The importance of multiple measurements.
Thanks to Steve's suggestion, I did some measuring at different places in my general listening position, a two seater couch. With mic placement in three different positions (about where my head would be), there are three very different response curves. Averaging them out seems to be important in not being overly influenced by a single reading when doing active EQ.
The image below shows three readings and an average (thicker red line).
Thanks to Steve's suggestion, I did some measuring at different places in my general listening position, a two seater couch. With mic placement in three different positions (about where my head would be), there are three very different response curves. Averaging them out seems to be important in not being overly influenced by a single reading when doing active EQ.
The image below shows three readings and an average (thicker red line).
Attachments
Thanks Steve.
A trip to B&Q is calling to get the MDF for my H frames. I'll then be in a position to try all sorts of things from simple free-floating as you suggest to a far more constrained method as I'm currently using.
The tiny silicone coaster bumpers have arrived, so I may try them instead of blutack in the exciter area.
For an an earlier effort, I used an H baffle with an Abstract frame on top of it (see attached sketch). One could freely hang a DML panel from the top of the frame or use one of the Abstracta clip solutions to secure the panel (with foam between clip and panel).
One could also (if required) use a cross bar to support the exciter.
Lots of options. Easy to assemble.
Attachments
lordarquin, On your post 8903, do you have the distortion curves for the equalized FR response curves?
It would be interesting to see what a swept triangular wave would produce a FR with the same equalization settings.
The reason for this is a triangular produces more harmonics than a sine wave an is better than a square wave on the transducer.
It would be interesting to see what a swept triangular wave would produce a FR with the same equalization settings.
The reason for this is a triangular produces more harmonics than a sine wave an is better than a square wave on the transducer.
I find the BL figure both difficult to come by (it's not often specified on the Dayton units) and I also find it's a poor predicter of performance. I tend to rely more on the response curves (for comparison purposes only!) because the foam panel test board that Dayton uses is not what I would use for my end product. But I can get some vague idea of response between their units.
I also keep in mind that a 3db apparent increase in sensitivity is equivalent sometimes to a doubling in drive signal, so a 93db driver being driven at 2VRMS will sound as loud as a 90dB driver being driven at 4VRMS. Or something like that.
But of course the main thing is that the efficiency of any driver is often over-shadowed by the physical properties of the panel that it's driving. A powerful, high efficiency driver might waste most of its energy in accelerating an over-damped, heavy surface, and it could possibly sound inferior compared to a lower-power, lower efficiency driver driving a low-density lightly-damped surface.
The only companies that actually have the NXT/HiWave/Redux intellectual property are Tectonic Labs and Google LLC, that is, all the scientific research data, formulae etc and also most of the NXT/HiWave/Redux engineering and scientific staff with their separate sectional acquisitions. Both companies are still doing research work in their separate areas, on bending wave, transverse wave, distributed mode, balanced mode, haptic etc technologies, which originated from NXT. There are still active patents, and some granted long after the "demise" of NXT -- its legacy lives on...in a way...
What we don't want to, or care to understand is that NXT was solely created to research and make patents, and sell licenses. That was their product. NXT was owned by venture capital. If that won't make the planned profit, then restructure and sell the company completely or in parts, which is what happened.
We, the general public, have no access to that intellectual property, except the measly patents, which they had to publish. Even, if we buy an expensive Tectonic DML, dismantle it, copy it one-to-one, we won't still get an exact copy, as we don't have the science, maths, physics, engineering that went into creating the original.
All we can do, atm, is learn from those measly patents, and try to clone as near as possible what they 'teach' there.
What we don't want to, or care to understand is that NXT was solely created to research and make patents, and sell licenses. That was their product. NXT was owned by venture capital. If that won't make the planned profit, then restructure and sell the company completely or in parts, which is what happened.
We, the general public, have no access to that intellectual property, except the measly patents, which they had to publish. Even, if we buy an expensive Tectonic DML, dismantle it, copy it one-to-one, we won't still get an exact copy, as we don't have the science, maths, physics, engineering that went into creating the original.
All we can do, atm, is learn from those measly patents, and try to clone as near as possible what they 'teach' there.
Well, if someone knows better, maybe they are hiring.
