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What are the main reasons for horn colorations ?
mouth diffraction ? size of the horn ? horn throat ?
Follow Ups:
Thread starter:"What are the main reasons for horn colorations ?
mouth diffraction ? size of the horn ? horn throat ?"
Later:
"I actually grow up assisting my dad building speakers, and sell them. From that time comes my passion,"
"I decide to go further, try other drivers, make my own horns, and i am enjoying to share my findings in forums, and to make progress. And be assured, i made a LOT of progress in 2 years...."
Angelo,
Not to put too fine a point on it, but if your "LOT of progress" doesn't include understanding basic horn/acoustical physics, thus resulting in your original question, I hope you're not one of those people who are trying to sell their product to unsuspecting customers who are duped into thinking that their "custom" supplier knows what they're doing. There is no shortage of DIY "experts" out there.
Lastly, in addition to the several excellent responses, I'll just add another cause: "the non-linearity of the air in the throat at high SPLs".
Get a book on horn physics, and read it. You can start with Olson's "Acoustical Engineering", and go from there.
Get a book on horn physics, and read it. You can start with Olson's "Acoustical Engineering", and go from there.
thanks for the advice.
Just saw Linn Olsons Site, which is also very informative :
http://www.nutshellhifi.com/library/speaker-design1.html
Hi angelo
You need to try H.F. Olson
Regards Philip
Thanks Phillip. That's the Olson I was talking about. Yes, Angelo, google Harry F. Olson.
btw, I realize that Acoustical Engineering has been out of print for many years, but it is available in university (and some public) libraries. On the other hand, his book "Music, Physics and Engineering" (Dover books) is still available through Amazon.com. Chapter 4 is particularly germaine to the physics of the question. I have both books, and they are STILL authoritative sources.
http://www.amazon.co.uk/Music-Physics-Engineering-Harry-Olson/dp/0486217698
Hi All
H.F. Olson's "Acoustical Engineering" had indeed been out of print for many years, but has been available in a reprinted edition from audioxpress since the 90's. At $59 & change it's a major audio bargain, not to mention the joy of paging through it and saying "So that's where_ got the idea for _" during the dark ages this book was hoarded by the lucky few. For some people, the most important audio discovery of the 70's was the existence of this book. For a good dose of Olson on line, you can download his "Dynamical Analogies" from Pete Millet's site Hopefully John Atwood (who donated the original to be cut up and scanned) has had a chance to read it now, so that he can see that some horn development has taken place since the work at Bell labs in the 30's.
Olson was THE MAN!
Paul
thanks for the link.i've google'd a little more.
about tractrix horns :
http://community.klipsch.com/forums/storage/6/1000059/Tractrix.Concat.pdf
and from :
http://sound.westhost.com/articles/waveguides1.htm
Double blind testing of various midrange horns [5] indicate that there is a definite set of characteristics that horns have that make them reliably identified as horns. This research stems from the fact that for high quality sound reproduction, most people prefer direct radiators, and the horns to which people object have a common set of characteristics. (Comments such as “honky”, and “nasal” are common.) These are ...
* Horn has many mouth reflections.
* Horn has discontinuities that cause diffraction.
* Horn is (too) long.Horns that do not have these characteristics cannot be reliably identified as horns in double blind testing, sounding more like direct radiators. We might well ask why?
One significantly different characteristic of a direct radiator is just that, it radiates directly to the air. Free air, unlike a duct, has mono modal propagation, this means that it can only propagate sound in the longitudinal mode and this happens at a constant velocity [6].
Inside ducts however, the sound can move multimodaly, and is dispersive, i.e. different frequencies move with different velocities, and the amount of this dispersive multimodal propagation has a lot to do with how good a fit the wave front in the duct is to the duct that is carrying it.
In theory the correct duct shape can propagate particular wave front shapes with no dispersion just like they propagate in free air, and this feature is the most likely reason that such ducts are free of “horn sound”.
This curvature effect was recognized a long time ago by Voight [7] which led him to develop the ”tractrix” horn. This type of horn has the reputation of not having the characteristic horn sound, the reason for this is most probably because it takes into account the gradual increase in curvature as the wave front propagates down the horn, and the incidence of multimodal propagation is much less than that which occurs in a exponential type of horn, meaning that the tractrix horn is very nearly a true waveguide.
I guess you know what I am going to say.
Conical horns have no sidewall deformities. The wavefront is not bounced around from one curving section to the next. The mouth reflection issue certainly is a problem.
