Altec 904-8A
Thiele-Small parameters
| Nominal size | 15" |
|---|---|
| Impedance | 8 Ω |
| Fs | 30.5 Hz |
| Qts | 0.164 |
| Qes | 0.18 |
| Qms | 1.83 |
| Vas | 401.5 L |
| Sd | 804 cm² |
| Xmax | 3.3 mm |
| Re | 5.2 Ω |
| Bl | 18.4 T·m |
| Mms | 61.4 g |
| Pe | 150 W |
| Sensitivity | 101.9 dB |
Alignment hint
| EBP | 169 · ported |
|---|---|
| Sealed Vb (Qtc ≈ 0.71) | ≈ 22.8 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 |
|---|---|---|---|---|---|---|---|---|
| Gauss 3540 GAUSS | 25 -5.5 | 0.16 = | 438.9 +37.4 | 5.1 +1.8 | 101.8 -0.1 | close | 4 Ω vs 8 Ω: amp load changes | + |
| DAS Audio G-30 | 29.4 -1.1 | 0.179 +0.01 | 337 -64.5 | 3.3 = | 99.2 -2.7 | close | + | |
| Altec 604-8K | 28.5 -2 | 0.204 +0.04 | 412.9 +11.4 | 3.8 +0.5 | 99.5 -2.4 | usable | 100 W vs 150 W: lower power handling | + |
| JBL E140 | 32 +1.5 | 0.183 +0.02 | 297.3 -104.2 | 3.6 +0.3 | 100.7 -1.2 | usable | + | |
| Gauss 3580 GAUSS | 25 -5.5 | 0.16 = | 438.9 +37.4 | 5.1 +1.8 | 99.2 -2.7 | usable | + | |
| GOTO SG38WNS | 28.1 -2.4 | 0.154 -0.01 | 348.6 -52.9 | 4 +0.7 | 97.4 -4.5 | usable | 16 Ω vs 8 Ω: amp load changes | + |
| Audax PR38S100 | 24 -6.5 | 0.171 +0.01 | 423 +21.5 | 4 +0.7 | 98.7 -3.2 | usable | + | |
| Fane COLOSSUS 15B | 30 -0.5 | 0.156 -0.01 | 267 -134.5 | 4 +0.7 | 99.9 -2 | usable | + | |
| Peavey 1504 v1981 | 35 +4.5 | 0.17 +0.01 | 312 -89.5 | 4 +0.7 | 104.4 +2.5 | usable | 4 Ω vs 8 Ω: amp load changes | + |
| DAS Audio MI-30 | 34.3 +3.8 | 0.203 +0.04 | 360 -41.5 | 4.3 +1 | 101.2 -0.7 | usable | + |
Compare the closest 3 against the 904-8A →
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.