Have you ever heard a beryllium driver in a 4001 horn? Or maybe the Yamaha JA6681B?
Or? https://www.sbaudience.com/index.php/products/compression-drivers/rosso-65cdn-t/
I have a pair of Radian 745neoBe https://www.usspeaker.com/radian 745neoBepb-1.htm which I had considered using in a pair of JMLC AH425 above Altec 416-8B midwoofers after reading about this Reddit poster's build.
But I learned today that his Radians are the 950Be , so the larger 2" diaphragms (and maybe also the 4" voice coil??) likely account for the immensity of the 3D sound stage he raves about. https://www.usspeaker.com/radian 951Bepb-1.htm
As much as I might be inclined to use the 745Be, if I wouldn't get that exact same kind of presentation in a two-way system then no. I can't afford any TAD drivers, but from your experience with them it's just as well. I emailed Radian if they would take an exchange for these brand new 745Be drivers and pay the difference but they declined.
I didn't ask about these https://www.usspeaker.com/radian 760neoBepb-1.htm or https://www.usspeaker.com/radian 850Bepb-1.htm
They are 2" diaphragms but have 3" voice coils.
Presumably, the only other beryllium alternative for a two-way would be to a pair of these https://www.usspeaker.com/homepage.htm then swap out the alumium diaphragms. US Speakers has Materion Be diaphragms for the JBL 2450 but at $2.3K pair the total cost is too high to risk without hearing such a system first.
Any alterative non-beryllium driver options for two-way system with AH-425 horns and my midwoofers?
https://josephcrowe.com/blogs/news/altec-416-8b-in-100l-sealed
Alternatively, if I was going three-way in a biradial horn, how would that Community M200 midrange compare with the B&C DCM50?
The 950 has a 2" diameter throat exit, and a 4" dome shaped diaphragm with a 4" voice coil.
The 745, 760, and 850 all use a 2" diameter throat exit, and a 3" dome shaped diaphragm with a 4" voice coil.
Be has better HF response than aluminum or titanium, so could improve sound stage detail by comparison.
The larger diaphragm is capable of more clean low frequency output than the smaller, but worse HF response.
The Community M200 has a 2" diameter throat exit, and a much smaller 2" dome shaped diaphragm with a 2" voice coil.
It has no phase plug, and it's compression ratio is only 1.84 /1, typical compression drivers have ratios more like 10/1.
Having no phase plug limiting excursion, and a much larger suspension, it's excursion can be greater than a typical 2" dome diaphragm high frequency compression driver.
The lack of phase plug creates a -20dB 2/3 octave wide cancellation dip centered at 5kHz, ~4kHz is its usable "Hi-Fi" limit.
The B&C DCM-50 has a 2" diameter throat exit, and a 2" diameter voice coil, but uses an annular ring cone shaped diaphragm.
The 2" interior of it's ~4" diaphragm makes no contribution to output, and is covered by it's phase plug.
It has less excursion potential, but far more Sd than the Community M200, so probably has a bit more low end output potential.
It's response is fairly smooth to 7kHz, so can be crossed higher.
Art
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According to these specs the 745Be has a 1.4" diaphragm and a 3" voice coil. https://www.usspeaker.com/radian 745neoBepb-1.htm
True, the Reddit poster made no mention of the HF response, and his reply only confirmed the Radian drivers he's using. He uses the NCore plate amps with some kind of DSP. https://www.madisoundspeakerstore.c...SWjWP4Q-KbT-wMBQ6AmxQSExoL3Tbx0hoCNzMQAvD_BwE
Besides, the crossover, who knows if it also allowed him to generate the contouring filter to flatten and extend the Radian 950Be's response-as Pierre had to perfect passively for the 745Be https://www.diyaudio.com/community/threads/beyond-the-ariel.100392/page-764
Presumably, the BMS4592 coaxial would need no such filter. Perhaps that's one reason why Arnaud Le Gac pretty much trashed the Radian 745Be and recommended the BMS4592. Docali recommend his horns but didn't specify model. https://alg-audiodesign.com/pavillons/
Here's today's reply:
Hello
Concerning the choice of drivers I would rather recommend the BMS especially for a 2-way system. The fact of being in Coax allows greater freedom in the choice of the frequency cutoff and even if the altec 416 is a speaker that can go quite high without difficulty, it is easier to find a balance by varying this cutoff value with a driver that goes down to 300 Hz.
