The Iwata series of horns are not constant directivity, their polar response is similar to your AH425.
The Iwata 200 is 900mm (34.4inch) wide, it can be used to a lower frequency than your AH425.
He uses a very large, beamy horn with an unusual driver sitting atop various cabinets in his unfinished system.
More than six years since he started on a quest to build his monitors, originally the plan was to copy the JBL M2 specs, a monitor using a shallow, wide constant directivity horn.
Audiohorn's largest X-Shape is less then half the width of the Iwata-200, his largest bi-radial has a similar width as the Iwata-300. They are not comparable in size or polar response to the beamy horns.
The Radian phase plugs are very similar to designs used by Altec, JBL, TAD, B&C and most every other manufacturer, regardless of their origin date.
I expect so, every different room will react differently to the loudspeakers used in it, and your reaction to each system will be different, as is every other individual's response listening to the same system.
Every person has a unique hearing pattern dictated by their pinna (outer ear), head shape and size.
You won't hear the same presentation as Troy, Pete, Joe, or anyone else reading.
It appears your chosen listening position(s?) in your laterally asymmetrical room will do more to degrade imaging than any choice of loudspeaker.
If you draw a full floor plan with all the structural details, window, doors, hallways, etc., I could suggest the best compromise for speaker and listening position for optimal imaging.
The sound stage width and depth are embedded in the recording.
Depth cues are largely reverberant, (less reverb= closer), width is usually level (pan pot balance) based, though may also contain phase/timing differences from stereo mic techniques or emulations.
These techniques can also make the apparent source position wider than the position of the speakers, though it requires a good frequency and level balance to be convincing, rather than an "out of phase mess".
For stereo imaging to present a reasonable facsimile of the recording, it is assumed an equilateral listening triangle will be used by the listener, as it was for the recording and mastering engineers:
Imaging progressively degrades outside the equilateral listening position.
I like to arrive or book seats early at movie theaters to get that position.
As my hearing has degraded with age, I find the "sweet spot" has become smaller, at most one row ahead or behind, and a seat or two left or right and the "suspension of disbelief" dies.
If you increase your equilateral triangle dimensions over the minimum required by your screen size, it makes the asymmetrical room reflections more apparent, degrading imaging.
Wider dispersion increases the coverage area, but won't improve imaging, hence my reluctance to recommend any constant directivity horn over your beamy (but very smooth) AH425s, considering you are the primary listener.
Art
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LeCleach style wavefront support is different as the infinite horn spirals on to itself with reducing radius, so if it's held thereabouts to where it rolls back, the reflected discrepancy at lower frequencies falls toward negligible and it gives full low frequency wavefront support as far as that goes.
If waveguide style analysis is what you want then the smaller vertical dimension rather than the horizontal, with the vertical's more difficult to establish narrow angle, should be considered when looking for limits.
That line of enquiry invites the question of why not to waveguide in both dimensions.
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Other than the lower Fc, how is the "wavefront support" different on the Le Cléac’h AH425 compared to the Le Cléac’h Iwata-200 or 300?
I suspect I haven't made my point clear and we are not yet on the same page.
I was marking the similarity between them to contrast the difference from waveguides since LeCleach horns turn themselves inside out. So they support their wavefront more than it appears to from the dimensions, but the directivity continues to widen like others of this type. In any case, the Iwata differs from the AH425 in other ways despite similarities in concept.
I was marking the similarity between them to contrast the difference from waveguides since LeCleach horns turn themselves inside out. So they support their wavefront more than it appears to from the dimensions, but the directivity continues to widen like others of this type. In any case, the Iwata differs from the AH425 in other ways despite similarities in concept.
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I agree, I think he should use the horns he has already, Very smooth off axis transition is the very important whether constant directivity or a beaming horn.
There is some room for prediction of out come don't you think? The matter of Direct vs Indirect sound should yield constant results.
I have a pair of these. https://www.usspeaker.com/radian 745neoBepb-1.htm
My builder Troy Crowe, who I hope will complete the building of my speakers with the horn/driver combo that I finally decide on, received these completed midwoofers ~ 18 months ago from Jim Salk, who cloned them from g3dahl's design. https://josephcrowe.com/blogs/news/altec-416-8b-in-100l-sealed
However, Arnaud Le Gac said that except for these https://alg-audiodesign.com/produit-pavillon-1-pouce/ , all of his horns are non-beamy constant directivity horns, like the one you had recommended. https://alg-audiodesign.com/pavillon-iwata-2/
But unless I'm wrong, on next page Weltersys claims that is not a CD horn, and shows a polar plot of it as beamy as the AH425 horn.
Beyond this, Marco strongly favors the JBL 2450Be over the 745Be-or more comparably, the 2" 760Be. https://www.usspeaker.com/radian 760neoBepb-1.htm Presumably, that's because it's 4" diaphragm offers a lower crossover point while still able to faithfully reach ~ 16kHz, and presumably with very low 3rd harmonic distortion, slow decay time and good off axis response.
