Unity horn script for akabak

[MaVo]

Hello,

since the TH project went really well, i thought about building a unity horn. I tried to design an akabak script to evaluate different variables as horn size, front and rear chamber, front chamber opening into the horn, driver and so on.

My plan is to use the Behringer digital crossover and active amplification to spare me the difficulties of designing a passive crossover. With its small delays for each driver and some carefull measurements, i hope to be able to align the drivers in time.

This is my first attempt at a simulation. If someone is interested, please try it out. I hope to get some feedback about the script. I just implemented all the parts i could identifie by reading alot of threads and looking at pictures of the design, as well as reading the patent.

This script includes just one driver section (in this case the midrange for 300-1000hz), since i dont want to script a compression driver in akabak. An additional woofer section could be implemented as a copy of this script with adjusted variables.

The layout is as follows:
Back enclosure -> Driver -> Front Chamber (duct) -> 2 Ports (duct) -> Horn (waveguide->waveguide->radiator)
(the ports, which connect the front chamber to the horn are connected between both waveguides)

The script: (copy paste into an empty akabak script, press F5 and OK.)

System 'Unity_Segment'

Def_Driver '6ND410'
SD=143cm2 dD1=5cm tD1=2.5cm |Cone
fs=120Hz Mms=8.2g Qms=2.2
Qes=0.27 Re=5.9ohm Le=0.67mH ExpoLe=0.618

Def_Const | Unit is cm
{
Fc_Len=2e-2; | Front chamber length
Fc_dD=14e-2; | Front chamber diameter
FcPort_Len=0.6e-2; | Port length
FcPort_dD=1e-2; | Port diameter
Hi = 2.54e-2; | Horn throat diameter
Mid = 8e-2; | Horn width & height where the ports are
Mouth = 100e-2; | Horn mouth width & height
Hi_Len = 8e-2; | Length of the hornsegment between compression driver and midrange ports
Mid_Len = 100e-2; | Length of the hornsegment between midrange ports and the end of the horn
}

Enclosure 'E1' Node=100 Vb=10L Lb=0
Enclosure 'E2' Node=101 Vb=10L Lb=0
Enclosure 'E3' Node=102 Vb=10L Lb=0
Enclosure 'E4' Node=103 Vb=10L Lb=0
Driver 'D1' Def='6ND410' Node=2=0=100=120
Driver 'D2' Def='6ND410' Node=2=0=101=121
Driver 'D3' Def='6ND410' Node=2=0=102=122
Driver 'D4' Def='6ND410' Node=2=0=103=123
Duct 'Du_Fc1' Node=120=130 dD={Fc_dD} Len={Fc_Len}
Duct 'Du_Fc2' Node=121=131 dD={Fc_dD} Len={Fc_Len}
Duct 'Du_Fc3' Node=122=132 dD={Fc_dD} Len={Fc_Len}
Duct 'Du_Fc4' Node=123=133 dD={Fc_dD} Len={Fc_Len}
Duct 'Du_BP1a' Node=130=150 dD={FcPort_dD} Len={FcPort_Len}
Duct 'Du_BP2a' Node=131=150 dD={FcPort_dD} Len={FcPort_Len}
Duct 'Du_BP3a' Node=132=150 dD={FcPort_dD} Len={FcPort_Len}
Duct 'Du_BP4a' Node=133=150 dD={FcPort_dD} Len={FcPort_Len}
Duct 'Du_BP1b' Node=130=150 dD={FcPort_dD} Len={FcPort_Len}
Duct 'Du_BP2b' Node=131=150 dD={FcPort_dD} Len={FcPort_Len}
Duct 'Du_BP3b' Node=132=150 dD={FcPort_dD} Len={FcPort_Len}
Duct 'Du_BP4b' Node=133=150 dD={FcPort_dD} Len={FcPort_Len}
Waveguide 'W1' Node=140=150 wTh={Hi} hTh={Hi} wMo={Mid} hMo={Mid} Len={Hi_Len} Conical
Waveguide 'W2' Node=150=160 wTh={Mid} hTh={Mid} wMo={Mouth} hMo={Mouth} Len={Mid_Len} Conical
Radiator 'Rad1' Def='W2' Node=160 x=0 y=0 z=0 HAngle=0 VAngle=0

[mefistofelez]

Dear MaVo,

this is an extremely timely post. I have built my implementation of Unity, but the measurements I have taken do not seem to agree with the measurements taken on the "real" Unity.

