My last try with Auto-Tech was about 5 years ago. That wasn't the first time that I tried--a few times from 2015. It's good to know they're responding now. Others have commented (even from the EU) that actually getting the horns may still be an issue.
Chris
Chris
It's been my subjective impression that the K-402 horn blows away smaller horns. If you're near an audio dealer than handles the new (introduced in June 2022) Klipsch "Heritage Jubilee", you can go and listen to one. The driver used in that design is the Celestion Axi2050 (i.e., a very "modern" driver by your standards), crossed at 340 Hz. A little more incidental information can be found on that subject here.
It seems to be a fact that bigger horns really do sound better than smaller ones (in terms of directivity control below ~800 Hz or so). Most people haven't heard good directivity control below 800 Hz and are categorically astounded when they do. This is a subject that has not been discussed very often, especially not in this forum: the subjective effects of full-range controlled directivity down to the room's Schroeder frequency). Here is a little tasty tidbit on that subject, especially when attention is paid to flattening the overall phase response through the crossover region and controlling early reflections in-room.
There is one other now-discontinued horn, the JBL 2360 "elephant cheek" horn. Reviewers that I can trust (i.e., have listened extensively to both the K-402 and in-room with the JBL 2360 at a pre-year-2000 Axpona on top of approximately equal folded horn bass bins) tell me that the K-402 still wins that match-up, but without personally hearing the two in the same room (both well set up) myself, I cannot really form an opinion on that subject. It's a moot point anyhow--since the 2360 series horns are discontinued.
In any case, making your own dual-flare horn a la Danley style will be your ticket to listening to full-range controlled directivity.
Chris
Beyma CP755ND / AL - 12 degrees. According to a few sources. including this site.
thanks , so the matching horn would be more a Yuichi A290 for the BEYMA CP755ND than a rapid flare as a JMLC Horn for 18Sounds or RADIAN 950PB rapid flare
The software here now is actually a PITA. It would be better if like on many fora it allowed you to quote several sections of a post, or multiple posts to a forum clipboard and allow you to post them all in the reply box to comment, rather than having to scroll up and down incessantly.
AVS Forum for example is much,, much better in this regard.
That is a a topic for another thread in another section of the forum.100%! It's somehow beneficial for the sound waves to remain in the horn for a while longer expand under the proper conditions to acquire the right tone, placement and become actual music. This maybe off topic and silly, I know. 😉 It's like trying to get a breeze with an air compressor. It works best if you're at least 6ft from the nozzle. In fact, for me, the closer I get to the mouth of the compression driver the closer the sound gets to 'sand blasting'.
Admire Audio and Tune Audio are great example of big modern horns that sound amazing.
Sorry I will again be off topic,
But as I asked and people gently replied, I will give an update.
Profiguy advised me parasound a23 to replace old lab gruppen. I have to admit it is worth every penny, especially when bought used in perfect condition from an old audiophile.
It is driving the faital hf108r from 1800 to 20k.
The sound is just clean, precise, defined, and very well built.
I wasn't expecting much difference from the old lab gruppen except less ground noise but it was worth swapping.
I am looking for a second one for the PHL 1140 now.
To be more topic related. The faital hf108r, is such a bargain for the price, it is a perfect compression to start a home system.
Regards Greg
But as I asked and people gently replied, I will give an update.
Profiguy advised me parasound a23 to replace old lab gruppen. I have to admit it is worth every penny, especially when bought used in perfect condition from an old audiophile.
It is driving the faital hf108r from 1800 to 20k.
The sound is just clean, precise, defined, and very well built.
I wasn't expecting much difference from the old lab gruppen except less ground noise but it was worth swapping.
I am looking for a second one for the PHL 1140 now.
To be more topic related. The faital hf108r, is such a bargain for the price, it is a perfect compression to start a home system.
Regards Greg
Also 100% for me. I'm not a fan of shallow waveguides. That is a personal subjective impression that I have not verified with blind testing. Still, as nice as some shallow horns can sound, I hear the driver too much, especially as levels increase. With a longer horn, I just hear the music, not the device reproducing the music.
A well designed expo horn can sound very nice on a smaller driver that would normally fall short on most other shallow profile horns. I really like the Selenium HM25-25 for its natural sound and reasonably good off axis HF.
