I believe that I finally found a good 12" neo coax that doesn't cost a fortune and has the build quality of a more expensive driver.
I ordered a pair of Eminence KL3012CX8 and was pleasantly surprised when I examined then a bit closer.
One of the key things critical to a good coax that uses the cone as a horn flare is a smooth transition from the horn throat to the cone. The KL3012CX8 has a smooth radiused pole piece that provides a very even tapered transition. I dont believe this was always the case for this model driver. Reason is that I recall Erich from Diy Sound Group working with Eminence on a new coax design for his Vortex line. The machined pole piece section looks almost the same on the stock Eminence KL3012CX and the Vortex 12 driver. Its possible Eminence adopted this design feature for they're drivers as well. I tried taking a picture of the pole piece through the screened dustcap. Hopefully its visble enough.
I haven't run any tests on this driver yet, but will put it through its paces hopefully soon. It looks like it will make well with the Celestion CDX1-1745 and maybe the B&C DE250 with the right adapter. A separate adapter allows you to visually check the taper and transition inside the throat and modify it if need to. A screw on driver won't allow for this.
I ordered a pair of Eminence KL3012CX8 and was pleasantly surprised when I examined then a bit closer.
One of the key things critical to a good coax that uses the cone as a horn flare is a smooth transition from the horn throat to the cone. The KL3012CX8 has a smooth radiused pole piece that provides a very even tapered transition. I dont believe this was always the case for this model driver. Reason is that I recall Erich from Diy Sound Group working with Eminence on a new coax design for his Vortex line. The machined pole piece section looks almost the same on the stock Eminence KL3012CX and the Vortex 12 driver. Its possible Eminence adopted this design feature for they're drivers as well. I tried taking a picture of the pole piece through the screened dustcap. Hopefully its visble enough.
I haven't run any tests on this driver yet, but will put it through its paces hopefully soon. It looks like it will make well with the Celestion CDX1-1745 and maybe the B&C DE250 with the right adapter. A separate adapter allows you to visually check the taper and transition inside the throat and modify it if need to. A screw on driver won't allow for this.
Attachments
http://www.loudspeakerdatabase.com/Eminence/KL3012CX-8
https://eminence.com/collections/neodymium-series/products/kl3012cx_8
Seems to come without compression driver, on sale 269$
https://eminence.com/collections/neodymium-series/products/kl3012cx_8
Seems to come without compression driver, on sale 269$
I'm trying to find a good adapter that will accomadate my 18sound NSD1095N. This driver uses that smaller 4 bolt pattern and the adapters I have which fit nicely in throat diameter are all drilled for 3 bolt and not large enough in flange diameter to be used for the 4 bolt pattern. The DE250 and CDX1-1745 both fit fine on the adapter, but the studs are too long to fully screw it on the coax driver so it bottoms out on the coax magnet asy. All the other adapters I have are drilled slightly too large for a smooth transition into the pole piece to avoid abrupt steps in the internal horn flare. I wish doing a 3D printed adapter wasn't such a big fuss with the thread being a complex model to create in CAD. I've never had decent luck doing this in the 3D design realm. A custom adapter would also bring the driver as close to the coax as possible for best time alignment.
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When you factor in the issue of needing a suitable adapter, it becomes a challenge to find one that works with the driver's exit angle and mounting format. It does help with getting the transition as smooth as possible m, which to me is more important than most other potential issues which occur on driver's that have a set type of CD you're stuck with. I have a plastic adapter that has the correct bolt pattern but runs on the large side and will cause issues in the throat.
I don't like the way it sounds. It has a very rough top end that is fatiguing to my ears. I'm not a fan of most Ti drivers, specifically the ones that have a Ti surround.
I see. That BMS mentioned above might be interesting then as it’s a polyester membrane and seems to have a smooth roll off in both directions from 3,5kHz up and down.
Another option could be the Selenium D250X with its phenolic membrane. But that’s actually a midrange. Not sure how that would work in a short flare like the coax is. Could be interesting with a high level low order high pass and see if it can flatten the behaviors. Like 1st order 10kHz.
Another option could be the Selenium D250X with its phenolic membrane. But that’s actually a midrange. Not sure how that would work in a short flare like the coax is. Could be interesting with a high level low order high pass and see if it can flatten the behaviors. Like 1st order 10kHz.
Ti is more commonly used in PA due to it's robustness.
For home, some listeners find the "brightness" in the treble objectional.
Personally, I prefer aluminum over Ti. My favorite are JBL 2420, Emilar and Radian.
I've used the d220 with pretty decent results in PA applications given it was crossed a little higher than usual. It had some bite in the lower mid that I couldn't live.with, but otherwise it had good clarity and musicality for a cheap driver. I also like the d205 crossed a little higher.
I don't regard the KL3012CX as a cheap driver at all. It has some expensive features which make it worthwhile using a decent CD with. My preference are generally the same for 1" drivers ie NSD1095N, DE250, CDX1-1745, CDX1-1730, HF108 (my.favorite to date). I haven't settled for a xover yet, but suspect it being in the lower 1k area. The drivers are more or less going to dictate that.
I don't regard the KL3012CX as a cheap driver at all. It has some expensive features which make it worthwhile using a decent CD with. My preference are generally the same for 1" drivers ie NSD1095N, DE250, CDX1-1745, CDX1-1730, HF108 (my.favorite to date). I haven't settled for a xover yet, but suspect it being in the lower 1k area. The drivers are more or less going to dictate that.
ok. are you sure it was the driver and not implementation? i only have a -5db horn loading eq around 2khz on a JBL PT waveguide. I can blast D220ti at any volume without harshness. i also tried B&C DE250, it felt slight more rounded over but less precise. not worth the price at all...
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You may want to tame the resonant peak with a conjugate network.
That may remove the lower mid bite.
Yes, I tried that but wasn't satisfied with the results. The resonant signature was still there.
I have several drivers to test on this coax and waiting for the other driver adapters to show up so I can try them all with the same measurement setup for consistency sake. The other issue is my laptop battery having died AGAIN, so that also needs addressing before I can break out my Clio and DATS setup.
The one question I do have for those of you high efficiency coax guys- do the high pressure waves from the LF section negatively affect the HF driver diaphragm loading ie increased IM distortion? I would think this can be an issue if the speaker is driven harder?
I have several drivers to test on this coax and waiting for the other driver adapters to show up so I can try them all with the same measurement setup for consistency sake. The other issue is my laptop battery having died AGAIN, so that also needs addressing before I can break out my Clio and DATS setup.
The one question I do have for those of you high efficiency coax guys- do the high pressure waves from the LF section negatively affect the HF driver diaphragm loading ie increased IM distortion? I would think this can be an issue if the speaker is driven harder?
Your results may in part be due to the PT WG. It tends to blend the throat transition from the driver to WG better than most WGs reducing resonances and reflections. I do agree the D220 is better at HF detail compared to much more expensive plastic diaphragm drivers. The DE250 can be good if the HF EQ is done right. It definitely is less fatiguing than the D220 in the mids, even with flat EQ. There are some ways to tame the D220 by modifying the rear chamber dampening with some felt. The stock D220 doesn't have any dampening in the back chamber. The Celestion CDX1-1430 is by far the most hifi sounding driver up top. It has the best HF extension of any reasonably priced 1" driver I've heard so far and isn't fatiguing either.