Fertin Acoustics LB 31 SONO

12" · 8 Ω · 200 W · 97.5 dB · datasheet ↗

Thiele-Small parameters

Nominal size	12"
Impedance	8 Ω
Fs	59.5 Hz
Qts	0.407
Qes	0.49
Qms	2.4
Vas	70 L
Sd	490 cm²
Xmax	4 mm
Re	6.8 Ω
Bl	13.4 T·m
Mms	34.4 g
Pe	200 W
Sensitivity	97.5 dB

Alignment hint

EBP	121 · ported
Sealed Vb (Qtc ≈ 0.71)	≈ 34.7 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 L12/568H	58.8 -0.7	0.41 =	72 +2	4 =	97.1 -0.4	close	100 W vs 200 W: lower power handling	+
RCF L 12/568H	58 -1.5	0.409 =	72 +2	4 =	98.1 +0.6	close		+
Beyma SM112 vp	57.8 -1.7	0.391 -0.02	64.6 -5.4	4.2 +0.2	97.7 +0.2	close		+
Faital PRO 12PR310-8	54 -5.5	0.396 -0.01	62.8 -7.2	4.9 +0.9	97.5 =	close		+
Fane COLOSSUS 12MBN	55 -4.5	0.396 -0.01	63 -7	5.5 +1.5	97.4 -0.1	close		+
LaVoce WSN122.50-16	53 -6.5	0.4 -0.01	65.84 -4.16	4.6 +0.6	96.5 -1	close	16 Ω vs 8 Ω: amp load changes	+
Audax PR330T0	55 -4.5	0.435 +0.03	73.7 +3.7	3.7 -0.3	97.3 -0.2	close	150 W vs 200 W: lower power handling · Xmax 3.7 mm < 4 mm: lower excursion-limited SPL	+
Faital PRO 12PR310	54 -5.5	0.4 -0.01	73.5 +3.5	4.92 +0.92	99 +1.5	close		+
RCF L12CX2K	59.7 +0.2	0.46 +0.05	65 -5	4 =	96.3 -1.2	close	75 W vs 200 W: lower power handling	+
Faital PRO 12PR300-8	54 -5.5	0.382 -0.02	73.5 +3.5	4.9 +0.9	98.2 +0.7	close		+

Compare the closest 3 against the LB 31 SONO →

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.