18 Sound 21NLW9000C
Thiele-Small parameters
| Nominal size | 21.5" |
|---|---|
| Impedance | 4 Ω |
| Fs | 29 Hz |
| Qts | 0.248 |
| Qes | 0.26 |
| Qms | 5.45 |
| Vas | 257 L |
| Sd | 1662 cm² |
| Xmax | 8.1 mm |
| Re | 2.7 Ω |
| Bl | 29.3 T·m |
| Mms | 453.8 g |
| Pe | 1800 W |
| Sensitivity | 100.5 dB |
Alignment hint
| EBP | 112 · ported |
|---|---|
| Sealed Vb (Qtc ≈ 0.71) | ≈ 36 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 |
|---|---|---|---|---|---|---|---|---|
| B&C 21 SW 150 | 29 = | 0.261 +0.01 | 254 -3 | 7.5 -0.6 | 99.4 -1.1 | close | Xmax 7.5 mm < 8.1 mm: lower excursion-limited SPL | + |
| B&C 21 DS 115 | 30 +1 | 0.234 -0.01 | 269 +12 | 7.6 -0.5 | 98.7 -1.8 | close | 8 Ω vs 4 Ω: amp load changes · Xmax 7.6 mm < 8.1 mm: lower excursion-limited SPL | + |
| LaVoce SAN214.50LD vp | 30 +1 | 0.223 -0.02 | 250 -7 | 7.2 -0.9 | 98.4 -2.1 | close | 8 Ω vs 4 Ω: amp load changes · Xmax 7.2 mm < 8.1 mm: lower excursion-limited SPL | + |
| Dayton Audio PSS545HE-4 VORTEX | 28.8 -0.2 | 0.27 +0.02 | 212.1 -44.9 | 8.6 +0.5 | 97.8 -2.7 | close | + | |
| Beyma 21QLEX1600/Fe | 30 +1 | 0.281 +0.03 | 309 +52 | 8.4 +0.3 | 98.1 -2.4 | usable | 8 Ω vs 4 Ω: amp load changes | + |
| RCF LF 21N451 v2017 | 30 +1 | 0.259 +0.01 | 375 +118 | 8.6 +0.5 | 99.3 -1.2 | usable | 8 Ω vs 4 Ω: amp load changes | + |
| 18 Sound 21LW400 | 28 -1 | 0.234 -0.01 | 385 +128 | 9.3 +1.2 | 99.5 -1 | usable | 8 Ω vs 4 Ω: amp load changes | + |
| Eminence NSW6021-6 | 29 = | 0.304 +0.06 | 224.6 -32.4 | 10.3 +2.2 | 97.7 -2.8 | usable | + | |
| PD PDN 2151 | 31.4 +2.4 | 0.276 +0.03 | 303.4 +46.4 | 6.7 -1.4 | 99 -1.5 | usable | 8 Ω vs 4 Ω: amp load changes · 1000 W vs 1800 W: lower power handling · Xmax 6.7 mm < 8.1 mm: lower excursion-limited SPL | + |
| Precision Devices PDN 2151 | 31.4 +2.4 | 0.276 +0.03 | 303.4 +46.4 | 6.7 -1.4 | 99 -1.5 | usable | 8 Ω vs 4 Ω: amp load changes · 1000 W vs 1800 W: lower power handling · Xmax 6.7 mm < 8.1 mm: lower excursion-limited SPL | + |
Compare the closest 3 against the 21NLW9000C →
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.