Jump to content

Zasto HORNE inace sta drugo


Beaver

Preporučeni Komentari

Evo i zasto...

 

 

Link to comment
Podeli na ovim sajtovima

Sizela i smirela...

Link to comment
Podeli na ovim sajtovima

Horna na ventilator sa elektromotornim pogonom - prtok vazduha

Link to comment
Podeli na ovim sajtovima

Horen na komprimovan vazduh

 

Link to comment
Podeli na ovim sajtovima

Sad kucna varijanta - 

G.I.P field coil horn speaker Western Electric reproduction

Link to comment
Podeli na ovim sajtovima

Silbatone, Western Electric Loudspeakers

 

Link to comment
Podeli na ovim sajtovima

High End 2014: G.I.P / Western Electric / Silbatone - "whole lotta love"

Link to comment
Podeli na ovim sajtovima

Live Sound Designs, amazing horn loudspeakers, RCA's, The Capital Audiofest

 

Koknulimu celijsku hornu...srednjetonac.

 

Link to comment
Podeli na ovim sajtovima

Гаврилова труба  

Гаврилова труба (рог) (или Торичелијева труба) је фигура коју је открио Евангелиста Торичели. Има бесконачну површину, али коначну  запремину. Име се односи на традицију идентификовања анђела Гаврила који свирајући трубу најављује Судњи дан.

Гаврилова труба  добија се ротирањем  графика функције  ac7c12ea4f7f410ba302e391399c6f4f.png, са доменом c62e85e2743e3a9c52cda5efb8af53b4.png (чиме се избегава асимптота у x = 0),  око  х-осе. Ово тело  откривено је коришћењем Кавалијеријевог принципа, пре открића математичке анализе, али се данас анализа користи за израчунавање запремине и површине трубе између x = 1 и x = a, где a > 1. Помоћу интеграције је могуће наћи запремину V, и површину Р  тела:

a9b0373e470e2d8fe74c97a51ebb26e6.pngc842705815256d2551666121d86f05e9.png0cc175b9c0f1b6a831c399e269772661.png може бити произвољно велико, али се из једначине може видети да запремина трубе између a255512f9d61a6777bd5a304235bd26d.png, и 50a20ce04c291ac897290a4f2e3bc9e2.png никад неће прећи 522359592d78569a9eac16498aa7a087.png – међутим, она ће бити све ближа 522359592d78569a9eac16498aa7a087.png како 0cc175b9c0f1b6a831c399e269772661.png расте.   Другачије речено, запремина тежи 522359592d78569a9eac16498aa7a087.png када 0cc175b9c0f1b6a831c399e269772661.png тежи бесконачности, што је само још један начин да се каже да је запремина трубе једнака 522359592d78569a9eac16498aa7a087.png.

 

Израз може бити записан помоћу лимеса :

216871e76f3a6e940efd944b26517f56.png

Површина је већа од 46a6c4d715584adb3e6681ee351d1df6.png пута природни логаритам од 0cc175b9c0f1b6a831c399e269772661.png. Не постоји горња граница за природни логаритам од 0cc175b9c0f1b6a831c399e269772661.png, како оно тежи бесконачности. То значи, у овом случају, да труба има бесконачну површину.  Запис помоћу лимеса има облик:

c2b598e0fd734fcb18227fc07324f712.png

gabrielshorn.png?w=450&h=212

У време када је овај објекат откривен, сматран је парадоксним, јер се ротирањем бесконачне површине око икс-осе добија коначна запремина. Неформално, ово се може описати као да је потребна бесконачна количина фарбе да би се офарбала унутрашњост трубе, али би упркос томе било могуће напунити унутрашњу запремину коначном количином фарбе, и на тај начин обавити и унутрашњу површину.

Решење парадокса је у последици да је потребна бесконачна количина фарбе да би се офарбала бесконачна површина ако је слој фарбе константне дебљине; ово у теорији није тачно у унутрашњости трубе, и у пракси је већи део трубе недоступан за фарбу, посебно тамо где је пречник трубе мањи од пречника молекула фарбе. – Ако се узме да је слој фарбе без дебљине, требало би бесконачно дуго времена да фарба стигне све до „краја“ трубе.

 

Link to comment
Podeli na ovim sajtovima

Bass Horn Design This article describes a theory helping you to design your own bass horn

Why would anybody want a horn system in his home, these things are really big and rather hard to position in a normal living-room. Besides that they are difficult to design, they are difficult to copy and you may end up with a system coloring your sound.

Despite of all it's disadvantages I'm a great fan of the horn systems. Not particularly for high- and midrange, but certainly for the low frequencies. Until today I've not met any "conventional" speaker system that equals the performance of a bass horn!

 

The horn:

Until now I've stated some major drawbacks of the horn. Has this system any advantages? Let's start with the disadvantages:

  • For a good job they tend to be really big
  • Specific designs need to be placed in a corner, not everybody has the possibilities
  • Bad designs color the sound too much
  • Difficult to design and/or to copy in comparison to "conventional" systems
  • The bandwidth is relatively small

But now the advantages!

