Subject: Center Speaker Recommendations for Main Horn Speakers

From my very recent awareness of the acoustical mechanism of critical distance it does appear that my assumption was correct that horn (source) directivity does at least has some quantifiable impact on the direct vs. reflected sound ratio.
https://en.wikipedia.org/wiki/Critical_distance

What led me to that assumption were mostly two things: Horn directivity and listening distance. For example, if the horn were a ~ 16" JMLC AH425-which due to its rapidly narrowing angular coverage at higher frequencies, has been criticized as a "head in vise" experience by some listeners-the wavefront (if that is an appropriate term) is so sharply focused, perhaps also even in the lower midrange, that the listener is getting mostly direct rather than reflected (reverberant) sound.

And second that the listener might be more likely to get even more direct sound if located closer to between those relatively high directivity speakers, and which would likely be so if the speakers and I were located in an equilateral triangle?

OTOH, though I don't see how, given the 425 horn's beamy directivity, to what extent might toeing the speakers in or out increase reflected sound-and create a palpable sensation of spaciousness?

Of course, due to my room size and dimensions, the corner speaker placement which Art Welter had recommended after evaluating my apartment's building plans, makes equilateral triangle placement less than user comfortable since if the center of the speakers can only be ~ 8 ft apart then I would be obligated to sit only that far from them, rather than the preferred 11 ft.

Referring to the above video in post 33 (click on the * icon in the Youtube player to reduce playback speed), while there's no way to truly evaluate Gary's room, given the apparent length of his projection screen, the center to center distance between his speakers looks to be at least 9 ft, though his friends on that sofa seem at least 12 ft away.

In any case, do not Gary's 425 horns focus the highs to lower midrange so much that any toeing (out?) angle will produce little if any spacious sound in those bandwidths? Thus, my thoughts about which constant directivity horn.

If yes, then would not a constant directivity horn be a better choice for my situation? But if so which?









Here’s a project which apparently ended happily with the JBL M2 horn in a two way with sealed 15”.

And the Klipsch K510 which Cask05 had recommended.
https://www.diyaudio.com/community/...ver-that-can-reach-500-hz.321521/post-8022282

and with the added “mumps” mod to reduce diffraction.

However, assuming the "mumped" K510 horn is free of it, would all of above horns except Troy's suffer from diffraction problems?

Otherwise, for my 15" sealed midwoofers and 23 ft x 11 ft corner, which horn (s) might you recommend?
 
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This distance, called the critical distance, dc, is dependent on the geometry and absorption of the space in which the sound waves propagate, as well as the dimensions and shape of the sound source.

In a reverberant space, the sound perceived by a listener is a combination of direct and reverberant sound. The ratio of direct sound is dependent on the distance between the source and the listener, and upon the reverberation time in [the room]. At a certain distance the two will be equal. This is called the "critical distance."

— Glenn White and Gary Louie (2005)[1]

But as critical distance is a balanced, and therefore apparently, ideal ratio of direct to reverberant sound, how then to modify the geometry and absorption of the southeast corner and/or rest of the room, and (consistent with other horn/driver performance goals) chose the size and shape of the horn?
 
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Otherwise, for my 15" sealed midwoofers and 23 ft x 11 ft corner, which horn (s) might you recommend?

From your list, I would go with the JBL M2 horn.

Is Auto-Tech in Poland still making big fiberglass SEOS horns? I had forgotten about them. For some reason I am unable to access their website; none of my browsers will load it.
 
From your list, I would go with the JBL M2 horn.

Is Auto-Tech in Poland still making big fiberglass SEOS horns? I had forgotten about them. For some reason I am unable to access their website; none of my browsers will load it.

Doesn't the JBL M2 horn have a 1" throat? If so, it can't work with a 1.5" driver like this, at least not without an adapter, which Docali and others warned me against using.

Otherwise, what (non-TAD) beryllium driver options for the M2?

Alternately, I have a pair of Radian 745neoBe drivers which I thought of using as tweeters in a three way system, and crossing with the B&C DCM50 2" midrange. Is there another horn with all the best of the M2 with a 2" throat? Or would it be best to stick with the ES290 midrange horn?

