BMS 4554 with my ATHEX 460-36: https://www.diyaudio.com/community/...-design-the-easy-way-ath4.338806/post-7428978
Essentially if you plan on running these all the way out to 20k without some kind of a LP filter, they’re all gonna have the breakup mode response ripples that people either describe as ‘harsh’ or ‘detailed’ except for the plastic diaphragm variants which have their own set of issues.
My long time favorite in this group for home us though is the Radian 745 For the overall smoothness of the response curve and the aluminum diaphragm whose break up mode is a little less chaotic than the titanium counterparts. The surround is damped with some kind of polymer which helps as well
You ‘can’ spend more but IMO, in this segment the higher cost is applied towards power handling and tour grade build quality, neither of which improve sound quality…..the Radian is as good as it gets.
The question you really need to answer first is how much that last octave of 10k-20k means to you and this is where a lot of horn speaker designs get it wrong. There’s no other way to slice this cake other than to accept the applied physics…..the larger diaphragm and throat aren’t the best at tackling high treble. ‘Home’ hifi use has been somewhat successful at tackling the issue with the 1” driver paired with a 12” woofer as the lower power handling but improved performance alternative. JBL continued for many years with the 1.5 and a titanium dome for 8khz on up, accepting the time alignment tradeoff for the smoother top end…..ymmv of course but if you’re heart is set on a 15” two way, I’d start designing around the super tweeter as less of an option and more a necessity. Best of luck whichever way you go.
My long time favorite in this group for home us though is the Radian 745 For the overall smoothness of the response curve and the aluminum diaphragm whose break up mode is a little less chaotic than the titanium counterparts. The surround is damped with some kind of polymer which helps as well
You ‘can’ spend more but IMO, in this segment the higher cost is applied towards power handling and tour grade build quality, neither of which improve sound quality…..the Radian is as good as it gets.
The question you really need to answer first is how much that last octave of 10k-20k means to you and this is where a lot of horn speaker designs get it wrong. There’s no other way to slice this cake other than to accept the applied physics…..the larger diaphragm and throat aren’t the best at tackling high treble. ‘Home’ hifi use has been somewhat successful at tackling the issue with the 1” driver paired with a 12” woofer as the lower power handling but improved performance alternative. JBL continued for many years with the 1.5 and a titanium dome for 8khz on up, accepting the time alignment tradeoff for the smoother top end…..ymmv of course but if you’re heart is set on a 15” two way, I’d start designing around the super tweeter as less of an option and more a necessity. Best of luck whichever way you go.
€400,- should buy you a 2" BMS Coax driver, €450 the small 1,4" B&C driver.
https://en.toutlehautparleur.com/br...axial-b-c-dcx354-16-16-ohm-1-4-inch-exit.html
Otherwise BMS4554 behaves very well at least up to 15/16kHz without these metal dome peaks.
https://en.toutlehautparleur.com/br...axial-b-c-dcx354-16-16-ohm-1-4-inch-exit.html
Otherwise BMS4554 behaves very well at least up to 15/16kHz without these metal dome peaks.
Have you ever heard the beryllium version? https://www.usspeaker.com/radian 745neoBepb-1.htm
What did you like/dislike about the sound?
Can the required equalization if done via DSP make them sound as good as if done with passive components?
I have not heard the Be diaphragms on any CDs……just dome tweeters……..and I’d be lying if I said I heard a difference with my Satori example. Measurements confirm the breakup mode is higher in frequency on domes and out of the passband of my hearing which at 56, is sadly limited to 13.5k level matched……..i can hear 15 and 16.3 with a 6db boost if that makes a difference to folks but I’ve had and made this argument before…….the highest note of musicality is the 4th harmonic of A7 played on a violin and it takes incredible skill from the player to excite it with any dynamics. Everything above that is just a huge cumulative of odd order harmonic…….like dog dander on a black marble floor.
The Radian drivers produce a smooth response……better than most on paper too. And they sound that way.
How they ‘sound’ is going to be heavily dependent on what horn you choose. I like the B&C ME90 when and even polar response is the goal…..and when it’s more about a smaller space and placement limitations, the Eminence H14EA is an excellent lens.
DSP will give you more design flexibility and faster results so in essence, yes….it can sound likely even better than passives in the case of mid/high CD drivers as the amp used can be chosen for such high efficiency and a reduced noise floor and a more stable impedance. No need for level matching using resistors…..just input gain staging. You won’t need much power for these so clean class A or Tube would be the way to go for these IMO…..you can use the cheaper class D or AB for the midwoofer.
