Spherical Horn / Kugelwellen - Trichter

[Hoerninger]

Member Linear started an interesting thread "Horn / Waveguide Contour Comparisons" which you can find here:
http://audioheritage.org/vbulletin/showthread.php?p=130824#post130824
There came up the question for the "Kugelwellentrichter" (spherical horn) developed by KLANGFILM around 1950. The following articel gives a detailed description.
____________
Peter

[Hoerninger]

Here are some more infos by pics. Btw. KLANGFILM always made square cross sectional areas.
____________
Peter

[northwood]

really very vintage stuff

I saw some fans r using it.

[northwood]

:)

[northwood]

this is what u want:D

[northwood]

:D

[northwood]

:)

[northwood]

Siemens 36 cm Smf.Lsp2a full range driver

[Hoerninger]

Runs with StarOffice or Open Office. Enjoy.
Download below.
___________
Peter

[Hoerninger]

EUROPEAN PATENT OFFICE

Searched here for number 279947:
http://ep.espacenet.com/numberSearch?locale=en_EP
(Patent is in German)
____________
Peter

[Ian Mackenzie]

http://www.diyaudio.com/forums/showthread.php?s=&threadid=100392&perpage=25&pagenumber=141

The above thread over on diyaudio.com is a huge canvas of all the issues around building a hi sensitivity system using large woofers and horns.

Certain well regarded members of the audio industry have also left some interesting post around the JBL K2.

I usually take all this type of stuff with a grain of salt but when the K2 and the Westies both get slammed by Charles Hanson of Ayre fame I take some notice.

This aspect of the discussion is around how far you can take up a woofer before audible problems ocurr.

This interests me because I am iconsidering a high senitivity two way system using the 2435 be driver, a horn of some sort and some sort of woofer. Lots of choices.

Of course it depends on your expectations of a diy project as to what is acceptable and what you think are the key important qualities. ie dynamics, timbre, imaging, low distortion.

Sadly the more sensitive systems seem to excel in the former and the latter. To get all four qualities seems both complex and expensive or is it?

Then there are the die hard opponents of CD and non flat power response horns and the guys who insist on coaxials and helper woofers and OB's.

Earl Geddes has recently published a kit what he claims has been optimised for all of the above qualities. The devil is in the details and Earl claims the results have little to do with hype or subjectivism of the designer but sheer science.

One interesting point that Earl Geddes and Lynn Olson agree on (they are of opposing view points most of the time) is that large woofers invite large boxes usually and this is recipe for box modes causing colouration and diffraction issues.

I wonder how much the above are the cause of apparent concerns about using large woofers to run up the horns?

I have only heard the JBL 1500 AL in one diy system that used tad 4003 compression drives, Tad horns and a Tad tweeter. One would be forgiven for thinking the 1500AL is ultimate 15 inch woofer.

As I recall the first and last qualities mentioned above were met with all the glory one would expect but I am not convinced of the other two particularly (given the serious financial outlay given these are soa parts.)


Perhaps Charles is right. Assuming he is then that whole scene is a bit more tricky than comming up with a souped up VOT.


iMac

[merlin]

One needs to remember that ones perception of timbre and image quality is as much influenced by the listening room acoustic as by anything else.

It's remarkable how tolerant we become of our own listening room's additions and how intolerant we are of others.

I personally believe that the compromises inherent in stretching a 15" drive unit to cover half the audible spectrum are no worse than those involved in adding another crossover point with all it's attendant baggage. Certainly all of the four way JBL's I've heard sound like that once "tweaked" by unhappy owners - IE they sound like four separate drive units rather than a homogenous whole.

The system you were referring to was a prototype of mine and whilst the timbre issue surprises as studio engineers and Stereophile reviewers have commented on it's perceived accuracy, the imaging is entirely down to suboptimal positioning required in a difficult room to maintain accuracy of timbre and linear FR. Hence my opening sentence.

Sadly for Earl and others there is no right way to do this - there is no universal panacea as there are no full range drive units capable of flat FR and even power response from 20hz to 20khz at 100db with vanishingly low levels of distortion.