Unfortunately, the ES2000 horn is for 1", not for 1.4" drivers.
https://josephcrowe.com/products/es-2000-biradial-wood-horn

And Troy never shows the vertical directivity plots of his horns.

But does it make good sense to use the Radian 745 Be as tweeters because it can cross so smoothly with the DCM50? Or would there be big sensitivity issues between them?

And Troy never shows the vertical directivity plots of his horns.

I never have a problem accessing this website.
https://horns-diy.pl/horns/seos/

As new problems have come to pass, any suggested alternatives?
 
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Thanks for your reply and suggestions. Cask05, a highly accomplished diyer, posting at diyaudio, audiokarma, Klipsch and other forums, also strongly agues that constant directivity horns sound more natural than the relatively beamy JMLC-or even Joseph Crowe’s largest exponential horn, which he also considers beamy towards HF, which
I would otherwise be inclined to go with. See sonogram here. https://josephcrowe.com/products/3d-cad-plans-for-es-290-biradial-horn-horn-no-1670

Chris’s system shown here with Klipsch K402 and/or one of the Synergy horns. https://www.diyaudio.com/community/members/cask05.73439/#about





Chris replying to my inquiry:

Generally, the Synergy Horns (SH, SM series) are what I was referring to, but there are others within Danley's offerings that are also useful. I recommend 90 degree x 60 degree coverage horns (like the SH-96 or SM-96 series) for a reasonable sized listening rooms. As the room gets smaller, then horn coverage angles likewise should get smaller.

But note: using smaller coverage horns (width and height) reaches a practical limit quite quickly as the room size gets smaller--and the horns must get fairly large in order to control their polar coverage to a low enough frequency. The practical limit is something like the SH-60 sized horn (full range horn loading--not direct radiating woofers).

Since you've already made the decision to buy direct radiating woofers, you've already compromised the ideal coverage at frequencies below ~500-800 Hz. That's a trade that candidly I wouldn't have made, preferring instead to employ full-range horns that control their polar coverage down to ~100-200 Hz. This means full-range horn loading (i.e., horns about 1 m wide having ~90 degrees coverage angles).

Thus, along with the K402 footprint and at least most of the Danley SH horns I’ve found (Danley doesn’t reply to my emails) appearing too big to safely sit atop my midwoofer cabinets, my use direct radiating woofers seems to have largely ruled out the practical use of such horns, as implied.

Then what constant directivity horn alternatives for my midwoofers? You recommended the 18Sound XT1464 and the Faital LTH142. But how well would their x and y coverage angles of those horns, above that of my midwoofers, work with my room’s dimensions? Compared to the sonogram of the K402 above, might they be too small for my room, as Chris implied above? See polar plots.


See attached room sketch.

But how might you explain Noah117’s issues with them?.

Yes, the B&C ME90’s polar plots are amazing. https://bcspeakers.com/en/products/horn/1-4/0/me90

But are you saying that because it has no round overed mouth-unlike the beamy JMLC AH425 horns, for example-where might the ME90’s response suffer due to consequent mouth edge diffraction?

Note that Chris and Joseph have some issues with how effectively mouth roundover will vary due to horn shape.

However, what horn for a two or three way system for my midwoofers and my room?
I have 2 pairs of Chris A (alias cask05) k402MEHs right now. They are a awesome set of horns!
 
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Looks intressting
 
I have 2 pairs of Chris A (alias cask05) k402MEHs right now. They are a awesome set of horns!
I'm sure they are but their sheer size makes them impractical if not acoustically wrong for my room size and unsafe to place atop my 2 ft w x ~ 20" d midwoofers. To get x & y coverage angles similar to that horn and for a 1.4" driver will probably have to go with something like an 18Sound 1464 horn.
 
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Yes,my room is 19' deep and 40' wide (open floorplan with 20' used for the wodthj), and room is 20,000cf. I changed my MEHs to a double stack with no cabinets (comp driver only in top horn. And 2 Celestion 15ftr3070c woofers in each horn and a pair of f20 horn subs. I love the spacious sound of the midbass with out cabinets, and the f20 takes me down to 15hz (20hz is the peak for the bass and I use a ski slope from 20hz to 20khz).
 
