Hi Chris (and others),
I hope this thread isn't dead.
Not dead...but probably waiting on progress reports from me.
The Autotech idea may be worthwhile for EU folks, and I'll certainly consider that. I believe, though, that the $1K(US) horn that Autotech makes is about the same weight/size as the K-402, so that isn't what I'd consider to be "reasonable" in price (i.e., a bit too high). It may be that the horn may be cheapest from the US (unless some politician does some really stupid thing to screw that up
)I'm currently working on the large horn--formerly called the "K-402-MEH" which I can no longer use as a name due to copyright restrictions. I'd call it a full-range modified tractrix MEH
...but...perhaps a better name will come to me soon. It's fairly hot/humid in Texas lately, and that translates to short pot life for thermoset resins...and staying conscious while working in the heat. I'm making progress but it's slower than I want. I've finally acquired the casting resin for the first couple of pours (which means that I've got to get on with it) and I am making finishing touches to the mold. I expect a steep learning curve after the first pour. Perhaps more good news within a month...?
There are no patent issues since the controlling SPL Unity horn patent has expired, and there are no other patents that apply to the horn.
My initial measurements indicate that the horn will weigh ~35 lbs...about 16 kgs. The added mass over the older K-402 ( which was 25 lbs) is there to make the horn stiff for use below 100 Hz. It might get a bit lighter over time...but then again it may get heavier after testing. Remember that the horn replaces the vented woofer in the "small syn" category. No bass bin is required because this horn uses two 15" woofers on the MEH itself.
The assembly will be quite easy: tap the woofer attachment holes for your favorite metric or US threads, attach the two woofers that you select and 2" compression driver via 4-stud standard connection, screw that assembly onto your box or baffle (not complex) from the front flange, and connect to your active crossover and amps. Dial it in. You're done.
If someone needs a passive crossover, there may be a way to do this economically with 3-4 band-pass attenuating filters ("PEQs") and a set of low-pass/high-pass crossover filters. I'll get to that passive crossover task again after the horn thing is under control.
Chris
The prototype easily can be run down to 32 Hz in an elevated center position above the floor about a metre. In the room corner, it will go lower. It's up to the user to choose whether or not to cross over to a sub in order to limit bass FM and AM distortion.
The 15" woofers can be something like a K-33 look-alike...like the Crites cast frame that I used on the prototype, Kappa 15, etc. Something with medium Qts (around 0.3-0.6) and low Fs (free air). The design is fairly insensitive to the exact woofers chosen or the box volume.
Chris
The 15" woofers can be something like a K-33 look-alike...like the Crites cast frame that I used on the prototype, Kappa 15, etc. Something with medium Qts (around 0.3-0.6) and low Fs (free air). The design is fairly insensitive to the exact woofers chosen or the box volume.
Chris
I have a question about using a 1.4" or 2" CD to get rid of the midrange problem. Will that nog give you a problem elsewhere? Was it not the point that people are using a 1" CD because the top end will suffer to much when you use a larger CD (mainly because of the larger throat size)?
And then the question is: how big is this problem then? For home audio I guess even if the top end is 10dB down, you can just EQ it? Specially if you have those big CD's that are more than 110dB anyway.. you're still left with 100dB/1W/1m. I guess anything above 95dB is good enough for domestic use.
And if this is THE solution to the Synergy mid problem: why did nobody do it for the last decade (and a bit)?
And then the question is: how big is this problem then? For home audio I guess even if the top end is 10dB down, you can just EQ it? Specially if you have those big CD's that are more than 110dB anyway.. you're still left with 100dB/1W/1m. I guess anything above 95dB is good enough for domestic use.
And if this is THE solution to the Synergy mid problem: why did nobody do it for the last decade (and a bit)?
In the first instance DIY efforts tried to copy the Unity and then the SH50. Both of which use 1" CD's and 4 midrange drivers. Later on there have been a number of different variations on the theme with the large CD and large woofers being the one Chris is using.
There are not that many good 1.4" or 2" CD's that can go both low enough and high enough, most of those are quite expensive so they aren't that attractive to the home experimenter.
There isn't a problem with using midranges in this fashion but it isn't straightforward to get it right. You do need to do your homework and test empirically if you don't copy a proven design exactly.
You can use EQ to bring up the level but most of the good large CD's don't need much. The bad ones have a very ragged response and EQ is going to struggle to fix that.
Using a large CD is one way to not use midranges, it isn't the only way. One reason for not doing it this way is if you want to keep the size of the horn down. That brings it's own problems of more limited pattern control etc.