So, if I would go with the very expensive ES290 horn, which Marco recommends,
https://josephcrowe.com/products/es-290-biradial-wood-horn?variant=41821876682836
it seems wiser to spend the extra money on a pair of these https://www.usspeaker.com/homepage.htm for Troy to swap into a pair of used JBL 2450J drivers, IF he's willing to restore them, though which I strongly doubt.
However, Arez cited someone in NJ who does such repairs.
https://www.diyaudio.com/community/threads/best-compression-drivers-today-2022.382609/post-7945686
For one thing whether the Iwata 200, which Docali had recommended https://alg-audiodesign.com/pavillon-iwata-2/ -and which designer Arnaud Le Gac claims is a constant directivity horn-would be good or bad for my room.
But Weltersys said he needs me to describe my room in more detail beyond that flaky sketch I posted. Looks like I have a schittier (asymetrical) room than I thought, leaving me with less choice among horn options without consequence. However, no matter his final evaluations of my room, Art will still probably nudge me towards using the AH425 horns, just because I have them. 😉
So let me get this straight, you have the altecs, you have the radian cd's and the azura 425's and you're just wringing your hands and stressing if they are the right choice but have not tried them? Life is short brotha.
That's an early "idealized" sketch, where I thought my room was acoustically better than you've now described it to be. Indeed, if my room's size and acoustical environment could support it, I'd much rather dedicated these speakers Troy's building for me (horn/driver TBD) for music only. And might those be best placed diagonally, as shown in the sketch?
Then have the TV towards the northeast corner on the east wall (it's there now). And get a pair of Revel, Wharfdale or other brand of mains and center speaker to use with my subs for a 3.1 system for DVD and BD movie sound. Hopefully, the reflections created by those extra objects in the room could still be reduced after careful boundary effects measurements and room treatment.
By dedicated Troy's build for music only and placed accordingly might that allow me more freedom to choose among horns?
Indeed it is, but I'd just don't want to end up wringing my hands even more fiercely by not choosing the horn which might give me the most desirable presentation, at least for which my room might allow. For example, Weltersys claims that sound stage width and depth are largely found in the recording. How strictly true is that?
Might a relatively large constant directivity https://alg-audiodesign.com/pavillon-iwata-2/ https://audiohorn.net/x-shape-horn/ https://audiohorn.net/next-gen-bi-radial-horn/ or even exponential horn https://josephcrowe.com/products/3d-cad-plans-for-es-290-biradial-horn-horn-no-1670 contribute substantially to sound stage size-at least if my room can acoustically support it?
However, in any case, as I am not an able DIYer, I can't "try" building with any horns or drivers. That all has to be done by Troy Crowe-and he's only going to do ONE build for me, and the deadline to decide on parts is end of April. Get it?
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I have a suggestion for you. Just limit the ONE build to the bass cabinet and let it send to you. Then use your Radian driver and the AH425 (sfaik you own both) and simply start to listen. If you do not like it then you can still use the bass cabinet simply with another horn.
The AH425 is for sure NO constant coverage horn. Not even almost constant. Also the Iwata and ES will beam. But the question is what amount of beaming you could accept and the AH425 would be a nice option to assess this.
Soundstage is apart of the source material... it can be skewed if the equilateral triangle is not used. Don't confuse soundstage with sweet spot. The sound engineer creates the sound stage... the loudspeaker creates the sweet spot. They are not the same thing...so thus, your question makes no sense. Soundstage is an illusion created by stereo. If you want a big sound stage then listen to recordings that have them.... you could distort the image to have a wider soundstage by moving the speakers, widely apart while not moving your listening position... but you have stepped into realm inaccurate imaging. The walls play a factor in how wide the sound stage seems as well.... once again, you are still stepping away from perfect imaging.
Some study points
Start back at the beginning of your favorite conversations, and then read up until current. There is already a lot of data in there that you have not digested fully. Take Notes. On a computer, its a matter of copy paste... Copy the comments you think you should remember and hold value, so that you can view these notes at any time, instead having to go back through threads looking for that important thing that you know someone said but can't remember what they said or why.
Learn what perfect imaging is, technically speaking and where it exists ( Outside? Anechoic chamber?) and why it exists (Great summing of crossing drivers?, Lack of indirect sound?) Then learn what happens in the best rooms... Geddes room is a trust worthy study, given his strict approach and appreciation of the sciences. The perfect room for me, would be outside... Most people don't really want the epitome of what perfect imaging gets you. I am outside the norm. Geddes and most others want some "air", some reverberation but its likely no where near the amount that you could find in some other random Hifi enthusiast who could very well be praised and said to have "the best room".... I think you can you help organize this thought by focusing on RT60 times. Another approach would be learn what is considered to be the best for a Mastering Studio.
These are a multitude of listening position measurements taken by "sound engineers" post to Gearslutz long ago.... Pay attention to the trends. I was happy to see that my Horn at my listening position, without any room treatment, or optimization other than some eq to get a decent FR had a that fit in with the trends of the sound studios of various and performance
@oltos cheers for putting in the time and research.