Particular care must be made with the first 30% of the horn over the range of operation. The first 30% of "squeezing" contribute greatly to the honk sound. I have found that above 100Hz a conical horn is best, below this frequency, and exponential horn is best.
In some case, a modified exponential, (Tractrix) produces a little honk, but you get a good low cutoff.
Pinching a conical horn at the throat , increase the output past 8kHz , at the expense of some directivity.
A conical horn has poor low end loading. This is not too great an issue with compression drivers.
You may note that almost all the early Edison cylinder mechanical recordings were done with conical horns, used as a microphone. This is also true of Navy "talkback" speakers.
In my opinion the mouth issue has not been solved. It is a systemic problem that requires the entire horn to be reshaped. I am fooling with this now, but it is a long haul.
Foam in the mouth or throat has minimal effect. Acoustic lenses work the best at the present time.
Mouth shaping, by foam, ellipsoidal shape, or Karlson like slits also have trade-offs. This is also true for the TAD AFAST mechanical filter. This is a clever idea.
I have spent a lot of time trying to discover what shape is best. I built a horn a number of years ago with movable walls- so I could change the shape on the fly.
Here are some tests with a 700Hz conical horn with and without a mouth.
The mouth has a 5cm radius on this horn. I have also done this with a sharpish bend ( A la Keele)- this worked the best.
I have never seen curves of horn with different shaped mouths. Anyone who has done this, I certainly would like to see these tests. Here are a few …
A final note about mouths and conical horns. there is always a trade-off of horn length Vs adding a second flare at the mouth in terms of the volume the horn takes up in a PA system, or in a home.
I have always found the longer horn, is the better choice.
Look carefully at the mouth tests. Note while the conical no-mouth is worse to 3khz on axis- it is better off axis. your direction clues are oriented to the higher frequencies. You don't hear the boost at 1Khz too much. At 10 degrees it is gone. This is the endless trade-of horn design.
I choose my design based on these tests, and listening test, with ever driver on the planet, save for ALE.
This includes horn loaded Hiel. cones, dome, ribbons etc.
Confused? me too, there is no single answer.
Bill
Bill
What about keeles article where the last 1/3 of flare has double included angle - better polars from memory
There are three constants in life: death, taxes, and the inevitability of a (speaker)wire thread being closed -SY
- http://www.xlrtechs.com/dbkeele.com/PDF/Keele%20(1975-05%20AES%20Preprint)%20-%20Whats%20So%20Sacred%20Exp%20Horns.pdf (Open in New Window)
The mouth has a 5cm radius on this horn. I have also done this with a sharpish bend ( A la Keele)- this worked the best.
From the AkaBak program ( my fav) Jorg Panzer
Conical (T -> infinite)
"The conical horn is the simplest horn shape. The cross-section increases linearly. The variation of the radiation impedance is similar to that of the diaphragm.
Compared with exponential horns, conical horns have a precisely defined radiation characteristic. They belong to a group for which the one-dimensional wave equation can precisely describe the states in the horn.
It is frequently used as the shape for so-called 'constant directivity' horns, which manifest a homogeneous radiation characteristic over a wide frequency range.
Another advantage is that the cross-sectional area in the vicinity of the horn throat increases more rapidly than for exponential horns. This thus reduces the sound pressure in the horn as well as distortions due to the compressibility of air.
The only disadvantage of the horn shape is its size."
there are some, that advocate straight sidewalls,( conical, oblate spheroid)horns, and others curved ( tractrix, exponential ). I guess i will have to make my own experiments, try out both, and so, find out by myself. I suspect, as deeper the horn, more honk. So a fast opening , but at the same time not too short, to aloud loading of the driver, could be a interesting compromise. I will probably try out first something in this direction.
Angelo
Hello Angelo,IMHO the most nasty source of coloration in the sound delivered by a "honky" horn is due to the interference between back reflected waves from mouth to throat and the direct waves. This is also related to diffraction at the mouth. A properly calculated or designed mouth can solve for the most part this source of honkiness but in the same time it leads to a larger horn. That's why when it came to the size of the horns many audiophiles use the "WAF" argument...