There is no one right way to do it, there is a compromise in every approach and you need decide which one(s) you want to make and can live with.
If you search for the xBush Synergy you will find a small fullrange driver being used in a similar fashion to the large CD but in a smaller horn. A different set of compromises are on offer there.
There are not that many good 1.4" or 2" CD's that can go both low enough and high enough, most of those are quite expensive so they aren't that attractive to the home experimenter.
There isn't a problem with using midranges in this fashion but it isn't straightforward to get it right. You do need to do your homework and test empirically if you don't copy a proven design exactly.
You can use EQ to bring up the level but most of the good large CD's don't need much. The bad ones have a very ragged response and EQ is going to struggle to fix that.
Using a large CD is one way to not use midranges, it isn't the only way. One reason for not doing it this way is if you want to keep the size of the horn down. That brings it's own problems of more limited pattern control etc.
There is no one right way to do it, there is a compromise in every approach and you need decide which one(s) you want to make and can live with.
If you search for the xBush Synergy you will find a small fullrange driver being used in a similar fashion to the large CD but in a smaller horn. A different set of compromises are on offer there.
It seems to me that you're trying to grasp the provenance of the K-402 and its conversion into a MEH. I invite you to read up on this horn used with a 2 inch compression driver on the K-forum.
The two-way home version Klipsch Jubilee has been in use by well over 30 home hi-fi enthusiasts now--its use starting in 2006. Its popularity in terms of bought new from the factory is increasing with more than a dozen new owners since December. Read about their listening experiences there (search for "K-402" and "Jubilee" on that forum).
This isn't a heritage-diyAudio MEH approach or a heritage Danley approach...although it clearly fuses the MEH design approach of Mr. Danley with the even more amazing horn of Roy Delgado (chief engineer for the Cinema product line for Klipsch). The crossover frequency of the two-way Jubilee is 425 Hz-- about the crossover frequency of the K-402-MEH, of which there are two owners presently...one being myself.
Yes, it's a different approach from what you're seeing on this forum's pages. No, it isn't "experimental" in the purist sense of the word. Yes, it's definitely DIY: if I could have bought the horn in MEH configuration from someone, I would have. It isn't "unproven", it's merely a relatively small step from an existing design, but one that apparently brings very large advantages over its big brother corner-horn configuration. It isn't a copy of a Danley design. It isn't the basic approach as is widely found on this forum for MEHs...but rather more an extension of another design from another company using the MEH idea to use its hitherto unused performance potential.
I've been listening to that horn profile for almost 10 years now and it's been the highlight of my day (outside of my family) for each of those 10 years. This is a project to bring that sound in improved configuration to perhaps other audio enthusiasts that cannot accommodate the size or cost of the large corner horns. The total cost of this design (all up) is about 1/5th to 1/10th that of its corner horn parent, and its performance in a home hi-fi role exceeds its heritage in some critical ways, including size (1/3 the volume and height), clarity of sound and controlled coverage without disruption 2 1/2 octaves lower than its parent--a full range horn-loaded loudspeaker.
The objective for this design and perhaps others that may follow based in its design principles isn't tinkering for its own sake to make small iterations in a lineage of cloned Danley designs, but rather a DIY to create a loudspeaker of unrivaled performance for the home hi-fi enthusiast that cannot be bought presently.
That's worth sharing, I think.
Chris
The two-way home version Klipsch Jubilee has been in use by well over 30 home hi-fi enthusiasts now--its use starting in 2006. Its popularity in terms of bought new from the factory is increasing with more than a dozen new owners since December. Read about their listening experiences there (search for "K-402" and "Jubilee" on that forum).
This isn't a heritage-diyAudio MEH approach or a heritage Danley approach...although it clearly fuses the MEH design approach of Mr. Danley with the even more amazing horn of Roy Delgado (chief engineer for the Cinema product line for Klipsch). The crossover frequency of the two-way Jubilee is 425 Hz-- about the crossover frequency of the K-402-MEH, of which there are two owners presently...one being myself.
Yes, it's a different approach from what you're seeing on this forum's pages. No, it isn't "experimental" in the purist sense of the word. Yes, it's definitely DIY: if I could have bought the horn in MEH configuration from someone, I would have. It isn't "unproven", it's merely a relatively small step from an existing design, but one that apparently brings very large advantages over its big brother corner-horn configuration. It isn't a copy of a Danley design. It isn't the basic approach as is widely found on this forum for MEHs...but rather more an extension of another design from another company using the MEH idea to use its hitherto unused performance potential.