I would leave 2 channel as 2-channel and get some Sonos speakers for TV
 
See attached room sketch.

Ajant, I should have asked you to clarify your room sketch, because I'm not sure I understand it.

It looks to me like the room is 11 feet in one dimension and 22 feet in the other. Is this correct?

Is your system on a long wall, or on a short wall?

Also, maybe you posted this already, but what are your priorities if you have to make a tradeoff between image precision versus spaciousness?

Likewise, for image precision versus having a soundstage width that extends laterally beyond the speakers? (This is a slightly different question from the preceding one.)

And, is the one-person "sweet spot" the top priority, or are you after good sound across a range of listening locations? I have been assuming the latter since you started out asking about a center-channel speaker, but that may be a mistake on my part.

Thanks!
 
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Ajant, I should have asked you to clarify your room sketch, because I'm not sure I understand it.

It looks to me like the room is 11 feet in one dimension and 22 feet in the other. Is this correct?

Is your system on a long wall, or on a short wall?

Also, maybe you posted this already, but what are your priorities if you have to make a tradeoff between image precision versus spaciousness?

Likewise, for image precision versus having a soundstage width that extends laterally beyond the speakers? (This is a slightly different question from the preceding one.)

And, is the one-person "sweet spot" the top priority, or are you after good sound across a range of listening locations? I have been assuming the latter since you started out asking about a center-channel speaker, but that may be a mistake on my part.

Thanks!
Hi Duke; appreciate your interest.

Living room is 23 ft from south wall to center of the trigonal shaped north wall, the latter having three ~ 42 h x 2 ft w windows. A ~ 3 ft w x 15 ft hallway opens to no west wall in the living room. The south is 11 ft long. Note the ~ 9 ft by 10 ft kitchen beyond the end of the south wall, and the staircase just north of it. The speakers will be placed in the southeast corner, as suggested by Art Welter who reviewed the attached apartment building plans.

Regarding image precision vs. spaciousness, while in the end it's all a matter of personal preference-what sounds right to the listener-it's been very enlightening to learn what others find right. No doubt, the most "extreme" on that spectrum that I've found yet was Art Welter, who said

I prefer something like a 99/1 ratio of direct to reverberated sound for listening to playback. I certainly wouldn't presume you would prefer a 50/50 mix, especially if you prefer a specific, sense of image position.
https://www.diyaudio.com/community/threads/radian-951be-vs-18sound-nd4015be.413585/post-8100119 Not surprisingly, I also recall Art saying that the only spaciousness he wants to hear is any extant in the recording.

And it's clear that Camplo also prefers a higher Direct/Indirect sound ratio. https://www.diyaudio.com/community/...w-distortion-with-a-2-way.334757/post-8121830 And he makes this most provocative claim or observation

Thats why I try to stick to the basics which leads me to believe that Sound Stage and Imaging and Clarity are all the same thing.... Spaciousness is an aspect of, but it is not, those things and can be caused by source or system and room or can be used subjectively which just leads to confusion.

Again, says Art: 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.



Again, though neither Art Welter nor Camplo share info on their speakers, Camplo said he prefers mostly direct sound, and Art Welter said he listens from about 5 ft to 3 ft from the speakers! Assuming they are not true near field monitors, I don't know if Art's just glibly joking. Though earlier Art said he prefers "99/1" direct/indirect sound; that he always wants to hear only those reflections extant in the recording. Indeed, Art was the one who introduced me to the term. https://en.wikipedia.org/wiki/Critical_distance And then I found Nicholas's treatment of the subject. https://audiohorn.net/sciences/critical-distance/ The take away from that is

There’s no one-size-fits-all solution. Experiment, consider the factors mentioned, and personalize your listening experience, there is no golden rule because every room acoustics is different, but we often see:
  • 90° constant directivity horn: 2/2m50 to 5/6m
  • 80/70° constant directivity horn: 5/6m and more
And last month in a pm Nicholas said this Most great acousticians say that listening a little bit beyond the critical distance is better for soundstage. It's true. In what way would you find that statement at odds with what Camplo said earlier about Sound Stage and Imaging and Clarity are all the same thing... ??