  • Very dynamic and articulated bass performance
  • Very low distortion
  • Excellent impulse behavior
  • High efficient and so easy to drive...

You may end up asking yourself; is this all there is? On paper it seems a more or less laborious system, but once you listen to a well designed horn, you are hooked! The performance pulls you into the music.

The final design:

I already made it clear that I'm a fan of horns, but how far can you go with these systems? With a lot of courage and some knowledge about what a horn can do I started (1985!) calculating the possibilities for my first "big" design. Finally, after two weeks, I finished the job. The calculated and practical data of my sub horns were:

Fc = 23,7 Hz, L = 3.67 m, Ah = 0,0354 m², Am = 0,8569 m², k = 0.8683

Quite a birth actually, for a twin ! The shape is stretched with only one curve at the end. I buried both horns underneath the floor of my listening-room, only the exits remain visible.

Both horn exits (two channels) lie close together, which enables a good response of 32 - 150 Hz (+/- 3dB). The used units at that moment were cheap and small Monacor SP60 chassis, 8 (!) per channel (two ranks of 4 parallel, both ranks serial because of the impedance). I chose these units because I wanted fast, small and inexpensive devices, the amount was required to adapt the total diaphragm-surface to the horn neck for maximum efficiency.

 

A theory © :

Is was not easy at all to determine the optimum shape of the horn for a specific speaker chassis. It is very convenient to know what the horn will do before you build one. It took me quite some time experimenting with models and formulas in finding the applicable ones for the horn shape, the needed mouth area and the volume of the closed cabinet in front of  the horn. Weeks of sweating over A4 size formulas with a fair amount of abracadabra. The formulas supplied in this article were extracted from the abracadabra and can be used to calculate the major points, which will do unless you want to prove the theoretical principles of the horn.

To be able to calculate a horn you first need the following data of your speaker chassis:

  • the resonance-frequency Fs in Hertz
  • the total Q-factor Qts
  • the compliance Vas in cubic meter

Before continuing we need to know whether or not the chosen unit is suitable for the design. The higher the Qts the smaller the usable bandwidth will be. This can be calculated by formula:

fh.gif

and:

fl.gif

The calculated values roughly indicate the range within the chassis can be used as driver for a bass horn. When this data is useful for a horn we can determine the throat area Ah (m²) with the next formula where (c = 343 m/s):

Note: all formula's mentioned below only hold on the calculated throat area Ah !!

ah.gif

Okay, that's done, now we only have to calculate the track from Ah to Am. To do this we need the following data:

  • The required resonance frequency Fg
  • The neck-surface Ah (m²)
  • The required "flair" T
  • The constant k (4 pi Fg / c)

The picture explains the "flair" T

flair.gif

 

The formula:

hypo.gif

where Ax (the calculated surface (m²), Ah (the throat area (m²), x (the distance from Ah (meter), xo (2 / k) and T (a variable that determines whether the horn is exponential (T=1) or hyperbolic (T <1) of shape). When you decide to build a common exponential horn then the last formula can be simplified to:

expo.gif

Now the exponential horn shows lower efficiency (and acoustic output) around its resonance frequency compared to the hyperbolic variety. The distortion, however, is less. Assuming that the horn is of infinite length and the wavelength "fits" the horn then the mouth area Am must comply to formula:

am.gif

The outcome is true when the horn is located in free air, but this is not likely to be useful in a normal room, we can happily divide the outcome by 2 (when the horn's exit is placed on the floor), by 4 (when the horn's exit is placed on the floor and against a wall) and by 8 (when the horn's exit is placed in a corner). The floor and walls are an extension of the horn! This is the reason why Klipsch and ACR designed their horns for corner loading. Its perfect for the lower frequencies, but usually not above 300 Hz.

A horn does not have a radial behavior but a more directive one. A common speaker system has a radial behavior and sounds best with free space around it (did you ever listened to a "conventional" speaker placed directly in a corner?).

Additional info to take into account:

Until now only a small part is explained, there is more to it! Now we mainly know how to calculate the actual horn it is useful to know how two horns beside each other have influence on the response, and how the driver cabinet (the back chamber) has influence on the speakers parameters when adapted to the horn.

When the mouth area Am of two horns are placed beside each other then the result will be a better performance in the lowest bass because the area is now doubled. The next formula can be used to see if we can lower the frequency Fg by the enlargement of Am.

Mind in the calculation where you want to place the horn, by placement in the corner the surface Amt must be multiplied by 8 !

fg.gif

An advantage is that the new horn can be calculated as being shorter. Because we work in stereo the efficiency is 6 dB higher (two speakers instead of one) and the power capabilities  (mechanical and electrical) improves.

What has changed is the larger (total) throat area Ah. In reverse you could say its the smaller (half) mouth area Am. The bigger the throat- or the smaller the mouth area the shorter the horn length.

Suppose a Fg of 30 Hz is wanted, according to the next formula the mouth area Am (m²) will be:

amt.gif

Placed in a corner the result will be 1.32 m². When two horns with their mouth close to each other are used, the result can be divided by 2 (0.658 m²). By calculating the contour (flair) of the horn it becomes clear that for the same Fg a shorter horn is sufficient. Of course it is possible to use more than one speaker in a horn, Ah is then multiplied by the amount of speakers.