I've been listening to that horn profile for almost 10 years now and it's been the highlight of my day (outside of my family) for each of those 10 years. This is a project to bring that sound in improved configuration to perhaps other audio enthusiasts that cannot accommodate the size or cost of the large corner horns. The total cost of this design (all up) is about 1/5th to 1/10th that of its corner horn parent, and its performance in a home hi-fi role exceeds its heritage in some critical ways, including size (1/3 the volume and height), clarity of sound and controlled coverage without disruption 2 1/2 octaves lower than its parent--a full range horn-loaded loudspeaker.
The objective for this design and perhaps others that may follow based in its design principles isn't tinkering for its own sake to make small iterations in a lineage of cloned Danley designs, but rather a DIY to create a loudspeaker of unrivaled performance for the home hi-fi enthusiast that cannot be bought presently.
That's worth sharing, I think.
Chris
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That is the whole point isn't it. Finding what compromise you can accept best. To know that you'll need to know all the pro's and con's.
If you guys have any links in stock to those projects I'd be interested
I guess they are not directly using the "classical" conical horn of the Synergy?True that. However one of the cheapest options with 4 mids will also cost you about 120 euro's (The Celestions for instance). If you add that money to the CD you're not very far of probably.
So either you spend time on the midrange setup, or you spend it on the horn topology.. tit for tat..
That's easy to answer...
...because the one man that has used the MEH configuration (its inventor) hasn't been given the resources and time to do a home hi-fi version of the MEH, i.e., one that doesn't have to advertise how loud it will play or how many acoustic watts it can put into the venue. If given that opportunity and latitude to design solely for home hi-fi, I have little doubt that he would have come up with this very same configuration.
Why was this design originated by another group of people? Because the inventor of the modified tractrix K-402 horn profile at another company (Roy Delgado) spent a great deal of his time patiently tutoring a group of owners/enthusiasts on the full range K-402/2" compression driver technique, giving lessons and listening sessions in the Klipsch anechoic chamber and in its adjoining listening room in Hope AR (Professional products), as well as developing the settings for a variety of 2" compression drivers and doing the testing necessary screening of compression drivers for use in this design --but without MEH woofer ports. (BTW: there are many 2" compression drivers that work, and I've heard a few of them on a K-402...in real life. I would also direct you to JBL and other two-way horn-loaded designs which use 2" compression drivers--this isn't the first time it's been done.)
The guy that's writing this right now is the one that realized that simply cutting woofer ports into that horn profile and attaching 15" woofers (or 12" or whatever you choose) would create a truly "full range" MEH of outstanding properties. The rest, as they say, is history. It's not rocket science. It's simply an extension/fusion of two ideas into a better idea--I believe a much more useful design for home hi-fi use...only.
Chris
I really wasn't talking about Tom here. I was rather talking about the DIY community. Maybe I have not been reading much about all the variants of the Synergy's and was only focused on the ones that were closest to the "gospel"
I really think a 2-way is a compelling idea, and an affordable kit would be cool as well. For me, size wise 65x65 cm would be about the maximum I could bare.
That's sufficient size for a full-range 60x60 degree modified tractrix two-way design. Perhaps that might be "in the cards", as they say. But one must crawl before walking (usually) and walk before running (always).
Or you could buy a used Danley Synergy and overdo the job... Danley's hardware cost for the SH-50 or -60 design is probably about $1800(US)...unburdened. That's pretty high.
A two-way design would probably be $400(US) less--perhaps less, even using an active crossover (miniDSP 2x4 HD)...and all at retail prices (i.e., apples to oranges).
Or you could buy a used Danley Synergy and overdo the job... Danley's hardware cost for the SH-50 or -60 design is probably about $1800(US)...unburdened. That's pretty high.
A two-way design would probably be $400(US) less--perhaps less, even using an active crossover (miniDSP 2x4 HD)...and all at retail prices (i.e., apples to oranges).
There are a large number of threads on different forums discussing all of the pro's and cons, I suggest a google search using the terms synergy horn, unity horn, multiple entry horn, Danley etc.
I don't have any bookmarked google is your friend. If it was a DIY wooden horn most are pure conical. The ones that use converted waveguides vary in what the makers describe them as.If you guys have any links in stock to those projects I'd be interested
As Chris said when designing for home you don't need insane SPL, Bill Waslo is getting enough output with one of the celestions and it hasn't done any damage to the polars.
