LII Audio FAST-15

15" · 16 Ω · 40 W · 99.3 dB · datasheet ↗

Thiele-Small parameters

Nominal size	15"
Impedance	16 Ω
Fs	36.5 Hz
Qts	0.311
Qes	0.324
Qms	7.583
Vas	366.4 L
Sd	938.2 cm²
Xmax	2 mm
Re	8.18 Ω
Bl	19.3 T·m
Mms	64 g
Pe	40 W
Sensitivity	99.3 dB

Alignment hint

EBP	113 · ported
Sealed Vb (Qtc ≈ 0.71)	≈ 87.9 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
Sphynx WRB15	38 +1.5	0.331 +0.02	376 +9.6	4 +2	99.2 -0.1	close		+
Altec 950-8A	31.5 -5	0.3 -0.01	410.6 +44.2	2 =	98.7 -0.6	close	8 Ω vs 16 Ω: amp load changes · 15 W vs 40 W: lower power handling	+
Sphynx SP-W15-SONO	38 +1.5	0.331 +0.02	376 +9.6	4 +2	100.9 +1.6	close	8 Ω vs 16 Ω: amp load changes	+
Monacor SP-38/200PA	38 +1.5	0.294 -0.02	287 -79.4	2 =	100.3 +1	close	8 Ω vs 16 Ω: amp load changes	+
Eminence GAMMA 15	33 -3.5	0.301 -0.01	314.1 -52.3	3 +1	98.7 -0.6	close	8 Ω vs 16 Ω: amp load changes	+
Eminence GAMMA 15 A2	33 -3.5	0.301 -0.01	314.1 -52.3	3 +1	98.7 -0.6	close	8 Ω vs 16 Ω: amp load changes	+
Sonido SCW-400	34 -2.5	0.339 +0.03	357 -9.4	5 +3	98.6 -0.7	close	8 Ω vs 16 Ω: amp load changes	+
Peavey 1504-4DT	31.3 -5.2	0.304 -0.01	385 +18.6	3 +1	101.2 +1.9	close	4 Ω vs 16 Ω: amp load changes	+
Eminence KAPPA 15 A	33 -3.5	0.318 +0.01	321.3 -45.1	5.5 +3.5	99.3 =	close	8 Ω vs 16 Ω: amp load changes	+
Iconic Speakers 165-8G	37 +0.5	0.265 -0.05	363.7 -2.7	3.5 +1.5	101.3 +2	close	8 Ω vs 16 Ω: amp load changes	+

Compare the closest 3 against the FAST-15 →

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.