[4313B]

Certain well regarded members of the audio industry have also left some interesting post around the JBL K2.

I usually take all this type of stuff with a grain of salt but when the K2 and the Westies both get slammed by Charles Hanson of Ayre fame I take some notice.I wouldn't bother... I highly doubt they have anything more to add that wasn't already known going in. The K2 is a product. The questions are: How many units have sold? How many units are selling? What are projected sales? Are we making any money selling them?
I personally believe that the compromises inherent in stretching a 15" drive unit to cover half the audible spectrum are no worse than those involved in adding another crossover point with all it's attendant baggage.That seems to be the long running argument.

[Ian Mackenzie]

Michael,

Your worship.

Never look up when the Gods are talkiing to you.

It's bad for your eye sight.

Was I specifically referring to you but if you feel as bad as the colour of your own shit then by all means have a clean out!

I have after all visited numerous violent acts of audio stupidity in asia minor over the past 10-+- years.

Your should of course be honoured to be part of end tails.of this thread.

Glad you edited your initial reply Michael but the nearfield never lies.

[Ian Mackenzie]

I wouldn't bother... I highly doubt they have anything more to add that wasn't already known going in. The K2 is a product. The questions are: How many units have sold? How many units are selling? What are projected sales? Are we making any money selling them?That seems to be the long running argument.


Was it charged coupled on the initial release or are the rumours of dealers soldering in Hovlands true? Just a question.

The community seeks answers not questions about sales in mother America.

I hope you are not making a pass at the Japanese marketplace.

As posted by an American(s):

quote:Originally posted by Charles Hansen


Well if you want to know what your speakers will sound like, just give a listen to the JBL K2 S9800's. That's pretty much what you've described. The 15" woofer has a paper cone coated with Aquaplas, and an alnico magnet with really cool multi-layer pole piece to keep flux modulation to a minimum.

We used a pair at the CES a couple of years ago and still have them here at our factory in Boulder. (We liked them enough to purchase them.) They have the "Special Edition" crossover that has much upgraded parts over the original version and we also replaced the Monster internal wiring with Cardas.

They're pretty darned good speakers, but certainly not perfect. The main differences between them and what you are planning to do are probably the open baffle (versus a vented box) for the woofer and the horn profiles. But in my estimation their greatest weaknesses (no speaker is perfect!) will not be addressed by your proposals.

To me the single biggest problem of these speakers is that there is *no way* to get a 15" (or even a 12") woofer to sound natural much past 300 Hz, let alone all the way to 800 Hz. But to each his own.

Let me know if you ever want to hear them. We're less than an hour from Fort Collins. From 800 Hz on up, the beryllium drivers create quite an extraordinary result.
Hi Charles, yes, I'd like to hear the JBL K2's. I live in Erie, no more than twenty minutes away from Boulder. You can see my e-mail address midway down the Nutshell High Fidelity (http://www.nutshellhifi.com/) website - let's make contact, I'd like to hear the big JBL's. I'm hoping they're in a somewhat higher class than the big TAD system I've heard so far. I appreciate the invite and would like to take you up on it.

I am partial agreement about the big woofers, which is why I'm keeping open the option of a pair of 12" drivers - again, used with a 700~850 Hz crossover. In this frequency range, I am more concerned about box modes than driver resonances.

The box modes in a big studio-monitor (or JBL K2) box are much harder to control, and to my ear, lend an annoying "droning" quality to the sound, a traditional part of the sound of big vintage loudspeakers. These modes are quite apparent when the drivers are pulled and you put your head in the box - you hear a droning, drumming quality to ambient sounds, and the box stuffing and damping, although reducing its magnitude, adds its own dull, murky quality to the droning sound. Many damping materials have their own sonic signature that overlays the basic box sound, resulting in a slow, sodden quality to the lower midrange and upper bass.