I think you could get very good results with a fairly basic conical horn and the same 2"/15" driver setup. The sort of horn Chris is building is the icing on the cake, well worth it if suits your needs.
Hi Chris:
A while back I asked Autotech for a quote:
"Pair of glossy white SEOS30 will costs 470 Eur
Painting for any colour 200 Eur/pair
Deilievery with custom clearance c.a. 500 Eur."
Enough said about that but if they were more reasonably priced and shipped I would have been tempted to use them. I hope yours aren't going to be glossy white. I have a never to be used white SEOS horn that my wife says reminds her of a bathroom fixture
I've been thinking a lot about woofer bandpass port size and whether or not to vent the woofer. It seems compelling to me that if I'm not going to hand off to subs at some significantly higher frequency, then I would indeed vent, tuning the box to 30-35 Hz. This both reduces the cone motion but also reduces the bandpass port size requirement.
But it also seems compelling to me to hand off to a woofer at some higher frequency. A high pass at 60 Hz or higher reduces the bandpass port size much more than does simply venting the woofer and minimizing the size of those holes is a dominant consideration. With a high pass at >=60 Hz, cone motion is already small but venting the woofer can reduce it further. My gut says don't chase this marginal improvement.
Are the woofer holes going to be cast into the horn or cut by the user? If the former, how are you sizing them?
Are you designing for the woofers to be mounted on the sides or top and bottom? I know your prototype had them on the sides but top and bottom mounting allows a tighter fit into corners.
A 60x60 modified tractrix? Sounds good! I've been playing with a design for a 60x60 conical, 2-way with 15" woofers. I now see it can work well in a corner with one vertical flare parallel to the near side wall and the other angled out from the front wall. I don't plan to build this; in plywood it would weight too much (your 35 lbs estimate looks attractive compared to 3/4" plywood) and I want to figure out how to add curved termination to it rather than a simple, diffracting secondary flare. Round over I can do. So far I haven't been able to get through the math (rather downloaded spreadsheets) for a tractrix or LeCleach mouth.
So I'm very interested in what you come up with.
Jack
A while back I asked Autotech for a quote:
"Pair of glossy white SEOS30 will costs 470 Eur
Painting for any colour 200 Eur/pair
Deilievery with custom clearance c.a. 500 Eur."
Enough said about that but if they were more reasonably priced and shipped I would have been tempted to use them. I hope yours aren't going to be glossy white. I have a never to be used white SEOS horn that my wife says reminds her of a bathroom fixture
I've been thinking a lot about woofer bandpass port size and whether or not to vent the woofer. It seems compelling to me that if I'm not going to hand off to subs at some significantly higher frequency, then I would indeed vent, tuning the box to 30-35 Hz. This both reduces the cone motion but also reduces the bandpass port size requirement.
But it also seems compelling to me to hand off to a woofer at some higher frequency. A high pass at 60 Hz or higher reduces the bandpass port size much more than does simply venting the woofer and minimizing the size of those holes is a dominant consideration. With a high pass at >=60 Hz, cone motion is already small but venting the woofer can reduce it further. My gut says don't chase this marginal improvement.
Are the woofer holes going to be cast into the horn or cut by the user? If the former, how are you sizing them?
Are you designing for the woofers to be mounted on the sides or top and bottom? I know your prototype had them on the sides but top and bottom mounting allows a tighter fit into corners.
A 60x60 modified tractrix? Sounds good! I've been playing with a design for a 60x60 conical, 2-way with 15" woofers. I now see it can work well in a corner with one vertical flare parallel to the near side wall and the other angled out from the front wall. I don't plan to build this; in plywood it would weight too much (your 35 lbs estimate looks attractive compared to 3/4" plywood) and I want to figure out how to add curved termination to it rather than a simple, diffracting secondary flare. Round over I can do. So far I haven't been able to get through the math (rather downloaded spreadsheets) for a tractrix or LeCleach mouth.
So I'm very interested in what you come up with.
Jack
I hope yours aren't going to be glossy white. I have a never to be used white SEOS horn that my wife says reminds her of a bathroom fixture
I hadn't realized that I was thinking the same thing...No, the default color is clear--and any type of transparent or opaque pigments (subject to the limitation of supply colors and my mixing abilities--which are as yet undetermined) is easy to do. I'm a big believer in single-piece flow concepts (lean mfg.).
There may be a possibility of "embedments" that might significantly improve the appearance, and perhaps veneer over the top, but that's certainly down the road in terms of proving out those embellishments. I need to produce horns first.