Last edited:
I'm probably a bit out of my depth here! If it can be done in REW, I can give it a go.
Simon
In my initial design (it was pre-Covid!) I had a rather ungainly arrangement which allowed anything from minimal 'hanging' to quite close coupling with the frame. On balance, I found attaching the panel to the frame gave the best results. I always seemed to end up with bits of the panel distorting quite badly with the simple hanging arrangement. Those panels were 400 x 550mm or thereabouts, either 3mm poplar ply or EPS.
Many so-called gurus had misdirected the people, by making them believe that the free hanging, rectangular panel with unsupported edges as the distributed mode loudspeaker (DML). Only, that was just the membrane, but not the distributed mode loudspeaker (DML). Just like the cone of the conventional speaker driver. Cut the surround off, and you'd hear the difference.
But, that rectangular panel becomes a distributed mode loudspeaker (DML) only when it covers certain criteria, the most basic being,
The above information is for us newcomers and for those, who are still thinking of making a distributed mode loudspeaker system. NXT had more than 40 scientists and engineers working there, some of whom later moved to Tectonic Labs together with the NXT intellectual property. There's absolutely no reason to reinvent the wheel. You don't really need to make large radiator panels, you can even make an efficient one of A5 size! The recipes are given in those patents and in a few more.
Anyway, the idea is to make a distributed mode loudspeaker, but not an uncontrollably wobbling, flapping sheet.
But, that rectangular panel becomes a distributed mode loudspeaker (DML) only when it covers certain criteria, the most basic being,
- a rectangular frame carrying
- a resilient suspension round its inner periphery
- which supports a distributed mode sound radiating panel.
The above information is for us newcomers and for those, who are still thinking of making a distributed mode loudspeaker system. NXT had more than 40 scientists and engineers working there, some of whom later moved to Tectonic Labs together with the NXT intellectual property. There's absolutely no reason to reinvent the wheel. You don't really need to make large radiator panels, you can even make an efficient one of A5 size! The recipes are given in those patents and in a few more.
Anyway, the idea is to make a distributed mode loudspeaker, but not an uncontrollably wobbling, flapping sheet.
Last edited:
Steve...I can't guarantee anything... It's a case of suck it and see..
And when you say 'reach', do you mean substantially flat to 20k?
Eucy
chadsl,
I can't let you off that easily. My brother has been a professional artist for 61 years. He sells his work all over Canada. Sometimes he doesn't include a frame with the sale. That art is still just as valuable as it would have been in the frame, minus the cost of a frame and installation. Just ask anyone who buys art as an investment, like the oil conglomerates who collect his works. Just because Spedge doesn't put a fancy frame around his speakers does not make the quality of their sound any less spectacular. I would put up his knowledge of the intricacies of what it takes to make a DML sound good against anyone, including those engineers at NSX. He has been to numerous audio shows that had their products featured and has preferred his DMLs to theirs over and over. As I said before, you have spectacularly picked the wrong person to denigrate. It's like saying Michaelangelo doesn't know much about marble. Drop it: you won't win this one because you have absolutely no facts on your side.
I can't let you off that easily. My brother has been a professional artist for 61 years. He sells his work all over Canada. Sometimes he doesn't include a frame with the sale. That art is still just as valuable as it would have been in the frame, minus the cost of a frame and installation. Just ask anyone who buys art as an investment, like the oil conglomerates who collect his works. Just because Spedge doesn't put a fancy frame around his speakers does not make the quality of their sound any less spectacular. I would put up his knowledge of the intricacies of what it takes to make a DML sound good against anyone, including those engineers at NSX. He has been to numerous audio shows that had their products featured and has preferred his DMLs to theirs over and over. As I said before, you have spectacularly picked the wrong person to denigrate. It's like saying Michaelangelo doesn't know much about marble. Drop it: you won't win this one because you have absolutely no facts on your side.
At least there's one member here, once a newcomer, mostly silent in this thread, had created few commercial grade distributed mode loudspeakers (DML), makes a living marketing them. After reading quite a few NXT patents, I can tell that, now I am quite inspired by his work. Now, I know that he had been doing lot of research, understood the facts, added his own ideas/knowledge into the effort, out came a highly crafted commercial grade loudspeaker. I had some argument with him in the past, for which I am genuinely sorry. I am not mentioning his username, respecting his privacy.
