Ideally, the adapter should be matched to the exit angle and - in the pursuit of perfection - also to the phase plug, taking into account
the path length from the diaphragm to the horn mouth. Constrictions and irregularities prevent a smooth expansion of the wavefront and are a (potential) source of (audible) aberration.
While this may suffice (ALG):
This is better:
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You must be thinking of another horn, the B&C ME90 horn throat is not slotted:
The Radian 750NEOBe on the ME90 response has a smooth (+/-2dB) falling response from 5-20kHz, and it's free air impedance with or without the horn is nearly identical in that range:
If the horn throat angle match was a problem, it would show as sharp upper discontinuities in the frequency and impedance response.
If by "better" you mean less boundary reflections, which mask location cues present in recordings, the more narrow dispersion horn is.
If by "better", you mean which has a larger coverage area at a given distance, the wider dispersion horn is.
Art
That may be but apparently that won't necessarily deliver an "I am There" sound.
Btw, have you ever actually heard the AH425 horns??
This time I will let a real LONG time AH 425 user answer for me, g3dahl. https://galibierdesign.com/wa-trip-01/
As Gary says, he prefers a “they are here” presentation as opposed to a “you are there” one.
Also, recall from p. 764 that Pierre was also long time AH425 user-AND used it continuously with the 745Be. So, I would think he should know better than most how its directivity pattern differs from his present 745Be/TH4001 combo, which he described to me as delivering a "you are there" sound.
No, but I have heard plenty of different horns with similar designs and polar patterns, so have no difficulty in understanding the difference between it and all the other design choices you have been considering.
Preferences are personal.
When listening carefully, I prefer to close my eyes and be transported to the acoustic space (real or imaginary) that is presented in the recording.
I find that it difficult to do that when beyond the critical distance, the distance at which the SPL of direct sound and the room’s reverberant sound are equal.
The higher the horn's DI index, the further the critical distance.
Art
I've been reading this for quite some time. Can I give @oltos some advice? You sound like you are searching for perfection the first try, and it typically is more of a journey and learning experience. I call this point, "Analysis Paralysis", and it leads to self-doubt after a big purchase.
I think you would be better served, by deciding whether you like the smoothly rising DI of the AH425 (or similar style) but have to sit in a certain zone to get the best, or prefer the wider area of the better tonal balance. I can tell you my preference, but we can't tell you yours. I kind of think of these as two schools of thought within higher efficiency speakers.
Imaging and soundstage have a hell of a lot more to do with the acoustics of your room, and speaker placement, than a specific horn/CD combo. [within some reasonable area of optimality]. I think, and I don't want to put words in his mouth, weltersys is leading you the that water.
At the end of the day, decide what listening style you like, what amps style you like**, and then learn what you need to do to move toward your end goal, cause there is your end.
I think, instead of seeking a grand-slam on the first hit, grab some good matching, economical CD/Horns of opposing style to experiment and try for yourself in your room with your music. Or find friends that have those styles. I did the later in my own journey.
At the end of the day, you learn, actually enjoy the system and likely spend less money. Be is when you are dialing in that last 0.1%, not where you are at IMO.
I am giving this advice from love. I was in your place 20 years ago and it was more of a distraction than an enjoyment. "suck it and see" is a crude way to say, you have to try it for yourself to have an opinion. Relying on other's opinions in different rooms and different preferences is how the whole audiophile-dissonance comes about IMO.
** the flea amp crowd tends to prefer the acoustic loading to not burn the watts. The comparably higher watt crowd tends not to care so much that you need to use EQ to flatten response for constant-directivity style horns/waveguides. IMHO, they both have their place, but my main listening is the later.
I think you would be better served, by deciding whether you like the smoothly rising DI of the AH425 (or similar style) but have to sit in a certain zone to get the best, or prefer the wider area of the better tonal balance. I can tell you my preference, but we can't tell you yours. I kind of think of these as two schools of thought within higher efficiency speakers.
Imaging and soundstage have a hell of a lot more to do with the acoustics of your room, and speaker placement, than a specific horn/CD combo. [within some reasonable area of optimality]. I think, and I don't want to put words in his mouth, weltersys is leading you the that water.
At the end of the day, decide what listening style you like, what amps style you like**, and then learn what you need to do to move toward your end goal, cause there is your end.
I think, instead of seeking a grand-slam on the first hit, grab some good matching, economical CD/Horns of opposing style to experiment and try for yourself in your room with your music. Or find friends that have those styles. I did the later in my own journey.