The advantage of more speakers is that the power (mechanical and electrical) improves, the throat can be enlarged (shorter horn) and, not less important, the speaker selection is less critical.

The back chamber:

A front loaded horn design needs a closed space behind the speaker for proper loading down to Fg. Its volume can be changed to adapt the horn to different speakers.

The back chamber volume Vb to be used with the calculated horn can be determined in order to optimize the speaker to the horn neck and given proper loading down to Fg. Take into account that Vas and Vb are in dm³ and m³.

vb2.gif

When Vas is smaller then Vb use formula:

vb.gif

The compression chamber:

Finally there is a possibility to create a compression chamber (Vf) between the driver and the throat (Ah) of the horn.

hoorn.gif

The volume of the compression chamber works like a low-pass filter (6 dB/oct.), the higher the frequency the higher the attenuation. The crossover point (-3 dB) can be calculated with formula:

fhc.gif

Vf is the volume. Note that a larger volume lowers the crossover frequency. The nice thing of these acoustical filters is that the output can be corrected without the use of extra electronics.

Another -3 dB "filter" frequency is due the driver moving mass corner of the driver according to the formula mentioned before (Fh).

When you decide to build your own horn system, I strongly advise an exponential design with the largest possible horn mouth. The used speaker unit(s) requires a strong magnet (Qts <0.3) to be able to drive the air in the horn. The early decline in the lower frequencies can be corrected actively which works well in the area where the horn is active (>Fg).

My Sources:

Design Factors in Horn-Type Speakers. Daniel J.Plach (October 1953) from "An anthology of articles on loudspeakers from the pages of the journal of the Audio Engineering Society".

Low-Frequency Horn Design using Thiele/Small driver parameters. D.B.Keele jr.. Preprint of the Audio Engineering Society.

Poreklo literature>

Link to comment
Podeli na ovim sajtovima

Horn Directivity

Author: N.H. Crowhurst

Like the original megaphone, horns tend to be directional in their radiation of sound. The strongest part of the wave is the section formed by the horn development. Radiation outside this angle is due to a kind of spill-over.

crowhurst_basic_audio_vol1-93.gif

Directivity of a megaphone

The directivity of a horn is dependent on its precise shaping. For example, a shape called the tractrix, which is nearly identical with the exponential shape, except at the mouth, is designed to produce hemispherical waves; in other words, to cover the entire 180° in front of its mouth. This ideal distribution from the tractrix only exists at the lower frequencies it radiates. At higher frequencies, the bell has progressively less effect.

crowhurst_basic_audio_vol1-94.gif

Difference in bell shape affects radiation

Link to comment
Podeli na ovim sajtovima

Meni imaju nekakav tunelski zvuk, kao da je svirka u  hangaru. Na cudan nacin reprodukuju neobicne zvuke, treba se navikavati na takav zvuk.

Odgovaraju instrumentima sa slicnim nacinom proizvodnje zvuka, ali to nisu recimo akusticne gitare, gudacki instrumenti..

Za orgulje, trube i ostale cunkove, horne su idealne.

Link to comment
Podeli na ovim sajtovima

hoorn.gif          Ovo je fora to jest osnovna sema za tehnicko resenje paragona...bas hornetinu i njeno zracenje ka spoljnoj strani gde se prelama zvuk o zakrivljenu povrsinu i uksrta sa drugim bas talasom...Gde je Vb zapremina predkompresione komore odakle gruva pomeraj membrane u jednom polozaju-oscilacije dok drugi polozaj fura kroz otvor horne Vf. Tako da prostor oznacen sa Vb moze da ima i bass reflex otvor ili druge kombinacije... 

post-1939-0-13663400-1458688018_thumb.jp

post-1939-0-12247800-1458688272_thumb.jp

Link to comment
Podeli na ovim sajtovima

Thnicka specifikacija paragona tj. rezovi skretnicom na basu - srednjem je prvo 500Hz, a sredni - visoki na 7000Hz.

T i S parametri basa MODEL LE 15A.(prikazani na slici)

Bas drajver je na 95db 1m/1w - osetljivosti

Disipacija zvuka je 120 stepeni 

Impedansa 8 oma

Tezina krmka 317 kg

Sema skretnice je u jpg formatu prikazana. 

post-1939-0-42173700-1458689949_thumb.pn

post-1939-0-14535400-1458690016_thumb.jp

d44000wxa__paragon.pdf

Link to comment
Podeli na ovim sajtovima

Kreiraj nalog ili se prijavi da daš komentar

Potrebno je da budeš član DiyAudio.rs-a da bi ostavio komentar

Kreiraj nalog

Prijavite se za novi nalog na DiyAudio.rs zajednici. Jednostavno je!

Registruj novi nalog

Prijavi se

Već imaš nalog? Prijavi se ovde

Prijavi se odmah
  • Članovi koji sada čitaju   0 članova

    • Nema registrovanih članova koji gledaju ovu stranicu
×
×
  • Kreiraj novo...