RCF LF21X451
Thiele-Small parameters
| Nominal size | 21" |
|---|---|
| Impedance | 8 Ω |
| Fs | 28 Hz |
| Qts | 0.37 |
| Qes | 0.39 |
| Qms | 6.9 |
| Vas | 385 L |
| Sd | 1700 cm² |
| Xmax | 14 mm |
| Re | 5.4 Ω |
| Bl | 30.5 T·m |
| Mms | 355 g |
| Pe | 2000 W |
| Sensitivity | 97 dB |
Alignment hint
| EBP | 72 · flexible |
|---|---|
| Sealed Vb (Qtc ≈ 0.71) | ≈ 145.2 L |
EBP 50-100: works in either a sealed or ported 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 21SW115 | 30 +2 | 0.37 = | 318 -67 | 14 = | 97 = | close | + | |
| RCF LF21N401 | 30 +2 | 0.37 = | 374 -11 | 11 -3 | 98 +1 | close | 1500 W vs 2000 W: lower power handling · Xmax 11 mm < 14 mm: lower excursion-limited SPL | + |
| 18 Sound 21LW2600 | 27 -1 | 0.33 -0.04 | 333 -52 | 14.6 +0.6 | 97 = | close | + | |
| 18 Sound 21NTLW5000 | 31 +3 | 0.36 -0.01 | 270 -115 | 17.5 +3.5 | 97 = | usable | + | |
| B&C 21SW115 | 33 +5 | 0.36 -0.01 | 278 -107 | 14 = | 97 = | usable | 4 Ω vs 8 Ω: amp load changes | + |
| 18 Sound 21NTLW5000 | 30 +2 | 0.32 -0.05 | 300 -85 | 17.5 +3.5 | 97 = | usable | 4 Ω vs 8 Ω: amp load changes | + |
| 18 Sound 21NLW5300 | 31 +3 | 0.32 -0.05 | 325 -60 | 15.3 +1.3 | 98.5 +1.5 | usable | + | |
| 18 Sound 21NLW9001 | 31 +3 | 0.34 -0.03 | 272 -113 | 14 = | 95 -2 | usable | 4 Ω vs 8 Ω: amp load changes | + |
| Beyma 21"LEX1600/Nd | 30 +2 | 0.29 -0.08 | 305 -80 | 14 = | 98 +1 | usable | + | |
| 18 Sound 21LW2600 | 27 -1 | 0.37 = | 190 -195 | 14.6 +0.6 | 97 = | usable | 4 Ω vs 8 Ω: amp load changes | + |
Compare the closest 3 against the LF21X451 →
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.