At the end of the day, you learn, actually enjoy the system and likely spend less money. Be is when you are dialing in that last 0.1%, not where you are at IMO.
I am giving this advice from love. I was in your place 20 years ago and it was more of a distraction than an enjoyment. "suck it and see" is a crude way to say, you have to try it for yourself to have an opinion. Relying on other's opinions in different rooms and different preferences is how the whole audiophile-dissonance comes about IMO.
** the flea amp crowd tends to prefer the acoustic loading to not burn the watts. The comparably higher watt crowd tends not to care so much that you need to use EQ to flatten response for constant-directivity style horns/waveguides. IMHO, they both have their place, but my main listening is the later.
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It certainly is, albeit subtle.
It's basically a vertical expansion while the horizontal remains constant, so no constriction.
Somewhat similar to the throat of the RCF HF94:
sfaik they can make an appropriate adapter to your driver. When done as an extension of the inner profile, such an adapter wouldn't be any issue.
As has been Weltersys and others here who have encouraged and helped educate me (still fighting to close big knowledge gaps) to make the most of this journey, you are kind and wise and I appreciate this advice. What’s sad about this journey is that the traveler is still a less than a competent DIYer, and worse simply would never have the time to learn enough and fast enough to complete these speakers on his own. I’ve tried for weeks to drum this fact towards Weltersys. That’s why well over a year ago I hired Troy Crowe https://josephcrowe.com/ to integrate the yet to be chosen horn/driver combo (hopefully it can be a two-way) with the clones Jim Salk did of g3dahl’s Altec midwoofers. https://josephcrowe.com/blogs/news/altec-416-8b-in-100l-sealed
At the time I couldn’t find anyone as experienced with horn speaker design as Troy and willing to do the build, though he only agreed to do so because he wanted to test my Altec drivers. Unfortunately for me Troy is > 400 miles away in Ontario. I don’t fly and as you may know there’s no train service from New York City to Ottawa, much less to Ontario. Instead, it’s a 12-hour train ride from NYC to Montreal, then another train to Ottawa and then a two-hour road trip to Picton. No way could I do that. So, I won’t even be able to hear the completed speakers before they’re shipped to me.
That’s why I’ve endeavored to choose the right horn/drive combo the first time. But the biggest obstacle to succeed in this has been finding members here and at and other such forums with (ideally two-way) horn speaker systems similar to those on my short list (including the AH425 horns which Weltersys keeps prodding me to use) to invite me for an hour-long listening session (via the owner’s DAC to play my recordings) and who are located within ~ 200 miles of New York City. Again, I don’t fly so I can’t travel much further than that. Thus, unlike most people I know, distance traveling is hardly fun for me, not that there aren’t places far from this grossly overpopulated island that I’ve always wanted to visit.
Next week it’s the Amtrak from NYC to Washington DC, plus a 13 mile taxi ride to one of Troy’s customers to hear his system. It’s a three-way using this exponential horn and a Fostex tweeter in his waveguide. https://josephcrowe.com/products/3d-cad-files-horn-no-1994-es450-biradial-for-jbl-2446-2-throat The midrange will likely be the B&C DCM50.
Of great importance is one of the aspects of the sound which the owner describes in his post at Troy’s website: “They sound great with both solid state and tubes and make you feel like the artist is right in front of you performing live!” Obviously, he’s depicting a “They are here” presentation, as g3dahl did with his AH425/Yamaha JA6681B combo https://galibierdesign.com/wa-trip-01 .
Perhaps that should not be surprising since while those two horn geometries are radically different, their directivity narrows towards higher frequencies, though the AH425 much more quickly. https://cdn.shopify.com/s/files/1/0...ot_2023-10-14_170306_480x480.png?v=1697317415
A week or so later I will jump on the invitation to hear horn designer NicoB’s two constant directivity horns, each in its own system and both owned by one of Nico’s customers-and so luckily just a short train ride to Brooklyn.
https://audiohorn.net/x-shape-horn/
https://audiohorn.net/next-gen-bi-radial-horn/
And as the polars show both are constant directivity types, so I’m hoping to therefore experience a “You are There” presentation.
I simply can’t know if I would enjoy their sound as much as Troy’s and NicoB’s horns, so I would very much want to hear the AH425s. Thus, I will be posting at several forums to request invites within 50 miles of Long Island and 75 miles of NYC to hear systems with the 425s, or these two constant directivity horns:
Recommended by Ro808 https://www.usspeaker.com/ciare pr614-1.htm
Recommended by Docali https://alg-audiodesign.com/pavillon-iwata-2/
Among these horn system auditions, the variable that I can least control is driver type. I’m hoping that I might still get to hear a beryllium driver (Radian, 18 Sound, TAD) before the end of April deadline. If I fail to then decide on a horn and driver by then Troy will opt out of building me anything, which as I’ve explained would be disastrous. So, if I go with a two-way, depending on the throat size of the horn I had most enjoyed hearing, it will be either a 1.4” or 2” Radian beryllium, and take my chances on enjoying the speakers with that driver.
