RCF LF 21N451
Thiele-Small parameters
| Nominal size | 21.5" |
|---|---|
| Impedance | 8 Ω |
| Fs | 30 Hz |
| Qts | 0.239 |
| Qes | 0.25 |
| Qms | 5.5 |
| Vas | 440 L |
| Sd | 1729.1 cm² |
| Xmax | 8.9 mm |
| Re | 5.5 Ω |
| Bl | 33.3 T·m |
| Mms | 268.1 g |
| Pe | 1500 W |
| Sensitivity | 100.4 dB |
Alignment hint
| EBP | 120 · ported |
|---|---|
| Sealed Vb (Qtc ≈ 0.71) | ≈ 56.7 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 |
|---|---|---|---|---|---|---|---|---|
| 18 Sound 21LW400 | 28 -2 | 0.234 = | 385 -55 | 9.3 +0.4 | 99.5 -0.9 | close | + | |
| RCF LF 21N451 v2017 | 30 = | 0.259 +0.02 | 375 -65 | 8.6 -0.3 | 99.3 -1.1 | close | Xmax 8.6 mm < 8.9 mm: lower excursion-limited SPL | + |
| Beyma 21LEX1600/Nd | 30 = | 0.272 +0.03 | 394 -46 | 9.3 +0.4 | 99.3 -1.1 | close | + | |
| 18 Sound 21NLW9000C | 29 -1 | 0.248 +0.01 | 257 -183 | 8.1 -0.8 | 100.5 +0.1 | usable | 4 Ω vs 8 Ω: amp load changes · Xmax 8.1 mm < 8.9 mm: lower excursion-limited SPL | + |
| B&C 21 DS 115 | 30 = | 0.234 = | 269 -171 | 7.6 -1.3 | 98.7 -1.7 | usable | Xmax 7.6 mm < 8.9 mm: lower excursion-limited SPL | + |
| Beyma 21PW1400FE | 30 = | 0.343 +0.1 | 401.5 -38.5 | 10 +1.1 | 98.6 -1.8 | usable | + | |
| Beyma 21QLEX1600/Fe | 30 = | 0.281 +0.04 | 309 -131 | 8.4 -0.5 | 98.1 -2.3 | usable | Xmax 8.4 mm < 8.9 mm: lower excursion-limited SPL | + |
| B&C 21 SW 150 | 29 -1 | 0.261 +0.02 | 254 -186 | 7.5 -1.4 | 99.4 -1 | usable | 4 Ω vs 8 Ω: amp load changes · Xmax 7.5 mm < 8.9 mm: lower excursion-limited SPL | + |
| PD PDN 2151 | 31.4 +1.4 | 0.276 +0.04 | 303.4 -136.6 | 6.7 -2.2 | 99 -1.4 | usable | 1000 W vs 1500 W: lower power handling · Xmax 6.7 mm < 8.9 mm: lower excursion-limited SPL | + |
| Precision Devices PDN 2151 | 31.4 +1.4 | 0.276 +0.04 | 303.4 -136.6 | 6.7 -2.2 | 99 -1.4 | usable | 1000 W vs 1500 W: lower power handling · Xmax 6.7 mm < 8.9 mm: lower excursion-limited SPL | + |
Compare the closest 3 against the LF 21N451 →
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.