JBL 128-H

12" · 8 Ω · 150 W · 93 dB

Thiele-Small parameters

Nominal size	12"
Impedance	8 Ω
Fs	20 Hz
Qts	0.241
Qes	0.25
Qms	7
Vas	280.3 L
Sd	527.1 cm²
Xmax	7.9 mm
Re	5.7 Ω
Bl	15.9 T·m
Mms	88 g
Pe	150 W
Sensitivity	93 dB

Alignment hint

EBP	80 · flexible
Sealed Vb (Qtc ≈ 0.71)	≈ 36.8 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
Eminence W1238R	21.5 +1.5	0.252 +0.01	236.6 -43.7	8.2 +0.3	93.6 +0.6	close		+
JBL 128-H vp ca1	21.2 +1.2	0.233 -0.01	222.7 -57.6	7.8 -0.1	93.1 +0.1	close	Xmax 7.8 mm < 7.9 mm: lower excursion-limited SPL	+
Audiotechnology 12D772510KAP	19 -1	0.257 +0.02	340 +59.7	8.6 +0.7	93.1 +0.1	close		+
JBL 128-H vp ca2	21.6 +1.6	0.24 =	214.6 -65.7	7.7 -0.2	93.1 +0.1	close	Xmax 7.7 mm < 7.9 mm: lower excursion-limited SPL	+
Audiotechnology FLEXUNITS 12 D 77 25 10 KAP	19 -1	0.25 +0.01	340 +59.7	8.6 +0.7	91.3 -1.7	close		+
Scan-Speak 32W/8878T11	21 +1	0.261 +0.02	235 -45.3	7.5 -0.4	92.1 -0.9	close	Xmax 7.5 mm < 7.9 mm: lower excursion-limited SPL	+
Focal 12V 726	19 -1	0.267 +0.03	340 +59.7	9 +1.1	92 -1	close		+
Fostex SLE 30 W	22 +2	0.302 +0.06	293 +12.7	9.5 +1.6	92.8 -0.2	usable		+
Visaton W300S4	23 +3	0.253 +0.01	300 +19.7	7 -0.9	96.4 +3.4	usable	4 Ω vs 8 Ω: amp load changes · Xmax 7 mm < 7.9 mm: lower excursion-limited SPL	+
JBL 2214H	23 +3	0.244 =	223.7 -56.6	6.6 -1.3	93.9 +0.9	usable	Xmax 6.6 mm < 7.9 mm: lower excursion-limited SPL	+

Compare the closest 3 against the 128-H →

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.