From this point until end of April success will hinge on luck and kindness and however much more I can learn and what I will have opportunities to hear towards making what I am am capable of determining are the right choices to realize measurable and subjective listening goals in the little time remaining.
Thanks to all.
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@oltos Have you ever heard a 2-way with a large format horn where you experienced "they are here" playback?
If yes, what were some characteristics of those speakers? If yes, what type of room did you listen in? If yes, was there acoustic treatment in that room?
With all due respect, if the answer is NO, then this quickly becomes a journey of chasing shadows.
Start here ^. Excellent advice and as you mentioned others have already tried to communicate this to you.
"There is no such thing as a perfect speaker" - Dr. Floyd Toole
Think of this hypothetical ... Troy Crowe shipped 10 different variations of 2-way large formats systems to your home.
How would you determine which one you like best?
I just drove near 1000 miles ( 1500 kms give or take ) for a specialist appointment, and that's one way. Still have to drive that far back home.
I'd fly, but the person I am accompanying does not. This is trip # 2 in less than two months, for the same specialist. Maybe your health is not good, but two train rides and a road trip would not bother me in the least.
I have been "prodding" you to listen to the horn driver combination you presently own in your own room.
Your room is not symmetrical.
The "right" horn dispersion would have to be different from the left to compensate for that fact alone.
You can compensate for the different left/right room reverb time/frequency response somewhat with EQ, but it is simply not possible to get as good a sound stage representation in a laterally asymmetrical room as one that is laterally symmetrical.
That is not a difficult goal to achieve, especially with an efficient loudspeaker capable of live performance peak levels with a few watts.
The more difficult goal is achieving the sense that multiple instruments and voices are placed exactly where they were in the recording.
More recordings are mixed and mastered on non-horn loaded systems, so obviously even the concept that there is a "right" horn driver that will deliver the exact sound stage the engineer had in mind is flawed.
Hope you enjoy your speaker auditions, just keep in mind they won't sound like they would in your room.
Also keep in mind that separating the sound of the room from the sound of a speaker is a skill set you won't acquire in a one hour audition, and auditory memories can be very confusing until that skill set is mastered.
Cheers,
Art
@marco_gea
Maybe the path is the goal for him. What you wrote makes more than sense to get everything from one source.
Maybe the path is the goal for him. What you wrote makes more than sense to get everything from one source.
That's encouraging except communicating with Arnaud Le Gac has been very difficult. He takes a week or longer to respond to emails and his replies obviously confuse BMS with Radian driver model numbers.
"These are not the 745neoBe but the 2950 in 2 inches that I was able to try and that I did not find very good for the proposed price so I did not delve into the question more than that, not being a fan of radian at the base."
AFAIK, there is no JBL, Radian or BMS driver with a 2950 model number. And in another reply Arnaud said
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.
However, it looks like he was, in fact, referred to the the BMS 4592 (which I did also ask about), saying
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.
However, it remains unclear if Arnaud has any experience with Radian Be drivers, or if he does seems unaware of how its HF response can be successfully flattened and extended with a properly designed filter, as Pierre had implemented.
Given the cryptic replies I don't know how wise it would be to work with him.
But I assume that Iwata 200 is among the best of the very few constant directivity horns available for above my midwoofers. https://josephcrowe.com/blogs/news/altec-416-8b-in-100l-sealed
And Camplo advised to go with the largest horn my cabinets and budget can support. So far, I can find only these constant directivity horns of comparable size.
https://audiohorn.net/x-shape-horn/
https://audiohorn.net/next-gen-bi-radial-horn/
How might these compare with the Iwata 200?
But conversing with NicoB has also sometimes left me confused. For example, he also has issues with Radians: I'm not a big fan of Radian—the phase plugs are outdated, and the Be diaphragms are embossed. I find less and less reason to use Be nowadays.
Weltersys dismissed the matter of the diaphragms. https://www.diyaudio.com/community/...orns-you-can-actually-buy.329476/post-7961398
As for the Radian 745Be's "outdated" phase plugs?