But there exists other source of reflection of waves inside the horn itself. As clearly explained in Bjorn Kolbrek's paper in AudioXpress March and April 2008 issues, the large majority of horns are badly calculated. By example most of the horns of the Salmon families have their profile calculated under the false hypothesis of planar wavefront. Srangely,the consequence of this is largely minored within the audiophile crowd... As soon as the length of such a horn increases this leads too a certain amount of "closing" of the horn mouth compared to the ideal expansion (equidistant curved wavefronts orthogonal to the walls). In the low frequency if the horn is long then you'll have a part of the energy of the direct waves backreflected. If you build a bass horn calculated on the basis of planar waves it will be resonant. I could listen here in France to one of the most expensive "full compression drivers + horns" system in the world (Goto and Ale system), the notes in the bass was exageratedly elongated due to this effect... This source of resonance is a reason why in the pro crowd it is often said that a horn should not be long...
Another source of honkiness could be due to the effects of HOMs, but it is more related to the highmid and treble range. For my own I think this is a minor source of coloration compared to the 2 previously mentionned.
Another source of distortion is due to non linearity of the air at high pressure at the throat of a horn but it is not audible in normal audiophile listening (H2 dominant).
Many people are also relating that certain negative sonic features due to the driver itself can be tamed using horns that improve the loading of the diaphragm (my own experience leads me to agree with that) but in the same time certain people disagree about the usefulness of an (acoustic resistive) loading.
Finally, if the acoustics of the auditorium is corrected I don't consider for myself the increased directivity of a horn with frequency as an important source of coloration.Best regards from Paris, France
Jean-Michel Le Cléac'h
> In the low frequency if the horn is long then you'll have a part of the energy of the direct waves backreflected.
Hi,
How did you come to this conclusion? Measurements, simulation, calculations? I am a bit rusty on my horn theory at the moment, but what I remember from measuring wave propagation in a short horn with a small mouth was that I saw a large amount of reflected energy from the mouth at low frequencies. I assumed this was from the small mouth causing an acoustic impedance mismatch between the horn and the surroundings (which would create a reflection). I also (iirc) saw that at the 1/4 wavelength frequency, all the air in the horn moved at the same time. Ie, there was no wave traveling down the horn at the speed of sound - all the air in the horn changed pressure at the same time. I'm not sure what influence this would have on sound, but it was an interesting thing to see. However, I have also measured stored energy in horns and it seems that around the low cutoff, they do store more energy in time. I would imagine these two effects are inter-related and provide a good argument for not using a horn down to its cutoff frequency. I would also think this would suggest making a horn longer, not shorter, to try to move these effects downward out of the desired bandwidth, but I don't think I have proven this. It is just a thought based on some experiments.
Hello John,
This sentence I wrote:
"In the low frequency if the horn is long then you'll have a part of the energy of the direct waves backreflected... "
has to be read in the context of what I said about the conventionnal Salmon horns which ones are calculated using the false hypothesis of plane wavefronts. Due to the way they are calculated they are progressively "pinched" from throat to mouth. That pinching of the horn (relatively to the theorical horn having equidistant curved wavefronts of the same expansion) is also a source of "diffuse" backreflected waves. I say "diffuse" because for decreasing frequency
the distance where backreflection is more efficient moves from mouth toward the throat. This source of backrefelected waves is different of the first case of back reflection due to impedance mismatch at the mouth. For conventional Salmon horns the two effects cumulate because of the way they are calculated (what I call "cut mouths") but is more noticeable for long horns. Even in long Salmon horns the mouth of which has been designed for low diffraction (rolled back lips, foam, Iwata slots...) the "diffuse" backreflection is active. (I think that may be you can try to identify this effect using FEM).
That's how I explain that those horns possess often a frequency response curve having a bell profile shape and also why their pulse reponse is quite bad.
I guess that Keele's recommandation to use a horn having a mouth perimeter around 1 wavelength (of the cut-off frequency) and the other classical recommandation to use the horn on less than 3 octaves are largely the consequence of the desire to reduce the effects of those 2 sources of backreflection (not only the backreflection from mouth).
With horns like the Kugelwellen or the Le Cléac'h (and at a lesser degree with the tractrix), those rules are largely useless IMHO...