Currently they are being cast in. There are a few reasons for this:
1) it provides stability for the back mold standoff thicknesses,
2) I do not wish to compete with Klipsch on K-402 horns. My horns will be MEHs. Klipsch has been a friend for the most part, and I don't wish to go into competition with them. If they start to produce relevant MEH horns for sale (and the price is reasonable), then I'd point you to their dealers instead.
3) It saves a significant amount of casting material, which is already up to ~3.5 gallons per horn. Savings in material by putting it in the right places is the real advantage of the approach that I've taken, as well as being able to make any finished shape without creating lots of waste (as compared to plywood/MDF approaches).
The size of the ports is for 10:1 compression ratio using dual 15" woofers (or lower compression ratio for smaller woofers) which is needed to maintain efficiency of the woofer pass band and relevant dialing-in EQ for those that might be measurement challenged DIYers that just want to build and not also dial in. The crossover frequency is about 400-500 Hz, which is the sweet spot for 2" compression drivers (regardless of what the manufacturers say in their spec sheets--which are trying to protect themselves from DJ/club users blowing drivers and claiming "part defects").
If there are other woofer sizes, port placements, and desired compression ratios in the future that tend to coalesce into another off-axis port configuration(s), then I'll certainly consider it using another back mold, but the costs of having multiple back molds would probably have to be absorbed into the prices/horn quantities. The back mold material isn't cheap due to the rear side intricate shapes and need to be able to release the parts. This has been the hard part thus far.
I've gone with a clone of the prototype for the first prototype horn, for obvious reasons. That means sidewall woofer ports. Putting them on top and bottom creates more severe box-woofer clearance issues and makes the entire assembly larger (if using a box instead of a baffle).
There are ways to do this, but they are more subtle, and it helps to have a real horn in your hands to visualize how to do it. I won't say that I've got a method that is 100% yet since I haven't yet tried it out, but it looks quite straightforward to do. The simplifying assumption is that you use a rectangular or square mouth profile--not round or elliptical--and then things get much easier.
It's nice that Geddes pointed out the shortcomings of round or even elliptical mouth horns (i.e., mouth cancellation at some distance from the horn mouth exit).
But that is the thing. If you are handing off to your tapped horn subs at 60 hz, or even just a small sealed 18" woofer used as a stand for the MEH, the hole size you need to get the particle velocity under 17 m/s (or some other figure, as determined by HR sim) is less than 1/2 the area you will come up with by the 10:1 rule of thumb.
Here is a screen shot of a sim of two 15" woofers on my 60x60 strawman design. The dark trace is the woofer throat port peak particle velocity with no high pass filter. The light part is with a BUT2 60 Hz high pass filter switched in. Peak particle velocity, and thus required hole size, changes by a factor of two. The top picture shows filtered with HPF vs unfiltered acoustical power.
The acoustical power is 120 db, my loudness target. I'm only using 50W to get this level. My hole size is 62 cm2. The compression ratio is 27:1. Suppose I up the hole size by 20% because I'm not now at 17 m/s, then double it to support full range operation, without the high pass filter. Then I'm not far from your 10:1.
Maximum excursion goes from 7.8 mm w/o the HPF to 2.5 mm with the HPF
I'm definitely going to high pass it for the modulation distortion reduction benefits. Thus I really want the smaller (half size) holes. I wonder if you can come up with a plug for the mold to give a simple way of switching between two hole sizes.
PS those are 1 PI sims
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Could you explain your rationale here a bit more? I believe that I'm missing something. It looks as if you are thinking that higher velocities are better--not worse--and that the net SPL (i.e., "sound pressure level") is a function of velocity, not pressure, at the ports.
The port sizes used in the horn are very much in-line with Danley's--which is where I got the 10:1 rule of thumb (actually they tend to use lower compression ratios, since the SH-50/SH-60 is using 12" woofers instead of 15"). Other companies that I'm aware of use 3:1 as their target.
I suppose that you could find a grommet or other material to do whatever trades that you choose. My goal is to support those that want a more turn-key kit, as well as those with measurement and modeling capabilities.
Note that the effect of the off-axis ports in the prototype were so mild (on-axis and off-axis polars) that I decided to lock the design at that point.
Danley chooses hole size to support SPLs probably above 130 db, at least 10 db higher than we'd want in our homes.
Most of those rules come from concerns about physically damaging the cone due to the forces that exist at high excursion with high compression but sound quality will suffer before damage occurs. Simulation can predict this and that is where velocity comes into the picture.
