Beyma Studnio - for example 12BR70. Will try post ejmlc300 measurements asap. Crossover in 2" coaxial BMS: 1-2uF capacitor. Ringradiator - all BMS drivers (and some JBL too).
This is a question for Erich: DIY Sound Group
From Poland shipping is about 100$ (<5kg). From US ca. 80$ (?)
From Poland shipping is about 100$ (<5kg). From US ca. 80$ (?)
Let us know what you find. It's definitely looking the same or cheaper to ship straight from autotech.pl to Australia ... I've queried some pricing from them. If they go close enough to the GB pricing, then I looks pretty sure that Aussies should just order direct.
Here are some horizontal measurements of the IWATA + TAD 1402.
An externally hosted image should be here but it was not working when we last tested it.
Yeah the worksmanship on these speakers is very nice. If BMS was an option on the Geddes speakers I would have opted for that, but I have a feeling that the extra cost and hassle wouldn't be worth it to him as a vendor. Basically you get a small improvement in performance at the cost of a new crossover and more expensive compression driver.
The shape of the diaphragm and phase plug makes a big difference in the directivity of waveguides, and this is one of the reasons that the BMS is quite interesting. As I understand it, the ideal wavefront is planar, like a flat disc. That's why dome tweeters don't work well on waveguides. (IE, they work, but their perfromance is 2nd rate to a compression driver.)
But the BMS diaphragm, as you can see in my pic, gets closer to that ideal.
Oddly enough, the phase plug on the BMS is quite crude. I'm not sure if this is because the ring radiator doesn't need a complex phase plug, or if they were just being cheap.
If anyone wants to learn a lot about directivity, grab a microphone and try making phase plugs. It's a real education.
There's an art and a science to getting that wavefront 'correct' at the throat.
It's also one of those things in audio that's "fractal" in nature. If the wavefront at the throat of a waveguide is screwed up, the problem propagates all the way to the mouth. This is kind of interesting I think, because a lot of improvements in audio are very incremental. For instance, swapping out a cheap inductor for an expensive inductor makes an incremental improvement. But getting that wavefront 'correct' has an effect on nearly everything. Frequency response, phase response, group delay. It's a very substantial effect.
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Glad to see some movement on this thread! And the plot thickens...there is now a smaller Iwata 600 for a 1" comp driver. Thanks for the measurements on the E-JMLC-300 jzagaja. Sounds like you're staying busy over there in Poland. Could you post some measurements for the Iwata 600 ?
As far as choosing a waveguide/reading these Directivity sonograms, what do people think about an Iwata 300 VS. a E-JMLC-300 ?
The E-JMLC-1000 with the BMS 4538 looks very nice to me. Crossover would have to be in the 1.5k area though.
Im wanting to build an actively bi-amped two way system for home listening and would like enough extension at the top to forgo a super tweeter and enough extension at the bottom to cross below 1k. Would consider 2", 1.4" or 1" comp drivers if possible, poly diaphragms preferred although their top end seems a bit limited.
Patrick ,the Faital Pro HF200 2" titanium diaphragm driver seems to be getting some use/interest on other forums. Not sure about the shape or phase plug style used though. Ive heard systems using 1" Beymas and B&C's . Still havent heard any BMS athough everyone seems to praise the build/sound quality.
Thanks everyone, Daniel
As far as choosing a waveguide/reading these Directivity sonograms, what do people think about an Iwata 300 VS. a E-JMLC-300 ?
The E-JMLC-1000 with the BMS 4538 looks very nice to me. Crossover would have to be in the 1.5k area though.
Im wanting to build an actively bi-amped two way system for home listening and would like enough extension at the top to forgo a super tweeter and enough extension at the bottom to cross below 1k. Would consider 2", 1.4" or 1" comp drivers if possible, poly diaphragms preferred although their top end seems a bit limited.
Patrick ,the Faital Pro HF200 2" titanium diaphragm driver seems to be getting some use/interest on other forums. Not sure about the shape or phase plug style used though. Ive heard systems using 1" Beymas and B&C's . Still havent heard any BMS athough everyone seems to praise the build/sound quality.
Thanks everyone, Daniel
Unless you have very deep pockets, a lot of time, and a very large room, I'd scale back your goals.
When you try and push a waveguide past four octaves, it gets very VERY VERY difficult to make it work. If you opt for a larger throat or a larger diaphragm, your high frequency response goes to hell. If you opt for a smaller diaphragm (a la BMS 4538) you trade low-frequency extension for high frequency extension.
