Thiele/Small Parameters

49ST9MR4

Re
3.60
Ohm
electrical voice coil resistance at DC
Krm
0.0028
Ohm
WRIGHT inductance model
Erm
0.68
WRIGHT inductance model
Kxm
0.0041
Ohm
WRIGHT inductance model
Exm
0.74
WRIGHT inductance model
Cmes
448.91
µF
electrical capacitance representing moving mass
Lces
4.56
mH
electrical inductance representing driver compliance
Res
15.66
Ohm
resistance due to mechanical losses
fs
111.3
Hz
driver resonance frequency
Mms
39.242
g
mechanical mass of driver diaphragm assembly including air load and voice coil
Mmd (Sd)
31.118
g
mechanical mass of voice coil and diaphragm without air load
Rms
5.582
kg/s
mechanical resistance of total-driver losses
Cms
0.052
mm/N
mechanical compliance of driver suspension
Kms
19.19
N/mm
mechanical stiffness of driver suspension
Bl
9.350
N/A
force factor (Bl product)
Lambda s
0.138
suspension creep factor
Qtp
0.969
total Q-factor considering all losses
Qms
4.916
mechanical Q-factor of driver in free air considering Rms only
Qes
1.130
electrical Q-factor of driver in free air considering Re only
Qts
0.919
total Q-factor considering Re and Rms only
Vas
10.2331
l
equivalent air volume of suspension
n0
1.200
%
reference efficiency (2 pi-radiation using Re)
Lm
92.99
dB
characteristic sound pressure level (SPL at 1m for 1W @ Re)
Lnom
93.45
dB
nominal sensitivity (SPL at 1m for 1W @ Zn)
rmse Z
3.69
%
root-mean-square fitting error of driver impedance Z(f)
rmse Hx
2.46
%
root-mean-square fitting error of transfer function Hx (f)
Series resistor
0.00
Ohm
resistance of series resistor
Sd
372.49
cm²
diaphragm area