Full or Extended Range Driver w/ Woofer on an Open Baffle ...

Open Baffle w/ 2 <strong>Driver</strong>s - Acoustic Response 12/27/12
Software : by Martin J. King
e-mail MJKing57@aol.com
Copyright 2012 by Martin J. King. All Rights Reserved.
Configuration : <strong>Extended</strong> <strong>Range</strong> <strong>Driver</strong> w/ Bass <strong>Driver</strong> Mounted on an Open Baffle
Unit and Constant Definition
cycle 2πrad
Hz cyclesec 1
Air Density : ρ 1.205kgm 3
Speed of Sound : c 344msec 1
Part 1 : Thiele-Small Consistent Calculation
Detailed User Input (Edit This Section and Input the Parameters f<strong>or</strong> the System to be Analyzed)
Power 1watt
(Input Power) Applied Voltage Reference ---> R ref 8Ω
<strong>Extended</strong> <strong>Range</strong> <strong>Driver</strong> Thiele / Small Parameters : Fostex FE-103E
f d
R e
L vc
79.5Hz
V ad 6.90liter
7.45Ω
Q ed 0.40
0.001mH
Q md 2.87
Bl 4.42 newton
1 1
Q td
amp
Q ed
S d π4 2 cm 2
Q td 0.351
Q md
1
Bass <strong>Driver</strong> Thiele / Small Parameters : Eminence Alpha 15" High Efficiency
f d
R e
L vc
41Hz
V ad 260liter
5.88Ω
Q ed 1.53
0.84mH
Q md 7.23
Bl 7.7 newton
1 1
Q td
amp
Q ed
S d 856.3cm 2
Q td 1.263
Q md
1

Instructions :
1. A Zobel, Trap, and L-Pad are available f<strong>or</strong> adjusting the <strong>Extended</strong> <strong>Range</strong> <strong>Driver</strong>'s SPL output.
2. Select the crossover frequencies, <strong>or</strong>ders, and types below.
3. Scroll down to the applicable crossover sections below and fill in the values of the circuit components.
a. The the<strong>or</strong>etical values are shown to the right of each schematic.
b, The<strong>or</strong>etical values are calculated using only the driver's DC resistance, a textbook solution.
c. Enter the actual component values, these should c<strong>or</strong>respond to available components.
d. Iterate the actual component values to optimize the crossover responses.
e. You can mix the crossover <strong>or</strong>ders and types by using only half of each pair of schematics.
4. Purchase the optimized actual component values and construct the crossover per the schematics.
Crossover Definition
F<strong>or</strong> Even Order Crossovers :
Type 1 = Linkwitz-Riley
Type 2 = Bessel
Type 3 = BEC
Type 4 = Butterw<strong>or</strong>th
Low Pass Filter
High Pass Filter
f LP
200Hz
f HP 500Hz
(Filter Frequency)
LP <strong>or</strong>der 2
HP <strong>or</strong>der 2
(Filter Order : 0, 1, 2, 3, <strong>or</strong> 4)
LP type 1
HP type 2
(Filter Type : 1, 2, 3, <strong>or</strong> 4 f<strong>or</strong> even <strong>or</strong>der only,
f<strong>or</strong> odd <strong>or</strong>der this entry is ign<strong>or</strong>ed)
Crossover Phase Connection and <strong>Extended</strong> <strong>Range</strong> <strong>Driver</strong> Attenuation
LP phase 1
HP phase 1
(Phase : 1 = in phase, -1 = out of phase)
L_Pad 1
dB (L Pad Attemuation of <strong>Extended</strong> <strong>Range</strong> <strong>Driver</strong>)

<strong>Extended</strong> <strong>Range</strong> <strong>Driver</strong> Compensation Circuits
(Default Actual Values Remove Circuits)
Zobel Components
User Specified Compensation Circuit Values
Suggested Values R zobel 9.313 Ω Actual Values R zobel 10 10 Ω
C zobel
0.012 μF
C zobel 10 10 μF
Resonance Trap Components
Suggested Values R trap 8.488 Ω
Actual Values R trap 10 10 Ω
C trap
671.795 μF
C trap 10 10 μF
L trap 5.966 mH
L trap 10 10 mH
L-Pad Components
Suggested Values R parallel 48.189 Ω Actual Values R parallel 10 10 Ω
R series
0.639 Ω
R series 0Ω

Crossover Definition - 1 st Order High and Low Pass
Schematic
C1
+
-
Midrange
The<strong>or</strong>etical Values
C 1
42.726 μF
+
L1
<strong>Woofer</strong>
L 1
4.679 mH
-
Enter Actual Component Values Below
High Pass
C 1
40μF
Low Pass
L 1
4.5mH
R 1 0.3Ω