Be sure to use the digital input on whatever DSP unit you choose……you want to avoid another AD/DA step in the process if possible, especially if you already have and use a high end DAC…..it would be redundant and better of eliminated from the signal chain.
IMO, high end crossover components can be really special, IF the designer is pretty gifted. The problem is always the coils…..no matter how good or expensive they are, they’re still a drain on the potential of the input signal. Some designers like a hybrid approach too as to preserve their love of high end caps…….but I think this is more about the coloration and expectation bias than anything else.
The Radian drivers produce a smooth response……better than most on paper too. And they sound that way.
How they ‘sound’ is going to be heavily dependent on what horn you choose. I like the B&C ME90 when and even polar response is the goal…..and when it’s more about a smaller space and placement limitations, the Eminence H14EA is an excellent lens.
DSP will give you more design flexibility and faster results so in essence, yes….it can sound likely even better than passives in the case of mid/high CD drivers as the amp used can be chosen for such high efficiency and a reduced noise floor and a more stable impedance. No need for level matching using resistors…..just input gain staging. You won’t need much power for these so clean class A or Tube would be the way to go for these IMO…..you can use the cheaper class D or AB for the midwoofer.
Be sure to use the digital input on whatever DSP unit you choose……you want to avoid another AD/DA step in the process if possible, especially if you already have and use a high end DAC…..it would be redundant and better of eliminated from the signal chain.
IMO, high end crossover components can be really special, IF the designer is pretty gifted. The problem is always the coils…..no matter how good or expensive they are, they’re still a drain on the potential of the input signal. Some designers like a hybrid approach too as to preserve their love of high end caps…….but I think this is more about the coloration and expectation bias than anything else.
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Based on much more recent experience I would not recommend current production PB950 on horns like the Yuichi A-290 and similar. They work well on some of the JBL resin/fiberglass horns though. They have a step in the throat which causes a discontinuity in the lower mid-range from memory. Gotta be other better choices. (I went to TAD TD-4001) The 951 might be OK, as far as I know it does not have a step in the throat. (I posted this because someone liked one of my posts extolling the virtues of the PB950 today and I have a very different feeling about it now.)
Attachments
As my room needs to be thoroughly evaluated, it's premature to speculate but I'm wondering if I would benefit from a 2nd speaker build with polars like these.
https://sphericalhorns.net/wp-content/uploads/2022/09/wn300alo_radpol_hrz-300x158.jpg
https://sphericalhorns.net/wp-content/uploads/2022/09/wn300alo_radpol_vrt-300x158.jpg
Using DSP rather than passive crossovers sounds like a shoe-in for a two-way speaker system https://www.diyaudio.com/community/attachments/possible-chain-png.822406/ , but wouldn't it rule out using two stereo DACs, as there would likely be clocking issues? Instead, a multichannel DAC, such as.
https://www.merging.com/products/interfaces/hapi
As for the passive crossovers which my Troy Crowe built three-way system will use, I think Troy will stick to Mundorf oil caps and coils, however good they are. And what the particular crossover design will be I hope he will share with me before building it. I do know that the passive crossover will be external to the speakers, so biamping of some sort is possible.
Is that “step” you’re referring to that eccentricity inside of the throat in that photo? How likely is that a manufacturing defect? If yes, why didn’t you return it to Radian to have them replace the defect part?
You said that the defect causes audible lower midrange discontinuity. Is that aberration something that can be measured and displayed as some kind of spectrograph?
However, you also said that yours and the “current” production runs of the 950 (close consecutive serial numbers) do work well on other horns, so could that eccentricity somehow not be a defect, or even an intentional feature of the throat geometry? Perhaps owing to my limited knowledge, I did have some trouble interpreting Vance Dickason’s measurements, otherwise both the 950 and 760 apparently measured very well in most respects. https://audioxpress.com/article/tes...eering-950pb-and-760neopb-compression-drivers
However, Vance evidently did no listening tests, and even if he had your experience proves that satisfactory performance with the 950 is very horn specific-likewise with Martin Poulin’s experiences with the Radian 760!
https://mapoulin.wixsite.com/audiobymartin/jmlc-measurement
https://mapoulin.wixsite.com/audiobymartin/radian-760pb-neo-on-340hz-jmlc
Might that same “step” eccentricity also be present in the 760 driver? Indeed, Martin found this driver’s measurements and/or sound quality also to be horn specific. https://mapoulin.wixsite.com/audiobymartin/midrange-test
Likewise, Alternative_Eye_3049 seems thrilled with his AH425/Radian 950Be combo.