I used to be puzzled why these modes in the 300~800 Hz regions were so obstinately difficult to control, until I got MLSSA in 1991 and found it took 2 feet of a wide variety of damping materials to merely reduce the floor bounce by 20~25 dB. I started with what I thought was plenty of damping, several inches of the fancy commercial foam stuff, combined with several layers of audiophile-grade wool felt, and it only reduced the floor bounce by 5 dB or so! It was nearly worthless!

Now, above 2 kHz, then the commercial stuff started to make a difference that was more worthwhile, particularly if you wanted to reduce the slap off the back of the cabinet. But frankly, anything I could buy on the market, had only the slightest effect in reducing the box modes - and the bigger the cabinet, of course, the lower in frequencies these modes are, and the less effective any type of damping, at any price. So all of the fancy damping we see in big box cabinets is mostly effective above 1 kHz, and does surprisingly little below that frequency. What it does do, though, is add odd colorations of its own, which is why lightly damped old-school speakers can sound better than modern, heavily-damped speakers. It's one of those pick-your-coloration things.

All it takes is a little playing around with MLSSA, or any MLS program, and looking at what it really takes to absorb the floor bounce. Since MLS systems can examine the frequency response of the bounce itself (by gating away the direct sound from the loudspeaker), you can examine at leisure what various damping material do in terms of absorption vs frequency. Carpeting, for example, does nothing below 8 kHz - it might as well be glass.

It was this discovery that made me realize just how hopeless the situation with conventional box speakers really is. The only way to get around it is confine the box speaker to very low frequencies (below the first mode) and use a sharp-cutoff crossover to avoid contaminating the more critical region of the spectrum. Otherwise, the box is going to result in murky, opaque, and congested bass - I suspect much of the merit of transmission-line speakers amounts to little more than clever control of box modes in the 300 to 800 Hz region. That's what I had in mind with the Ariel - it was the box-mode region I was most interested in, not the deep bass. Even so, transmission lines have their own set of awkward compromises in this frequency region.

Although I grant that big drivers in the 12 to 15-inch range are starting to get into trouble, with the spider and surround being the first resonance to appear, I feel the box modes are the most prominent and objectionable - and due to the lack of good LF absorbers, the hardest to control. My instinct is that more than 20~30 dB of smooth, broadband absorption is needed, and existing damping and absorbing materials just don't provide that in the box-mode region. Thus, the proverbial "box" coloration which is so noticeably absent in bass horns and dipoles - since we are all so used to this particular coloration, it is most noticeable when it disappears.

For me, the charm of OB isn't so much the dipole radiation pattern, with the claim to less room coloration (which I am not all that sure of), but the more genuine advantage of side-stepping a prominent coloration in a very important frequency range - upper bass and lower midrange. True, driver colorations remain, but I feel these are much milder in the 300~800 Hz region than the much more noticeable 1~4 kHz region, where small-format midbass drivers are commonly used.


Last edited by Lynn Olson on 05-07-2008 at 09:49 AM

[4313B]

Was it charged coupled on the initial release or are the rumours of dealers soldering in Hovlands true? Just a question.Why would you care? How would knowing further your life goals?
The community seeks answers not questions about sales in mother America.What community? What answers? Why?
I hope you are not making a pass at the Japanese marketplace.I have no idea what you mean.



As for the cut and paste above, yeah, we went through that whole discussion at the beginning of Project May.

This aspect of the discussion is around how far you can take up a woofer before audible problems ocurr.

This interests me because I am iconsidering a high senitivity two way system using the 2435 be driver, a horn of some sort and some sort of woofer. Lots of choices.Well fortunately all you need to do is satisfy yourself. How about a pair of LE14H-4's? Greg likes their slight increase in sensitivity over the older LE14's. He uses them to great effect in the S4600. The LE14H-3's and LE14H-4's are probably the best bet for a 2-way without a subwoofer. I just posted the LE14H-4 in the Transducer Information section.

[Robh3606]

Was it charged coupled on the initial release or are the rumours of dealers soldering in Hovlands true? Just a question.


Yes with Mylars and PP bypass.