Best regards from Paris,
Jean-MIchel Le Cléac'h
Did you get out your peak reading SPL meter?? I wonder if it's a HOM issue like Geedes describes?? Could be your peak SPL is limited by available power so there is not enough SPL for them to become objectionable. No HOM's no honk.
angelo, as you know i am also using the speakers with the bd design orphan horn utilizing BMS dual concentric driver from 270hz above (i think).
there were some comments that the output from such a horn has to be coloured due to a same horn being loaded with both mid and tweeter drivers with a similar acoustic / phase centre.
i don't know if my experience is very relevant as my room is a bit too small for a definitive judgement (22m2, 3.5m to the listening position) however what i noticed is the horn coloration is much more prominent when different SS or chip amps are used (such as a j-fet bufferred gainclone or altmann BYOB).
what really puzzles me is that there is almost no honk once a decent SET is employed - i tried trafomatic 2A3 and a DIY 6C33 SET with only halves of the dual triodes used for better linearity: the honk was pretty much gone or it was too minor to bother.
does anyone have a similar experience or a comment, why it is like that when no acoustic parameters of the horn's geometry are affected?!
hi Gordan
coloration was never a issue with the Orpheans, at least in my setup. Coloration matters in the midrange, not treble, so the comment you heard, i don't believe. There are some people that use your BMS in a Jabo72 horn. My experience with a 25" horn was very positive. Big, open, incredibly dinamic and natural sound, and no honk and coloration anymore. I like it MUCH more than the smaller 20" horn. Lower midrange is better loaded, and more present. Actually, i suspect, that lower midrange in the 300 - 500hz region is missing in your Swing's. You can accostume very easily with it, but when you compare, you find it out.
Angelo
angelo, the honk is prominint mostly on the voice reproduction and that's definitely a midrange:)
what amps you are/were using with the orphans and what horns you moved on from them?
hi Gordan
i use a Viva Solista Integrated SET amp, and own made 20" MDF tractrix horns.
can you compare your own MDF horns soundwise with the orphans?
maybe you should ask these questions at the bd-design forum...
hi Gordan
i have compared my own horns with the Radian 950pb, and the Orphean's. The first day i made the comparison, i decided to sell the Orpheans. I wrote some time ago the differences between the two here on the forum, but there seemed to be people who bothered, and the post were removed. If you want to know the differences, send me a private mail.
I suggested Bert at his forum to make a try with a 25" horn with the BMS, but he removed the post....
Angelo
Angelo,
You are leaving out most of the history, leading to deletion of your post on that other forum.
You used the Orphean incorrectly, ie you used a (cheap) amp with a known bad interaction with the filter of the Orphean. Bert predicted it would give an over-emphasized treble and gave you an additional filter to fix it, but you refused to use it. Furthermore, you listened to the overly bright result and said you loved it, were over the moon and preferred it to anything else. Only THEN did you build your own tractrix horns and now you claim they are better, because they are less bright.
You explained on numerous occasion that your experience with horns and even loudspeakers is limited. You have left a trail of posts on many forums. They show your enthusiasm for anything horn, mostly the theoretical documentation and glossy pictures of design cabinets. You reply to lots of threads and start your own and make a lot of statements that reflect your understanding at that moment of time. However, you don't mention your inexperience and you never add post scripta to old threads when you reach a new level of understanding. Basically, your thread of posts is a thread of misinformation. It is bad for the community.
You were hanging around at Bert's forum, first picking his brain for info about the Orphean, then presenting a commercial clone and commenting negatively on his product. You're not especially knowledgeable, experienced, friendly or polite. Gee, I wonder why he deleted the post in which you suggested he chose the wrong size horn...
The clone thing was also a very negative thing, which showed your lack of serious expertise. Asking very meticulous details about cabinet volume and tuning, then wanting to install a differently sized driver with different TS parameters.
Basically, I think you could conduct yourself better online...
There's no tone problem with Bert's horns. I listened them with 7-8 amps so far, gainclones, Altmann, 2A3, 6C33 etc - and they never fail to impress with their tone, especially considering there are no esoteric drivers behind.
They are particularly not bright - if you have such a result, you should look elsewhere in your room, but to the amps in the first place. The sound they produced with 2A3 amp was bloody spectacular by any account, even given a number of restrictions I have (small room, acoustics). Except for the bass that was due to amp's poor PS.
Gordan
i have not said the Orpheans have a tone problem. They sound quite neutral, no horn colorations. I won't go into controversies. You are happy with them, that's what counts.
Angelo
Angelo,
You are leaving out most of the history, leading to deletion of your post on that other forum.You used the Orphean incorrectly, ie you used a (cheap) amp with a known bad interaction with the filter of the Orphean.
Ivo, i understand that you advocat for Bert's products, since you use them , and like them. Nothing bad with that.However, before accusing me, you should remember that i used the Trend's only for a couple of month, but all my observations are made, using the Viva SET amp.
Bert predicted it would give an over-emphasized treble and gave you an additional filter to fix it, but you refused to use it.
in fact, i went back , using the Viva, so no need anymore.
Furthermore, you listened to the overly bright result and said you loved it, were over the moon and preferred it to anything else.