I am wondering, whether akabak could model the "real" unity with some degrees of precision, which would give me the confidence to try to model my implementation.

I have looked at akabak, but it seems rather complicated, do you have any practical experience with it? Would you be willing to help me?

If so, perhaps e-mailing me would be a better means of communication than the forum: mefistofelez _ at _ hotmail _ dot _ com.

Thank you,

M

[MaVo]

I just send you a mail.

[JLH]

I edited your script to model the Misco Speakers model JC5RTF-B sealed back mid range driver. It models in an ideal way. The acoustic pressure rises with frequency to compensate for the falling response of the conical horn. Acoustic power is almost completely flat from 225Hz to 1.6KHz. It looks very good. I've e-mailed Misco Speakers, but have not received a reply yet. I hope they are willing to sell to the general public, or at least in small lots.

Here is the edited script:

Def_Driver 'MidDriver' |Misco Speakers Model JC5RTF-B 5" mid
SD=73.9cm2 dD1=5cm tD1=2.5cm |Cone
fs=500Hz Mms=8.2g Qms=6.4
Qes=2.24 Re=6.7ohm Le=0.78mH ExpoLe=0.618

Def_Const | Unit is cm
{
Fc_Len=0.744e-2; | Front chamber length
Fc_dD=9.7e-2; | Front chamber diameter
FcPort_Len=0.635e-2; | Port length
FcPort_dD=1e-2; | Port diameter
Hi = 2.54e-2; | Horn throat diameter
Mid = 9.2027e-2; | Horn width & height where the ports are
Mouth = 46.223e-2; | Horn mouth width & height
Hi_Len = 6.35e-2; | Length of the horn segment between compression driver and midrange ports
Mid_Len = 33.21e-2; | Length of the horn segment between midrange ports and the end of the horn
}


Radiator 'Diaphragm1' Node=100 SD=73.9cm2
Radiator 'Diaphragm2' Node=101 SD=73.9cm2
Radiator 'Diaphragm3' Node=102 SD=73.9cm2
Radiator 'Diaphragm4' Node=103 SD=73.9cm2
Driver 'D1' Def='MidDriver' Node=2=0=100=120
Driver 'D2' Def='MidDriver' Node=2=0=101=121
Driver 'D3' Def='MidDriver' Node=2=0=102=122
Driver 'D4' Def='MidDriver' Node=2=0=103=123
Duct 'Du_Fc1' Node=120=130 dD={Fc_dD} Len={Fc_Len}
Duct 'Du_Fc2' Node=121=131 dD={Fc_dD} Len={Fc_Len}
Duct 'Du_Fc3' Node=122=132 dD={Fc_dD} Len={Fc_Len}
Duct 'Du_Fc4' Node=123=133 dD={Fc_dD} Len={Fc_Len}
Duct 'Du_BP1a' Node=130=150 dD={FcPort_dD} Len={FcPort_Len}
Duct 'Du_BP2a' Node=131=150 dD={FcPort_dD} Len={FcPort_Len}
Duct 'Du_BP3a' Node=132=150 dD={FcPort_dD} Len={FcPort_Len}
Duct 'Du_BP4a' Node=133=150 dD={FcPort_dD} Len={FcPort_Len}
Duct 'Du_BP1b' Node=130=150 dD={FcPort_dD} Len={FcPort_Len}
Duct 'Du_BP2b' Node=131=150 dD={FcPort_dD} Len={FcPort_Len}
Duct 'Du_BP3b' Node=132=150 dD={FcPort_dD} Len={FcPort_Len}
Duct 'Du_BP4b' Node=133=150 dD={FcPort_dD} Len={FcPort_Len}
Waveguide 'W1' Node=140=150 wTh={Hi} hTh={Hi} wMo={Mid} hMo={Mid} Len={Hi_Len} Conical
Waveguide 'W2' Node=150=160 wTh={Mid} hTh={Mid} wMo={Mouth} hMo={Mouth} Len={Mid_Len} Conical
Radiator 'Rad1' Def='W2' Node=160 x=0 y=0 z=0 HAngle=0 VAngle=0