The box modes in a big studio-monitor (or JBL K2) box are much harder to control, and to my ear, lend an annoying "droning" quality to the sound, a traditional part of the sound of big vintage loudspeakers. These modes are quite apparent when the drivers are pulled and you put your head in the box - you hear a droning, drumming quality to ambient sounds, and the box stuffing and damping, although reducing its magnitude, adds its own dull, murky quality to the droning sound.

Do your boxes sound like that?? I would think the tuning would be more of an issue with the older vintage designs although some of those boxes are a bit loose.

Rob:)

[Hoerninger]

To come to the bottom of this thread what about an augmented two-way system?

I remember
JBL's New Maximum Output Midrange/Low Frequency Transducers. (http://www.jblpro.com/pages/tech_lib.htm) (TechNote 24)
which introduces the 2012H and 2020H as speakers with
1. extended power response
2. high efficiency
3. low mass, high resonance
4. low distortion
5. adaptability to horns
6. high reliability,
these are qualities to have an eye on.

When using one of these speakers with a horn 100 Hz to about 1000 Hz you have no boxiness (The back chamber is presumably very small), the cone will behave better than that of a 15 inch one.
It might be that time delays between the mid bass horn and the mid/highs horn are less significant.
The deep bass will be augmented by your choice,the speaker will only be fed up to 100 Hz, surely an advantage.

Regarding the mid/highs horn, a Kugelwellentrichter has a wider dispersion than a tractrix horn as it is shorter. The length influences time delay additionally.

An example with a midbass horn and an augmented bass you can see at volvotreters home page (http://www.volvotreter.de/new_system.htm)
__________
Peter

[Mr. Widget]

One needs to remember that ones perception of timbre and image quality is as much influenced by the listening room acoustic as by anything else.Amen!



It's remarkable how tolerant we become of our own listening room's additions and how intolerant we are of others.We also can become very tolerant of frequency response anomalies in systems... for example when listening to a system in your car, it still sounds acceptable even though the curve will be far from neutral. I have discovered that for fairly minor inaccuracies in frequency response we will automatically "correct" the response in in our brains after a few minutes of listening.

I am not saying that a neutral frequency response is unimportant, but we are quite capable of adapting to a system and finding musical enjoyment despite it's having a colored sound.



I personally believe that the compromises inherent in stretching a 15" drive unit to cover half the audible spectrum are no worse than those involved in adding another crossover point with all it's attendant baggage.You bring up an interesting point. I'd suggest the correct set of compromises are determined by the individual. For me, I am not happy with the sound of a large woofer being asked to play very high. I prefer the additional time smear and lobing one gets with an additional driver. :) I don't look for time smear and lobing, but If they are controlled, I find they can be more easily overlooked than the beaming, harmonic distortion, and sonic qualities caused by using a 15" woofer up into the mid range. Once again, it is dealing with compromise.



Widget

[Mr. Widget]

Michael,

Your worship...


Just to amuse me, could you tell me what constitutes the near field in my living room and what the critical distance is? I presume you are in posession of the RT60 figures or are you simply puffing up your colonial chest?Now come on you two... no need to get personal here.

FWIW: In the research I have done, RT60 measurements in smaller rooms like those we all live in, RT60 measurements are pretty well useless.


Widget

[Mr. Widget]

Peter, sorry for my contributions toward veering off topic. I think it's time we return to your spherical horn discussion.


Widget

[Ian Mackenzie]

The type of horn is often dependant on the lower frequency driver you decide to use and the reasons behind that.

Perhap the penny will drop in a moment if I make it easier for some of you to step outside the JBL square.

Regardless of JBL's marketing direction or commerical decisions there are laws of physics which tell us a lot about the effect of cone size on the cone behaviour.

Every cone driver has a break up point and break up modes beyond a certain frequency. This is well documented and discussed in the above diyaudio thread.

Beyond the breakup frequency the cone no longer operates in piston mode. This means the driver will no longer be an accurate transducer as a pure piston mode driver and it wont sound as good. (this is why woofers that have straight cones sound better)

Some people try and damp the cone or use stiff materials to moderate the break up mode behaviour. The problem does not go away and usually pops up some where else.

