Marco has done it again!

The easiest build kick bin IV seen!

105db 1w/1m

From a single 12"
smiley32

hornplans.free.fr/mkt30.html

I'm sorry but I don't get 105 db 1w 1m @2pi with my sim with same cab and driver.

Uuummmm interesting!

What sort of plot are you getting bitzo?

Assuming the simulation is correct, it only just manages one octave, does nothing below 100Hz and probably has a horrible phase/transient response due to being effectively a scoop. Not a particularly useful kick bin really.

Fare point , but there must be some good to this cab as Marco is a very good designer!

It is a scoop I suppose , it works 100hz and up yes but if it where to work and sound good would meet something like a cubo18 very nicely as the cubo is best crossed about 100hz!


Its got me intreaged as to how this sounds , Marco designs are normally spot on!

joeysub wrote: Uuummmm interesting!

What sort of plot are you getting bitzo?

Here's my attempt. It's a simplified version of mine script. As you can see you can switch into a full horny scoop but the original plan hasn't any deflector. Enjoy.

Def_Const
{
h0=73.58e-3;
h1=0.11;
h2=0.216;
h3=0.3;
h4=0.3;

l01=68.42e-2;
l12=0.11;
l23=0.18;
l34=0.118;

conearea=80.42e-3;
conevolume=1.5e-3;
baf=35e-2;
width=34e-2;
vtc=35.52e-3;
ltc=vtc/atc;
}
Def_Driver 'Driver'
|Rcf mb12g301
Sd=530.00cm2
Bl=17Tm
Cms=1.8E-04m/N
Rms=3.55Ns/m
fs=53Hz
Le=0.7mH
Re=5.4ohm
ExpoLe=1

System 'System'

Driver Def='Driver''Driver'
Node=1=0=4=10

Duct 'Throat chamber'
Node=4=5
hD={baf} wD={width}
Len={Ltc}
visc=0
|waveguide 'horn1'
| node=5=51
| wth={width} hth={h0}
| wmo={width} hmo={h1}
| len={l01}

duct 'horn1'
node=5=51
wd={width} hd={h0}
len={h1}

waveguide 'horn1'
node=51=52
wth={width} hth={h1}
wmo={width} hmo={h2}
len={l12}

|waveguide 'horn1'
|node=52=60
|wth={width} hth={h2}
|wmo={width} hmo={h3}
|len={l23}

duct 'horn1'
node=52=60
wd={width} hd={h2}
len={h3}

Duct 'Port'
Node=60=6
hD={h4} wD={width}
Len={l34}
Visc=0

radiator 'Port'
Node=6
hD={h4} wD={width}
label=1

duct 'cone'
node=10=20
sd={conearea}
len={conevolume/conearea}

Radiator 'Horn mouth'
Node=20
sd={conearea}
y={h4+baf/2}
label=3

I've test your script, but it don't works on akabak

but the original plan hasn't any deflector

many tapped horn haven't deflectors, and they works good. A scoop isn't too different from a TH, just scoops have a rear volume, a large throat chamber (compared to TH), but nothing that is different than TH
Search on Diyaudio.com, there's a post where Tom Danley explain that an italian retailer has forget the reflectors on the lab Sub, but when he compared with and "without deflectors", the "without deflector" has more level than the "with deflectors", the path is also longer. The only problem could be phase cancellation, but if the internal high is 650mm, first cancellation would be 260Hz, so not a probléme if to run before 200Hz.

JJD wrote: I've test your script, but it don't works on akabak

but the original plan hasn't any deflector

many tapped horn haven't deflectors, and they works good. A scoop isn't too different from a TH, just scoops have a rear volume, a large throat chamber (compared to TH), but nothing that is different than TH
Search on Diyaudio.com, there's a post where Tom Danley explain that an italian retailer has forget the reflectors on the lab Sub, but when he compared with and "without deflectors", the "without deflector" has more level than the "with deflectors", the path is also longer. The only problem could be phase cancellation, but if the internal high is 650mm, first cancellation would be 260Hz, so not a probléme if to run before 200Hz.

ops...you're right I forgot atc. So just add atc=width*baf; before ltc

The script works now. You put 35 liters in the throat chamber, but I measure only 17 liters on the plan, and you have to remove the driver which is 3 to 4 liters i think, so TC is 13 to 14 liters. It makes a big difference. Now with this new TC value, your script seems near the pdf.

Script with new TC:

Def_Const
{
h0=73.58e-3;
h1=0.11;
h2=0.216;
h3=0.3;
h4=0.3;

l01=68.42e-2;
l12=0.11;
l23=0.18;
l34=0.118;

conearea=80.42e-3;
conevolume=1.5e-3;
baf=35e-2;
width=34e-2;
vtc=14.00e-3;
atc=width*baf;
ltc=vtc/atc;
}
Def_Driver 'Driver'
|Rcf mb12g301
Sd=530.00cm2
Bl=17Tm
Cms=1.8E-04m/N
Rms=3.55Ns/m
fs=53Hz
Le=0.7mH
Re=5.4ohm
ExpoLe=1

System 'System'

Driver Def='Driver''Driver'
Node=1=0=4=10

Duct 'Throat chamber'
Node=4=5
hD={baf} wD={width}
Len={Ltc}
visc=0
|waveguide 'horn1'
| node=5=51
| wth={width} hth={h0}
| wmo={width} hmo={h1}
| len={l01}

duct 'horn1'
node=5=51
wd={width} hd={h0}
len={h1}

waveguide 'horn1'
node=51=52
wth={width} hth={h1}
wmo={width} hmo={h2}
len={l12}

|waveguide 'horn1'
|node=52=60
|wth={width} hth={h2}
|wmo={width} hmo={h3}
|len={l23}

duct 'horn1'
node=52=60
wd={width} hd={h2}
len={h3}

Duct 'Port'
Node=60=6
hD={h4} wD={width}
Len={l34}
Visc=0

radiator 'Port'
Node=6
hD={h4} wD={width}
label=1

duct 'cone'
node=10=20
sd={conearea}
len={conevolume/conearea}

Radiator 'Horn mouth'
Node=20
sd={conearea}
y={h4+baf/2}
label=3

I get the error
here's how I calculated the chamber
vrc=width*(
baf*panelb+
cos(anga)*sin(anga)*panela^2/2+
(baf-cos(anga)*(panela)-thick)*sin(anga)*panela)-drivervolume;

here's the correction
vrc=width*(
baf*panelb+
cos(anga)*sin(anga)*panela^2/2+
(baf-sin(anga)*(panela)-thick)*cos(anga)*panela)-drivervolume;

too much messing around modelling.