| Model ID | 15 |
| Form Factor | Floorstanding |
| Signal Path | Passive Hardware |
| Dimensions | 55.9 × 68.6 × 39.4 cm (W × H × D) |
| Weight | 76lbs (Net), 84lbs (Shipped) |
| Frequency Response | 30Hz-20kHz |
| Treble | Horn (Altec 32C, Altec) |
| Midrange/Bass | 12" Paper Cone (Altec) |
| Sensitivity (500Hz-3kHz) | 90dB/W/4' (Shelving Controls Max: 94dB/W/4') |
| Impedance (Nominal) | 8Ω |
| Crossover Frequency | 1.7kHz |
| Maximum Output (4') | 111dB |
| Dispersion (Vertical) | 120° |
| Dispersion (Horizontal) | 120° |
| Recommended Amplifier Power | 12-250W |
| Power Handling (Nominal) | 60W |
| Enclosure Type | Bass Reflex |
| Finish | Walnut, Oak (Grill: Black) |
| MSRP (1978) | $479 |
| Notes | Distinguished from Series I by addition of decorative plastic trim piece on bass reflex port. |