There are a few choices.

Do nothing about it if the primary goal is simplicity and the benefits of the larger cone like sensitivity and low frequency output.

Lower the crossover point and use a larger horn. This is where the grey matter comes in regards the style of horn. The lower a horn goes the larger its mouth and axial length.

Ever seen a 500 hz conical horn? Obtaining uniform power response and low distortion and wide bandwidth with a lower horn frequency is not easy.

Use a smaller woofer cone. The smaller cone will have a higher break up modes and will operate in piston mode at higher frequencies. It may not have the same sensitivity or low frequency output.

The smart loudspeaker builder can get around this by using multiple woofers that reperesent a line array at low freqnencies and a point source at higher frequencies. The tailoring the high frequency of each driver progressively you can obtain extended bass response and output while mantaining good sensitivity and low distortion.

The narrower box also has less diffraction issues.

As a result this frees up the contraints on the type of horn.

Big horns have a low waf factor and require a seriously good compression driver for them to work properly.

Dr Geddes an authority on horns maintains (if you can understand his disucssions) that there is not a lot of merit to using a waveguide (at least ) below 1000 hertz.

Looking at it from another angle why make it hard for yourself by accepting you must use a large diameter woofer? I guess people need to impress themselves or the market.

The question of constant power response is a design decision and there is a lot of debate over this point with horns.

But there is no mistake on breakup performance and this underpins IMHO the midrange performance any loudspeaker.

I have discussed one approach above and there are others like using a smaller or multiple samer bass mid drivers and a crossover point between 50-100 hertz and an activr sub below this frequency. This approach has alot of merit because the requirement of the low bass can be dealt in such a manner as to not compromise the rest of the loudspeaker.

Large drivers located lower or near a floor boundary are going to have issues if they are operating in the midrange.

It is interesting to note Bose has sold lots of loudspeakers because of good brand marketing. Des that make them a good loudspeaker. No.

It is also interesting to note that critical comments about the JBL K2 and the E2 focus on what happens below the horn crossover frequency. What happens with the horn is brilliant and that is its strength.

Tad went about it differently and its regarded as a superior loudspeaker..

[Ian Mackenzie]

Yes with Mylars and PP bypass.



Do your boxes sound like that?? I would think the tuning would be more of an issue with the older vintage designs although some of those boxes are a bit loose.

Rob:)

Rob,

If you check out the links in the Eighteensound web page they have kit designs with box diapgrams that address this problem. The use of non parralell sides and liberal use of damping at the back of the box and the ends helpe mimimise the issue.

[Hoerninger]

This interests me because I am iconsidering a high senitivity two way system using the 2435 be driver, a horn of some sort and some sort of woofer. Lots of choices.

Ian,
are you in the phase of discussing basics or is it the search of a good mid bass / mids driver? I am still looking for a candidate, have not found it yet. (Years ago an AUDAX PR170MO predecessor was a candidate which I used - now out of production, but cone brake ups are apparent.)

Then it is a question of making it concrete, fulfilling your design goals. And that is as always a question of compromises (not meaning faults).

Interested to follow your headway.
___________
Peter

PS:
http://www.audioroundtable.com/PiSpeakers/messages/13339.html
discussing some JBL and 18Sound 6ND410, which is quite nice

[Earl K]

Hi,

Peter, are you able to post a version of your spreadsheet that opens in MicroSofts' Excel ?

Thanks < Earl

[Hoerninger]

Earl,
wait a bit (a month ;)), in my vacation I will do it.
Normally there is no Windows at hand for me.
__________
Peter

[Earl K]

Hi


Earl, wait a bit (a month ), in my vacation I will do it.
Normally there is no Windows at hand for me.

- Okay, I understand the need to wait ( since soon I'll be away on my golfing vacation ) .

- If you're strictly Mac based , how about making it an AppleWorks spreadsheet ? ( many of us still have that software standing by to do something useful ) . Or are you Linux based ?

