A different route

[TundraLTD]

Trying to figure out exactly what to do with my pair of B&C 18SW115 drivers. I came up with this tonight. Here is my rough Akabak script. The whole thing should fit in a 48x48x22.5

Opinions?

Def_Const
{

S1 = 208.00e-4;
S2 = 835.00e-4;
S3 = 2410.00e-4;
S4 = 2748.00e-4;
S5 = 4495.72e-4;

L12 = 23.00e-2;
L23 = 312.60e-2;
L34 = 46.00e-2;
L45 = 63.40e-2;

Vtc = 15746.00e-6;
Atc = 2420.00e-4;



Sd = 2420.00e-4; |Total diaphragm area for 2 parallel drivers (sq m)

Ltc = Vtc / Atc;
}

Def_Driver 'Driver'

Sd=1210.00cm2
Bl=30.32Tm
Cms=8.96E-05m/N
Rms=9.91Ns/m
fs=32.0003Hz
Le=1.90mH
Re=5.30ohm
ExpoLe=1

System 'System'

Driver Def='Driver''Driver 11'
Node=1=0=5=11
Driver Def='Driver''Driver 21'
Node=1=0=5=11

Filter 'HP1' |24dB Butterworth High pass filter
fo=23Hz vo=1
{b4=1;
a4=1; a3=2.613126; a2=3.414214; a1=2.613126; a0=1; }

Filter 'LP1' |48dB LR Low pass filter
fo=90Hz vo=1
{b0=1;
a8=1; a7=5.226252; a6=13.656854; a5=23.069792; a4=27.313708; a3=23.069792; a2=13.656854; a1=5.226252; a0=1; }


Duct 'Throat chamber'
Node=5=9
SD={Atc}
Len={Ltc}
Visc=0

Waveguide 'Horn segment 1'
Node=8=9
STh={S1}
SMo={S2}
Len={L12}
Conical

Waveguide 'Horn segment 2'
Node=9=10
STh={S2}
SMo={S3}
Len={L23}
Conical

Waveguide 'Horn segment 3'
Node=10=11
STh={S3}
SMo={S4}
Len={L34}
Conical

Waveguide 'Horn segment 4'
Node=11=12
STh={S4}
SMo={S5}
Len={L45}
Conical

Radiator 'Horn mouth'
Node=12
SD={S5}

 

[Etocynned]

Okay, this is my first crack at interpreting Akabakese!

is this a parallel dual driver back loaded horn?

the bandpass filter, is it an electronic one?

if im even close yay, if not tell me where i missed the port.

this might just wail and scare some people.

im conceptualizing on using a horn basd sub in a car to turn heads to a really loud single driver solution for hatchbacks.

looking forward to seeing drawings and real wood.

 

[Thawach]

seeing clearly it likes the tapped horn. do u draw the plan yet?🙂

 

[TundraLTD]

Yes it is a TH. The filter are sims of active filters that would be in place. I'm working on/finishing the layout in Sketchup today.


w/o filters

An externally hosted image should be here but it was not working when we last tested it.

 

[Etocynned]

Nice response, flat in room to 20hz. Is it for a theater?

Also, are both drivers going in one enclosure? Oops yeah i see that now.

 

[TundraLTD]

I'll probably use it for live sound and outdoor movie nights. I'm building something else for home theater using a MTX T9515-04 (just arrived Thursday 😀 )

 

[m R g S r]

:Like:

 

[NEO Dan]

Ah fun, I've thrown together a sub for outdoor movies too 🙂
I went back and Keystoned it because I overshot the Fb a few Hz, worked out great too. 😀

 

[TundraLTD]

The design is still a little rough but this is what I drew up today. It came out a little bigger at 52x52x22.5

An externally hosted image should be here but it was not working when we last tested it.

