So essentially a large dome tweeter with a phase plug in front of it. I dont see that being anything new or revolutionary. The Celestion CDX1-1415/1425/1430 is made the same way. May not go quite as low, but certainly about as small. The DE111 isn't all that great considering the price, but in the case of this new compact driver, it likely fills the need as a smaller driver which can be tightly arrayed for more output and lighter weight.
The Celestion CDX1-1415 recommended minimum crossover is an more than an octave higher (2500 Hz vs 1000Hz) and has ~17mm larger height and 10mm deeper than the "HLX" B&C DH350. Similar power handling, but ~4dB less sensitivity.
Does the Celestion CDX1- series employ a radially twisted helical phase plug like the B&C "HLX" DH350/DH450 ?
Bennett Prescott's comment that the DH350 can achieve +5dB more output with the same IM distortion compared to their conventional phase plug DE111 using the same 36 mm (1.4 in) diaphragm is definitely something to consider for those planning to use the drivers at higher (PA) levels.
The DH350 also has higher sensitivity and smoother response in the 1.2k-4kHz range, reflected in the impedance response, simplifying passive crossover design while allowing a wider range of horn profile choices.
With only a 48 mm (1.89 in) overall diameter and the M5 heat sink mounting hole, a lot of them could pack in a small package.
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No, the 1430 doesn't have a twisted phase plug. It does however sound better than 99 percent of CDs for hifi use. Thats the only thing I'm interested in. I could care less about large scale PA stuff. I once did, but even so, most sounds guys have no clue how to do a decent live mix except for some of the old timers who are all dying off now.
As for the published curves, I'll believe them if I measure them myself. Most CDs I measure with a WG have a much worse impedance curve in reality. The only CDs I end up using for my builds in hifi or monitors are ones which don't have any peaks or significant wiggles in the desired passband.
With the exception of LF drivers, I dont use any drivers in their self resonant range. Unlike most speaker designers, I dont believe you can just EQ out a resonance and any audible trace or artifact just magically disappears, never to be noticed.
As for the published curves, I'll believe them if I measure them myself. Most CDs I measure with a WG have a much worse impedance curve in reality. The only CDs I end up using for my builds in hifi or monitors are ones which don't have any peaks or significant wiggles in the desired passband.
With the exception of LF drivers, I dont use any drivers in their self resonant range. Unlike most speaker designers, I dont believe you can just EQ out a resonance and any audible trace or artifact just magically disappears, never to be noticed.
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There are plenty of CDs out there which can be successfully used for hifi and monitor purposes. It all depends on your own priorities and how much coloration you're willing to accept in the specified range.
As I said, the impedance curve is your tell all for most bad traits. You can tell alot by just that and the rest can be figured out by a quick listen with a neutral EQ correction. You'll be able to tell the rough spots by listening to spoken word, vocals and piano notes.
The HD curve will typically reflect those findings as well. Distortion measurements can be tricky and aren't easily comparable to other people's like measurements. Most of time its the WG which shows problems but second to that comes the CD when it reveals its weaknesses either interacting with the WG or just being ill behaved on its own. There are people who believe the CD is mainly to blame.for most of the bad behavior, but WGs can have their own issues, with or without interacting with CDs. Alot of times its just an incompatibility issue between the two ie exit angle mismatch or expansion rate.
The two new B&Cs look promising, but I haven't seen any specific 3rd party reviews yet. I remember the fairal HF1440 getting a ton of following when it first came out but now it sort of has faded into the distance after the initial hype died down.
The Celestion Axi2050 also gets mixed reviews, despite it being used in the Klipsh Jubilee. I think that's mainly down to the coloration which each driver has and how pleasant or interesting it sounds with the other supporting hardware. There's always some coloration there and drivers with minimal amounts tend to be less popular than those with distinct colorations, especially with slightly higher amounts of K2 in the higher range. Very rarely do horn speakers sound clinical or dry, due this observation.
As I said, the impedance curve is your tell all for most bad traits. You can tell alot by just that and the rest can be figured out by a quick listen with a neutral EQ correction. You'll be able to tell the rough spots by listening to spoken word, vocals and piano notes.
The HD curve will typically reflect those findings as well. Distortion measurements can be tricky and aren't easily comparable to other people's like measurements. Most of time its the WG which shows problems but second to that comes the CD when it reveals its weaknesses either interacting with the WG or just being ill behaved on its own. There are people who believe the CD is mainly to blame.for most of the bad behavior, but WGs can have their own issues, with or without interacting with CDs. Alot of times its just an incompatibility issue between the two ie exit angle mismatch or expansion rate.
The two new B&Cs look promising, but I haven't seen any specific 3rd party reviews yet. I remember the fairal HF1440 getting a ton of following when it first came out but now it sort of has faded into the distance after the initial hype died down.
