Ground Zero GZTW 30T

12" · 4 Ω · 400 W · 90.7 dB · datasheet ↗

Thiele-Small parameters

Nominal size	12"
Impedance	4 Ω
Fs	25 Hz
Qts	0.443
Qes	0.49
Qms	4.58
Vas	110 L
Sd	500 cm²
Xmax	11.9 mm
Re	3.8 Ω
Bl	12.5 T·m
Mms	129.1 g
Pe	400 W
Sensitivity	90.7 dB

Alignment hint

EBP	51 · flexible
Sealed Vb (Qtc ≈ 0.71)	≈ 71.1 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
Ground Zero GZTW 30	25 =	0.44 =	110 =	11.2 -0.7	90.7 =	close	Xmax 11.2 mm < 11.9 mm: lower excursion-limited SPL	+
JL Audio 13W6V2-D4	24.3 -0.7	0.434 -0.01	111.6 +1.6	10.6 -1.3	88.3 -2.4	close	8 Ω vs 4 Ω: amp load changes · Xmax 10.6 mm < 11.9 mm: lower excursion-limited SPL	+
Blaupunkt VCS 1200	23 -2	0.487 +0.04	102 -8	13 +1.1	89.9 -0.8	close		+
TC Sounds EPIC 12 DVC v2009	24 -1	0.399 -0.04	91.2 -18.8	11.7 -0.2	90.1 -0.6	close	Xmax 11.7 mm < 11.9 mm: lower excursion-limited SPL	+
TC Sounds EPIC 12 DVC v2014	24 -1	0.394 -0.05	91 -19	12.2 +0.3	90.2 -0.5	close		+
TC Sounds EPIC 12 DVC v2012	24 -1	0.394 -0.05	91.1 -18.9	12.5 +0.6	90.2 -0.5	close		+
JL Audio 12W3V3-4	26.7 +1.7	0.446 =	80.6 -29.4	10.9 -1	90.6 -0.1	close	Xmax 10.9 mm < 11.9 mm: lower excursion-limited SPL	+
Dayton Audio DSC305-4	23 -2	0.408 -0.04	116 +6	9.3 -2.6	91 +0.3	close	250 W vs 400 W: lower power handling · Xmax 9.3 mm < 11.9 mm: lower excursion-limited SPL	+
Infinity KAPPA PERFECT 12.1	23.32 -1.68	0.44 =	99.97 -10.03	14.15 +2.25	86.2 -4.5	close		+
Rockford Fosgate RFR2212	24 -1	0.376 -0.07	93 -17	13 +1.1	90.5 -0.2	close		+

Compare the closest 3 against the GZTW 30T →

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.