Radian 5215 B-8

15" · 8 Ω · 625 W · 98.2 dB · datasheet ↗

Thiele-Small parameters

Nominal size	15"
Impedance	8 Ω
Fs	38.7 Hz
Qts	0.316
Qes	0.35
Qms	3.24
Vas	189.7 L
Sd	789 cm²
Xmax	5.5 mm
Re	6 Ω
Bl	18 T·m
Mms	77.8 g
Pe	625 W
Sensitivity	98.2 dB

Alignment hint

EBP	111 · ported
Sealed Vb (Qtc ≈ 0.71)	≈ 47.3 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
Radian 5215B	39 +0.3	0.313 =	192.4 +2.7	5.5 =	98.5 +0.3	close		+
Fane SOVEREIGN PRO 15-500	40 +1.3	0.319 =	192 +2.3	6 +0.5	99.4 +1.2	close		+
Audax PR38ST250	38 -0.7	0.311 -0.01	193 +3.3	4.9 -0.6	98.4 +0.2	close	250 W vs 625 W: lower power handling · Xmax 4.9 mm < 5.5 mm: lower excursion-limited SPL	+
RCF L 15L601	38 -0.7	0.305 -0.01	190 +0.3	5 -0.5	97.9 -0.3	close	Xmax 5 mm < 5.5 mm: lower excursion-limited SPL	+
PHL Audio 5102	36 -2.7	0.306 -0.01	190 +0.3	6.1 +0.6	97.8 -0.4	close	400 W vs 625 W: lower power handling	+
18 Sound 15ND830	39 +0.3	0.32 =	213 +23.3	6.5 +1	98 -0.2	close	450 W vs 625 W: lower power handling	+
PHL Audio 5100	39 +0.3	0.297 -0.02	180 -9.7	5.6 +0.1	98.8 +0.6	close	400 W vs 625 W: lower power handling	+
RCF MB 15X301	38 -0.7	0.345 +0.03	195 +5.3	6 +0.5	98.3 +0.1	close		+
JBL 265H-1	39 +0.3	0.32 =	170 -19.7	5 -0.5	98.3 +0.1	close	300 W vs 625 W: lower power handling · Xmax 5 mm < 5.5 mm: lower excursion-limited SPL	+
LaVoce WAF154.03	38 -0.7	0.29 -0.03	188 -1.7	5.2 -0.3	98.6 +0.4	close	Xmax 5.2 mm < 5.5 mm: lower excursion-limited SPL	+

Compare the closest 3 against the 5215 B-8 →

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.