And then Ian Mackenzie: Yes the coverage angle is a bit of a conundrum but you’re overthinking it. The most important thing is determining if you prefer 50/50, 60/40 or 40/60 direct to reflected sound. We all have our preferences and only you can work that out. This is because room dimensions, size and specifically where you put your loudspeaker and where you sit matter more than the horn coverage angle.

Some people prefer a more 40/60 ratio in the mid field 5-8 metres. Others like me more 50/50 in the 2.0 - 5 M distance.


Me, I would think that if one chooses to pursue accurate reproduction of a recording then listening further from or even at the critical distance

might then be "adding" to spaciousness to what was not in the recording. Without decent speakers, which I currently don't have, there's no way that I can judge what I might or might not like about adding amount of spaciousness-must less any acoustically generated anomalies-to recordings.
Thus, I'm inclined to opt for at least 80 direct/20 indirect sound.

However, this does not mean that I would necessarily prefer horns with a highly focused horizontal coverage pattern-like my pair of Azurahorn 425, which from day one Art has been pestering me to use, never mind that I've I told him endlessly I have poor DIY skills and zero time and work space to develop them. So, as much as I probably prefer direct sound, like most I known of at these forums, I'd mostly likely prefer a constant directivity waveguide. Indeed, while not probably not having a CD pattern vertically, Nicholas said that Pierre's TH4001 horns look like this.
https://audiohorn.net/img/bi-radial/TAD-TH4001-polar.jpg Indeed, while first starting with the Radian 745 Be drivers in the 425 horns he has long since used them like this. Post 15266. https://www.diyaudio.com/community/threads/beyond-the-ariel.100392/page-764

As for listening sweet spot, am I right in assuming that if one has CD pattern waveguides with good horizontal coverage, then the off-axis response would be good enough where if the center of the speakers and I were placed ~ 9 ft equillaterally between each other then I could move 4 or 5 ft left or right without a drop in frequency response, yes?

And my other goal is to have that if I choose to have the speakers somewhere between 9 and 7 ft apart that standing up I would receive mostly constant output across the AF range and accross the 180 arc of both speakers within that ~ 5 ft wide sweet spot.
 

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Subject: Requesting Waveguide Suggestions

Regarding the JBL M2 option, of course there are several threads here and at other forums on builds using the JBL M2 waveguide.
https://reconingspeakers.com/product/jbl-m2-horn-lens-5025594/

And I found pos’s contributions towards the building of one such system. https://www.diyaudio.com/community/search/2366730/?c[users]=pos&o=date

At last, I thought that I finally found a waveguide that looks to have reasonably good constant x & y directivity.
https://www.audiosciencereview.com/forum/index.php?attachments/1686977580827-png.292851/
https://www.audiosciencereview.com/forum/index.php?attachments/1686977605941-png.292852/ and which also should be compatible with
a respectable driver with the desired 3” beryllium diaphragm. https://reconingspeakers.com/product/jbl-2435hpl-driver-125-30001-00x/

Luckily, before I made any sorry moves, I learned from pos that the M2 is part of a closed system: It was designed for this driver
https://reconingspeakers.com/product/jbl-d2430k-tweeter-jbl-446213-001x-for-vtx/ and won’t do without active DSP crossovers.

Though aware of the sonic advantages of active crossovers-including the ability to use drivers with disparate sensitivities-for both practical and
ear safety reasons I need for Troy Crowe to finish building my speakers with passive crossovers.

There are waveguides with a 90 x 60 coverage pattern. With those, then when seated and listening on-axis would the vertical coverage be large enough even when standing up ~ 9 feet away?

If yes, which such waveguides have throats compatible with drivers like JBL2450 or JBL 2435hpl, and where such combos would deliver excellent imaging, no coloration, very low third harmonic and IM distortion?

