GRS 18PT-8

18" · 8 Ω · 350 W · 92.5 dB · datasheet ↗

Thiele-Small parameters

Nominal size	18"
Impedance	8 Ω
Fs	23 Hz
Qts	0.547
Qes	0.58
Qms	9.59
Vas	467 L
Sd	1234 cm²
Xmax	7.8 mm
Re	6.9 Ω
Bl	19.4 T·m
Mms	218.9 g
Pe	350 W
Sensitivity	92.5 dB

Alignment hint

EBP	40 · sealed
Sealed Vb (Qtc ≈ 0.71)	≈ 695.9 L

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
Zeuz DC181125ip	22.2 -0.8	0.458 -0.09	429.3 -37.7	8.5 +0.7	95 +2.5	usable	4 Ω vs 8 Ω: amp load changes · 250 W vs 350 W: lower power handling	+
FI Audio IB318-SINGLE2	22.3 -0.7	0.652 +0.1	381 -86	12.3 +4.5	93.4 +0.9	usable	4 Ω vs 8 Ω: amp load changes	+
Faital PRO 18FH500	30 +7	0.53 -0.02	450.1 -16.9	9.45 +1.65	97 +4.5	usable	16 Ω vs 8 Ω: amp load changes	+
Mach 5 Audio MAC MAH CWA46	27 +4	0.448 -0.1	470.3 +3.3	10 +2.2	96.2 +3.7	usable		+
AE Speakers IB18HT-8	18.4 -4.6	0.568 +0.02	632.1 +165.1	16.7 +8.9	91.5 -1	usable		+
Pyle Audio PPA18 vp	24.2 +1.2	0.39 -0.16	503.2 +36.2	6 -1.8	93.1 +0.6	usable	16 Ω vs 8 Ω: amp load changes · Xmax 6 mm < 7.8 mm: lower excursion-limited SPL	+
AE Speakers IB18HT-4ohm	18.4 -4.6	0.567 +0.02	632.1 +165.1	16.7 +8.9	94.5 +2	usable	4 Ω vs 8 Ω: amp load changes	+
Aura Sound NS18-992-4A	20 -3	0.47 -0.08	322 -145	14.5 +6.7	93.2 +0.7	usable	4 Ω vs 8 Ω: amp load changes	+
Dayton Audio UMII18-22 ULTIMAX II DVC	22 -1	0.53 -0.02	248.2 -218.8	13.8 +6	90.7 -1.8	usable		+
SB Audience BIANCO-18SW500	30 +7	0.516 -0.03	335 -132	9.2 +1.4	95.8 +3.3	usable		+

Compare the closest 3 against the 18PT-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.