The suspension seems unavoidable to maintain stability. FEA does some good analysis, but there are still some limitations. The same limitations that occurs in suspension FEA as well, namely, material characteristics model. As long as we know how limited these are, FEA is good for analysis of both.
Hi,
Sure, however it is possible to combine mechanical and magnetic means to maintain stability AND make the suspension more linear, the commonly used halve roll rubber edges and corrugated cloth spiders are a very economical (read cheap) solution, but linear they are rarely.
As for example the cantilever suspended Goodmans Axiom 80 proved (needs correct adjustment though) it is possible to make linear suspensions and JBL as well as others have shown that to make linear magnet systems which minimise both BL and Le modulation is actually quite trivial (but costs more than the generic magnet systems most so-called High End Driver manufacturers buy in from the lowest bidder in China).
However, despite techniques to massively improve the linearity of drivers that are royalty fee by now (patents have lapsed and expired) the makers of so-called High End HiFi Drivers have mainly proven highly resistive in adopting such innovation (there are a few notable exceptions), preferring instead to dazzle the customers with tales of magic cone materials, while ignoring the Elephant in the room...
So the drivers that Joachim works are highly non-linear past the small signal region, something he no doubt is fully aware of and elected to ignore (in any design there are choices to be made).
There a number of solutions, use active drive with motional feedback to reduce the high level non-linearity of the LF System, use more linear drivers (they exist, but not in the catalogs of the manufacturers Joachim prefers for his own reasons) or simply listen closeup and not very loud, which seems Joachim's stated goal anyway.
Me?
I'd probably have a punt at a long throw 15" - 18" Pro Audio / Sound Reinforcement Subwoofer Driver (improve linearity by reducing excusion first) with MFB (improve linearity by NFB) as bass for a small system (like if I want to avoid Shearer horns), but I like to listen loud and in the farfield... Most HiFi Drivers I take one close look at the magnet system and say "forgetaboutit!"...
So, its Horses for courses.
Ciao T
Sure, however it is possible to combine mechanical and magnetic means to maintain stability AND make the suspension more linear, the commonly used halve roll rubber edges and corrugated cloth spiders are a very economical (read cheap) solution, but linear they are rarely.
As for example the cantilever suspended Goodmans Axiom 80 proved (needs correct adjustment though) it is possible to make linear suspensions and JBL as well as others have shown that to make linear magnet systems which minimise both BL and Le modulation is actually quite trivial (but costs more than the generic magnet systems most so-called High End Driver manufacturers buy in from the lowest bidder in China).
However, despite techniques to massively improve the linearity of drivers that are royalty fee by now (patents have lapsed and expired) the makers of so-called High End HiFi Drivers have mainly proven highly resistive in adopting such innovation (there are a few notable exceptions), preferring instead to dazzle the customers with tales of magic cone materials, while ignoring the Elephant in the room...
So the drivers that Joachim works are highly non-linear past the small signal region, something he no doubt is fully aware of and elected to ignore (in any design there are choices to be made).
There a number of solutions, use active drive with motional feedback to reduce the high level non-linearity of the LF System, use more linear drivers (they exist, but not in the catalogs of the manufacturers Joachim prefers for his own reasons) or simply listen closeup and not very loud, which seems Joachim's stated goal anyway.
Me?
I'd probably have a punt at a long throw 15" - 18" Pro Audio / Sound Reinforcement Subwoofer Driver (improve linearity by reducing excusion first) with MFB (improve linearity by NFB) as bass for a small system (like if I want to avoid Shearer horns), but I like to listen loud and in the farfield... Most HiFi Drivers I take one close look at the magnet system and say "forgetaboutit!"...
So, its Horses for courses.
Ciao T
I found generally that a stiffer suspension is more linear. That is usually the case with bigger diameter woofers that have higher cone mass. As Thorsten has pointed out, the speaker i am developping here is no super duper, top high end giant killer but just something that can be build by a DIYer without tremendoes outlay or expensive tools. The reason i started this thread is that i found little information on the web about dispersion and especially diffraction. The speaker that will eventually will come out of that is just a prove of concept. I especially hope that it will be well balanced tonally and throws the kind of 3 dimensional soundstage i like. If you are searching for a speaker that can recreate a big venue classical event or stadium rock look elswhere.
