Akabak for beginers

Hi Chana,

Your sim looks ok so far. The reason it is not working is....... When you copy paste the info to the script page you still need to define how it works. speaker to rear chamber to front chamber etc (nodes) below is the script you are missing.

System 'Bass'
BassUnit Def='Bu1'
Node=1=0
x=0 y=0 z=0 HAngle=0 VAngle=0

Basicaly this turns on the speaker... your full script should look like this.

System 'Bass'
BassUnit Def='Bu1'
Node=1=0
x=0 y=0 z=0 HAngle=0 VAngle=0

Def_BassUnit 'BU1'
SD=683cm2 |Piston
fs=35.97Hz Mms=153.6g Qms=6.835
Qes=0.289 Re=5.8ohm Le=1.5H ExpoLe=0
Vb=80L fb=42.0Hz Qb/fo=0.1
|Performance in vented enclosure:
| fsb Qtr fD f3
| 36.0Hz 0.277 370.6Hz 43.3Hz
| Lwmax Pelmax UoRms t60 Ripple
| 0 0 0 98.46ms 0

Hope this helps. By changing the values for your ports will change the spl wave now. have fun playing around.

Regards

Ben

very good post.

I'm serching how to simulate the bass reflex port on the floor.

For example, the X1.
the port is 45.3cm, which gives a 41/42Hz tuning in theory, but i'm pretty sure the port is tuned around 31/32Hz (like 85cm) when the port is on the floor. The floor acts like an extension of the vent. Also the lower wall of the X1 which is part of the vent.

So, how to calculate the correction of the lenght?

i think the correct x1 chamber and port sizes are as follows..

Rear Chamber (Vb1) 180 Litres
Front Chamber (Vb2) 64 Litres

Rear tuning (Fb1) 38.5Hz
Front tuning (Fb2) 73.5Hz

Bandwidth -3dB 56.7Hz

hope this helps.

Very good stuff, i havent seen this before, (mainly as i dont come here much because the layout isnt so familliar...)

I thought i'd post my simple ported horn script i have been playing about with, maybe it will help people, and maybe people can help me!!

Its not a very good design, but its something to play about with, i was just trying to get it working! I've put some notes on it so people know what they're changing

Def_Driver 'Dr1'
dD=18in
fs=30Hz
Mms=160.76g |Driver parameters
Qms=7.33
Qes=0.26
Re=5.4ohm

System 'S1'

Driver Def='Dr1' Node=1=0=20=30 | Driver Nodes, (20 = front of driver, 30=back)

horn 'w1' node=20 | horn on the front of driver
Sth=650cm2 smo=4000cm2 | Sth=Throat, smo= Mouth
Vf=45L Len=85cm T=1 | Vf= Throat chamber, Len=horn lenth, T=flare rate

duct 'd1' Node=30=31 | Port on rear of driver
dD=15cm len=28cm vf=75L | 15cm diameter, 28cm long, with a 75L chamber
| - before it (rear chamber)

Radiator 'r1' def='d1' node=31=0 | port output, Referancing 'd1' the name of the port
x=0 y=0 z=0 HAngle=0 VAngle=0

Akabak Script for single 1850 Horn

Def_Driver 'Dr1' |In this instance, for PD1850 Driver
dD=18in
fs=30Hz
Mms=216.4g
Qms=6.04
Qes=0.22
Re=5.4ohm

System 'S1'

Driver Def='Dr1' Node=1=0=2=3

Enclosure 'E1' Node=3
Vb=54.5L Lb=36cm

Horn 'W1' Node=2
STh=480cm2 SMo=6000cm2
Vf=2.34L Len=2.1m T=1

Does any one want a go at designing a 6th order bandpass box.......

Front chamber....64L
Front port.....270mm len x 120mm Height x 552mm Width
Front chamber port tuning 73.5hz

Rear chamber.....180L
Rear Port..... 435mm len x 120mm height x 552mm width
Rear chamber port tuning 38.5hz

Outer box dimentions 606mm width x 770mm Height x 800mm Depth
Inner box dimentions 570mm width x 734mm Height x 764mm Depth.

Driver to use P-audio sd18

fs 33.2hz
re 5.1 ohm
sd 0.125 sqmt
qms 7.11
qes 0.27
qts 0.26
vas 264.3 Lt
le 1.95 mh
mms 192.1 gr


10 points if you can guess which cab this is............

Post your attempts up here........

X1

I'm trying to sim 12pi sub horn, a moded version of lab sub but it's a mess, 2 driver mounted in different position to get push pull effect....
however...next step will be mighty dubpass

i would not know where to start in siming that one....... im rearly still a nube myself when it comes modeling complexed cabs in akabak... full marks for the x1 smiley32 . Im still playing about with the sim i have done for the x1 ill post up the script when im happy that its the same as the original plots.....

Jake_Fielder wrote: Very good stuff, i havent seen this before, (mainly as i dont come here much because the layout isnt so familliar...)

I thought i'd post my simple ported horn script i have been playing about with, maybe it will help people, and maybe people can help me!!

Its not a very good design, but its something to play about with, i was just trying to get it working! I've put some notes on it so people know what they're changing

Def_Driver 'Dr1'
dD=18in
fs=30Hz
Mms=160.76g |Driver parameters
Qms=7.33
Qes=0.26
Re=5.4ohm

System 'S1'

Driver Def='Dr1' Node=1=0=20=30 | Driver Nodes, (20 = front of driver, 30=back)

horn 'w1' node=20 | horn on the front of driver
Sth=650cm2 smo=4000cm2 | Sth=Throat, smo= Mouth
Vf=45L Len=85cm T=1 | Vf= Throat chamber, Len=horn lenth, T=flare rate

duct 'd1' Node=30=31 | Port on rear of driver
dD=15cm len=28cm vf=75L | 15cm diameter, 28cm long, with a 75L chamber
| - before it (rear chamber)

Radiator 'r1' def='d1' node=31=0 | port output, Referancing 'd1' the name of the port
x=0 y=0 z=0 HAngle=0 VAngle=0

Hi jake,
I'm playing on a similar cab, I'm newbie so... I exported from hr a ported horn....so the porting need 2 duct and a radiator, one is rear chamber connected in series with the second that is the real port.
But I need a question, if the flare is empty and the baffle haven't the same width of whole cab, this creates other 2 chambers and 2 other ducts. The duct connected in series with rear chamber, and the ducts in series with "flare chambers". Is it a good approach? Could I simplifly using only one flare chamber (doubled volume and one duct dobled too)?

i would go with 2 chambers 2 ducts, this way you know whats what so to speak... i dont know if akabak would plot it the same I have never tried it.