Akabak for beginers

So...after some play...
the 2 ducts and 2 chambers seems the more correct solution, so close to real, but give a lot of resonance. Even the 1 duct 1 chamber doesn't give the measured plot, so different at all. The most similar modelling to the measured plot is only one rear chamber added of the 2 empty flare chamber volume (no ducts).
Another question....if you model the driver putting dd1, Td1, etc.... akabak measure the cone volume....but have you to add the magnet volume on the rear chamber? And if there's a phase plug or woodfiller in the throat chamber...How can we model them? Just a reduction of volume or some other elements definition? My doubts comes out after seeing the example horn for compression driver in the help.

bitzo im just off out to my djing gig now but ill take a proper look at you probs tomorrow. the only way i can see in modeling a plug is to reduce the volume of the throat chamber!!!! this is how i have done it. working out the magnet volume is fairly straight forward. i use a web site i found to work out volumes ( www.rkm.com.au/CALCULATORS/CALCU ... phere.html ) just measure the width of the magnet.
smiley2

Just continuing have play with akabak....
I defined the driver putting td1, dd1, dd etc...but akabak don't calculate the throat chamber adding the cone volume.
I solve the problem about the difference between the measured plot and the sim.... the default measurement units are meters....not cm.

sorry re read your post bitzo no i dont think you need to add the volume for the magnet. as far as i know there is no script to do this.

so....
we need to correct one of the value that describe the rear chamber. Hd or Wd? or both? so the same reasoning could be applied for the duct of vtc. What a mess...
Regarding the flare chamber issue I make a mistake ....more chambers means less resonances (note: don't sim at 3 am). See the graph.

but how sim the dampening? visc seems the right variable but manual is not so clear at all.

Bitzo i can tell you rearly getting in to akabak now lol what i have found is the more you play with it the more complexed the script becomes but the better the plots get more true to life..... i think you are correct with visc and the duct of vtc!!!!!!! but im only guessing at this point you are at the same stage by the sounds of it to my stage of learning. smiley29

System 'scoop'

Driver Def='Driver''Driver'
Node=1=0=5=6

Radiator 'Diaphragm'
Node=5
wd={lar} hd={htc}
Label=1

Duct 'Throat chamber'
Node=6=8
wd={lar} hd={htc}
Len={Ltc}
Visc=0

Waveguide 'Horn segment 1'
Node=8=9
wth={lar} hth={w1}
wmo={lar} hmo={w2}
Len={L12}
Conical

duct 'Horn segment 2'
Node=9=10
wd={lar} hd={w2}
Len={L23}


Waveguide 'Horn segment 3'
Node=10=11
wth={lar} hth={w3}
wmo={lar} hmo={w4}
Len={L34}
Conical

Waveguide 'Horn segment 4'
Node=11=12
wth={lar} hth={w4}
wmo={lar} hmo={w5}
Len={L45}
Conical

Waveguide 'Horn segment 5'
Node=12=13
wth={lar} hth={w5}
wmo={lar} hmo={w6}
Len={L56}
Conical

Radiator 'Horn mouth'
Node=13
wd={lar} hd={w6}
Label=2


where htc is the baffle height;
where w1, w2,....w6 are cross section heights;
where l12, l23... l56 are lenght's section
lar is the internal cab width
ltc is vtc/(htc*lar)

hi i've been using akabak for a while now, i seem to be in the same sort of place as you lot, and was wondering if anyone could shead some light on the visc peramiter, my help file seems to have been somehow deleated smiley7 but i seem to remember it claming it should be between 0 and 1 altho it seems to make no diffrence untill you get to 5 or so even with high frequences smiley5


btw this is a very informative thread with a great expalnation of how to get started leant a few things i missed learning it on my own thanks bee smiley20

ps nice forum i've been on the other side for a bit desided to come see what all the fuss is about i'm quantum sounds on sp, from what i see this is just as rich with info

send me a private message with ya email and ill email you the original help file......

i don't seem to be able to send you a pm, not sure why says i can't send to this group??

the help file would be very usefull but as i remember it is not in this instance the visc def is not to comprihensive