21″ / 533 mm
Nominal diameter
30 Hz
Resonance
0.26
Q factor
96 dB
Sensitivity
± 13 mm
Linear excursion
3000 W
Program Power
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
Available on (affiliate link)
Amazon.com
$$$
Specifications
Sensitivity (1w, 1m, infinite baffle)
SPL1W
96.4
dB
Frequency response
30 - 1000
Hz
Thiele & Small parameters
Resonance frequency (free air)
fS
30.0
Hz
Mechanical quality factor
QMS
6.10
Electrical quality factor
QES
0.27
Total quality factor
QTS
0.26
Large signal parameters
Maximum linear excursion
xmax
13.0
mm
Maximum excursion before damage
xlim
29.0
mm
Air volume displaced at xmax
VD
2210
cm³
Power handling
P
1500
W
Program power
Pmax
3000
W
Voice Coil
Nominal impedance
Z
8
Ω
DC resistance
RE
5.6
Ω
Inductance (1kHz)
LE
3.0
mH
VC Diameter
114
mm
Winding height
HVC
34
mm
Magnet
Force factor
Bl
34.5
N/A
Motor constant
Bl/√RE
14.6
N/√W
Air gap height
HAG
15
mm
Diaphragm
Effective diameter
470
mm
Effective area
SD
1700
cm²
Moving mass
MMS
315
g
Moving mass (without air load)
MMD
266.1
g
Suspensions
Stiffness
KMS
10.87
N/mm
Compliance
CMS
92
µm/N
Equivalent volume to the compliance
VAS
375
L
Mechanical resistance
RMS
9.73
N·s/m
Spider material
with silicon damping
Dimensions
Nominal diameter
21
″
533
mm
Overall diameter
547
mm
Baffle cutout diameter
512
mm
Overall depth
249
mm
Volume occupied by the driver
6.5
L
Net weight
10.9
kg
Similar subwoofers to RCF LF21N451
21″Subwoofer
fS
28 Hz
SD
1660 cm²
24 - 2000 Hz
QTS
0.24
xmax
9.5 mm
SPL1W
97 dB
Bl/√RE
15
Pmax
1600 W
18″Subwoofer
fS
30 Hz
SD
1220 cm²
28 - 2500 Hz
QTS
0.28
xmax
9.5 mm
SPL1W
96 dB
Bl/√RE
11
Pmax
1400 W
18″Subwoofer
fS
31 Hz
SD
1225 cm²
28 - 2500 Hz
QTS
0.29
xmax
9.0 mm
SPL1W
96 dB
Bl/√RE
11
Pmax
1400 W