4.75″ / 120 mm
Nominal diameter
72 Hz
Resonance
0.55
Q factor
85 dB
Sensitivity
± 1.5 mm
Linear excursion
Driver
Port
Combined
Frequency response
Hz
Impedance
Ω
Impedance Phase
°
Excursion
mm
Velocity
m/s
SPL
dB
Acoustical Phase
°
Group Delay
ms
Transient response
ms
Sensitivity (1w, 1m, infinite baffle)
SPL1W
84.8
dB
Frequency response
200 - 4000
Hz
Thiele & Small parameters
Resonance frequency (free air)
fS
72.0
Hz
Mechanical quality factor
QMS
8.30
Electrical quality factor
QES
0.59
Total quality factor
QTS
0.55
Large signal parameters
Maximum linear excursion
xmax
1.5
mm
Air volume displaced at xmax
VD
7.5
cm³
Voice Coil
Nominal impedance
Z
8
Ω
DC resistance
RE
6.4
Ω
Inductance (1kHz, estimated)
LE
0.25
mH
VC Diameter
25
mm
Winding height
HVC
7
mm
Former material
Black fiber glass
Magnet
Force factor
Bl
5.2
N/A
Motor constant
Bl/√RE
2.06
N/√W
Air gap height
HAG
4
mm
Diameter
90
mm
Weight
0.44
kg
Diaphragm
Effective diameter
80
mm
Effective area
SD
50
cm²
Moving mass
MMS
5.5
g
Moving mass (without air load)
MMD
5.2
g
Material
Kevlar/Carbon fiber
Suspensions
Stiffness
KMS
1.11
N/mm
Compliance
CMS
900
µm/N
Equivalent volume to the compliance
VAS
3.2
L
Mechanical resistance
RMS
0.3
N·s/m
Dimensions
Nominal diameter
4.75
″
120
mm
Overall diameter
120
mm
Baffle cutout diameter
98
mm
Mounting depth
64
mm
Volume occupied by the driver (estimated)
0.44
L
Net weight
1.1
kg
Frame material
Die cast aluminum
Similar speaker drivers to Wavecor MR120BD02
4″Woofer
fS
70 Hz
SD
57 cm²
70 - 7000 Hz
QTS
0.47
xmax
3.2 mm
SPL1W
86 dB
Bl/√RE
2.25
Pmax
50 W
5″Woofer
fS
76 Hz
SD
54 cm²
75 - 9200 Hz
QTS
0.50
xmax
2.8 mm
SPL1W
86 dB
Bl/√RE
1.99
Pmax
60 W
5″Mid-range
fS
70 Hz
SD
54 cm²
70 - 12000 Hz
QTS
0.48
xmax
4.0 mm
SPL1W
86 dB
Bl/√RE
1.98
Pmax
60 W