B&C 8FMB51
Thiele-Small parameters
| Nominal size | 8" |
|---|---|
| Impedance | 8 Ω |
| Fs | 67 Hz |
| Qts | 0.28 |
| Qes | 0.31 |
| Qms | 3.07 |
| Vas | 20.7 L |
| Sd | 227 cm² |
| Xmax | 5.5 mm |
| Re | 4.7 Ω |
| Bl | 11.3 T·m |
| Mms | 20.2 g |
| Pe | 250 W |
| Sensitivity | 96.5 dB |
Alignment hint
| EBP | 216 · ported |
|---|---|
| Sealed Vb (Qtc ≈ 0.71) | ≈ 3.8 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 8MDN51 | 68 +1 | 0.27 -0.01 | 17.5 -3.2 | 6 +0.5 | 97 +0.5 | close | 16 Ω vs 8 Ω: amp load changes | + |
| B&C 8MBX51 | 60 -7 | 0.29 +0.01 | 23 +2.3 | 6 +0.5 | 96.5 = | close | + | |
| 18 Sound 8NW650 | 63 -4 | 0.25 -0.03 | 17.8 -2.9 | 5.5 = | 96 -0.5 | close | + | |
| 18 Sound 8NW650 | 62 -5 | 0.25 -0.03 | 18.99 -1.71 | 5.5 = | 95 -1.5 | close | 16 Ω vs 8 Ω: amp load changes | + |
| Beyma 8WRS300 | 65 -2 | 0.28 = | 15 -5.7 | 6 +0.5 | 95 -1.5 | close | + | |
| Faital PRO 8PR210 | 65 -2 | 0.29 +0.01 | 15.4 -5.3 | 6.92 +1.42 | 95 -1.5 | close | + | |
| Beyma 8WR300 | 65 -2 | 0.27 -0.01 | 15 -5.7 | 6 +0.5 | 95 -1.5 | close | + | |
| B&C 8FMB51 | 68 +1 | 0.39 +0.11 | 20.5 -0.2 | 5.5 = | 96 -0.5 | usable | 16 Ω vs 8 Ω: amp load changes | + |
| B&C 8MBX51 | 68 +1 | 0.38 +0.1 | 22 +1.3 | 6 +0.5 | 97 +0.5 | usable | 16 Ω vs 8 Ω: amp load changes | + |
| Sica 8 Fe 2.5 CP | 73 +6 | 0.28 = | 15.6 -5.1 | 4 -1.5 | 96.7 +0.2 | usable | Xmax 4 mm < 5.5 mm: lower excursion-limited SPL | + |
Compare the closest 3 against the 8FMB51 →
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.