And where such a two-way system would create tight coherency with my midwoofers.
https://josephcrowe.com/blogs/news/altec-416-8b-in-100l-sealed

But how impressively could all goals be achieved with passive crossovers using the suggested waveguide (s)?
 
On a somewhat related note, I have been fine tuning my L-R channel balance, using primarily Rogers Waters' Late Home Tonight, Pt. 1, which was recorded in QSound.
> On a well-aligned stereo system, the dripping water at the start of Late Home Tonight, Pt. 1 should feel like it’s coming from behind your left shoulder, almost as if there’s a leaky faucet somewhere just out of sight.
 
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Living room is 23 ft from south wall to center of the trigonal shaped north wall, the latter having three ~ 42 h x 2 ft w windows. A ~ 3 ft w x 15 ft hallway opens to no west wall in the living room. The south is 11 ft long. Note the ~ 9 ft by 10 ft kitchen beyond the end of the south wall, and the staircase just north of it. The speakers will be placed in the southeast corner, as suggested by Art Welter who reviewed the attached apartment building plans.

Thanks. With a little help from some White-Out, I have attached two .pdf files of the room that I think you are describing, one without speakers and one with speakers in the general area I think you're describing. Let me know if I got it close.

Regarding image precision vs. spaciousness, while in the end it's all a matter of personal preference-what sounds right to the listener-it's been very enlightening to learn what others find right. No doubt, the most "extreme" on that spectrum that I've found yet was Art Welter, who said

I prefer something like a 99/1 ratio of direct to reverberated sound for listening to playback. I certainly wouldn't presume you would prefer a 50/50 mix, especially if you prefer a specific, sense of image position.
https://www.diyaudio.com/community/threads/radian-951be-vs-18sound-nd4015be.413585/post-8100119 Not surprisingly, I also recall Art saying that the only spaciousness he wants to hear is any extant in the recording.

I agree with Art aboout "the only spaciousness he wants to hear is any extant in the recording". But I take a different approach to getting there. Ime "reflections done right" (which includes not arriving too early!) can act as "carriers" for the reverberation tails on the recording, and therefore support the "sense of space" on the recording being perceptually dominant over the "sense of space" inherent to the playback room.

And it's clear that Camplo also prefers a higher Direct/Indirect sound ratio. https://www.diyaudio.com/community/...w-distortion-with-a-2-way.334757/post-8121830 And he makes this most provocative claim or observation

Thats why I try to stick to the basics which leads me to believe that Sound Stage and Imaging and Clarity are all the same thing.... Spaciousness is an aspect of, but it is not, those things and can be caused by source or system and room or can be used subjectively which just leads to confusion.

There is one aspect of "Soundstage" that imo does NOT go hand-in-hand with Imaging and Clarity, and that is Soundstage width: Strong early same-side-wall reflections will widen the Soundstage, BUT at the same time they decrease Imaging precision and Clarity, as well as Soundstage depth. I mention this just so you are aware that conventional wide-pattern cone-n-dome speakers will normally result in a WIDER soundstage because of those strong early same-side-wall reflections, BUT imo the tradeoff isn't worth it. Strong early same-side-wall reflections are strong conveyors of the playback room's spatial signature, and ime you are more likely to end up with "only the spaciousness extant on the recording" WITHOUT those particular reflections.

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.

Yup. Imo a good "you are there" experience, combined with good image precision, is the "holy grail" of stereo spatial quality.

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.

Imo it is the EARLY reflections which are detrimential to "you are there". And imo LATE reflections (if they are done right) CONTRIBUTE TO "you are there".

And last month in a pm Nicholas said this Most great acousticians say that listening a little bit beyond the critical distance is better for soundstage. It's true. In what way would you find that statement at odds with what Camplo said earlier about Sound Stage and Imaging and Clarity are all the same thing... ??

I'm not sure I can reliably comment directly on Nicholas' recommendation.

Imo "you are there" is enabled by a fairly long time gap in between the arrival of the direct sound and the strong onset of spectrally-correct reflections. Late reflections done right are beneficial with no downside, but imo early reflections always have a downside. My approach is to use a constant-directivity pattern wide enough to cover your listening area, and then to deliberately add more late-onset reflection energy than you would have otherwise gotten from your narrow-pattern speakers. I can go into more detail about this if you'd like; it involves something that I have a commercial interest in.

