Yeah I do agree for an absolute sphere or rather hemisphere.
We are talking some degrees of compromise for almost everything. Not that we cannot get pretty close, because man spherical domes are slices, where the axial wave sees less mismatch with the start of the flare, which could also be adjusted to give a uniform propagation through the flare. Maybe conical transition to OS
There is not the perturbation of the phase plug.
Hey just reading the other post now - interesting
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Pete,
Adapters going from small to large, a 1" to 1.5" or 2" are not a problem, other than 1.5" -2" entrance horns have to be "pinched" to have wide dispersion at HF, with the attendant diffraction issues that make them sound worse at high throat pressures (high SPL).
Plumbing going from a larger to smaller throat is a no-no if extended HF is desired, as it creates an acoustical band pass (cuts highs) as well as a peaking response, and nasty diffraction. Also tends to be lossy at the bottom end of the horns response, as the acoustic loading is hosed.
I'm sure that Peavey has made many 1" exit HF drivers, but the ones I heard on old SP1 speakers of the era similar to yours used a voice coil with round wound wire (literally looked like motor winding wire), they dropped like a rock (like 24 dB per octave) above 10 or 12 kHz, a typical 1" phenolic had as much HF. Those diaphragms were simply beyond what EQ could bring back at HF, though they withstood typical club abuse with a passive crossover around 500 Hz.
There are certainly better 1" drivers available now, but that is not to say what you have is the same as I heard - they could have been re-diaphragmed with something later and better.
If you are satisfied with the low end of that horn, but dissatisfied with the HF extension, look for a decent 1.75"-2" diaphragm 1" exit driver, if you want more mid guts as a 3" diaphragm can provide, you will need a different horn.
I do have plenty of Maltese horns (and adapters for various size drivers) left if you are interested, but the 13 degree pattern does require a fairly small listening area.
Within that 13 degree tunnel (widens below 2000 Hz) the accuracy of reproduction (and sensitivity) is rather stunning, if I do say so myself.
Or, as Bob Oswood said, in classic Minnesotan: "Art, some guys would say you made a beamy horn", which is why most of them now have been converted to patio furniture 😱.
If you listened to the recordings of the various drivers here:
http://www.diyaudio.com/forums/multi-way/212240-high-frequency-compression-driver-evaluation.html
you have heard the Maltese horn.
Art
It worries me when the word "should" is used, I should be perfect, I'm not. Words. Which do you then feel, is the design that most nearly or *does* present this nearly perfect wavefront or are other designs that deviate from the "ideal phase plug designs simply way around a patent as usual and guilty of more issues. HOMs = modal resonances, high frequency modal resonance, the same as LOM's or MOM's so I suppose HOMs deal only high ones right? So we dealing with the same issues that horn loaded woofer deal with only higher right? And the same issue that Peavey and other dealt with when they used a phase plug on a big cone compression mid driver MOMs I guess. I'm simply trying to de-mystify this for the layman, and semi initiated as well I appreciate your help in clarifying issues that are sometimes IMO purposely obfuscated for "wow and awe" marketing reasons and I know you are a data guy who does nor need smoke and mirrors, and great products like yours sell themselves. thanks.
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You are the shizzle dude!!!
Careful Wayne P. the Royal Order of Mystical Speaker Makers Guilds will come in the night, put a dead horses head in you bed or something.
The Maltese horn (AKA "Welter's folly) was named because when the side walls of the horn are laid flat, they look like a Maltese cross, and it sounds cool, like the Maltese Falcon 😉.
Originally designed as a three way nested horn within a horn concept, the large outer bass horn was intractable.
Later, after discarding the 67" deep x 45" x 45" outer shell, the mid high portion was usable. Thousands of dollars of custom steel rigging frames were sold as scrap, bringing enough money to buy one pizza.
Some Maltese cabinets are still being used for PA work 21 years after being built, but most of the HF horns have become stools 🙄.
Some of the stools mouths have been shortened, did not realize there were plywood eating termites in Madrid, New Mexico...
Art
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And this could be an inverted dome with flat face. Could be very rigid and light too.