<> :)

[4313B]

Tad went about it differently and its regarded as a superior loudspeaker..Ian, it sounds to me like you have it all figured out and might want to talk to Mr. Widget about getting some TAD transducers. Did you get a chance to hear his system when you visited?

[merlin]

T
This means the driver will no longer be an accurate transducer as a pure piston mode driver and it wont sound as good.

Assuming that the one follows the other is dangerous and ignores all the other variables in speaker design.

In my experience wide baffled designs simply sound more natural and convincing. Narrow baffles sound like good hifi. I'm after music not good hifi. Whether it's to do with the shifting of the baffle step or something else I don't know but I certainly prefer wide baffled loudspeakers by a considerable margin..

[Hoerninger]

Or are you Linux based ?

No (,not yet.)
I am using IBM's OS/2, I grew up with it.
You can still buy it as eComStation, it is a niche product.

[I am using two screens with 1600 x 1200 each. It is useful to look at PDFs with 1600% resolution. Regarding earlier postings in this forum I will give a an additional remark soon ( ;) ), at least for long term readers.- Hello Mr.Widget!]
___________
Peter

[Fangio]

... a version of your spreadsheet that opens in MicroSofts' Excel ?

Thanks < Earl <> :)

xml - opens in MS Excel 98-2008/Mac (including 2001/Mac)
xls - should open in MS Excel 5.0/Mac and later versions.

Enjoy

[Ian Mackenzie]

Ian, it sounds to me like you have it all figured out and might want to talk to Mr. Widget about getting some TAD transducers. Did you get a chance to hear his system when you visited?

I am not suggesting I have anything figured out . If I had a stock K2 and E2 to measure and collect some hard data when I could talk some real fact about those systems.

Beyond that it is really basic engineering principles and working through the compromises you are prepared to accept.

One thing to point out is getting low harmonic distortion and power compression in the Mid midrange is a challenge and there is a requirement for displacement. Hence I would not do smaller than an 8 inch to get sensitivty in the mid early 90's.

No, Mr Widget was moving shop when I was there last but Bo's enthusiasm for that system is inspirational.

Peter,

Have a read of this article. That driver is quite exceptional.

http://www.troelsgravesen.dk/JA8008.htm

[Ian Mackenzie]

Ian,
are you in the phase of discussing basics or is it the search of a good mid bass / mids driver? I am still looking for a candidate, have not found it yet. (Years ago an AUDAX PR170MO predecessor was a candidate which I used - now out of production, but cone brake ups are apparent.)

Then it is a question of making it concrete, fulfilling your design goals. And that is as always a question of compromises (not meaning faults).

Interested to follow your headway.
___________
Peter

PS:
http://www.audioroundtable.com/PiSpeakers/messages/13339.html
discussing some JBL and 18Sound 6ND410, which is quite nice

Hi Peter,

I have been doing my home work and once you start to have a good look around the constraints or the square you thought you had to work in is not necessarily the case.

What I am looking at is a 2 or 2.5 way system with moderately high sensitivity (92-96 db) that I can run hi end 20 watt class a amps into without the issue of biamping @ 300 hertz and without resorting to the old formula we keep seeing from JBL which are nice but its still the west Coast sound.

I mean I can go and buy better loudspeaker off the floor like a B&W 800 series or a Focal Utopia Be or an Usher Dancer but it will be in the low 90 db senitivity and I will have to resort to 250 watts (which I have). That is not the point of the exercise and I rather not spill $6000 on Feastrex FRD right now looking at the other extreme, Nor am I into into full range drivers that beam like a flash light at high frequencies.(The GPA 604 is supposed to be a vast impovement..perhaps I should hang out for the reviews)

I agree some of the eighteensound drivers are quite nice as are the nitride treated compression drivers. I prefer to use my 2435 be if I can but that depends on finding a suitable horn / wave guide ( not a PA horn).

http://jantzen-audio.com/download/ja8008-tw034-kit/JA8008_TW034_article_v2_ja_web.pdf

The same driver presented in this project can use used in a 3 way biamped scenario with a larger 15 inch woofer.