Below is the Acoustic Pressure



And below is the Acoustic Power



Looks pretty good to me.



Rgs, JLH

[JLH]

Here is the script I came up with for the complete Unity horn. It includes the TAD compression driver, 4 of the Misco mids and the Lambda crossover. The pressure and power responses don't look too good, but I don't think this tells the whole story. I hope you guys enjoy playing with this. It was a lot of work and research to compile this script.

Rgs, JLH

Right below is a picture of the components and node numbers. Hopefully you will be able to read it. The node numbers are in Red text.




System 'Unity_Segment'

Def_Driver 'CompDriver' | TAD TD-2001 compression driver

Sd=18.10cm2
Bl=7.20Tm
Cms=1.60E-04m/N
Rms=2.72Ns/m
fs=310.2990Hz |Mmd = 1.60g not recognised by AkAbak, fs calculated and used instead
Le=0.06mH
Re=6.30ohm
ExpoLe=0.618

Def_Driver 'MidDriver' |Misco Speakers Model JC5RTF-B 5" mid

Sd=73.90cm2
Bl=5.90Tm
Cms=2.07E-04m/N
Rms=0.24Ns/m
fs=500.8646Hz |Mmd = 0.14g not recognised by AkAbak, fs calculated and used instead
Le=0.78mH
Re=6.70ohm
ExpoLe=0.618

Def_Const | Unit is cm
{
Fc_Len=0.744e-2; | Front Mid chamber length
Fc_dD=9.7e-2; | Front Mid chamber diameter
FcPort_Len=0.635e-2; | Mid Port length
FcPort_dD=1e-2; | Mid Port diameter

Rg = 3.00; |Amplifier output impedance (ohms)

R1Comp = 25; |TAD Driver Crossover R1 resistance (ohms)
R2Comp = 25; |TAD Driver Crossover R2 resistance (ohms)
R3Comp = 5; |TAD Driver Crossover R3 resistance (ohms)
R4Comp = 3; |TAD Driver Crossover R1 resistance (ohms)

C1Comp = 2.7e-6; |TAD Driver Crossover C1 capacitor (Farads)
C2Comp = 5.7e-6; |TAD Driver Crossover C2 capacitor (Farads)

L1Comp = 1e-3; |TAD Driver Crossover L1 inductor (Henries)



C1Mid = 45e-6; |Mid Driver Crossover C1 capacitor (Farads)

R1Mid = 12; |Mid Driver Crossover R1 resistance (ohms)
R2Mid = 2; |Mid Driver Crossover R2 resistance (ohms)

L1Mid = 0.2e-3; |Mid Driver Crossover L1 inductor (Henries)


S1 = 5.07e-4; |WG1 throat area (sq cm)
S2 = 84.69e-4; |WG1 mouth area and horn segment 2 throat area Mid tap point(sq cm)
S3 = 2136.63e-4; |WG2 mouth area and horn segment 3 throat area (sq cm)
S4 = 3674.66e-4; |WG3 mouth area Mouth Flare(sq cm)

L12 = 6.35e-2; |WG1 axial length Mid tap point(cm)
L23 = 33.21e-2; |WG2 axial length (cm)
L34 = 8.17e-2; |WG3 axial length Mouth Flare(cm)

