Is there a calculation for creating a midrange conical horn? I have been playing around with hornresp but I don’t have most of the t/s specs for my 2” compression driver.
I want the horn’s cutoff to be 300 hz, the CD I am using is a b&c dcm50
I want the horn’s cutoff to be 300 hz, the CD I am using is a b&c dcm50
https://www.grc.com/acoustics/an-introduction-to-horn-theory.pdf
http://www.jmargolin.com/sono/refs/ref26_2008-015_Kolbrek_-_Horn_Theory_An_Introduction_Part_2.pdf
https://www.xlrtechs.com/dbkeele.com/PDF/Keele (1977-05 AES Preprint) - LF Horn Design Using TS Paras.pdf
https://www.xlrtechs.com/dbkeele.co...AES Preprint) - Whats So Sacred Exp Horns.pdf
Only infinite exponential horns have a defined cutoff but there are guidelines for other horn types (mouth size, horn length etc.). You might want to design something more complicated than a conical horn as the horn will be overly long for the low frequency performance and exhibit medioca pattern control. I have been working on a midrange horn here: https://www.diyaudio.com/community/...per-scripts-and-m200-fun.385493/#post-7003214 my current plans are: exponential flared 200Hz Fc dual driver throat adaptor -> common 4" square throat -> conical -> conical (flare). This is mainly for ease of contruction as the horn portion can be built using a table saw and flat boards and the throat adaptor cast. As the DCM50 goes to 10KHz the horn you may want to design could be closer to the ATH4 designed horns (smoothly increasing directivity), it all depends on your intended usage... unfortunatly a small, perfect pattern control well loading horn is imposible, you have to trade off.
http://www.jmargolin.com/sono/refs/ref26_2008-015_Kolbrek_-_Horn_Theory_An_Introduction_Part_2.pdf
https://www.xlrtechs.com/dbkeele.com/PDF/Keele (1977-05 AES Preprint) - LF Horn Design Using TS Paras.pdf
https://www.xlrtechs.com/dbkeele.co...AES Preprint) - Whats So Sacred Exp Horns.pdf
Only infinite exponential horns have a defined cutoff but there are guidelines for other horn types (mouth size, horn length etc.). You might want to design something more complicated than a conical horn as the horn will be overly long for the low frequency performance and exhibit medioca pattern control. I have been working on a midrange horn here: https://www.diyaudio.com/community/...per-scripts-and-m200-fun.385493/#post-7003214 my current plans are: exponential flared 200Hz Fc dual driver throat adaptor -> common 4" square throat -> conical -> conical (flare). This is mainly for ease of contruction as the horn portion can be built using a table saw and flat boards and the throat adaptor cast. As the DCM50 goes to 10KHz the horn you may want to design could be closer to the ATH4 designed horns (smoothly increasing directivity), it all depends on your intended usage... unfortunatly a small, perfect pattern control well loading horn is imposible, you have to trade off.
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I like to define designs from their final specifications and maximize performance within those specs:
max mouth horizontal
max mouth vertical (horizontal and vertical origin are seperable in my later designs)
desired coverage angle v (sets intial conical flare angle)
deseried coverage angle h
maximum length
initial conical flare cut off frequency
there are a bunch of calculations in the github link I have more up-to-date stuff but it would be difficult to construct an example as its under active development so if there is something missing from that code let me know.
max mouth horizontal
max mouth vertical (horizontal and vertical origin are seperable in my later designs)
desired coverage angle v (sets intial conical flare angle)
deseried coverage angle h
maximum length
initial conical flare cut off frequency
there are a bunch of calculations in the github link I have more up-to-date stuff but it would be difficult to construct an example as its under active development so if there is something missing from that code let me know.
Yes, though of the referenced docs I didn't see anything I recognized for what you're asking for, a classic conical (bull) horn
Driven with a 2" comp. driver tuned to 400 Hz normally requires either an ideal 200 Hz, 1 WL long axial length or a 400*0.81 = 324 Hz horn with minimal power handling and as already noted, there's no cutoff per se and overall poor polar response.
At 149+L, 172 cm axial length + driver, 54.75 cm dia. mouth I assume the ideal is way too big, so your max size is going to govern the horn's performance parameters and maybe require a different flare factor or Keele's CE flare for a 300 Hz flare frequency.
34400/pi/200 = ~54.75 cm diameter = 54.75^2*pi/4 = ~2,354.22 cm^2 mouth
Means it's net + whatever its construction volume = larger gross volume will be.
Good question, don't recall ever seeing the math/reasoning for it, just know from reverse engineering many pioneer horn designs + IME to get the desired tuning requires it to be a bit bigger to 'hit it on the numbers' or in this case the driver's 400 Hz Fb.
You're welcome!
ok so the formula you are using is:
Axial length = wavelength of desired frequency
Mouth Diameter = speed of sound/π/desired frequency
so for a 300 Hz conical
Axial length = 114 cm
Mouth Diameter = 34300/π/300 = 36 cm
That equals about a 18° coverage angle. What happens if I double the mouth diameter to 72cm?