The loudspeaker model consists of two main components: the voice coil DC resistance (RE) and the voice coil inductance (LE).

The electrical equivalents of the major mechanical components of suspension compliance, cone mass and suspension losses, may also be specified (LCES, CMES and RES).

All model parameters can be calculated from the Thiele-Small parameters published by the manufacturer.

External model

As an alternative to using the internal model, it is also possible to use an external model by specifying the name of the subcircuit in the MODEL parameter. The subcircuit must have the following interface:

.SUBCKT <subcktname> P N
.ENDS <subcktname>


During interactive simulation, you can animate the speaker symbol by specifying values for one of the following three parameter groups:

The above parameters have no electrical function, they are only used for animation of the speaker symbol during interactive simulation.


Parameter Description Units Default
RE Voice coil DC resistance. Ohms 8
LE Voice coil inductance. If equal to zero, the inductance is not used. Henries 0
LCES Suspension compliance. If this parameter is zero, the LCES component is not used. Henries 0
CMES Cone mass. If this parameter is zero, the CMES component is not used. Farads 0
RES Suspension losses electrical resistance. If this parameter is zero, the RES component is not used. Ohms 0
MODEL Specify the name of the subcircuit. If this parameter is not specified, the internal model consisting of RE, LE, LCES, CMES and RES is used.    
WMIN Minimum power required to display the animation. W  
WRAT Nominal speaker power. From minimum power to rated power, a growing wave is displayed. W  
WMAX Maximum speaker power. A still image is displayed beyond the maximum power. W  
IMIN Minimum current required to view the animation. A  
IRAT Rated current in the speaker. From minimum current to rated current, a growing wave is displayed. A  
IMAX Maximum current in the speaker. A still image is displayed beyond the maximum current. A  
VMIN Minimum voltage required on the speaker terminals to display the animation. V  
VRAT Rated voltage at speaker terminals. From minimum voltage to rated voltage, a growing wave is displayed. V  
VMAX Maximum voltage at speaker terminals. A still image is displayed beyond the maximum voltage. V  


Speaker Fullrange 15W 8Ω

RE=6.8, LE=0.2m, WMIN=0.1, WRAT=15, WMAX=30

Loudspeaker 35W 8Ω

RE=5.8, LE=0.51m, CMES=464.9µ, LCES=6.1m, RES=64.5, WMIN=1, WRAT=35, WMAX=50

Loudspeaker 75W 8Ω

MODEL=G12T75, WMIN=1, WRAT=75, WMAX=100

R_RL P 2 7.5
R_RD1 2 3 15
L_LD1 3 2 20mH
C_CD1 2 3 190u
R_RD2 3 4 0.5
C_CD2 3 4 50u
L_LD2 4 3 100uH
L_LD3 N 4 100uH
R_RD3 N 4 20
.ENDS G12T75

Electro Mechanical Buzzer with internal drive circuit 12VDC

RE=522, VMIN=7, VRAT=12, VMAX=16

Electro Mechanical Buzzer 5V ac

RE=88, IMIN=26m, IRAT=40m, IMAX=64m