P.Audio SD-18

18" · 8 Ω · 800 W · 99.5 dB · datasheet ↗

Thiele-Small parameters

Nominal size	18"
Impedance	8 Ω
Fs	33.2 Hz
Qts	0.26
Qes	0.27
Qms	7.11
Vas	264.3 L
Sd	1250 cm²
Xmax	5 mm
Re	5.1 Ω
Bl	27.4 T·m
Mms	190.4 g
Pe	800 W
Sensitivity	99.5 dB

Alignment hint

EBP	123 · ported
Sealed Vb (Qtc ≈ 0.71)	≈ 41.3 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
RCF LF 18N401	32 -1.2	0.259 =	257 -7.3	8.8 +3.8	98.9 -0.6	close		+
18 Sound 18NLW9400	33 -0.2	0.26 =	268 +3.7	9.5 +4.5	98 -1.5	close		+
Mercuriale PAR 465 M0	35 +1.8	0.265 +0.01	251 -13.3	6 +1	98.5 -1	close	600 W vs 800 W: lower power handling	+
RCF LF18N401	32 -1.2	0.26 =	257 -7.3	9 +4	98 -1.5	close		+
JBL 2242H	35 +1.8	0.274 +0.01	282.3 +18	5.1 +0.1	100.5 +1	close	400 W vs 800 W: lower power handling	+
PD PD 184	33.4 +0.2	0.266 +0.01	304 +39.7	7.2 +2.2	99.9 +0.4	close	600 W vs 800 W: lower power handling	+
Precision Devices PD 184	33.4 +0.2	0.266 +0.01	304 +39.7	7.2 +2.2	99.9 +0.4	close	600 W vs 800 W: lower power handling	+
RCF LF 18G401	33 -0.2	0.289 +0.03	268 +3.7	8.2 +3.2	99.3 -0.2	close		+
18 Sound 18LW1250	35 +1.8	0.271 +0.01	268 +3.7	8.7 +3.7	100.2 +0.7	close		+
B&C 18 PZB 100 (prodance)	33.7 +0.5	0.289 +0.03	263 -1.3	7.6 +2.6	99 -0.5	close		+

Compare the closest 3 against the SD-18 →

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.