Hi,
One of the problems with the titanium based diaphragm compression drivers is the breakup around 11khz-13khz. There are a couple of ways I have been reading it has been dealt with as below:-
a) Use of non titanium materials that inherently dont have breakup in the pass band, these have some sort of plastic like engineered material
b) Titanium based diaphragms with embossed strengthening pattern to increase stiffness and move the breakup above the 20Khz range
c) Use of ring radiator diaphragms, the ring is driven by the mechanical center and ring stays pistonic to a very high frequency, the material thus is less important here I believe
I think such driver when implemented correctly with a good matching waveguide and crossover can take away the harshness of CD and make it sublime like a good dome or even a ribbon.
So, can we have a list of such drivers please?
Here are few I know :-
1) JBL CDs with embossed pattern, probably of titanium.
2) Then F151M-8 1" Ceramic ring radiator from Eminence.
3) JBL D2,revolutionary driver, with two rings facing each other, now patent has expired and so several clones available at Alibaba
4) B&C DE360
Please post here if you come across more.
Thanks and Warm Regards
WonderfulAudio
One of the problems with the titanium based diaphragm compression drivers is the breakup around 11khz-13khz. There are a couple of ways I have been reading it has been dealt with as below:-
a) Use of non titanium materials that inherently dont have breakup in the pass band, these have some sort of plastic like engineered material
b) Titanium based diaphragms with embossed strengthening pattern to increase stiffness and move the breakup above the 20Khz range
c) Use of ring radiator diaphragms, the ring is driven by the mechanical center and ring stays pistonic to a very high frequency, the material thus is less important here I believe
I think such driver when implemented correctly with a good matching waveguide and crossover can take away the harshness of CD and make it sublime like a good dome or even a ribbon.
So, can we have a list of such drivers please?
Here are few I know :-
1) JBL CDs with embossed pattern, probably of titanium.
2) Then F151M-8 1" Ceramic ring radiator from Eminence.
3) JBL D2,revolutionary driver, with two rings facing each other, now patent has expired and so several clones available at Alibaba
4) B&C DE360
Please post here if you come across more.
Thanks and Warm Regards
WonderfulAudio
1) cure worse than disease. Look for waterfall plots, the JBL ribbed Ti dias fare worse than the smooth ones.
2-4) all ring radiators (including the fancy JBL D2) give up low-frequency extension, and/or lead to increased distortion below 1kHz, due to displacement limits. So you gain something (>10kHz, which may or may not be audible), but you lose something else (<1kHz, which is definitely audible).
The only "fix" for break-up in the 10-13kHz range that actually works is a Beryllium diaphragm. But, of course, that's expensive.
2-4) all ring radiators (including the fancy JBL D2) give up low-frequency extension, and/or lead to increased distortion below 1kHz, due to displacement limits. So you gain something (>10kHz, which may or may not be audible), but you lose something else (<1kHz, which is definitely audible).
The only "fix" for break-up in the 10-13kHz range that actually works is a Beryllium diaphragm. But, of course, that's expensive.
If you are looking at JBL's you want SL diaphragm's. They don't completely eliminate but reduce the effects. They are smooth and coated with aquaplas. Second waterfall is coated Mg which unfortunately is not available. 2450Sl vs. 435Be and 2453Sl driver first measurement and waterfall.
Rob 🙂
https://reconingspeakers.com/product/jbl-2452sl-d8r2452sl-diaphragm/
Rob 🙂
https://reconingspeakers.com/product/jbl-2452sl-d8r2452sl-diaphragm/
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