BMS 15N840

15" · 8 Ω · 1200 W · 95 dB

Thiele-Small parameters

Nominal size	15"
Impedance	8 Ω
Fs	35.6 Hz
Qts	0.3
Qes	0.32
Qms	5.75
Vas	145.7 L
Sd	845 cm²
Xmax	11 mm
Re	5 Ω
Bl	24.6 T·m
Mms	137 g
Pe	1200 W
Sensitivity	95 dB

Alignment hint

EBP	111 · ported
Sealed Vb (Qtc ≈ 0.71)	≈ 32 L

EBP > 100: favours a ported (bass-reflex) 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
RCF LF15X401	34 -1.6	0.29 -0.01	146 +0.3	12 +1	96.5 +1.5	close		+
BMS 15N840 v2015	35.6 =	0.303 =	145.7 =	9.9 -1.1	97.1 +2.1	close	Xmax 9.9 mm < 11 mm: lower excursion-limited SPL	+
RCF LF 15X401	34 -1.6	0.289 -0.01	146 +0.3	10.3 -0.7	96.4 +1.4	close	Xmax 10.3 mm < 11 mm: lower excursion-limited SPL	+
Beyma 15LEX1200Nd	36 +0.4	0.3 =	127 -18.7	11 =	97 +2	close		+
Beyma 15P1000	35 -0.6	0.293 -0.01	146 +0.3	8.7 -2.3	96.3 +1.3	close	Xmax 8.7 mm < 11 mm: lower excursion-limited SPL	+
18 Sound 15NLW9500	34 -1.6	0.29 -0.01	147.5 +1.8	9 -2	96 +1	close	4 Ω vs 8 Ω: amp load changes · Xmax 9 mm < 11 mm: lower excursion-limited SPL	+
Fane COLOSSUS 15XS	36.3 +0.7	0.307 +0.01	149.7 +4	9.1 -1.9	97.3 +2.3	close	Xmax 9.1 mm < 11 mm: lower excursion-limited SPL	+
Fane COLOSSUS PRIME 15XS	36.3 +0.7	0.307 +0.01	149.7 +4	9.1 -1.9	97.3 +2.3	close	Xmax 9.1 mm < 11 mm: lower excursion-limited SPL	+
B&C 15SW100	37 +1.4	0.31 +0.01	110 -35.7	12.5 +1.5	95 =	close		+
B&C 15NBX100	36 +0.4	0.29 -0.01	125 -20.7	10 -1	97 +2	close	Xmax 10 mm < 11 mm: lower excursion-limited SPL	+

Compare the closest 3 against the 15N840 →

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.