Saw some good figures with a shallow waveguide using Vifa inverted cone driver. The one well known and esteemed if you dont cross it too low.
i
Art as the chef down here would say "BAM!" Your clarity dish is served I got it! The driver I am pleased with albeit radical EQ is the second generation 22a with an aluminum surface on the big Keele/EV clone Ch-1 aka MBX-1 aka top of SP-1 in fact they were more or less made for each other but no way HiFi with standard XO, with active hell yes and oddly it does make it down to 500, the bottom horn makes it to 550 with ease so its LR24 and EQ. Oddly the high end is more than tolerable barely perceptable ringing, I'm almost there. But it sounds as if I call not adapt your favorite driver to these horns (going down to screw in 1x") damn so I guess I will turn into Ahab and go hunting for some true Electro Voice White Whales 9040s I guess. Thanks you!
Art as the chef down here would say "BAM!" Your clarity dish is served I got it! The driver I am pleased with albeit radical EQ is the second generation 22a with an aluminum surface on the big Keele/EV clone Ch-1 aka MBX-1 aka top of SP-1 in fact they were more or less made for each other but no way HiFi with standard XO, with active hell yes and oddly it does make it down to 500, the bottom horn makes it to 550 with ease so its LR24 and EQ. Oddly the high end is more than tolerable barely perceptable ringing, I'm almost there. But it sounds as if I call not adapt your favorite driver to these horns (going down to screw in 1x") damn so I guess I will turn into Ahab and go hunting for some true Electro Voice White Whales 9040s I guess. Thanks you!
Which would be a shame in this case. Whether I started it or not, it was my intention as
usual to get to the chase on some of these difficult question without a bunch pedantic bloviation and other than me using the word above instead of B.S. that is what is happening in spades.
Yeah? Well I'm begining to see visions of *simple* dome radiators *not compression drivers* but mechanically as efficient as possible, that cover as much of the critical midband as possible on simple conical horns with as narrow a dispersion. patted as tolerable (balancing horn gain with dispersion of course) and tiny little bullet tweeters, the kind iysed in autos, coaxially mounted and designed so as to present as little diffraction as possible in my dreams
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Point 1: Klipsch offers the "Jubilee". A corner is not absolutely required, but near a corner will certainly augment the low end
Point 2: As with any fun speaker, it does have a biggish footprint and little WAF
Point 3: Yes, it be great!
I was not refering to this very thread, but another one, which also happens to contain the word "Secret". 😉
IG
With Neo magnets it is all happening 95dB plus the starting point.
Genelec and Behringer already do it for the small studio monitors.
I am sorry to say that I don't follow you (not the first person to say that I suppose). What is the question?
The sources that we have are what we have. Virtually all compression drivers seek to provide a circular plane wave at their exit. Just how good any of them are at doing this is not clear since I don't know anyone who has studied this. (Well not publicly at least.) I have always want to look at just how "flat" the wave fronts are but its just another task on the list. Its a little tricky, but nothing insurmountable. The whole Bob Smith phase plug concept is flawed, but to what extent this is a problem is not clear because "there is no data".
Oh yea, I just listened and we're good. 😉
Beyond that, I don't know what your question is.
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Yeah. Sorry about that, a habit I picked up from some of my less technically minded freinds in mainstream "journalism" It was worse before one of the mods wisely edited it. You would be supprized how few companies own all the mags.
By "flat circular piston" I simply mean the assumed exit from a compression driver. Its being a rigid piston or not is not important, its just that it has constant amplitude and phase across the entire surface.
My first test of the OS waveguide did use a flat rigid piston - a 1" honeycomb unit from Panasonic. Great little device that. Proved the theory to a "T".
LOL - that's very funny because a buddy once showed me photos of a big, all horn system he had visited on Malta. (one of the amps was his) I don't think I've ever seen such a huge system in person. All GOTO drivers, IIRC. Don't know where the horns were made, but they were certainly Maltese after the install. 🙂
Yeah Doc, you are in fact one of the first people I've heard that from, In fact I may hear "Yes I understand, I get it" occasionally. I have a pretty fair habit of detailing queries and issues down to the annoyance level. Ironically I have been often employed to make the technical easier to understand for millions of readers. Sometimes this is tough without stepping on extended toes.
I realize these are not necessarily simple concepts we are discussing and in reality this is not our discussion, it is for the benefit of those who follow our paths, nevertheless, you can be quite certain that in the future I will be a lot more specific in my questions and especially any issues I may have. Appreciate your knowledge and I know you will understand my directness as I attempt to clarify some of this terminology for myself and others. In fact I will try to make point of such clarification.
Often, in fact a bit too often, I encounter "new" terms. These new terms are many times concepts that most of us that frequent groups such as this one readily and easily understand but oddly, are strangely cloaked in a "brand new word" that means the same damn thing. Hopefully this post is not obtuse.
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