JBL G125-8
Thiele-Small parameters
| Nominal size | 12" |
|---|---|
| Impedance | 8 Ω |
| Fs | 65 Hz |
| Qts | 0.32 |
| Qes | 0.34 |
| Qms | 5.5 |
| Vas | 70.8 L |
| Sd | 527.1 cm² |
| Xmax | 2.5 mm |
| Re | 5.2 Ω |
| Bl | 14.4 T·m |
| Mms | 33 g |
| Pe | 200 W |
| Sensitivity | 101.4 dB |
Alignment hint
| EBP | 191 · ported |
|---|---|
| Sealed Vb (Qtc ≈ 0.71) | ≈ 18.2 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 |
|---|---|---|---|---|---|---|---|---|
| Fertin Acoustics B34D77 | 66.6 +1.6 | 0.324 = | 52.5 -18.3 | 2.5 = | 102 +0.6 | close | 4 Ω vs 8 Ω: amp load changes | + |
| Celestion TN1225 | 60.5 -4.5 | 0.33 +0.01 | 53.9 -16.9 | 2.5 = | 99 -2.4 | usable | + | |
| RCF MB 12G300 | 61 -4 | 0.301 -0.02 | 57 -13.8 | 4.3 +1.8 | 100.1 -1.3 | usable | + | |
| Monacor SP-312CX | 55 -10 | 0.328 +0.01 | 64 -6.8 | 3 +0.5 | 98.2 -3.2 | usable | + | |
| Electro-Voice DL12BFH | 60 -5 | 0.307 -0.01 | 55 -15.8 | 4 +1.5 | 100.3 -1.1 | usable | + | |
| B&C 12 CX 32 | 57 -8 | 0.284 -0.04 | 79 +8.2 | 4 +1.5 | 100.8 -0.6 | usable | + | |
| 18 Sound 12NCX750 | 58 -7 | 0.296 -0.02 | 63 -7.8 | 4.6 +2.1 | 99.7 -1.7 | usable | + | |
| 18 Sound PWX12 | 61.3 -3.7 | 0.341 +0.02 | 56.2 -14.6 | 2.9 +0.4 | 98.6 -2.8 | usable | + | |
| B&C 12 PH 32 (prodance) | 56.8 -8.2 | 0.333 +0.01 | 92.7 +21.9 | 3 +0.5 | 100.3 -1.1 | usable | + | |
| Peavey 1205-8 v1993 | 55.6 -9.4 | 0.281 -0.04 | 69 -1.8 | 4.5 +2 | 100 -1.4 | usable | + |
Compare the closest 3 against the G125-8 →
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.