True. With the Viva,that i was used to listen before, the treble was darker. With the Trend's,treble was overly bright. In the beginning , it was very appealing. Bert tried out the Redwine, and his findings made me understand, that the brightness was a result of impedance behaviour of the T-amps, an no linear frequency response. A friend of mine came visit me, liked the combo of the T amp with the Orpheans also a lot better, and i sold him the Trends....
Only THEN did you build your own tractrix horns and now you claim they are better, because they are less bright.
wrong conclusion.
You explained on numerous occasion that your experience with horns and even loudspeakers is limited.
I actually grow up assisting my dad building speakers, and sell them. From that time comes my passion, but only 2 years ago i started to interest myself closer again.
The clone thing was also a very negative thing, which showed your lack of serious expertise. Asking very meticulous details about cabinet volume and tuning, then wanting to install a differently sized driver with different TS parameters.
The bass actually does very fine, the cab size is o.k. as well.
Ivo, i don't obligate you to follow my steps and believe what i say. Think about me whatever you want. If you think you are well served with Bert's product's, that is fine. I decide to go further, try other drivers, make my own horns, and i am enjoying to share my findings in forums, and to make progress. And be assured, i made a LOT of progress in 2 years....
I'm a DIY-er.
Ivo
Tonal balance - ie, non-flat frequency response. However, this is just my opinion based on my experience... EQ'ing will fix this to a large degree, but not completely depending on the directivity of the horn, the room, etc.
So another factor will be the directivity of the horn and how it changes with frequency. Also, how you match up the directivity of different horns through the crossover region. This effects how the horn(s) interact with the room.
Geddes says higher order modes are what causes 'honk', but this would be after frequency response, imo. (I'm positive Geddes would have equalized out frequency response in the studies he did to come to this conclusion, and the 'imo' part is that broad frequency response deviations would be a more noticeable effect).
I think these three things are going to dictate the macro level success or failure of a horn project. Once you get these taken care of, then you can look at things like energy storage (in time) which limits usage on the high and low end, various types of distortion (also limiting low and high frequency range), etc.
John
hi John
Also, how you match up the directivity of different horns through the crossover region. This effects how the horn(s) interact with the room.
in my case, i will cross a 38" tractrix , midbass horn, to a midrange JMMLC similar horn. Crossover point is ~ 700hz to 1000hz/6db ( i will have to figure out still, what works best ). Some advocat for a small horn , ~ 12". Others ( most ) use bigger horns, around 20" to 25" mouth size. What horn size, do you think, would match best, to get the smoothest passage close to crossover point?
Angelo
Excellent post John!
Hopefully this was not overlooked in the discussion, as there were several very good posts in the thread. If you limit the bandwidth of a peaky driver and slap a waveguide on it (and thereby limit the higher order modes), this will not guarantee that the honk will go away. Incidentaly the word "honk" does not appear in Dr. Geddes' "Audio Transducers", and. for that matter I could'nt find "coloration" or "horn coloration" in the index either. You have more faith than me that EQ can fix resonant peaks in the horn/driver combination. Though it probably can help to some degree, active EQ can cause more problems than it solves. Almost once a year someone seems to post here with a question along the lines of whether digital EQ can get rid of horn honk/colorations. I'd say no, but I try to keep an open mind...
Paul.
Hi Paul,
I think you misunderstood me. I wouldn't want to use EQ to fix resonant peaks. I would not want to use a horn / driver in a range where it had bad resonances. However, most horn / driver combinations that I've measured have not measured anywhere near flat in a broad, general sense. Ie, if you use something like 1/3 octave smoothing, you will smooth out the narrow peaks, but you'll still see larger trends, and it's those larger trends I'm talking about. If you don't eq that characteristic, you color everything that is reproduced by that driver. If you're just assuming that a driver / horn combination will have flat response, you will probably be disappointed.
John
While both you or I would not address resonant peaks in a diver/horn combination with EQ, there seems to be a prevailing feeling here that this is a realistic approach to the problem. My comments were aimed at this, I guess I could have been more specific. I have found that resonant peakiness is the major cause of honk/horn colorations in horn/driver combinations, and dealing with these effectively is the first thing you should do to minimize any honk. Getting a broad flat (as possible) frequency response out of a horn/driver is certainly a holy grail. Getting this over a reasonably broad coverage patern is another. Getting both of these at once is like geting the grail inside of the Ark of the Covenant delivered free to your front door. One or the other is hard enough to find. Angelo was rather light on the details in his original question, and did'nt supply any freq. response measurements, which could have perhaps shown narrow peakiness, or maybe a more broad roll off trend, or even a combination of both. With this limitation several posters tried to offer advice, a rather heroic guessing game. Your post had the most concise protocol for addressing the honk IMHO, that is if I understood it correctly ; )
Paul
TrackTrix horns show less colorations.