On the other hand I have already had the opportunity to test the Radian 4592 beryllium and I was very disappointed by the result. The sound is very "hard" to listen to if we compare it to the TAD 4001 beryllium too and it is a driver that ultimately does not go up in the treble, we observe a big attenuation from 10 kHz and suddenly without recovery with another element it will lack detail and precision in the high end of the spectrum.
For the horns, there are several possibilities, but I would recommend (still for a 2-way configuration) the Kinoshita RH3. They will allow you to go a little below 400 Hz with the BMS but also to be able to have a good result for everything else (same type as the Ray Audio configuration with the RM series) The TAD is a little less open therefore more directional and the Arai 290 will also be quite directional and will preferably require to be integrated into a 3-way system.
To summarize, for a good balance quite malleable without too much directivity my choice would be the Kinoshita RH3 with the BMS 4592 driver.
The last solution which would be for me even more successful would be to go with a 15-cell horn. It easily goes down to 300 Hz, has no directivity at all and allows to have very soft treble with a significant detail. But which is no longer in the same budget or the same size.
https://www.facebook.com/arnaud.legac.9/
His multicell price plus shipping, Trump tax make those no option; and they look to be too big for my Altec cabinets. Too bad.
What do you think of that Kinoshita RH3? I wonder if it's anything like the crazy expensive Yamamoto SS-300 that Marco recommended for the JBL2450J or other 2" drivers.
However, Arnaud said he only has customers on the west coast, so no chance for me to hear them. At least if he had Geddes plots or waterfalls of the horns at his website. Maybe will ask.
But if I do go three-way how would you describe the tonality and potential sound stage size of the M200 vs the DCM50?
Pooh here referred to the Community M200A. How different is it from the M200, which Biamp told me today is still in production?
You might want to check out Horneydude and John Sheerin's replies.
https://www.diyaudio.com/community/threads/beyond-the-ariel.100392/page-779
As above, Arnaud likes the BMS4592 coaxial but Pooh here said": Well I've had the BMS and thought it was "bleached out" and resonant sounding, and not in a good way.
Implementation issues or flaws in driver design?
JBL rebadges BMS drivers. do you know anybody who uses Radian at all ? i don't.
why buy a driver just for material used ? don't you think other companies have access to Beryllium ? Radian uses it because they have nothing else going for them.
if RCF or some other real deal company made a Beryllium driver i would say go for it. Radian ?
Porsche 911 has engine in the worst possible location - and is still the best sports car - because it's a Porsche
buy reputation not gimmicks
why buy a driver just for material used ? don't you think other companies have access to Beryllium ? Radian uses it because they have nothing else going for them.
if RCF or some other real deal company made a Beryllium driver i would say go for it. Radian ?
Porsche 911 has engine in the worst possible location - and is still the best sports car - because it's a Porsche
buy reputation not gimmicks
No, it says the throat (the part that connects to the horn) diameter is 1.4", it's 3" dome diaphragm is surrounded by a 3" voice coil.
Generally, one chooses a driver horn that matches the horn's throat diameter to avoid using throat adapters.
The driver's throat diameter won't describe what is behind the throat any more than a car tire rim size determines the tire diameter or how the tire might handle with a particular suspension.
The annular ring tweeter diaphragm of the BMS4592 has less mass rolloff than a 2", 3", or 4" dome diaphragm, so would require different filters to achieve the same upper frequency response.
A co-axial requires two sets of filters.
Every different compression driver requires different filters to achieve the same target frequency response.
If compared without filters, a driver with more midrange or less high frequency could be said to "lack detail and precision in the high end of the spectrum", or could also be said to said to sound less "harsh", and have more "weight".
It is a wide horizontal dispersion bi-radial distributed source horn, I think it would sound like that type of horn. I've never heard one of that type of horn with a BMS 4592 co-ax driver, and don't know how well the top octave would distribute through the exponential distribution diffraction section.
The horn determines most of the sound stage, and the filters used determine most of the tonality.
