RCF LF 21N401

21.5" · 8 Ω · 1500 W · 98 dB · datasheet ↗

Thiele-Small parameters

Nominal size	21.5"
Impedance	8 Ω
Fs	30 Hz
Qts	0.378
Qes	0.4
Qms	6.8
Vas	374 L
Sd	1730 cm²
Xmax	10.6 mm
Re	5 Ω
Bl	27.3 T·m
Mms	315.7 g
Pe	1500 W
Sensitivity	98 dB

Alignment hint

EBP	75 · flexible
Sealed Vb (Qtc ≈ 0.71)	≈ 149.6 L

EBP 50-100: works in either a sealed or ported alignment.

Rules of thumb from T/S parameters only. Verify against a real simulation before cutting wood.

Substitute candidates

Driver	Fs (Hz)	Qts	Vas (L)	Xmax (mm)	Sens (dB)	Fit	Notes	Compare
MC Kenzie FRL-21/1200-LF	30 =	0.378 =	374 =	9.5 -1.1	98 =	close	Xmax 9.5 mm < 10.6 mm: lower excursion-limited SPL	+
RCF LF 21X451	28 -2	0.369 -0.01	385 +11	13 +2.4	97 -1	close		+
Beyma 21PW1400FE	30 =	0.343 -0.03	401.5 +27.5	10 -0.6	98.6 +0.6	close	Xmax 10 mm < 10.6 mm: lower excursion-limited SPL	+
LaVoce SAF214.50 vp	30 =	0.401 +0.02	311 -63	11.6 +1	96.4 -1.6	close		+
18 Sound 21NLW9000	29 -1	0.347 -0.03	304 -70	10.7 +0.1	96.4 -1.6	close		+
RCF 21LNW9000	29 -1	0.347 -0.03	304 -70	10.7 +0.1	96.4 -1.6	close		+
Beyma 21SW1600ND	33 +3	0.382 =	268 -106	8.9 -1.7	97.6 -0.4	usable	Xmax 8.9 mm < 10.6 mm: lower excursion-limited SPL	+
B&C 21 SW 115	32.5 +2.5	0.404 +0.03	268.7 -105.3	9.9 -0.7	99.2 +1.2	usable	4 Ω vs 8 Ω: amp load changes · Xmax 9.9 mm < 10.6 mm: lower excursion-limited SPL	+
SB Audience NERO-21SW1100D	32 +2	0.339 -0.04	312.6 -61.4	8.1 -2.5	98.6 +0.6	usable	1100 W vs 1500 W: lower power handling · Xmax 8.1 mm < 10.6 mm: lower excursion-limited SPL	+
LaVoce SAF214.50	30 =	0.435 +0.06	267 -107	11.6 +1	95.6 -2.4	usable		+

Compare the closest 3 against the LF 21N401 →

Ranked on parameter similarity only (Qts, Fs, Vas, Xmax, sensitivity). Same nominal size required. A hint, not a simulation, model the swap before cutting or buying.

Used in enclosures (0)

No enclosure in the catalog uses this driver yet.