After 20 years of experimenting with horn and driver combos, I'll stress the point that speakers are only part of that equation. The room is another significant part. Ultimately your ears are the final judge, jury and executioner... IOW the most important part.
You already have the ears and the listening room. Two major pieces to the puzzle.
Start to be proactive NOW and use ANY speaker you currently own to address your room first. Or you can drop serious cash, get extremely disappointed/frustrated and address the room after 🙂
For what is it is worth, I wasted a few years trying different driver/horn combo's only to be extremely disappointed every time. This naturally led to researching acoustics and room treatments which resulted in massive step in the right direction. I could finally hear most of my speaker's capabilities instead of the multiple room issues. In hindsight, I incorrectly discounted reputable compression drivers/horns as poor performers because of my room acoustics. The room is equally as important as the speakers and you don't need to travel or fly anywhere to address it.
If possible, consider changing your listening position to north wall between bay windows. Try to understand/research what @weltersys implied, he is even offering to help you with your optimal layout. That room is going to be a major issue with the current layout. No symmetry with regards to listening position. The direct sound and reflected sound will be messy, unpleasant and uneven to your ears. I guarantee the left side will sound completely different to the right side. Throwing money at expensive speakers won't fix it. Many ridiculous high end exotic speakers often have in-home setup included. They know poor placement will result in a $500K pile of crap and disappointed clients. If side north wall is not an option then lean to the expertise of acoustic companies (or members here). GIK Acoustics will provide free estimates with layouts for their acoustic solutions, they'll need your room dimensions, furniture layout, etc.. I learned a boat load from their assessment of my room.
Its normal that small tweaks could be required to the address the room and placement as you swap out speakers with different characteristics.
Get familiar with your room. Listen to it. Try some subtle adjustments or treatment. Listen again. Rinse and repeat. Listen again. Otherwise you'll never know what challenges it presents.
After 20 years of experimenting with horn and driver combos, I'll stress the point that speakers are only part of that equation. The room is another significant part. Ultimately your ears are the final judge, jury and executioner... IOW the most important part.
You already have the ears and the listening room. Two major pieces to the puzzle.
Start to be proactive NOW and use ANY speaker you currently own to address your room first. Or you can drop serious cash, get extremely disappointed/frustrated and address the room after 🙂
For what is it is worth, I wasted a few years trying different driver/horn combo's only to be extremely disappointed every time. This naturally led to researching acoustics and room treatments which resulted in massive step in the right direction. I could finally hear most of my speaker's capabilities instead of the multiple room issues. In hindsight, I incorrectly discounted reputable compression drivers/horns as poor performers because of my room acoustics. The room is equally as important as the speakers and you don't need to travel or fly anywhere to address it.
If possible, consider changing your listening position to north wall between bay windows. Try to understand/research what @weltersys implied, he is even offering to help you with your optimal layout. That room is going to be a major issue with the current layout. No symmetry with regards to listening position. The direct sound and reflected sound will be messy, unpleasant and uneven to your ears. I guarantee the left side will sound completely different to the right side. Throwing money at expensive speakers won't fix it. Many ridiculous high end exotic speakers often have in-home setup included. They know poor placement will result in a $500K pile of crap and disappointed clients. If side north wall is not an option then lean to the expertise of acoustic companies (or members here). GIK Acoustics will provide free estimates with layouts for their acoustic solutions, they'll need your room dimensions, furniture layout, etc.. I learned a boat load from their assessment of my room.
Its normal that small tweaks could be required to the address the room and placement as you swap out speakers with different characteristics.
Get familiar with your room. Listen to it. Try some subtle adjustments or treatment. Listen again. Rinse and repeat. Listen again. Otherwise you'll never know what challenges it presents.
The best thing about horns/waveguides and high DI is that we already begin to remove the room... which lends to less acoustic treatment and a more consistent result from room to room being that the rooms input is less and less as DI increases
I like the idea of HF (highest I can hear is ~16-17khz) being only big enough for what I consider the smallest acceptable for me... and then a smooth expansion.
I like the idea of HF (highest I can hear is ~16-17khz) being only big enough for what I consider the smallest acceptable for me... and then a smooth expansion.
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In my miserably undersized room here on Schiit Island, I'd hate sitting on the short wall. That's why I've been hoping all along that Weltersys, GIK Acoustics and/or https://acousticfrontiers.com/ would e able to help the speakers sound pleasant if placed at some angle diagonally across my room-or is that pretty much asking for trouble?
The bounce from the backwall (past your head) will to a certain degree increase with high DI, so I recommend diffusers in that spot if possible, or damping. My thoughts about this, is that the rooms input is not neccesarily diminished with higher DI (the acoustic power put in the room stays the same) but rather the reflections behave in a different way or are spread across the room differently. If listening in far field, it is i.m.o. still wise to consider room treatment with high DI speakers, but the treatment may be different then for low DI speakers.