PDA

View Full Version : horn calculations



jellyfish420
08-08-2005, 08:21 AM
i've been searching all over for a couple formulas maybe someone could help me. i'm looking for the formula for throat area and compresion chamber area. i've searched all over and everytime i find them...there is just a big d@mn X where the formula should be.

here is a link to where i found the fomulas, or where the formulas should be...
http://www.melhuish.org/audio/horndesign.html

pwnt by pat
08-08-2005, 08:30 AM
Throat area:
At=(2(pi)*Fs*Qts*Vas)/c

At is the area of the throat (m2)
FS is the nominal air resonance of the driver
QTS is the total Q of the driver (note, some formulas use QES, the electrical Q here - Bruce Edgar for one)
VAS is the equivalent volume suspension (m3)
c is the speed of sound (344 m/s)

Compression chamber:
Vb=Vas/Fc/(Fs*Qts)

VB is the back volume (volume of compression chamber next to horn throat, the front chamber in the diagram on the previous page)
Vas, Fs, and Qts are standard driver parameters
Fc is the lower cutoff frequency of the horn flare (I think)

jellyfish420
08-08-2005, 10:07 AM
on the compression chamber volume...what unit of measure is that in? meters^3, feet^3, liters, what?

JimJ
08-08-2005, 10:23 AM
Meters squared, because he's using Vas in that value.

pwnt by pat
08-08-2005, 12:17 PM
That's actually directly from that site. The only thing that isn't showing up for you is the equations, which I listed because they showed up for me. Don't ask me how to apply them, I have no idea... heh.

jellyfish420
08-08-2005, 12:19 PM
ya i can get every thing but the equations. thanks!
thanks jack...i'm doing a little bit of experaminting :up2somet:

pwnt by pat
08-08-2005, 12:23 PM
From what it looks like, I think the result is in liters...