You can make a tractrix have more coloration and honk than an exponential horn. The main contributor of coloration in the tractrix is using too long a neck. If you build a 150Hz tractrix and use it with a 1” throat compression driver it will have a ton of coloration and will honk. However, the same horn terminated with a 4” throat and used with a cone driver will not have much coloration. The problem people run into is they don’t understand that one horn type is not better than another. It is all in how you use them. People also need to understand that as the throat of the tractrix horn tapers down at the throat, it starts to approximate the exponential horn. To get the most benefit from the tractrix you have to keep the throat short. Otherwise, you basically have an exponential horn at the throat and a tractrix at the mouth.
I roll my eyes every time I see people running huge horns with 1” compression drivers. I already know what they are going to sound like because I’ve built them before and learned my lesson. A tractrix horn should only be made as large as it needs to be. If you listen to your tractrix horn and it has coloration, the only thing you can do is start raising the crossover point until the coloration starts to diminish. Of course this will defeat the purpose of your large tractrix horn; which leads you back to my point of not making it any bigger than necessary. If you truly believe you need that low of a frequency then you need to pick a different horn type.
Hello,I quite disagree with you.
You can use a 1 inch compression driver with a long Tractrix (or a Kugelwellen horn or a Le Cléac'h horn) and it will give you wondeful sonic results IF you don't use the horn in the frequency range inside which throat reactance dominates.
This means that you have to cut electrically the driver something around 1 octave above the acoustical cut-off frequency of the horn.
If you don't, what happens is a rapid increase of the group delay when the frequency decreases toward the acoustical cut-off. ( a voice seemingly coming from the depth of the horn, is often mentionned to describe such a sound). The fundamental of one note may be delayed of more than 1 meter relatively to its harmonics. The waveshape of the note is distorted and this is audible.
A very good example of very good results using a 1 inch compression driver with a long horn is the use of a TAD TD2001 driver on the Sato horn (which one is inspired but somewhat different of the Western Electric WE22A).
You should remember also that the Western Electric horn reference WE15A was used with the famous WE555W compression driver, which one is less than 1 inch.
Best regards from Paris, FranceJean-Michel Le Cléac'h
hi JohnTom Danley does use i guess it is a 1" compression driver in his SH50 speakers, which use a quite big conical horn, but the comments were very positive :
http://db.audioasylum.com/cgi/m.mpl?forum=hug&n=128355&highlight=sh50
when i had the Orphean's from BD-design, with tractrix horn, honk or coloration did not bother me. In this regard, they were O.K. they cross lower than 300hz, with 22" mouth size. Afterwards, i made a pair of tractrix horn's with 20" mouth, utilizing a Radian 950pb. I crossed it at 300hz, and had more lower midrange output, but horn coloration. How come, if size of the horn was almost the same, crossover point as well, and throat exit, too ?
What i am interested in next, is to make a horn to use with the Radian, above 800 - 1000hz, and choose the best possible horn profile. It will be combined with a 150hz tractrix midbass horn. I am looking for lowest possible horn coloration.. Any suggestion ? There is a lot of talk about oblate spheroid waveguide, but these are so short, how will it load the driver ? how about something between tractrix , and a short waveguide ?
Angelo
Yes the SH50 uses a 1" HF, but that is crossed over to 4 5" drivers for mids and then to 2 12" for lows.
Believe me, the 1" is NOT going down to 150Hz!
Yes, all the drivers share the same horn, but that is to get a single impulse (signal alignment) and to have different expansion rate for each of the different pass bands for proper horn loading.
You can read about how it all works here:
http://www.danleysoundlabs.com/pdf/danley_tapped.pdf
.
Probably due to mouth angle.Ofcourse tractix polar pattern narrows with increasing frequency.so they all have different trade offs.
There are three constants in life: death, taxes, and the inevitability of a (speaker)wire thread being closed -SY
Several factors. There is an equation to figure 2HD from the throat,and bandwidth.
Very good link.Hard to find info all at once like this,online.
Mike.E
'horn honk measurements etc'
There are three constants in life: death, taxes, and the inevitability of a (speaker)wire thread being closed -SY
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