The DCM50 can be used almost an octave higher than the M200.
The M200A still dies at 4kHz, but response above is more attenuated than the M200, simplifying the filters required crossing over to a tweeter.
Without filters, the reduction of the 7kHz peak would make it sound a bit more "dull" when used as a paging (public address) driver.
Art
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You must be joking.
Radian/Emilar drivers sound absolutely great.
Many French Audiophiles used the 475pb when they could not afford the TAD 2001.
Right after Meyer Sound ditched the
MS 1401a (Yamaha JA6681b) they used a Radian driver until they came up with their own design. Radian drivers are used in many cabs of respected Brands.
My Radian 850pb was not far behind the JA6681 from 500hz on up extending past 18khz putting out nice high frequency. With a bigger back cover having good absorbing material it could be further improved for domestic use.
All my 1" Emilar/Radian Renkus Heinz drivers are smoth and detailed but should not be used below about 1khz.
BTW some Sound Engineers reportedly use Radian diaphragms in their Augspurger Monitors because they get listening fatigue from the Beryllium equiped TAD drivers.
Klaus
Which seems to be another reason to avoid using the 1.4" throat Radian 745Be. Indeed, Marco said here at post # 228 that the 4001 horn was designed for a 2”, not a 1.4” throat driver, thereby avoiding the need for an adapter, which presumably can cause resonances or other errors if its geometry doesn't interface perfectly with the driver and horn.
https://www.diyaudio.com/community/...001-clones-makers.375215/page-12#post-7801875 ,
And I think these are both 1" horns which would therefore need a 1/4" adapter for the 745Be. https://audiohorn.net/x-shape-horn/
https://audiohorn.net/next-gen-bi-radial-horn/
Ditto for Troy Crowe's. https://josephcrowe.com/collections/300hz-horns
It seems that 2" drivers are more popular than 1.4" ones because many builders prefer two-way speaker designs to maximize coherency by omitting a tweeter, if possible, such as with drivers like the JBL2450, as Marco seems to be saying. But also, to optimally cross with the midwoofer to minimize distortion and beaming from both drivers, even if a tweeter needs to be added, like several of Troy's speakers. But most rich investors get consistently richer via military stocks, so I guess we won't be seeing sane prices on the 2" Radian 950Be and/or Materion Be diaphragms for a long time.
Regarding driver tonality, how much or in what way does "voicing" (?? what kind of EQ filter animal is that??) impact the sound of a driver in a system compared to its diaphragm material, structural design and/or Theil/Small parameters? And can voicing just as successfully be implemented via a Windows software plugin versus a hardware wired passive or active filter?
How much would this be an example of voicing: When Troy added that 6.8uf cap in the signal path (across the power amp inputs?) to change the response of the and somehow also the tonality of DCM50? https://josephcrowe.com/blogs/news/es-450-biradial-no-2143
I think that’s what I will be hearing next month when visiting Troy’s customer who has the ES450 horns.
I may find them very pleasing. OTOH, as Pierre might say, how much more desirable would a pair of neutral sounding beauty/garbage in/out pair of Radian 950Be be instead? And in what way to “voice” them, if at all?
Or as Troy and/or Pierre might suggest, a 45 or 300BSET, Sony VFET or my First Watt J2 amp (if Troy can keep system impedance well above 8 ohms for it) https://www.stereophile.com/content/first-watt-j2-power-amplifier-measurements , as many horn speaker owners seem to find measured amounts of 2nd harmonic distortion to be pleasing?
However, voicing or not, please suggest other 2” drivers which might the most like the Radian 950Be and the JBL 2450J Be, even if I had to do a three-way.
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The "old school" large format Tad 4001, JBL 2450 4" diaphragm/2" exit drivers share the same long throat taper going back to the Western Electric days.
Altec Lansing used a 2.8" diaphragm with a 1.4" exit with about the same taper.
One can extend the taper of a 1.4" up to a 2", but choking it down is bad.
Horns are designed with different throat tapers in mind, so some work better with different drivers. None of these 3" and 4" diaphragm Radian drivers have the "old school" long throat taper:
"1/4" adapter"?