The Celestion Axi2050 also gets mixed reviews, despite it being used in the Klipsh Jubilee. I think that's mainly down to the coloration which each driver has and how pleasant or interesting it sounds with the other supporting hardware. There's always some coloration there and drivers with minimal amounts tend to be less popular than those with distinct colorations, especially with slightly higher amounts of K2 in the higher range. Very rarely do horn speakers sound clinical or dry, due this observation.
The Celestion CDX series basically IS a dome tweeter. Above is a pic of my CDX1-1425 that's been taken apart. As you can see, it's a plain ol' aluminum dome with a very simple phase plug attached.
I think it's possible that the improved performance may be due to a relatively low compression ratio.
IE, with 'conventional' compression drivers, you have a concave dome, typically titanium or mylar, and a phase plug with a very high compression ratio. Basically, 80-90% of the diahpragm is masked off.
With the CDX series, it's a convex dome (like any ol' hifi tweeter) and the phase plug is 90% open. Compression ration is around 2:1 I'd estimate.
The B&C neodymium compression drivers with 0.7" and 0.5" throats are built the same way, but the B&C uses some type of soft plastic, whereas Celestion uses aluminum.
More here: https://www.diyaudio.com/community/threads/diy-compression-drivers.317125/page-2
Yes,, I'd agree with you on the compression ratio. That definitely makes a difference, but it still manages good sensitivity, especially up top. Most CDs with inverted domes don't sound this good IMO. Installing some dampening in the back cavity of the 1430 improves it even more on the lower end and reduces the primary impedance peak somewhat.
The DE5 and DE7 are also pretty decent despite the crude phase plug. The smaller diameter help the too end alot compared to the theoretical 13k limit on 25mm throat drivers.
The 1430 also has ferrofluid, which explains why the same dome / diaphragm asy can handle more power in the 1430 vs the 1425 and 1415. I tested the 1430 with 40 watts continuous for 2 hrs and it survuved without any parameter change compared to being heavily broken in. I.havent found any better CD for dedicated HF use above 3k, with exception of the JBL 2407 and BMS 4538 on the QSC WG.
The copper shorting ring is also unexpected on the Celestion 1430. Don't be inclined to remove the FF thinking the top end will improve. It won't. It just adds more sizzle to the whole upper FR, as I suspect the FF controls the upper end breakup a bit.
If the new B&C DH350 can do better than the 1430 and also go lower cleanly. I'd give it a shot. I'd say its pretty closely comparable to the 1430 given the VC diameter and physical dimensions.
I'd want to experiment with open up the outer phase plug on the 1430 and trying it on a smaller, shorter horn for better HF dispersion. As it stands now, it sounds great on both the H1-7050 and STH100. Above 3k the 1430 sounds just as good as any larger metal hifi dome, maybe a bit more engaging too. Cymbals, horns and flutes are reproduced so cleanly and with great depth / width throughout the entire listening window, which is surprisingly wide with even the STH100. The slight edge goes to the H1-7050 though. I think the phase plug does show its limitations by the extreme top end, dropping off sharply like a rock. The 2407 does this too along with other ring radiator clones like the Eminence 151 and PRV D260. For the money, the D260 is amazing, being that it only costs 50 bucks retail. I use this one ALOT on small PA builds crossed above 2.5k on the ME20 and STH100 WGs. Below is DE260 on ME20 and 2 x Beta8A
The DE5 and DE7 are also pretty decent despite the crude phase plug. The smaller diameter help the too end alot compared to the theoretical 13k limit on 25mm throat drivers.
The 1430 also has ferrofluid, which explains why the same dome / diaphragm asy can handle more power in the 1430 vs the 1425 and 1415. I tested the 1430 with 40 watts continuous for 2 hrs and it survuved without any parameter change compared to being heavily broken in. I.havent found any better CD for dedicated HF use above 3k, with exception of the JBL 2407 and BMS 4538 on the QSC WG.
The copper shorting ring is also unexpected on the Celestion 1430. Don't be inclined to remove the FF thinking the top end will improve. It won't. It just adds more sizzle to the whole upper FR, as I suspect the FF controls the upper end breakup a bit.
If the new B&C DH350 can do better than the 1430 and also go lower cleanly. I'd give it a shot. I'd say its pretty closely comparable to the 1430 given the VC diameter and physical dimensions.
I'd want to experiment with open up the outer phase plug on the 1430 and trying it on a smaller, shorter horn for better HF dispersion. As it stands now, it sounds great on both the H1-7050 and STH100. Above 3k the 1430 sounds just as good as any larger metal hifi dome, maybe a bit more engaging too. Cymbals, horns and flutes are reproduced so cleanly and with great depth / width throughout the entire listening window, which is surprisingly wide with even the STH100. The slight edge goes to the H1-7050 though. I think the phase plug does show its limitations by the extreme top end, dropping off sharply like a rock. The 2407 does this too along with other ring radiator clones like the Eminence 151 and PRV D260. For the money, the D260 is amazing, being that it only costs 50 bucks retail. I use this one ALOT on small PA builds crossed above 2.5k on the ME20 and STH100 WGs. Below is DE260 on ME20 and 2 x Beta8A
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