VrcComp = 0.14e-3; |TAD Rear chamber volume (litres)
LrcComp = 2.70e-2; |TAD Rear chamber average length (cm)
VtcComp = 0.81e-6; |TAD Throat chamber volume (cc)
AtcComp = 18.10e-4; |TAD Throat chamber cross-sectional area (sq cm)

ArcComp = VrcComp / LrcComp; |Conversions for CompDriver
LtcComp = VtcComp / AtcComp;
}

Radiator 'Diaphragm1' Node=100 SD=73.9cm2
Radiator 'Diaphragm2' Node=101 SD=73.9cm2
Radiator 'Diaphragm3' Node=102 SD=73.9cm2
Radiator 'Diaphragm4' Node=103 SD=73.9cm2
Driver 'D1' Def='MidDriver' Node=0=42=100=120 |Note reverse polarity as seen in Lambda X-over
Driver 'D2' Def='MidDriver' Node=0=42=101=121
Driver 'D3' Def='MidDriver' Node=0=42=102=122
Driver 'D4' Def='MidDriver' Node=0=42=103=123
Duct 'Du_Fc1' Node=120=130 dD={Fc_dD} Len={Fc_Len}
Duct 'Du_Fc2' Node=121=131 dD={Fc_dD} Len={Fc_Len}
Duct 'Du_Fc3' Node=122=132 dD={Fc_dD} Len={Fc_Len}
Duct 'Du_Fc4' Node=123=133 dD={Fc_dD} Len={Fc_Len}
Duct 'Du_BP1a' Node=130=150 dD={FcPort_dD} Len={FcPort_Len} |Note a total of two ports
Duct 'Du_BP2a' Node=131=150 dD={FcPort_dD} Len={FcPort_Len} |per mid driver
Duct 'Du_BP3a' Node=132=150 dD={FcPort_dD} Len={FcPort_Len}
Duct 'Du_BP4a' Node=133=150 dD={FcPort_dD} Len={FcPort_Len}
Duct 'Du_BP1b' Node=130=150 dD={FcPort_dD} Len={FcPort_Len}
Duct 'Du_BP2b' Node=131=150 dD={FcPort_dD} Len={FcPort_Len}
Duct 'Du_BP3b' Node=132=150 dD={FcPort_dD} Len={FcPort_Len}
Duct 'Du_BP4b' Node=133=150 dD={FcPort_dD} Len={FcPort_Len}
Driver 'D5' Def='CompDriver' Node=22=0=31=32



Duct 'CompRearChamber' |TAD rear compression chamber
Node=30=31
SD={ArcComp}
Len={LrcComp}
Visc=0

Duct 'CompFrontChamber' |TAD front throat chamber
Node=32=140
SD={AtcComp}
Len={LtcComp}
Visc=0



Resistor 'Amplifier Rg' |Amplifier output impedance
Node=1=2
R={Rg}



Resistor 'R1Comp'
Node=2=20
R={R1Comp}

Resistor 'R2Comp'
Node=20=0
R={R2Comp}

Resistor 'R3Comp'
Node=21=22
R={R3Comp}

Resistor 'R4Comp'
Node=22=0
R={R4Comp}

Capacitor 'C1Comp'
Node=2=20
C={C1Comp}

Capacitor 'C2Comp'
Node=20=21
C={C2Comp}

Coil 'L1Comp'
Node=20=0
L={L1Comp}




Capacitor 'C1Mid'
Node=2=40
C={C1Mid}

Resistor 'R1Mid'
Node=40=41
R={R1Mid}

Resistor 'R2Mid'
Node=42=0
R={R2Mid}

Coil 'L1Mid'
Node=41=42
L={L1Mid}

Waveguide 'WG1'
Node=140=150
STh={S1}
SMo={S2}
Len={L12}
Conical

Waveguide 'WG2'
Node=150=160
STh={S2}
SMo={S3}
Len={L23}
Conical

Waveguide 'WG3'
Node=160=170
STh={S3}
SMo={S4}
Len={L34}
Conical

Radiator 'Horn mouth'
Node=170
SD={S4}
x=0
y=0
z=0
HAngle=0
VAngle=0

[JLH]

I need to say a few things about my script. Since I use tube amplifiers, I put in a provision for accounting for its higher output impedance. The value for Rg can be changed in the script if you use solid state amplifiers. Second, the conical horn areas and lengths are not from the real Unity horn dimensions. I didn't have that information, so I just came up with my own conical horn design. If anyone has the original Unity horn dimensions and areas please share them.