The X horns have 1" and 1.4" throats, you could use your 1.4" exit drivers on the X34 or X40.
Not what Marco is saying.
The 4" diaphragm 2" exit format probably had more market penetration for 2way crossovers around 500Hz than others primarily because of JBL's dominance of the field for so many decades.
The choice between 4" diaphragms and 3" diaphragms trades more low frequency output potential for worse high frequency response, but eliminating a separate HF horn can definitely increase coherency.
The choice of a larger exit requires more throat compromises to achieve wide upper dispersion.
Diaphragm materials and phase plug designs are a "means to an end".
T/S parameters are a measurement of the driver.
Only sweeping generalities can be made as to the impact of each aspect of design.
"Voicing" is a general trend of upward, flat or downward on axis response.
The filters used to voice depend on the corrections the horn and driver require, and what is possible to do- a passive approach could use 30 pounds of components to do what a postage stamp sized chip could do.
With the same "voicing" achieved with EQ , either passive, active analog or digital filters, any driver that covers the bandwidth without gross problems can be made to sound nearly the same.
You can listen to a wide variety of drivers "voiced" the same in this evaluation, the HF is a recording of the horn driver mixed with the original signal below the crossover point.
Best to use headphones to eliminate the room response.
The capacitor is simply put in series with the "+" or "-" terminal of the driver, a passive "single pole" filter.
The capacitor reduced output by -10dB, half as loud as the red raw response from 600Hz and below, tapering off to no change in the upper response.
That single pole filter results in an upward rising voicing, which might be called "forward". If the curve looked the opposite, "relaxed".
To address the upper peaks to provide a "flat" voicing would require another four poles or so.
On a horn/ driver combination like your AH425/Radian which has smoother response, a simple cap on the HF and coil on the LF might get it near flat.
A "hardwired" passive or active filter implements only one choice in voicing (equalization).
DSP (digital signal processing) is just manipulation of binary code, the operating system used to manipulate it does not affect the end result.
If DSP is used in series with a simple crossover, any voicing can be achieved, and instant changes can be recalled to suit the program material, when, where and how you are listening.
Art
using a horn adapter will make horn expansion rate slower which increases distortion.
distortion in compression drivers comes from nonlinearity of compressed air which is a function of expansion rate and frequency.
larger drivers and larger apertures reach the same SPL with lower compression of air thus lower nonlinearity and lower distortion.
of course larger drivers cost more and shorter horns ( horns with faster expansion rate ) don't have the same low end reach.
this is why the trend has been to move away from midrange compression drivers that used to be a thing in the past but no longer are - because those require long horns with low expansion rate.
the modern approach is short and wide horns that cover the treble only but achieve better directivity and lower distortion than old designs.
JBL Technical Notes Vol 1, Number 8, and Vol 1, Number 21 seem to touch on this.
this distortion is at higher drive levels and higher frequencies.
and we're talking about drivers capable of 130+ decibels so if you're only listening at 80 decibels this may be completely irrelevant to your case.
but regardless of how compression drivers are USED they are DESIGNED for high SPL levels and at THOSE levels this is the main distortion mechanism.
and the evolution of the drivers was around minimizing that.
this is also why you see a move from domes to ring radiators because intuitively you think a larger dome surface would produce lower distortion but with compression drivers it is not excursion that causes distortion ... and distortion is primarily in high frequencies where the dome isn't pistonic anyway ... so having a large dome ( versus ring radiator with same VC diameter but smaller area ) accomplishes NOTHING except necessitating high tolerances and a complex phase plug unnecessarily adding to cost and weight ...
this is why i spoke negatively of Radian because they seem to be basically GRS on steroids - offering a lower cost versions of classic designs from decades ago rather than being pioneers ...
those Beryllium TAD drivers were all the rage when i was in high school but now it's more about BMS coaxials and otherwise ring radiators like Axiperiodic while Radian is just bringing you back the good old days at a price some may actually be able to afford ... same as GRS with their clone ribbons and planars ...
doesn't mean Radian is bad i just don't see them as being on the same level as JBL, BMS, Faital etc. and TAD used to be the best but Japan has been on the decline for decades and currently Italy is the superpower when it comes to audio.