And then Ian Mackenzie: Yes the coverage angle is a bit of a conundrum but you’re overthinking it. The most important thing is determining if you prefer 50/50, 60/40 or 40/60 direct to reflected sound. We all have our preferences and only you can work that out. This is because room dimensions, size and specifically where you put your loudspeaker and where you sit matter more than the horn coverage angle.

Some people prefer a more 40/60 ratio in the mid field 5-8 metres. Others like me more 50/50 in the 2.0 - 5 M distance.


Again, I look through a little bit different lens: Imo what you want to end up with is really good first-arrival sound, followed by at least ten milliseconds with minimal reflections (or at least minimal reflections in the horizontal plane), followed by spectrally-correct reflections which are neither too loud nor too quiet; which arrive from multiple directions; and which decay smoothly and neither too fast nor too slow. That very last bit is a room acoustics thing (you don't want an overdamped room); imo the rest of it can be addressed by loudspeaker design and set-up.

I'm inclined to opt for at least 80 direct/20 indirect sound.

My guess is that, if deliberately adding the right amount of spectrally-correct late-onset reflections enabled a good "you are there" presentation with no downside, it wouldn't really matter what the exact resulting ratio is.

I'd mostly likely prefer a constant directivity waveguide.

That is my preference as well, with a pattern wide enough to cover the listening area when both speakers are strongly toed-in (to avoid the aforementioned strong early same-side-wall reflections).

As for listening sweet spot, am I right in assuming that if one has CD pattern waveguides with good horizontal coverage, then the off-axis response would be good enough where if the center of the speakers and I were placed ~ 9 ft equillaterally between each other then I could move 4 or 5 ft left or right without a drop in frequency response, yes?

Just to clarify: Do you mean the listening area is 5 feet wide, or that the listening area extends 5 feet to either side of the central sweet spot (so, 10 feet wide)? A 10 foot wide listening area with 9-feet-apart speakers IS possible, but your waveguide choices would be limited.

And my other goal is to have that if I choose to have the speakers somewhere between 9 and 7 ft apart that standing up I would receive mostly constant output across the AF range and accross the 180 arc of both speakers within that ~ 5 ft wide sweet spot.

What is the "AF" range?

And... I'm confused. Are you asking about both speakers having constant-directivity behavior across a 180 degree arc? That sounds to me like it is very different from the kinds of Altec-plus-bighorn systems I've been envisioning. But then you mention a sweet spot about 5 feet wide. I must be misunderstanding you somewhere.

Would it be feasible for you to print the "empty room" .pdf file attached, and pencil in your listening area (you can just draw a circle or an oval) and roughly where the speakers will be? Then can you scan it and post it? I will try to come up with a suggestion for a radiation pattern width ballpark.
 

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There are waveguides with a 90 x 60 coverage pattern.

Can you post links to the ones you have in mind? Ime the specifics matter.

With those, then when seated and listening on-axis would the vertical coverage be large enough even when standing up ~ 9 feet away?

Looks likely to me. If your seated ear height is the same as the center of the horn, when you stand up nine feet away, even if you're pretty tall you ears will only be about 18 degrees off-axis vertically. If you raise the speakers up such that your seated ear height is about midway between woofer and horn, you'll be closer to about 15 degrees off-axis vertically.

If yes, which such waveguides have throats compatible with drivers like JBL2450 or JBL 2435hpl, and where such combos would deliver excellent imaging, no coloration, very low third harmonic and IM distortion?

I don't know. Perfection is unlikely. Hopefully the manufacturer(s) will provide the needed information.

But how impressively could all goals be achieved with passive crossovers using the suggested waveguide (s)?

I don't know yet, but probably so. Will Joseph Crowe be designing the crossovers?
 