May I ask you again what driver do you have exactly? The 745Be or 951Be? sfaik the larger driver has a 5 slit pp and few drivers on the planet have 5 slits. And it is known that the THD4001 can only produce such high HF level because it uses some kind of suspension resonance.
But to designate something as outdated is relative. The JBL 2450/2451 may also be designated as “outdated” but many report a nice sound.
It seems that you have already contacted everything that is well known in the scene ;-) But shipping costs may be very high if you want something not being available on your continent. But so long as you have not heard different setups, you may not take the right decision for you. Are there no HiFi shows in your vicinity?
Your bass cabinets are still not ready? I think you start with them without a perfect horn match. There are some cheap 1.4 inch plastic horns out there with interesting traditional shape, but I have missed the source.
But to designate something as outdated is relative. The JBL 2450/2451 may also be designated as “outdated” but many report a nice sound.
It seems that you have already contacted everything that is well known in the scene ;-) But shipping costs may be very high if you want something not being available on your continent. But so long as you have not heard different setups, you may not take the right decision for you. Are there no HiFi shows in your vicinity?
Your bass cabinets are still not ready? I think you start with them without a perfect horn match. There are some cheap 1.4 inch plastic horns out there with interesting traditional shape, but I have missed the source.
The last two horn systems I heard were two way, but that was nine years ago. First I heard Joe Bolger's
Given Joe's DIY abilities, I was astounded by my reactions to what I heard with my best source material. One thing I'll never forget is how seriously directional that horn was. Joe had me on this swivel chair on the hard floor of that huge room. Every time I went to change a CD and sat back down, Joe would get behind me to make sure that I was on axis with that horn. But whether Joe's or my recordings it just didn't work for me. Presumably, the build was a work in progress; those subs were not hooked up then and perhaps there was some bug further up in the frequency range at that time.
That same year I heard Pete Grzybowski's Volti speakers in his living room; may not have been properly placed when I heard them. Pete had no DAC with that system so I couldn't play any WAV files of CD track rips. His amps were Border patrol 300Bs and a preamp with a phono section designed by a known expert from upstate NY. Pete played an old vinyl lp of a Louis and Ella duet of "Autumn in NY". I might have perceived the air around his trumpet during that bridge. It all sounded quite good, though I suspect better speaker placement would have much improved the realism.
Sadly, I don't fly and I was never much for distance traveling so I've missed out on hearing so many potentially satisfying systems.
And given the obscene housing costs and property taxes (~ 68% school taxes) here on grossly overpopulated Schiit Island, few here are likely inclined to induge in high end audio, save for those in the Hamptons, Brookville, Muttontown, et al. I tried numerous times to find local DIYers. I found one, quite accomplished and known here with his own website but he's not much into sharing.
Sadly, what I heard from those two sessions was long ago, too brief and for the most part underwhelming to accurately recall how if those two 2-way systems presented an I am There or They are Here sound.
I expect my trip to hear a Troy Crowe 3-way system next week will be different. It's 3.5 hours via Amtrak and two overnight hotel stays, so it will cost. But how else to get these references? Far more luckily, a week or so later a short trip to Brooklyn to hear both of these constant directivity horns, each in its own system. https://audiohorn.net/next-gen-bi-radial-horn/
https://audiohorn.net/x-shape-horn/
I never imagined there could be one either, so I was never in pursuit of it. But clearly the more one knows about horn and driver design and system building the easier it will be to select among configurations towards one's own satisfaction during listening sessions. Trouble is there may be too many big gaps in my knowledge for that approach to work for me in time to meet my builder's deadline end of April to decide on horn and driver for a two or three-way.
I flew twice in my life. Last time was THE last time for me, NY to Atlanta to visit my brother. I thought MY EARS were going to explode!!!!!!!!!! Enough said.
Schiit Island is so overpopulated that if you blink too often while driving you may not be able to avoid getting hit by some Schiithead. It's all I can take to drive for my day job >20 miles roundtrip. So, if not for the LIRR and Amtrak then no listening sessions.
How could the AH425/Radian 745Be solve address that problem any better than either of these constant directivity horns?
https://alg-audiodesign.com/pavillon-iwata-2/
https://audiohorn.net/next-gen-bi-radial-horn/
https://audiohorn.net/x-shape-horn/
Or are you saying that due to my room's asymmetries the best I can hope for is to forget about achieving a large wide and/or deep sound stage and just opt for the most accurate imaging-which presumably the AH425s can deliver?
FWIW, here's a sad little sketch I did a while back.
If you have the budget, you might hire an acoustician to improve on your room. Probably makes a bigger difference than a Be vs. non-Be driver.