It is very interesting what happens to the impedance seen by the source when you start changing the crossover values. You can change the Unity’s overall impedance quite a bit without messing up the simulated response. If you need a 16 ohm speaker or an 8 ohm speaker, no problem.

Hopefully we can build on this and come up with a reliable DIY version of the Unity horn.

Rgs, JLH

[JLH]

I put together another script to model a smaller mid driver. I did this to see if I could raise the crossover point some. After poking around I'm pretty pleased with the results. The mid driver I chose are the Misco model JN4C 4" mid. They should be very inexpensive. I made some changes to the crossover values to get a smoother acoustic power response, and a better upward tilting acoustic pressure response to compensate for the conical horn's falling response. The result looks pretty good from 100Hz up past 16KHz. Of course all of this is neat, but the real challenge will be building it. I'm not really in the position to be building anything right now. Man...I hate having to work for a living.

Rgs, JLH




System 'JN4C_Unity_Horn'

Def_Driver 'CompDriver' | TAD TD-2001 compression driver

Sd=18.10cm2
Bl=7.20Tm
Cms=1.60E-04m/N
Rms=2.72Ns/m
fs=310.2990Hz |Mmd = 1.60g not recognised by AkAbak, fs calculated and used instead
Le=0.06mH
Re=6.30ohm
ExpoLe=0.618

Def_Driver 'MidDriver' |Misco Speakers Model JN4C 4" mid

Sd=47.17cm2
Bl=4.3Tm
Cms=1.01E-03m/N
Rms=0.27Ns/m
fs=95Hz |Mmd = 2.59g not recognised by AkAbak, fs calculated and used instead
Le=0.62mH
Re=6.70ohm
ExpoLe=0.618

Def_Const | Unit is cm
{
Fc_Len=0.81e-2; | Front Mid chamber length
Fc_dD=7.75e-2; | Front Mid chamber diameter |Front chamber volume ~38CC
FcPort_Len=0.635e-2; | Mid Port length (cm)
FcPort_dD=1.18e-2; | Mid Port diameter (cm)

Rg = 3.00; |Amplifier output impedance (ohms)

R1Comp = 25; |TAD Driver Crossover R1 resistance (ohms)
R2Comp = 39; |TAD Driver Crossover R2 resistance (ohms)
R3Comp = 3.3; |TAD Driver Crossover R3 resistance (ohms)
R4Comp = 10; |TAD Driver Crossover R1 resistance (ohms)

C1Comp = 5.1e-6; |TAD Driver Crossover C1 capacitor (Farads)
C2Comp = 3.9e-6; |TAD Driver Crossover C2 capacitor (Farads)

L1Comp = 0.8e-3; |TAD Driver Crossover L1 inductor (Henries)

C1Mid = 36e-6; |Mid Driver Crossover C1 capacitor (Farads)

R1Mid = 18; |Mid Driver Crossover R1 resistance (ohms)
R2Mid = 6.8; |Mid Driver Crossover R2 resistance (ohms)

L1Mid = 0.15e-3; |Mid Driver Crossover L1 inductor (Henries)


S1 = 5.07e-4; |WG1 throat area (sq cm)
S2 = 63.98e-4; |WG1 mouth area and horn segment 2 throat area Mid tap point(sq cm)
S3 = 2136.63e-4; |WG2 mouth area and horn segment 3 throat area (sq cm)
S4 = 3674.66e-4; |WG3 mouth area Mouth Flare(sq cm)