Joachim,
Yes. And buy the right kind of these woofers and you get a very linear magnet system thrown into the deal and a copper or aluminum cap on the center piece that kills Le dead and so kills Le modulation (you cannot modulate what is not there)...
JBL makes a few good ones like that (and has for decades), not necessarily the super flattest response, but usable. I still remember the custom JBL Systems we used to install in the occasional club (most took the cheaper Ramsa stuff), set right these made awesome High Fi...
Ciao T
Yes. And buy the right kind of these woofers and you get a very linear magnet system thrown into the deal and a copper or aluminum cap on the center piece that kills Le dead and so kills Le modulation (you cannot modulate what is not there)...
JBL makes a few good ones like that (and has for decades), not necessarily the super flattest response, but usable. I still remember the custom JBL Systems we used to install in the occasional club (most took the cheaper Ramsa stuff), set right these made awesome High Fi...
Ciao T
There are lots of tradeoffs in speaker design. I've currently been focusing on drivers in the 3" to 8" range. The key is for a certain level of max SPL, how can we get as linear operation within the intended audio band of operation up to that SPL as possible. I have looked into a few unique suspension designs, which also include cantilever designs like what is used in the Jordan Watts. Each design has it's own pros and cons. But some times certain nonlinearity can be compensated electronically, which also explains why sometime we measure high distortion in amplifiers that quite often sound very good. It takes lots of effort to find a cost effective combination. Building it might not be so difficult for the DIYer, but all the up front design work certainly is not easy.
Field coils are certainly interesting, but I have not seen much measurements on these. I guess they just want to keep the secret for the big spenders
Field coils are certainly interesting, but I have not seen much measurements on these. I guess they just want to keep the secret for the big spenders
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It has a reason why speakers are build the way they are. What i have learned from Klippel is not the use of any exotic suspension but building a speaker in a larger series and looking how a design can be optimised in terms of consistency and narrowing tolerances.
Making a state of the art speaker without any monitary limmits is something totally different. I have a feeling that some here do not understand what i am trying to do in this thread. It is not about building the best speaker in the world but doing something that the average person can build with mimimal outlay and difficulty that has some unique properties. I call that DIY.
Making a state of the art speaker without any monitary limmits is something totally different. I have a feeling that some here do not understand what i am trying to do in this thread. It is not about building the best speaker in the world but doing something that the average person can build with mimimal outlay and difficulty that has some unique properties. I call that DIY.
Let's not forget the development of prototypes are somewhat like DIY. I respect what you are doing, but things like spheres are not to popularly available. Anyway, the route you are taking is a very interesting one. I have not tried that approach, and thus very interested in the results and the process as well, and with hopes to learn some things, like about the powerful capability of correct application of EQ I've learned from this thread.
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Joachim,
I've been following this thread without posting. I just want to say that I appreciate what you are doing. I find your posts very informative. You have great experience and perspective on audio and you are not afraid to express your opinions, even if they may ruffle people's feathers.
Also, you are the only one who actually builds stuff here (well, maybe apart from NP). Most other so-called experts just come and post and tell us how things should be without really giving any useful information.
So, thanks! Keep it up! There are a lot us here (I'm sure) who are simply enjoying this thread. I wish you can come up with another design that can go loud, is linear and can produce life-like dynamics.
I've been following this thread without posting. I just want to say that I appreciate what you are doing. I find your posts very informative. You have great experience and perspective on audio and you are not afraid to express your opinions, even if they may ruffle people's feathers.
Also, you are the only one who actually builds stuff here (well, maybe apart from NP). Most other so-called experts just come and post and tell us how things should be without really giving any useful information.
So, thanks! Keep it up! There are a lot us here (I'm sure) who are simply enjoying this thread. I wish you can come up with another design that can go loud, is linear and can produce life-like dynamics.
This project was delayed much. One reason was that i set up my new company Neue Seite 1 and the other reason was, that i was not 100% happy with the sound of the nylon spheres. By chance Jan Didden offered me a pair of reworked IKEA bowls that are ideal for the purpose. They have metal stabilizing rings designed by EUVL.
My wife was asking what that is because she likes it. This is a good star i think.
My wife was asking what that is because she likes it. This is a good star i think.
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