Def_Const
{

S1 = 0.50e-4;
S2 = 477.84e-4;
S3 = 358.38e-4;
S4 = 901.38e-4;
S5 = 1205.46e-4;
S6 = 1813.62e-4;
S7 = 2280.60e-4;
S8 = 2519.52e-4;
S9 = 3105.96e-4;
S10 = 3659.82e-4;
S11 = 4496.04e-4;

L12 = 8.60e-2;
L23 = 21.90e-2;
L34 = 22.30e-2;
L45 = 130.10e-2;
L56 = 57.30e-2;
L67 = 142.30e-2;
L78 = 48.30e-2;
L89 = 25.80e-2;
L910 = 21.60e-2;
L1011 = 5.50e-2;

Vtc = 15746.00e-6;
Atc = 1210.00e-4;



Sd = 2420.00e-4; |Total diaphragm area for 2 parallel drivers (sq m)

Ltc = Vtc / Atc;
}

Def_Driver 'Driver'

Sd=1210.00cm2
Bl=30.32Tm
Cms=8.96E-05m/N
Rms=9.91Ns/m
fs=32.0003Hz
Le=1.90mH
Re=5.30ohm
ExpoLe=1

System 'System'

Driver Def='Driver''Driver 11'
Node=1=0=5=16
Driver Def='Driver''Driver 21'
Node=1=0=5=16

Filter 'HP1'
fo=22Hz vo=1
{b4=1;
a4=1; a3=2.613126; a2=3.414214; a1=2.613126; a0=1; }

Filter 'LP1'
fo=83Hz vo=1
{b0=1;
a8=1; a7=5.226252; a6=13.656854; a5=23.069792; a4=27.313708; a3=23.069792; a2=13.656854; a1=5.226252; a0=1; }

Duct 'Throat chamber '
Node=5=10
SD={Atc}
Len={Ltc}
Visc=0

Waveguide 'Horn segment 1'
Node=8=9
STh={S1}
SMo={S2}
Len={L12}
Conical

Duct 'Horn segment 2'
Node=9=10
HD=54.3cm WD=8.8cm Len=21.9cm

Duct 'Horn segment 3' |*
Node=10=11
HD=54.3cm WD=6.6cm Len=22.3cm

Waveguide 'Horn segment 4'
Node=11=12
STh={S4}
SMo={S5}
Len={L45}
Conical

Waveguide 'Horn segment 5'
Node=12=13
STh={S5}
SMo={S6}
Len={L56}
Conical

Waveguide 'Horn segment 6'
Node=13=14
STh={S6}
SMo={S7}
Len={L67}
Conical

Waveguide 'Horn segment 7'
Node=14=15
STh={S7}
SMo={S8}
Len={L78}
Conical

Waveguide 'Horn segment 8'
Node=15=16
STh={S8}
SMo={S9}
Len={L89}
Conical

Waveguide 'Horn segment 9' |*
Node=16=17
STh={S9}
SMo={S10}
Len={L910}
Conical

Waveguide 'Horn segment 10'
Node=17=18
STh={S10}
SMo={S11}
Len={L1011}
Conical

Radiator 'Horn mouth'
Node=18
SD={S11}

 

[m R g S r]

thats going to be one heavy *** sub! you plan on moving this thing regularly?

 

[NEO Dan]

You get wood for free? It looks super expensive to build?

 

[TundraLTD]

Not sure how often it'll will get used honestly, I just enjoy design/building/listening. I'm guessing it'll weigh in around 400lbs. I don't get the wood free (I wish) near me its about $60 for a 5x5 18mm BB, but there is always a discount for volume.

 

[AndrewT]

Why have you joined the two TH together?
You will get a 26.75*52*22.5 box that is much easier to move around @ ~55% of the weight.

 

[TundraLTD]

it isn't going to be moved regularly. The weight isn't really and issue for me, so why not one large cabinet it will use less wood in the long run anyway

 

[m R g S r]

The Hulk huh? 400lb cab? Pshhh no problem! 😛