L12 = 5.25e-2; |WG1 axial length Mid tap point(cm)
L23 = 34.92e-2; |WG2 axial length (cm)
L34 = 8.17e-2; |WG3 axial length Mouth Flare(cm)

VrcComp = 0.14e-3; |TAD Rear chamber volume (litres)
LrcComp = 2.70e-2; |TAD Rear chamber average length (cm)
VtcComp = 0.81e-6; |TAD Throat chamber volume (cc)
AtcComp = 18.10e-4; |TAD Throat chamber cross-sectional area (sq cm)

ArcComp = VrcComp / LrcComp; |Conversions for CompDriver
LtcComp = VtcComp / AtcComp;
}

Enclosure 'E1' Node=100 Vb=2L Lb=6.35cm
Enclosure 'E2' Node=101 Vb=2L Lb=6.35cm
Enclosure 'E3' Node=102 Vb=2L Lb=6.35cm
Enclosure 'E4' Node=103 Vb=2L Lb=6.35cm
Driver 'D1' Def='MidDriver' Node=0=42=100=120 |Note reverse polarity as seen in Lambda X-over
Driver 'D2' Def='MidDriver' Node=0=42=101=121
Driver 'D3' Def='MidDriver' Node=0=42=102=122
Driver 'D4' Def='MidDriver' Node=0=42=103=123
Duct 'Du_Fc1' Node=120=130 dD={Fc_dD} Len={Fc_Len}
Duct 'Du_Fc2' Node=121=131 dD={Fc_dD} Len={Fc_Len}
Duct 'Du_Fc3' Node=122=132 dD={Fc_dD} Len={Fc_Len}
Duct 'Du_Fc4' Node=123=133 dD={Fc_dD} Len={Fc_Len}
Duct 'Du_BP1a' Node=130=150 dD={FcPort_dD} Len=0.635cm |Note a total of two ports
Duct 'Du_BP2a' Node=131=150 dD={FcPort_dD} Len=0.635cm |per mid driver
Duct 'Du_BP3a' Node=132=150 dD={FcPort_dD} Len=0.635cm
Duct 'Du_BP4a' Node=133=150 dD={FcPort_dD} Len=0.635cm
Duct 'Du_BP1b' Node=130=150 dD={FcPort_dD} Len=0.635cm
Duct 'Du_BP2b' Node=131=150 dD={FcPort_dD} Len=0.635cm
Duct 'Du_BP3b' Node=132=150 dD={FcPort_dD} Len=0.635cm
Duct 'Du_BP4b' Node=133=150 dD={FcPort_dD} Len=0.635cm
Driver 'D5' Def='CompDriver' Node=22=0=31=32

Duct 'CompRearChamber' |TAD rear compression chamber
Node=30=31
SD={ArcComp}
Len={LrcComp}
Visc=0

Duct 'CompFrontChamber' |TAD front throat chamber
Node=32=140
SD={AtcComp}
Len={LtcComp}
Visc=0

Resistor 'Amplifier Rg' |Amplifier output impedance
Node=1=2
R={Rg}

Resistor 'R1Comp'
Node=2=20
R={R1Comp}

Resistor 'R2Comp'
Node=20=0
R={R2Comp}

Resistor 'R3Comp'
Node=21=22
R={R3Comp}

Resistor 'R4Comp'
Node=22=0
R={R4Comp}

Capacitor 'C1Comp'
Node=2=20
C={C1Comp}

Capacitor 'C2Comp'
Node=20=21
C={C2Comp}

Coil 'L1Comp'
Node=20=0
L={L1Comp}

Capacitor 'C1Mid'
Node=2=40
C={C1Mid}

Resistor 'R1Mid'
Node=40=41
R={R1Mid}

Resistor 'R2Mid'
Node=42=0
R={R2Mid}

Coil 'L1Mid'
Node=41=42
L={L1Mid}

Waveguide 'WG1'
Node=140=150
STh={S1}
SMo={S2}
Len={L12}
Conical

Waveguide 'WG2'
Node=150=160
STh={S2}
SMo={S3}
Len={L23}
Conical

Waveguide 'WG3'
Node=160=170
STh={S3}
SMo={S4}
Len={L34}
Conical

Radiator 'Horn mouth'
Node=170
SD={S4}
x=0
y=0
z=0
HAngle=0
VAngle=0

[JLH]

