A4X/1505B
| Brand | Altec |
| Manufacturer | Altec Corporation |
| Series | Voice of the Theatre |
| Function | Speaker |
| Produced | 1975 |
| Country | United States |
| Model ID | A-4-X |
| Form Factor | Floorstanding |
| Signal Path | Passive Hardware |
| Dimensions | 204.5 × 275.6 × 100.3 cm (W × H × D) |
| Weight | 788lbs |
| Treble | 3x5 Multicellular Horn (Altec 1505B, Altec 30172, Altec 288-16G (x2)) |
| Midrange/Bass | 15" Paper Cone (x2) (Altec 515B) |
| Sensitivity (500Hz-3kHz) | 107dB/W/m |
| Crossover Frequency | 500Hz (Altec N-500-F) |
| Dispersion (Horizontal) | 105° |
| Dispersion (Vertical) | 60° |
| Power Handling | 100W |
| Enclosure Type | Front-Loaded Horn, Bass Reflex (Altec 210) |