JBL D123
Thiele-Small parameters
| Nominal size | 12" |
|---|---|
| Impedance | 8 Ω |
| Fs | 45 Hz |
| Qts | 0.45 |
| Qes | 0.5 |
| Qms | 4.5 |
| Vas | 135.9 L |
| Sd | 527.1 cm² |
| Xmax | 2.5 mm |
| Re | 6 Ω |
| Bl | 11 T·m |
| Mms | 35.8 g |
| Pe | 50 W |
| Sensitivity | 97.2 dB |
Alignment hint
| EBP | 90 · flexible |
|---|---|
| Sealed Vb (Qtc ≈ 0.71) | ≈ 92.5 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 |
|---|---|---|---|---|---|---|---|---|
| JBL 2125 | 45 = | 0.45 = | 135.9 = | 2.5 = | 97.2 = | close | + | |
| Philips AD12202/M8 | 45.6 +0.6 | 0.419 -0.03 | 138 +2.1 | 4 +1.5 | 96.8 -0.4 | close | + | |
| Eminence BETA 12LT | 45 = | 0.507 +0.06 | 136.3 +0.4 | 3.2 +0.7 | 95.9 -1.3 | close | + | |
| Eminence BETA 12CX v2019 | 47 +2 | 0.476 +0.03 | 120.9 -15 | 3.5 +1 | 97.5 +0.3 | close | + | |
| Eminence BETA 12CX | 47 +2 | 0.48 +0.03 | 120.94 -14.96 | 3.5 +1 | 97.3 +0.1 | close | + | |
| Goodmans AXIOM 201 | 42.5 -2.5 | 0.421 -0.03 | 157.7 +21.8 | 2.5 = | 97.5 +0.3 | close | 30 W vs 50 W: lower power handling | + |
| Eminence BETA-12LTA | 45 = | 0.51 +0.06 | 136.3 +0.4 | 3.2 +0.7 | 95.4 -1.8 | close | + | |
| Conrad PA 12 | 42.9 -2.1 | 0.462 +0.01 | 129.2 -6.7 | 4 +1.5 | 95.2 -2 | close | + | |
| Eminence DELTALITE II 2512 | 44 -1 | 0.406 -0.04 | 134.9 -1 | 4.9 +2.4 | 97.9 +0.7 | close | + | |
| Eminence DELTALITE II 2512 v2014 | 44 -1 | 0.406 -0.04 | 134.9 -1 | 4.9 +2.4 | 97.9 +0.7 | close | + |
Compare the closest 3 against the D123 →
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.