Here is one using the B&C Speakers DE250 compression driver and the MISCO JN4C mids



System 'JN4C_Unity_Horn'

Def_Driver 'CompDriver' | B&C Speakers DE250
Sd=15cm2
Bl=7.5Tm
Cms=2.0E-05m/N
Rms=1.00Ns/m
Fs=1110Hz
Le=0.025mH
Re=6.30ohm
ExpoLe=0.618

Def_Driver 'MidDriver' |Misco Speakers Model JN4C 4" mid

Sd=47.17cm2
Bl=4.3Tm
Cms=1.01E-03m/N
Rms=0.27Ns/m
fs=95Hz |Mmd = 2.59g not recognised by AkAbak, fs calculated and used instead
Le=0.62mH
Re=6.70ohm
ExpoLe=0.618

Def_Const | Unit is cm
{
Fc_Len=0.81e-2; | Front Mid chamber length
Fc_dD=7.75e-2; | Front Mid chamber diameter |Front chamber volume ~38CC
FcPort_Len=0.635e-2; | Mid Port length (cm)
FcPort_dD=1.18e-2; | Mid Port diameter (cm)

Rg = 3.00; |Amplifier output impedance (ohms)

R1Comp = 10; |B&C Speakers DE250 Crossover R1 resistance (ohms)
R2Comp = 33; |B&C Speakers DE250 Crossover R2 resistance (ohms)
R3Comp = 3.3; |B&C Speakers DE250 Crossover R3 resistance (ohms)
R4Comp = 8; |B&C Speakers DE250 Crossover R1 resistance (ohms)

C1Comp = 10e-6; |B&C Speakers DE250 Crossover C1 capacitor (Farads)
C2Comp = 3.3e-6; |B&C Speakers DE250 Crossover C2 capacitor (Farads)

L1Comp = 1.8e-3; |B&C Speakers DE250 Crossover L1 inductor (Henries)

C1Mid = 47e-6; |Mid Driver Crossover C1 capacitor (Farads)

R1Mid = 15; |Mid Driver Crossover R1 resistance (ohms)
R2Mid = 8; |Mid Driver Crossover R2 resistance (ohms)

L1Mid = 0.15e-3; |Mid Driver Crossover L1 inductor (Henries)


S1 = 5.07e-4; |WG1 throat area (sq cm)
S2 = 63.98e-4; |WG1 mouth area and horn segment 2 throat area Mid tap point(sq cm)
S3 = 2136.63e-4; |WG2 mouth area and horn segment 3 throat area (sq cm)
S4 = 3674.66e-4; |WG3 mouth area Mouth Flare(sq cm)

L12 = 5.25e-2; |WG1 axial length Mid tap point(cm)
L23 = 34.92e-2; |WG2 axial length (cm)
L34 = 8.17e-2; |WG3 axial length Mouth Flare(cm)

VrcComp = 0.08e-3; |B&C Speakers DE250 Rear chamber volume (litres)
LrcComp = 1.27e-2; |B&C Speakers DE250 Rear chamber average length (cm)
VtcComp = 0.75e-6; |B&C Speakers DE250 Throat chamber volume (cc)
AtcComp = 15.0e-4; |B&C Speakers DE250 Throat chamber cross-sectional area (sq cm)

ArcComp = VrcComp / LrcComp; |Conversions for CompDriver
LtcComp = VtcComp / AtcComp;
}