Well, perhaps as a change of pace to earlier "axiomatic statements", Pano...maybe you could simply cite some shallow horns where you can "hear the device reproducing the music". This isn't something that I've heard in my hi-fi experience...
Chris
When you look at the horn that you referenced:
You can see why the horn might do better off-axis, even though you identified it as an exponential horn. The picture above shows the visibility of a significant amount of the horn throat open area off-axis at a large angle, which in my experience is required for a non-midrange-only horn to have good off-axis polars.
I've found that this is an easy screening criterion (by inspection alone) for horns that otherwise might be labeled "exponential" or "hyberbolic-exponential" that really conform to a more straight-sided-throat horn with mouth roll-out.
Just my $0.02
Chris
I know exactly what you mean Pano. The life-like, effortless dynamics and texture that I here in a good, long and well loading horn is just not there in the shallower wave guides.
good to know we are on the same 'wavelength' on the subject. 😉 So far the best imaging horn I heard was an Altec 311-90 with 288 driver. It was in a vintage audio store and I didn't have any knowledge of the electronics use or choice of material played but the 3D imaging was uncanny. I prefer my 4001 for resolution and natural high frequency reproduction and everything else but it makes me want to try bigger horns.
Who made axiomatic statements? Was it me? I just stated what I hear in different styles horns and admitted that I have not blind tested it.
Is a list of any use?
Well, right now, I have no idea of what a "shallow horn" might actually be, so your statement has no meaning.
Here are the -6 dB polars of the 311-90 midrange horn (i.e., not full-range to 20 kHz) with midrange 288 driver (500 Hz up to 8 kHz):
and the dimensions/horn profile:
For comparison's sake, here is the same -6 dB horizontal and vertical polar plots of a K-402 full-range horn (<200 Hz up to 20 kHz) with a K-69 driver (without phase plug extension):
The length of the K-402 is ~17.5 inches, and the mouth size is 35 x 21 inches (without flanges). Its advertised nominal coverage is 90 x 60 degrees. Note the difference in lower frequency (202 Hz vs. 500 Hz) and higher frequency (20480 Hz vs. 8000 Hz) in the polar plots.
Is this a "shallow horn" or "longer horn"?
Chris
Chris,
I never heard the K402 except on you tube vid i don't know how to explain the subjective report of 'hearing the driver'.
🙂
I never heard the K402 except on you tube vid i don't know how to explain the subjective report of 'hearing the driver'.
🙂
That horn is the beginning of long in my view. It is very wide but the vertical expansion is slow giving it a sort of long neck. Not what I call a shallow waveguide or shallow horn. If it were as tall as it is wide, then I would probably consider it a shallow horn.
A hodgepodge list of what I considered shallow and too direct would be:
None of these in the list gave me the kind of sound I want and can get from a bigger, deeper horn with a slower expansion.
A hodgepodge list of what I considered shallow and too direct would be:
- Dayton 8” round waveguide
- Dayton 10” round waveguide
- Several 8-12” coaxial drivers
- Gedlee Abbey
- Gedlee Summa
- A half dozen unknown at audio shows around North America
None of these in the list gave me the kind of sound I want and can get from a bigger, deeper horn with a slower expansion.
I don't why people go to YouTube to do this. There is no way, after the original recorded conversion to AAC, the microphone used to re-record and it's placement in-room (which are together confounding variables that overwhelm the "signal"), that it has any real significance. [Rant over.]
If you actually get a chance to hear a real K-402 in person, I strongly recommend it. I think it will reset more than one scale that you consider "the best I've heard", IMHO. However, be careful with the setup any room acoustics when forming any opinions. Poor listening rooms (acoustically) really cannot be overcome, and there are apparently still many of those used for commercial hi-fi sales listening rooms. More on the sensitivity of the horn/driver to crossover/setup conditions here and below (i.e., getting the phase response flattened along with early reflections around the loudspeakers and listening position(s) controlled--the following taken from another source):
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Thanks to Pano's kindly last reply, I think I have a better understanding of the phenomenon being bantered about. I can, in principle, agree with this but I can also say that having too narrow a coverage angle (the best example I can think of is the SH-50 from Danley with 50x50 degree coverage, which is way too narrow horizontally...you need two side-by-side for each of the left and right channels to get a good in-room polar coverage, IMO) is also a big contributor to a feeling of "listening to the loudspeaker" instead of "listening to the music". Of course, not EQing carefully in-room is at least an equal factor in perception faults.
Chris