Crossover Definition - 2 nd Order High and Low Pass
Schematic
C1
+
L1
-
Midrange
The<strong>or</strong>etical Values
C 1
L 1
24.653 μF
4.11 mH
+
-
L2
C2
<strong>Woofer</strong>
L 2
C 2
9.358 mH
67.668 μF
Enter Actual Component Values Below
High Pass
C 1
L 1
25μF
4mH R 1 0.3Ω
Low Pass
L 2
C 2
10mH
R 2 0.5Ω
68μF

Crossover Definition - 3 rd Order High and Low Pass
Schematic
The<strong>or</strong>etical Values
+
-
C1
L1
C2
Midrange
C 1
L 1
C 2
28.484 μF
1.779 mH
85.452 μF
+
-
L2
C3
L3
<strong>Woofer</strong>
L 2
C 3
L 3
7.019 mH
180.448 μF
2.34 mH
Enter Actual Component Values Below
High Pass
C 1
L 1
C 2
28μF
1.75mH
R 1 0.2Ω
85μF
Low Pass
L 2
C 3
L 3
7mH R 2 0.5Ω
180μF
2.5mH
R 3 0.2Ω

Crossover Definition - 4 th Order High and Low Pass
Schematic
C1 C2
+
L1 L2 Midrange
-
L3 L4
+
C3 C4 <strong>Woofer</strong>
-
The<strong>or</strong>etical Values
C 1
L 1
C 2
L 2
L 3
C 3
L 4
24.671 μF
1.503 mH
42.738 μF
6.479 mH
8.82 mH
215.391 μF
4.41 mH
Enter Actual Component Values Below C 4 47.874 μF
High Pass
C 1
L 1
C 2
L 2
25μF
1.5mH
R 1 0.1Ω
43μF
6.5mH
R 2 0.3Ω
Low Pass
L 3
C 3
L 4
C 4
9mH R 3 0.5Ω
215μF
4.5mH
R 4 0.3Ω
48μF
End of Detailed Input
End of Part 1 Input

OB <strong>Driver</strong> Impedance
90
Phase (deg)
argZ r
deg
45
0
45
Impedance (ohms)
Z r
90
10 100 110
3
50
40
30
20
10
0
10 100 110
3
r
r
Frequency (Hz)
<strong>Driver</strong> RMS Displacements (Red Curve - <strong>Woofer</strong>s, Blue Curve - <strong>Extended</strong> <strong>Range</strong> <strong>Driver</strong>)
5
RMS Deflection (mm)
x Lr
mm
x Hr
mm
4
3
2
1
0
10 100 110
3
rdω Hz
1
Frequency (Hz)

Part 2 : Detailed SPL Response Calculation
Calculation Includes :
Position of <strong>Driver</strong>s on the Baffle.
Open Baffle Defraction f<strong>or</strong> the <strong>Driver</strong>s.
Flo<strong>or</strong> Reflection f<strong>or</strong> the <strong>Driver</strong>s.
Geometry
Co<strong>or</strong>dinate System :
Origin is the lower left c<strong>or</strong>ner of the front baffle
y = h<strong>or</strong>izontal direction
z = vertical direction
The variables num_r, n_low, and n_high control the number of simple sources used in the
calculations. Increasing each will improve accuracy at the expense of longer calculation
times. Increase each variable until final plotted SPL stops changing at which point the
solution has converged.
Enclosure Geometry Input
X 0
Y 0
θ 0
Z 0
2ft
1.5ft
45deg
8ft
stand
0m
num_r 10
(Front Baffle Distance from Rear Wall > Depth of Enclosure)
(Front Baffle Distance from Side Wall)
(Rotation Towards Room Center)
(Flo<strong>or</strong> to Ceiling Distance)
(Height from Flo<strong>or</strong> to Bottom Edge of Front Baffle)
(Number of Points per Unit Length of Baffle Edge)
C<strong>or</strong>ner Co<strong>or</strong>dinates
Y co<strong>or</strong>dinate
Z co<strong>or</strong>dinate
y o0
y o1
y o2
y o3
20in
20in
z o1 38in
0in
z o2 38in
0in
(Bottom Right C<strong>or</strong>ner)
(Top Right C<strong>or</strong>ner)
(Top Left C<strong>or</strong>ner)
(Bottom Left C<strong>or</strong>ner)
<strong>Extended</strong> <strong>Range</strong> <strong>Driver</strong> Geometry Input
y dc
z dc
8in
32in
n_high 4
(<strong>Driver</strong> Center y Co<strong>or</strong>dinate)
(<strong>Driver</strong> Center z Co<strong>or</strong>dinate)
(Number of Points Across Diameter)
<strong>Woofer</strong> <strong>Driver</strong> Geometry Input
y w1
z w1
10in
10in
n_low 10
(Lower <strong>Driver</strong> Center y Co<strong>or</strong>dinate)
(Lower <strong>Driver</strong> Center z Co<strong>or</strong>dinate)
(Number of Points Across Diameter)

