We all know that replacement original Berilium diaphragms are pretty much unavailable and if you're lucky enough to find them the price is astronomical. But I also read about replacing original Be parts with Radian diaphragms with some success. I'm particularly interested in hearing about this procedure done to TAD-4002 drivers. Can you hear/measure much difference compared to the originals?
AFAIK there are no alternatives to the original TAD diaphragms. There is an old Materion data sheet floating around but they never actually sold one. I havet tried the Radian Alu phrams in my 4001's and they are ok but not great.
They work well in the lower end of the spectrum but robs the driver of its "magic" higher up.
My driver of choice right now is the JBL 2451 with Radial Be phrams. I like them better than the 4001 with original Be. Sounds really clean and consistent over the whole BW, like an electrostatic on steroids.
//Anders
They work well in the lower end of the spectrum but robs the driver of its "magic" higher up.
My driver of choice right now is the JBL 2451 with Radial Be phrams. I like them better than the 4001 with original Be. Sounds really clean and consistent over the whole BW, like an electrostatic on steroids.
//Anders
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I never liked TAD 4001 - too bright - and much preferred JBL 2441. But TAD 4002 seems to be a different beast. But, again, the ones with original diaphragms are very expensive and those with Radian parts...well, that the question...
They are plenty available, but the cost is a different matter. IMO that's an ill conceived idea. Is like doing an LS engine swap on a Ferrari: it still drives fine but it's not a Ferrari anymore. You may as well sell your broken TAD and buy BMS or Celestion.
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What horns and crossover are you using? The 4001 is my absolute dream driver but you need to really do your homework with the crossover and put it on the correct horn.
I take it that its design is such that you only need a fraction of a watt for your desired peak SPL, otherwise need up to a 500/2^4 = 31.25 Hz cutoff depending on its flare factor/frequency for its standard -24 dB minimum protection.
strange? In a three way all horn system...are you familiar with dr. Edgar horn designs?
Are you talking about the impedance inverter- type xover? That's not something I ever experimented with.
even though the question is not addressed to me, since I've been there and done that, optimal horn would be a tractrix horn 300Hz or thereabouts...
I kind of hijacked the thread. Sorry about that. I think I got my second spot of covid and I am a little out of it.
In his paper on horns, Kolbrek doesn't seem to think tractrix profile are as good at loading the driver as exponential or hyperbolic. Edgar horns are also tractix/catenary types, right?
How important is this point, practically speaking?
Did you use the trick of winding then HF coil to the LF inductor?
In his paper on horns, Kolbrek doesn't seem to think tractrix profile are as good at loading the driver as exponential or hyperbolic. Edgar horns are also tractix/catenary types, right?
How important is this point, practically speaking?
Did you use the trick of winding then HF coil to the LF inductor?
I rubbed elbows with Dr. Edgar for over thirty years. As far as midrange - and I'm sold on this - Tractrix rules. Where we differed - I much prefer rectangular mid range horns over round.
Absolutely! Just look at the profile comparisons........from this we see that each iteration (flare factor) from the pure bass horn's hyperbolic is moving towards conical's pure waveguide with all the good/bad this implies.
Also, we see that like any box alignment there's an optimum driver design range for each with tractrix being a popular mids-up compromise between loading/off axis response, but like its 'slower' expanding horns it too shrouds the off axis response too much for many, forcing high aspect ratio profiles and/or toeing in the speakers hence the popularity of 'faster' expanding and/or truncated tractrix variants or going with pure constant directivity horns.
In short, one is always 'robbing Peter to pay Paul', so it's a balance of design trade-offs based on the needs of the app.
