Monacor SP-450PA

18" · 8 Ω · 125 W · 95.6 dB

Thiele-Small parameters

Nominal size	18"
Impedance	8 Ω
Fs	25 Hz
Qts	0.488
Qes	0.56
Qms	3.82
Vas	670 L
Sd	1250 cm²
Xmax	4.3 mm
Re	6.5 Ω
Bl	15.5 T·m
Mms	132.5 g
Pe	125 W
Sensitivity	95.6 dB

Alignment hint

EBP	45 · sealed
Sealed Vb (Qtc ≈ 0.71)	≈ 609.3 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
Fertin Acoustics 46EX 05.0V	22.2 -2.8	0.416 -0.07	667.7 -2.3	3 -1.3	96.1 +0.5	usable	Xmax 3 mm < 4.3 mm: lower excursion-limited SPL	+
Mach 5 Audio MAC MAH CWA46	27 +2	0.448 -0.04	470.3 -199.7	10 +5.7	96.2 +0.6	usable		+
Eminence KAPPA 18 A	28 +3	0.408 -0.08	475.5 -194.5	4.8 +0.5	95.9 +0.3	usable		+
Monacor SPA-45PA	29 +4	0.457 -0.03	440 -230	4 -0.3	96.5 +0.9	usable	Xmax 4 mm < 4.3 mm: lower excursion-limited SPL	+
Zeuz DC181125ip	22.2 -2.8	0.458 -0.03	429.3 -240.7	8.5 +4.2	95 -0.6	usable	4 Ω vs 8 Ω: amp load changes	+
Carvin PS18-8	35 +10	0.48 -0.01	531.785 -138.22	6 +1.7	97.7 +2.1	usable		+
Dibeisi PS1805-8	27.1 +2.1	0.4 -0.09	473.8 -196.2	7 +2.7	96.1 +0.5	usable		+
Pyle Audio PPA18 vp	24.2 -0.8	0.39 -0.1	503.2 -166.8	6 +1.7	93.1 -2.5	usable	16 Ω vs 8 Ω: amp load changes	+
TAD TL-1801	26 +1	0.372 -0.12	500 -170	3.8 -0.5	96.3 +0.7	usable	Xmax 3.8 mm < 4.3 mm: lower excursion-limited SPL	+
GRS 18PT-8	23 -2	0.547 +0.06	467 -203	7.8 +3.5	92.5 -3.1	usable		+

Compare the closest 3 against the SP-450PA →

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.