Enclosure 'E1' Node=100 Vb=2L Lb=6.35cm
Enclosure 'E2' Node=101 Vb=2L Lb=6.35cm
Enclosure 'E3' Node=102 Vb=2L Lb=6.35cm
Enclosure 'E4' Node=103 Vb=2L Lb=6.35cm
Driver 'D1' Def='MidDriver' Node=0=42=100=120 |Note reverse polarity as seen in Lambda X-over
Driver 'D2' Def='MidDriver' Node=0=42=101=121
Driver 'D3' Def='MidDriver' Node=0=42=102=122
Driver 'D4' Def='MidDriver' Node=0=42=103=123
Duct 'Du_Fc1' Node=120=130 dD={Fc_dD} Len={Fc_Len}
Duct 'Du_Fc2' Node=121=131 dD={Fc_dD} Len={Fc_Len}
Duct 'Du_Fc3' Node=122=132 dD={Fc_dD} Len={Fc_Len}
Duct 'Du_Fc4' Node=123=133 dD={Fc_dD} Len={Fc_Len}
Duct 'Du_BP1a' Node=130=150 dD={FcPort_dD} Len=0.635cm |Note a total of two ports
Duct 'Du_BP2a' Node=131=150 dD={FcPort_dD} Len=0.635cm |per mid driver
Duct 'Du_BP3a' Node=132=150 dD={FcPort_dD} Len=0.635cm
Duct 'Du_BP4a' Node=133=150 dD={FcPort_dD} Len=0.635cm
Duct 'Du_BP1b' Node=130=150 dD={FcPort_dD} Len=0.635cm
Duct 'Du_BP2b' Node=131=150 dD={FcPort_dD} Len=0.635cm
Duct 'Du_BP3b' Node=132=150 dD={FcPort_dD} Len=0.635cm
Duct 'Du_BP4b' Node=133=150 dD={FcPort_dD} Len=0.635cm
Driver 'D5' Def='CompDriver' Node=22=0=31=32

Duct 'CompRearChamber' |B&C Speakers DE250 rear compression chamber
Node=30=31
SD={ArcComp}
Len={LrcComp}
Visc=0

Duct 'CompFrontChamber' |B&C Speakers DE250 front throat chamber
Node=32=140
SD={AtcComp}
Len={LtcComp}
Visc=0

Resistor 'Amplifier Rg' |Amplifier output impedance
Node=1=2
R={Rg}

Resistor 'R1Comp'
Node=2=20
R={R1Comp}

Resistor 'R2Comp'
Node=20=0
R={R2Comp}

Resistor 'R3Comp'
Node=21=22
R={R3Comp}

Resistor 'R4Comp'
Node=22=0
R={R4Comp}

Capacitor 'C1Comp'
Node=2=20
C={C1Comp}

Capacitor 'C2Comp'
Node=20=21
C={C2Comp}

Coil 'L1Comp'
Node=20=0
L={L1Comp}

Capacitor 'C1Mid'
Node=2=40
C={C1Mid}

Resistor 'R1Mid'
Node=40=41
R={R1Mid}

Resistor 'R2Mid'
Node=42=0
R={R2Mid}

Coil 'L1Mid'
Node=41=42
L={L1Mid}

Waveguide 'WG1'
Node=140=150
STh={S1}
SMo={S2}
Len={L12}
Conical

Waveguide 'WG2'
Node=150=160
STh={S2}
SMo={S3}
Len={L23}
Conical

Waveguide 'WG3'
Node=160=170
STh={S3}
SMo={S4}
Len={L34}
Conical

Radiator 'Horn mouth'
Node=170
SD={S4}
x=0
y=0
z=0
HAngle=0
VAngle=0

[Sheldon]

Thanks for that. Now to learn how to use it.


Sheldon

[John Sheerin]

John,
You left out the interaction of the midrange chambers with the compression driver (I think - I've never used Akabak). I think it would go between WG1 and WG2 in your schematic. This is an important thing to include in my experience if you want to evaluate effects of the midrange geometry on the tweeter's output. It looks like you did put in the horn segment between the mids and tweeter for the midrange drivers though.