Ports chuff above about 17 m/s. If the velocity is below that, then they are big enough. If you do the sims, you can see sound power and/or pressure falling off if the holes are too small but the velocity will be above 17 m/s before that happens.
I think a 3:1 reduction in excursion needs no further explanation re' reducing modulation distortion, to say nothing about the fact that with m any woofers you would already be at Xmax where other nonlinearities have become apparent.
But plugging into the formula for FM distortion from PKs paper
d(%) = .033 * (excursion in inches) * (highest frequency)
= .033 * .3 * 400 = 3.96%
That - the FM distortion in presence of a very loud low tone - isn't insignificant. But that is the rationale for using subs. Once you commit to the subs, you can and should commit to the smaller holes, assuming there is some benefit to that.
Is there some benefit to reducing the hole size? You claim not or that its small; in effect saying don't worry about those sharp dips around 400 Hz in my prototype (polars posted earlier in this thread); they are inaudible. However I had no such artifacts around the mid XO in my horn that used very small holes nestled tightly in the corners of the horn - so there might be some room for improvement there. I think this is one detail worth obsessing over; the effect of large holes relatively close to the throat is the one area where a 2-way MEH is compromised relative to a 3-way.
Most of those rules come from concerns about physically damaging the cone due to the forces that exist at high excursion with high compression but sound quality will suffer before damage occurs. Simulation can predict this and that is where velocity comes into the picture.
Ports chuff above about 17 m/s. If the velocity is below that, then they are big enough. If you do the sims, you can see sound power and/or pressure falling off if the holes are too small but the velocity will be above 17 m/s before that happens.
I think a 3:1 reduction in excursion needs no further explanation re' reducing modulation distortion, to say nothing about the fact that with m any woofers you would already be at Xmax where other nonlinearities have become apparent.
But plugging into the formula for FM distortion from PKs paper
d(%) = .033 * (excursion in inches) * (highest frequency)
= .033 * .3 * 400 = 3.96%
That - the FM distortion in presence of a very loud low tone - isn't insignificant. But that is the rationale for using subs. Once you commit to the subs, you can and should commit to the smaller holes, assuming there is some benefit to that.
Is there some benefit to reducing the hole size? You claim not or that its small; in effect saying don't worry about those sharp dips around 400 Hz in my prototype (polars posted earlier in this thread); they are inaudible. However I had no such artifacts around the mid XO in my horn that used very small holes nestled tightly in the corners of the horn - so there might be some room for improvement there. I think this is one detail worth obsessing over; the effect of large holes relatively close to the throat is the one area where a 2-way MEH is compromised relative to a 3-way.
I'm one of those small room guys too, Chris. I'll keep following this thread, and I hope that some day the smaller system becomes a reality.
Thanks for that. I'm finding that many listening rooms have dimensions that like the smaller horizontal coverage angle, i.e., narrower rooms, or even low ceiling basement rooms that are wide (by turning the midrange horn sideways to avoid early ceiling bounce).
If you've got carpet down on the floor and have controlled coverage horns of about 60 degrees vertically, if you're trying to control or delay ceiling bounce (thus delaying near-field reflections), you merely need to aim the centerline of the loudspeakers toward the floor. This works well, especially with thicker carpet on floors.
The current 90x60 MEH horn can be used in vertical orientation, and aimed at the floor to delay low-ceiling bounce issues, too.
This observation is also applicable to most current midrange horns that have short vertical mouth sizes (i.e., all the Klipsch Heritage series, Smith horns, etc.), this puts a lot of midrange acoustic energy on the ceiling and floor at about the frequency where the vertical mouth dimension equals 1/2 wavelength...on down to the crossover point to the bass bin.
If you've got carpet down on the floor and have controlled coverage horns of about 60 degrees vertically, if you're trying to control or delay ceiling bounce (thus delaying near-field reflections), you merely need to aim the centerline of the loudspeakers toward the floor. This works well, especially with thicker carpet on floors.
The current 90x60 MEH horn can be used in vertical orientation, and aimed at the floor to delay low-ceiling bounce issues, too.
This observation is also applicable to most current midrange horns that have short vertical mouth sizes (i.e., all the Klipsch Heritage series, Smith horns, etc.), this puts a lot of midrange acoustic energy on the ceiling and floor at about the frequency where the vertical mouth dimension equals 1/2 wavelength...on down to the crossover point to the bass bin.