A couple of pages ago, there were pictures of Radian compression drivers with beryllium diaphragms. I think that's a great example of what I'm arguing here. Those diaphragms will buy you another half octave of output, but the driver and diaphragm cost about as much as TEN "run of the mill" compression drivers.
If I had a clean sheet of paper, and six months to blow in the garage, the end result would look a lot like a Gedlee Nathan. Four octaves of bandwidth from the compression driver, four octaves of bandwidth from the woofer, and some subs to pick up the low end. This is a damn-near bulletproof set of compromises. A crossover frequency around 1300hz give or take 15% is a great solution IMHO
Off the top of my head, here are some dollar figures :
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Celestion CDX1-1425 ($70) + your choice of horn or waveguid ($50 to ???) - for a hundred and twenty bucks, this will get you four octaves, from 1500hz to 24000hz
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B&C DE250 ($129) + your choice of horn or waveguide ($50 to ???) - for $179, this will get you four octaves, from 1000hz to 16000hz
Radian 950PB ($400) + Beryllium diaphragm ($600) + your choice of horn or waveguide ($50 to ???) - for $1050 bucks, this will do 500hz to 18000hz. That last half an octave just cost you $1860 per pair.
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Please wait until we finish Iwata-600. Remember - large horns no matter what you do don't spread HFs as wide as SEOS/EOS/OS and require rather large room above 30m2. I doubt you could find any better than BMS ringradiators (4550, 4538, 4524, 4590). On waveguides they require very simple filters.
My suggestion - hi-end 3-way system based on SEOS-18 or 15 and four Beyma 6MI90 V-shaped in short conical horn, MTM. Active distributed subs with hypex DSP. This will be small advanced system that fits most rooms well.
My suggestion - hi-end 3-way system based on SEOS-18 or 15 and four Beyma 6MI90 V-shaped in short conical horn, MTM. Active distributed subs with hypex DSP. This will be small advanced system that fits most rooms well.
Where on earth do you keep all these molds?
A quarter of my garage is already a mess of waveguides, molds, and science experiments.
And my biggest waveguide is 12" across
Autotech has few thousand molds and audio is only a small part "for fun":
http://www.autotech.pl/pdf/firma.pdf
CDX1-1425 - I heard it's best sounding HF driver, haven't tried yet.
http://www.autotech.pl/pdf/firma.pdf
CDX1-1425 - I heard it's best sounding HF driver, haven't tried yet.
That's very interesting! What a great idea for this project. I live in the Pacific Northwest, and because there are so many boatbuilders, there are a lot of places that have the skills to build horns and waveguides. But the cost is prohibitive, because it's time consuming.
About a year back I looked into having some waveguides injection molded in China, and the numbers just don't work out unless you can figure out a way to sell hundreds/thousands.
So doing these "on the side" at your facility is a great benefit to the DIYer.
I like the BMS too, but here in the states the wait to get them can be long, and the Celestion gives good "bang for the buck."
If I was in Europe, BMS would be on my short list. Here in the states it's easier to get Eminence, B&C, Selenium, etc...
Right down the road!
QSC Audio Products, LLC.
1665 MacArthur Blvd. Costa Mesa, Ca 92626
Dir: 714-327-4664 Fax: 714-754-6173
QSC Audio Products
SP-000086-GP
It's a nice alternative to the BMS 4540ND. I am not aware of another compression driver that can go above 15khz at this price.
If QSC won't sell it to you it's availabe here too:
GP Acoustics (UK) LTD Celestion CDX1-1425 High Quality Lightweight Compression Driver Speaker Cabinet Components at Markertek.com
Have you seen the measurements for the TAD 2" CDs....those are the best period when it comes to 2" CDs. The BMS 4590 is also a great 2" choices.
IMO, the IWATA-300 deserves a 2" CD. Its pointless to have a large horn and not XO it below 500Hz. 2" CDs give us a lower XO point. If someone has a hard on for directivity > 10KHz then they can add a super tweeter or similar.
Its all choice, there are 1000s of JBL screen array systems with 2" CDs used for HF and all my testing so far with the TADs tell me that for me there simply isnt enough difference > 10KHz vs my Ribbon design for me to fuss over. Im loving the TADs but now I have make sure the BMS 4590s are good.
FWIW, I have the CDX 1425 and the CDX 1745. Im the one that sent the CDX-1425 to augerpro for measuring (on the QSC HPR 121 waveguide).
The 1425 can not be XOed below 2KHz so I find zero reason to use it vs the 1745. If Im buying celestion, Im buying the 1745 from QSC parts store.