Oxygen SPIRAL 12.1

12" · 4 Ω · 150 W · 88.7 dB · datasheet ↗

Thiele-Small parameters

Nominal size	12"
Impedance	4 Ω
Fs	27 Hz
Qts	0.749
Qes	0.885
Qms	4.872
Vas	94 L
Sd	490 cm²
Xmax	7 mm
Re	3.6 Ω
Bl	9.3 T·m
Mms	124.4 g
Pe	150 W
Sensitivity	88.7 dB

Alignment hint

EBP	31 · sealed
Sealed Vb (Qtc ≈ 0.71)	Qts too high

EBP < 50: favours a sealed (closed) 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
Peerless XXLS-P830845 v2025	29 +2	0.654 -0.09	91.9 -2.1	7.6 +0.6	88.5 -0.2	close	8 Ω vs 4 Ω: amp load changes	+
Kenwood KFC-W3013	25 -2	0.82 +0.07	83.7 -10.3	7.6 +0.6	87.3 -1.4	close		+
Pioneer TS-W306R	24.6 -2.4	0.815 +0.07	102.1 +8.1	11.6 +4.6	87.9 -0.8	close		+
Focal 30A4	24.7 -2.3	0.671 -0.08	86.9 -7.1	8.5 +1.5	87.3 -1.4	close	8 Ω vs 4 Ω: amp load changes	+
Focal 30A4 vp	24.7 -2.3	0.671 -0.08	86.9 -7.1	8.5 +1.5	87.3 -1.4	close	8 Ω vs 4 Ω: amp load changes	+
Pioneer TS-W300R	29.5 +2.5	0.646 -0.1	93.2 -0.8	6.8 -0.2	91.6 +2.9	usable	Xmax 6.8 mm < 7 mm: lower excursion-limited SPL	+
JL Audio 12WX-4	27 =	0.562 -0.19	94.5 +0.5	8.5 +1.5	90.5 +1.8	usable		+
JL Audio 12W0V3-4	28.4 +1.4	0.67 -0.08	71.6 -22.4	9.3 +2.3	88.3 -0.4	usable	8 Ω vs 4 Ω: amp load changes	+
MTX Audio RTL12-44 DVC	30.4 +3.4	0.761 +0.01	74 -20	7.1 +0.1	91.7 +3	usable		+
MTX Audio TH6000 6124	29.7 +2.7	0.66 -0.09	78.4 -15.6	7.4 +0.4	90.3 +1.6	usable		+

Compare the closest 3 against the SPIRAL 12.1 →

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.