[Earl K]

Thanks Fangio !

- Unfortunately, I can't open 2003 Excel files ( only 2001 & previous to that ) .

- Are you able to do a "Save As" into a 2001 Excel file for Mac or PC ? ( & then repost the attachement ? ) ( Yes, I know I'm quite a beggar ) ;)

<. EarlK :)

[Robh3606]

One interesting point that Earl Geddes and Lynn Olson agree on (they are of opposing view points most of the time) is that large woofers invite large boxes usually and this is recipe for box modes causing colouration and diffraction issues.

Hello Ian


Yes but that's about it. Earl just builds a better box and see's no advantage to going to an Open Baffle approach which for some reason seems to be the rage on that forum. There is some pretty jaded and opinionated stuff in that thread. That whole set-up is going to end up being an OB version of a larger format monitor using classic horns with changing directivity and all the attendant issues that brings. Some good discussions but the bottom line is nothing new there.

Rob:)

[Fangio]

Thanks Fangio !

- Unfortunately, I can't open 2003 Excel files ( only 2001 & previous to that ) .

- Are you able to do a "Save As" into a 2001 Excel file for Mac or PC ? ( & then repost the attachement ? ) ( Yes, I know I'm quite a beggar ) ;)

<. EarlK :)

Done. One of them should work. :hmm:

[Hoerninger]

One of them should work.

Proved and tested, ok.
:)
Thank you, Fangio.
____________
Peter

[Earl K]

Thanks Fangio !

- The second file ( .xls ) opened for me .

:)

[audiovoice]

might the best solution be a 38" tractrix horn, with a 8" driver (http://www.audiovoice-acoustics.com/forum/showthread.php?t=227)?


Angelo

[Hoerninger]

Hello Angelo :) ,

please specify "best solution".
The Tractrix has an inferior sound dispersion compared to a Kugelwellentrichter
__________
Peter

[audiovoice]

hi Peter

as far as i know, the horn flare tractrix x spherical / kugelwellentrichter is almost the same. I am wrong ?

Angelo

[Hoerninger]

Angelo,

unfortunately yes. The tractrix you know. A wealth of information about the Kugelwellentrichter you can find by the links here:
http://www.audiovoice-acoustics.com/forum/showthread.php?p=579#post579

(I know German is no problem for you ;) )

On your site (http://www.audiovoice-acoustics.com/forum/) you gave a link (http://www.audiovoice-acoustics.com/forum/showthread.php?t=260)to the Klipsch forum for the article

"Acoustical Studies of the Tractrix Horn part I and II"
by R.F.Lambert and A.O.Jensen,
The Journal of the Acoustical Society of America
Volume 26, Number 6, November 1954

In the summary of part II there is stated:


The polar response data do show a pronounced columination of the radiated energy along the principal axis of the horn, a result characteristic of horn radiation in general.
Concerning the divergence of the Kugelwellentrichter some data are available.

It would be interesting to have some data of a modern horn which is not too long and which opens wide.
For example the horn of the Everest II.
____________
Peter

[audiovoice]

It would be interesting to have some data of a modern horn which is not too long and which opens wide.
For example the horn of the Everest II.
____________
Peter

hi Peter

the Jean Michel LeCleac'h horn has this characteristic : it is shorter, opens wider, and has a better dispertion . It would be very big , when used in the lower midrange, replacing for example the tractrix horn.

Angelo

[Hoerninger]

Angelo,

it looks interesting.
But the mathematics can only be found in the spreadsheet. There is a language problem, the translator will not handle the spreadsheet.
The measurements do not show the dispersion.
___________
Peter

[audiovoice]

Angelo,

it looks interesting.
But the mathematics can only be found in the spreadsheet. There is a language problem, the translator will not handle the spreadsheet.
The measurements do not show the dispersion.
___________
Peter

hello Peter

according to Klang & Ton 4/91 the Kugelwellenhorn , and Tractrix horn , are identical :

http://www.audiovoice-acoustics.com/forum/showthread.php?p=746&posted=1#post746

see Part 2 of the article series.