Last edited:
@jaxboy
With respect, I have no interest in this matter. My mistake was in getting provoked and replying. Invite you to read the post #8,908 and #8,911, one after the other, that is, if you want. By the way, I've stuck exciters in all kinds of materials, and that was the mistake. First, I should've read the patents, especially the NXT ones, for they invented to distributed mode radiator panel, the exciter for that and the loudspeaker, 3 different things, which together becomes the whole. Good night!
With respect, I have no interest in this matter. My mistake was in getting provoked and replying. Invite you to read the post #8,908 and #8,911, one after the other, that is, if you want. By the way, I've stuck exciters in all kinds of materials, and that was the mistake. First, I should've read the patents, especially the NXT ones, for they invented to distributed mode radiator panel, the exciter for that and the loudspeaker, 3 different things, which together becomes the whole. Good night!
Chdsl, what is ironic is that you are worst of all the self proclaimed Gurus. You drastically change stances and contradict yourself all the time almost every day.
It seems you are now singing NXT praises when just around a week ago you were against NXT calling them pseudoscience. Quote> More you read NXT patents, more you find them as somewhat pseudo-science.
You also said this and I quote> This places the NXT patents (and others following/copying them) somewhat on its head.
Quote> Sometimes I think, why we are running after failed NXT ideas.
It seems you are now singing NXT praises when just around a week ago you were against NXT calling them pseudoscience. Quote> More you read NXT patents, more you find them as somewhat pseudo-science.
You also said this and I quote> This places the NXT patents (and others following/copying them) somewhat on its head.
Quote> Sometimes I think, why we are running after failed NXT ideas.
Yea , yawl ran him off.
This is what I mean about you changing stances and having to back peddle (apologize) because a lot of times you are wrong for the mere fact that you do not have enough "HANDS ON EXPERIENCE".Sheet Control/Mescalito pro has many youtube vids for all to listen as like I said the proof is in the pudding. The sad part is some of yawl like to burn bridges, I highly doubt Alvipet will help anyone anymore especially after the way some of yawl treated him.
Steve,
What do you think of what Sandasnickaren has been using for a driver in his projects - the modified Tectonics BMR? High power handling, high BL and the high end slopes upward to near 20K. I experimented with it here on post 4458 After seeing his work, I need to revisit the use of that driver!
https://www.parts-express.com/pedocs/specs/297-2156--tectonic-tebm65c20f-8-spec-sheet.pdf
Bruce
As it turns out, even Azima viewed a free edge panel as a distributed mode loudspeaker.
From this patent:
https://patentimages.storage.googleapis.com/ea/0e/93/9583fcf9a1db27/US20020044668A1.pdf
True, I did say that. I said, more I read NXT patents, I find them more like pseudoscience. It still does, but you have to keep on reading.
I am not going into the physics and maths of their work. I'll dig enough info to clone a loudspeaker. I have enough time, waiting for the cold to end. More you read, more you more you change, That's why I say to the newcomers, read. Say, but not tell.And, I'd like to point out that Sandasnickaren came in with his project replyingto one my post. And, that was good turning point. He cloned the Göbel DML. That inspired me, and I read the Göbel patent. Then asked Veleric to point out to his creations. Took some time, but finally I had a look at his work. He didn't clone, but that's alright. So, one day, I said I'd read all Azima's patents. There was lot of fun comments directed at me by some, but I wanted to read, and find out. On the way, I found there are others, much more important than Azima on this distributed mode matter. So, my "stance" changes as I read.
So, I say to everyone newcomer, or who still wants to make a good distributed mode loudspeaker, just read the patents.
May I politely suggest not to use the word "yawl"? There's only one other person who did that here in this thread in the past. He too used capital letters to emphasis. Anyone simply searching the word "yawl" in the search box above, in this thread would find only two people using that word, and the mode of expression.Yea , yawl ran him off.
Sheet Control/Mescalito pro has many youtube vids for all to listen as like I said the proof is in the pudding. The sad part is some of yawl like to burn bridges, I highly doubt Alvipet will help anyone anymore especially after the way some of yawl treated him.
Last edited: