorrelated phase response. As DML mostly are dipoles orient the null towards the regular stereo position. The DML(s) will light up the room with inherently diffuse sound, derived in case as mono from the two stereo channels. It can be easily equalized to the need. To apply some delay in the range of 5ms will decouple the DML(s) entirely from the stereo sensation due to the precedence (de Haas) effect.

The DML is the prime contender for such an innovative set-up. The benfits are easily identified. Try it.

(Only if somebody asks: no, this isn't precedented by somebody else's idea, and it is not patent worthy. I published it years before on this board ;-)

 

[Sedge]

I'm tempted to reiterate another idea, closely related to the DML.

People are talking so much about (a) perfect on axis frequency response and (b) still perfect off axis response, the latter as to fill up the room with (again) perfect sound because the rooms is assumed to be perfect.

Two tasks for the same speaker pair, which doesn't make too much sense.

Let the two stereo main speakers be of narrow dispersion. Narrow because listening too far off-axis will turn the otherwise highly applauded stereo-effect to a nightmare anyway. Neglect to some degree the off axis response other than it shall be minimized within reason. In consequence the direct on-axis sound can be deliberately equalized without disturbing the indirect, reverberant soundfiled in room.

This arrangement is supplemented by one or more DML speakers with inherently uncorrelated phase response. As DML mostly are dipoles orient the null towards the regular stereo position. The DML(s) will light up the room with inherently diffuse sound, derived in case as mono from the two stereo channels. It can be easily equalized to the need. To apply some delay in the range of 5ms will decouple the DML(s) entirely from the stereo sensation due to the precedence (de Haas) effect.

The DML is the prime contender for such an innovative set-up. The benfits are easily identified. Try it.

(Only if somebody asks: no, this isn't precedented by somebody else's idea, and it is not patent worthy. I published it years before on this board ;-)

Firemen.
Can you give a link to where you published your article, it would be interesting to read.
Although my panels have a very good sound stage and depth that is perfectly good wherever you sit in the room.
With certain types of panel this could be an option.
I have talked to people who like to have their panels edges pointing towards them.
I have even tried this myself many years ago.
But I preferred to toe them out a bit to get the best of both worlds.
It depends on what effect you want?
There are many ways to implement dml panels.
What would the full range narrow speaker look like and of what type ?
Steve.

 

[fineMen]

Firemen.
Can you give a link to where you published your article, ...
What would the full range narrow speaker look like and of what type ?
Steve.

I would find it if somebody feels to claim a patent on it

The full range, e/g a (relatively) huge combo of 12" mid and horn/waveguide as te pros use it. I've got promissing results (before I switched for a while to KEF R3s) with 12" JBL 2026 bass, 18sound 12NDA502 (w/ aic) mid and 'econowave deluxe' QSC horn 90°x60° w/ BMS 4550 plus subs of course to make it increadibly bulky. Combined using passive/active/digital x-over. The DML was Fane MiniPro mono, with some delay and e/q.

edit: btw, see there: https://www.audiosciencereview.com/...s-genelec-monitors.44549/page-20#post-1590895

These guys here are more concerned about--what should I say? No chance that anyone here claims a patent. I'm going, I'll do, to find a fancy new skirt like in the magazines. Ain't I pretty? In short and serious, I tried to bring the topic to discussion on 'scientific' grounds to no avail.

But thanks for asking

 

[Duke]

Let the two stereo main speakers be of narrow dispersion. Narrow because listening too far off-axis will turn the otherwise highly applauded stereo-effect to a nightmare anyway. Neglect to some degree the off axis response other than it shall be minimized within reason. In consequence the direct on-axis sound can be deliberately equalized without disturbing the indirect, reverberant soundfiled in room.

This arrangement is supplemented by one or more DML speakers with inherently uncorrelated phase response. As DML mostly are dipoles orient the null towards the regular stereo position. The DML(s) will light up the room with inherently diffuse sound, derived in case as mono from the two stereo channels. It can be easily equalized to the need. To apply some delay in the range of 5ms will decouple the DML(s) entirely from the stereo sensation due to the precedence (de Haas) effect.

Very interesting!

In my opinion being able to adjust the reflection field independent of the direct sound is a good idea, and I can see a DML being a good candidate for this application in the configuration you described.

I use a different approach to independently adjusting the reflection field, but the overall concept is arguably similar.

 

[fineMen]

Very interesting!

In my opinion being able to adjust the reflection field independent of the direct sound is a good idea, and I can see a DML being a good candidate for this application in the configuration you described.

I use a different approach to independently adjusting the reflection field, but the overall concept is arguably similar.

Duke, thanks for your attention. But it is done, the board didn't show the slightest interest. I know from being employed in the US for some time that this means 'eff off'. They follow, some desperately, the channel down the rabbit hole of perfect stereo with two speakers dead center sitting straight in the middle like manequins 'critical listening' and call it enjoying music, 'classic' of course ;-)

 

[Duke]

But it is done, the board didn't show the slightest interest.

Did you start a thread about your speaker system and I missed it? That's possible, as my participation here is somewhat sporadic.

(I only found this thread because I did a Google search for "Distributed Mode Loudspeakers", after you had mentioned them in another thread, and this page came up.)

Can you post a link to whatever it was that "the board didn't show the slightest interest" in?

 

[fineMen]

Did you start a thread about your speaker system and I missed it? That's possible, as my participation here is somewhat sporadic.

(I only found this thread because I did a Google search for "Distributed Mode Loudspeakers", after you had mentioned them in another thread, and this page came up.)

Can you post a link to whatever it was that "the board didn't show the slightest interest" in?

C'mon, it is really done. I use the board as to scrutinize my personal wisdom. Sometimes people get me to rethink my ideas. That's the benefit in participating, the implicated deconstruction of all pride. Alas, some ideas, consequently still alive, can't be put down due to whatever reason. Don't think it is too complicated and overwhelming given capacities, but only a bit off-center. I'm a diplomat, ain't I?

 

[Duke]

C'mon, it is really done.

Okay.

I found your thread, and what you describe makes sense to me. And I will respect your wishes that "it is really done."