Angelo

[Hoerninger]

Angelo,

I have to disagree, go through the mathematics and you will see the difference. The tractrix contour will merge into a baffle by definition, the Kugelwellentrichter will form a shape that is closed at the back, if you go on calculating.

I know the Klang&Ton pretty well. Nice paper but I would not call it a reference. Concerning horns they are writing what others have done before. And the Kugelwellentrichter is mostly unknown in Germany - and elsewhere.

In your site you will find some links to original Kugelwellentrichter literature. (I have used your site to depose there a lot of links relating scientific reserches and implementations mainly connected with JBL - and KLANGFILM.)
__________
Peter
http://audioheritage.org/vbulletin/attachment.php?attachmentid=19890&stc=1&d=1161873567


hello Peter

according to Klang & Ton 4/91 the Kugelwellenhorn , and Tractrix horn , are identical :

http://www.audiovoice-acoustics.com/forum/showthread.php?p=746&posted=1#post746

see Part 2 of the article series.

Angelo

[Hoerninger]

An explanation in English for the spherical wave horn (Kugelwellentrichter) you find in

audioXpress
Horn Theorie:
An introduction, part 2, page 1
by Bjorn Kolbrek, 2008

Links for part 1 and 2:
http://www.audioxpress.com/magsdirx/ax/addenda/media/kolbrek2884.pdf
http://www.audioxpress.com/magsdirx/ax/addenda/media/kolbrek2885.pdf
___________
Peter

[JBL 4645]

:)
http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=20138&stc=1&d=1162585502


No need to play that loud in the home the warmth of the sound will be nice around 75db. That look’s smashing in the rosewood or what ever very stylish and elegant looking.
:applaud:

[Hoerninger]

Recently I found the Siemens/ Klangfilm patent to this topic:
http://worldwide.espacenet.com/publicationDetails/biblio?DB=worldwide.espacenet.com&II=1&ND=3&adjacent=true&locale=en_EP&FT=D&date=19561115&CC=DE&NR=952179C&KC=C

The patent started January 12, 1940, shortly after the beginning of war. The patent came to public 1956.
In the early 50s Siemens/ Klangfilm built the huge "EURONOR II" based on spherical wave horns, which had short distances to the screen. There had been a predecessor "EURONOR" with 2 meter long HF horns. It had great success with its introduction in 1938. Production stopped with the beginning of war.
http://www.filmsoundsweden.se/backspegel/euronor.html

(http://www.filmsoundsweden.se/backspegel/euronor.html)This Klangfilm document shows that they used the expression Sperical Wave horn:
http://www.klangfilm.org/data/documentations/loudspeakers/loudspeakers/c71233-a6-a1/01.jpg

An English description of Spherical Wave Horn you find on Kolbreks home page:
http://kolbrek.hoyttalerdesign.no/images/misc/horntheoryintroarticle.pdf

(http://kolbrek.hoyttalerdesign.no/images/misc/horntheoryintroarticle.pdf)The copied artikel of post #1 is taken from
Prof.Dr.-Ing. W.Reichardt „Grundlagen der Elektroakustik“(S.359 – S.362) , Akademische Verlagsgesellschaft Geest & Portig K.-G., Leipzig, 3. Auflage 1960

Benutzer der deutschen Sprache lesen besser hier:
VISATON Diskussionsforum, Anleitungen (Tutorials), Bücher- und Linklisten:
http://www.visaton.de/vb/showthread.php?t=27995
(http://www.visaton.de/vb/showthread.php?t=27995)____________
Peter

[gibber]

Thanks for this wrap-up, Peter

It is indeed a different expansion. Also wasn't aware it requires a dome to begin with. Was that the reason some of the German monster horns of the 80's used Dynaudio D54 as a driver? I would have thought like Bruce Edgar and others had it, i.e. same as tractrix, until reading this and your visaton.de thread.

Highly appreciated. Sad we have 700 miles or so between us, but let me know if you plan to be in Munich sometime this year !

Ralph