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Just to clarify: Do you mean the listening area is 5 feet wide, or that the listening area extends 5 feet to either side of the central sweet spot (so, 10 feet wide)? A 10 foot wide listening area with 9-feet-apart speakers IS possible, but your waveguide choices would be limited.
Thanks Duke for this informative and detailed treatment. Yes, your modded version of my floor plan with with placement is essentially correct, attached: The listening space would be the southeast corner, ~ 1 ft from the right of my TV on the east wall and across to ~ 1ft before the end of the south wall; ~ 12 ft. Art said to first place the speakers in that southeast corner, a sub to the left of the left speaker and to the right of the right speaker.

As for setting the distance between the speakers and my listening position, please advise so to determine the ideal waveguide.
 

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Thanks Duke for this informative and detailed treatment. Yes, your modded version of my floor plan with with placement is essentially correct, attached: The listening space would be the southeast corner, ~ 1 ft from the right of my TV on the east wall and across to ~ 1ft before the end of the south wall; ~ 12 ft. Art said to first place the speakers in that southeast corner, a sub to the left of the left speaker and to the right of the right speaker.

As for setting the distance between the speakers and my listening position, please advise so to determine the ideal waveguide.

Thanks!

Just so I'm not making a mistake on "where the goal posts are": How wide do you want your listening area to be? Was it 5 feet wide total, or 5 feet to either side of the centerline?

Also, can you let me know what those 90 by 60 waveguides are that you mentioned?
 
What is the "AF" range?
AF range = ~ 20Hz to 20kHz

Can you post links to the ones you have in mind? Ime the specifics matter.
These constant directivity horns are all that I'm currently aware of:


Based on my last post, please try to recommend one or more of these or any you know about.
However, please list models which you may know to have been measured or otherwise known to produce very low distortion, fast decay, no coloration, excellent frequency response and imaging and ensured coherency with my midwoofers in a two-way system
 
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My Problem with Active Crossovers: Too Scared to Use Them

True or False: Constant Directivity speakers are less popular than those which tend to narrow in focus with progressively higher frequency?

If true, then is one reason why constant directivity horns are not especially popular is because they usually require DSP, or at least an active analog crossovers? Of course, when discussing any kind of speaker design in DIY circles these days use of DSP crossovers is likely assumed. Active crossovers have some big advantages over passives, and if I were to use them, and unless you can think of a better interface, I might be using a multichannel DAC like this. https://www.merging.com/products/interfaces/hapi

But as mentioned at diyaudio.com, audiosciencereview.com and stereonet.com, aside from perhaps a little more than some basic knowledge about digital conversion, I know nothing about DSP processing. So, if Troy Crowe
couldn’t build a perfectly good passive crossover for the chosen constant directivity two-way speaker, I’d have to hire someone like Mitch to remotely work with me to design the software based crossovers, take room measurements to implement some degree of room correction and then finish with multiple subwoofer management.
https://accuratesound.ca/digital-room-correction-drc-calibration/

All that will take some time and money. But the real problem is that no matter how the biamping beyond the pc’s digital output is implemented I don’t think I’d ever be comfortable with having my 98 db midwoofers and whichever ~ 112 db compression driver I end using each connected directly to the output of a 25w amplifier.

To feel reasonably safe, beyond what level settings are saved in the DAC’s software interface file, I’d have to be able to measure or at least perform estimated calculations of all impedances between the converter outputs feeding the main amps and the Rythmik subs’ balanced plate amp inputs, and then give those measurements to someone who could build me a balanced passive or active multichannel attenuator. That way once the levels are set from that hard wired box the amplifiers could never receive more input voltage than that set by those attenuators, assuming they never short out.

Also, I thought that either buy something like a 1.5 wpc 2A3 two channel tube amp to drive the horn’s driver and/or hire someone to build me one or two very low wpc Class A or AB stereo power amps. https://www.diyaudio.com/community/threads/1-to-2-wpc-class-a-amp-for-biamping.433272/#post-8136827 But I don’t see that as being much if any kind of additional fail safe.

So, until I can find a constant directivity waveguide and compatible beryllium driver for my midwoofers and listening space and send those specs to Troy Crowe, I won’t know if he can implement an audibly satisfactory passive crossover.
 
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