Listening Position (Default Location is at 1 m Distance Along the <strong>Driver</strong>'s Axis)
n_listen = 0
radius 1m
θ
z p
0deg
z dc
(Listening Position Relative to Speaker)
(Calculation Radius, Effective Radius is Greater if y p
is Changed from Default)
(0 deg is along the <strong>Driver</strong>'s Axis, -80 deg < < 80 deg)
(Default Height is Equal to <strong>Driver</strong> Height)
n_listen = 1
X p
Y p
10ft
7ft
Z p z dc stand
n_listen 0
(Listening Position Relative to the Room C<strong>or</strong>ner)
(Default Height is Equal to <strong>Driver</strong> Height)
(Method Selection)
Flo<strong>or</strong> Condition
Reflect 1
(0 = hardwood <strong>or</strong> concrete, 1 = carpeted)
Refective Surface Selections (if 1 reflective surface is included, if 0 reflective surface is removed)
Inc_flo<strong>or</strong> 1 (Flo<strong>or</strong>, Z = 0)
Inc_rear 0 (Rear Wall, X = 0)
Inc_side 0 (Left Side Wall, Y = 0)
Inc_ceiling 0
(Ceiling)

<strong>Extended</strong> <strong>Range</strong> <strong>Driver</strong> and <strong>Woofer</strong> : Simple Source Pattern with Baffle Edge Outline
1
z d
z w
z o
0.5
0 0.5 1
y d y w y
o

Three Dimensional View
Axis Length (m) axis 2

Plotted Response f<strong>or</strong> the <strong>Extended</strong> <strong>Range</strong> <strong>Driver</strong>
Dashed Red - Infinite Baffle Response
Dashed Magenta - Baffle Response
Dashed Brown - Crossover Response
Solid Red - Combined Response
SPL (dB)
10
5
SPL IBr 0
5
X_over r 10
SPL
15 BFr
20
SPL nr 25
30
35
40
10 100 110 3
110
4
180
rdω Hz 1
Phase (degrees)
Phase r
deg
120
60
0
60
120
SPL (dB)
180
10 100 110
3
110
rdω Hz 1
105
100
95
90
SPL Hr 85
80
75
70
65
60
10 100 110 3
110
4
rdω Hz
1
Frequency (Hz)

Plotted Response f<strong>or</strong> the <strong>Woofer</strong> <strong>Driver</strong>
Dashed Red - Infinite Baffle Response
Dashed Magenta - Baffle Response
Dashed Brown - Crossover Response
Solid Red - Combined Response
SPL (dB)
10
5
SPL IBr 0
5
X_over r 10
SPL
15 BFr
20
SPL nr 25
30
35
40
10 100 110 3
110
4
180
rdω Hz 1
Phase (degrees)
Phase r
deg
120
60
0
60
120
SPL (dB)
180
10 100 110
3
110
rdω Hz 1
105
100
95
90
SPL Lr 85
80
75
70
65
60
10 100 110 3
110
4
rdω Hz
1
Frequency (Hz)

Plotted System Response f<strong>or</strong> the <strong>Extended</strong> <strong>Range</strong> and <strong>Woofer</strong> Open Baffle Design
180
120
Phase (degrees)
Phase r
deg
60
0
60
120
SPL (dB)
180
10 100 110 3
110
4
rdω Hz 1
110
105
SPL r
100
95
SPL
90 Hr
85
SPL Lr
80
75
70
65
60
10 100 110 3
110
4
rdω Hz
1
Frequency (Hz)

System Time Response f<strong>or</strong> an Impulse Input
100
<strong>Woofer</strong> Sound Pressure in Time Domain
p wooferr
Pa
50
0
50
0 510 3 0.01 0.015 0.02 0.025 0.03 0.035 0.04 0.045 0.05
210
3
rdt
System Sound Pressure in Time Domain
110
3
p summedr
Pa
0
110 3
210 3
0 510 3 0.01 0.015 0.02 0.025 0.03 0.035 0.04 0.045 0.05
rdt
Time (sec)