But might this harrowing dice roll also be true of my NOS Radian 745Bes? https://www.usspeaker.com/radian 745neoBepb-1.htm
Given your startling and serious news, I am glad for Troy Crowe’s available driver/combo options, which I’ve had the opportunity to hear at some length last month. I generally found Troy’s ES450/DCM50 combo/Fostex T96A + waveguide delivered satisfactory sound in most if not all respects, except for less spaciousness than I had hoped for. I suspect that might be due to room acoustics and/or the size of this exponential horn.
https://josephcrowe.com/products/3d-cad-files-horn-no-1994-es450-biradial-for-jbl-2446-2-throat
https://cdn.shopify.com/s/files/1/0...ot_2023-10-14_170306_480x480.png?v=1697317415
Presumably, there would have been a greater sense of expansiveness if the system heard had used this horn.
https://josephcrowe.com/products/3d-cad-plans-for-es-290-biradial-horn-horn-no-1670
https://cdn.shopify.com/s/files/1/0...BMS_4591-8_off-axis3_480x480.png?v=1649504045
I had considered purchasing a pair of 760Bes and have Troy test them in the ES290 but given yours and Martin Poulin’s experience with the unpredictable performance history of Radian driver/horn combos, buying the 760Bes seems unwise anytime soon. Alternately, I thought to have Troy test my Radian 745Bes but only if the ES290 horn he had available in his test bed had a 1.4” entrance hole, which is very unlikely. And I’ve been sufficiently warned against using/testing throat adapters with any driver, much less with these unpredictable Radians.
Instead, I think it’s wiser to test and hopefully use my 745Bes or the Radian 760Bes with a CD horn for a two-way system in another speaker build, after sufficient room data can be evaluated for choosing compatible CD horn/Radian 3” Be diaphragm driver.
So, the build to go with now looks like the Athos ES290/”newly improved” DCM50 combo and T96A+waveguide, assuming those big horns can safely sit on my midwoofers cabinets.
The *eccentricity" is caused by the angle at which the picture was taken is and not the issue. The step he is talking of is the lighter coloured ring in the back of the throat which is causing a discontinuity.
Regards
Charles
Regards
Charles
Thanks, but how likely is Radian Engineering aware that this condition-whether an intentional part of the design or not-is causing this lower midrange performance degradation? And so there's no way to correct that-other than pair the 950 driver with another horn at random-and hope that the combo doesn't generate this lower midrange artifact?
And this same condition exists in most Radian 950Be drivers?
And most of these?
https://www.usspeaker.com/radian 760neoBepb-1.htm
And most of these?
https://www.usspeaker.com/radian 745neoBepb-1.htm
How can I tell if my NOS pair of 745NeoBes have the defect?
It is the circle highlighted by my arrow, in the back of the throat.
And no it is not a defect, it is sadly produced like that.
Why return something you have bought that the manufacturer says is "within specifications"?
The 951 is a better bet, the 950 is a 951 with that adapter that has clearly been altered at some point.
As has been stated many times before.
Since you referred to audioxpress/voice coil mag, go look up the 4015Be review and you will see the effect of a similar throat debacle made by the reviewer.
No it is a native 1,4" exit.
Look into the throat opening of the driver? use a concentrated light source if necessary for a good view.
But they do not have it.
And it is not a defect.. It is a part that has been purposefully machined and fitted to a 951PB "base", as to make the 950PB.. But that detail was not so in some of the earlier produced drivers for sure.
As for the 760 it did not use to be like that either, is all i can say for sure. Look at the picture and you can see the expansion in the throat, not just a abrupt step.
Radian 950PB datasheet is last pic, take a close look at the picture. what do you see? 🙂
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Maybe others read so here, but not I.
Finally, some good news for change. Thanks.
Depends on your room, your personal preference and your favorite recordings……there’s no reference anywhere here…..purely subjective and open to interpretation.
keep distortion at bay….keep phase close to quadratic…..that’s the protein……everything else is seasoned to taste.
some ancient truth…..run a quality 15” woofer from 50hz to 800hz ……..that’s all the fat and flavor right there.