Here are my finished speakers based on the Spanish Beyma drivers (12XA30/Nd). Box is only 30ltrs and ported due to very low Q of drivers. There is bracing and dampening inside and very simple external Xover at 2Khz. Over all efficiency now is 98db. Built these to work with my low power tube and SS amps. Drivers are rated to 350W! There is not much low bass and therefore I use them with my powered stereo sub-woofers (pictured).
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Very nicely done. I use a smaller 8" coax Beyma for my main speakers. Are you happy with the sound? Also, where did you source the speaker grilles? Do they have an impact on the sound?
Grills are off when speakers in use. I'm enjoying the sound. Reverb is three dimensional still balancing woofer and tweeter. My 2.5W 6EM7 amp plays real loud through these.
Nice! I briefly auditioned a pair on OBs awhile back and was impressed overall, but its HF was a bit too sharp/grainy for me, so was wondering if they have Ti diaphragms.
GM
GM
The HF unit of the 12XA30Nd is basically the CP755Ti and uses its diaphragm, so yes, a Ti dome.
The sharpness also come from resonances inside the back chamber, if you damp the chamber it improves quite a bit.
I used its bigger brother, the 15XA38Nd (Avatar pic), for quite a while in a fully active DSP-driven OB project...
The sharpness also come from resonances inside the back chamber, if you damp the chamber it improves quite a bit.
I used its bigger brother, the 15XA38Nd (Avatar pic), for quite a while in a fully active DSP-driven OB project...
When I was looking around for a high efficiency driver to base this build on I know I read some where that the domed tweeter was titanium. But now I cant find where that is written.
Good to know, thanks! FWIW, I use to airbrush a mist coat of Dammar on early Ti domes to good effect.
GM
nice - according to spec that's a 4" woofer coil ! - I've got light motor Beyma 12cx - their qts measured higher than spec - the woofer is more extended than Beta 12cx and the tweeter much like an APT50 IIRC.
http://www.diyparadiso.com/datasheets/speaker/beyma/12cx.pdf
http://www.diyparadiso.com/datasheets/speaker/beyma/12cx.pdf
Got to play the Beymas with my 0.5W UX-171A amp and new tube and Pass B1 preamp yesterday. Hard to believe the amp is just 0.5W. I had the tweeter section padded down 6 db. I have now only padded the tweeter down 1.5db for a big improvement in sound and of course more volume. I'm really starting to love these Beymas.
Is it possible to Buy the Beyma from Australia.?
I have looked at Altec & Etone, both don't seem very keen to sell. when i rang etone the chap who answered seem to think West Australia was on the moon.
I would like a 15 or 18 inch driver with very low QTS. 0.25.
tried a Chinese made Neo driver but the QTS was .75 not .33 as claimed. Too boomy!! and sensitivity 93Db not 98db.
Phil
I have looked at Altec & Etone, both don't seem very keen to sell. when i rang etone the chap who answered seem to think West Australia was on the moon.
I would like a 15 or 18 inch driver with very low QTS. 0.25.
tried a Chinese made Neo driver but the QTS was .75 not .33 as claimed. Too boomy!! and sensitivity 93Db not 98db.
Phil
It is a coaxial speaker, not a fullrange speaker.
But, in general quite a good brand, think about them as the European pro level JBL.
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