Theta III
| Brand | STR |
| Manufacturer | Sound Technology Research |
| Function | Speaker |
| Produced | 1975 |
| Country | United States |
| Form Factor | Bookshelf / Stand Mounted |
| Signal Path | Analog Hardware |
| Dimensions | 33 × 15.2 × 24.8 cm (W × H × D) |
| Weight | 5lbs |
| Frequency Response | 4kHz-40kHz |
| Driver | Horn-loaded Piezo (x3) |
| Impedance (Nominal) | 20Ω |
| Crossover Frequency | 4kHz |
| Dispersion (Horizontal) | 180° |
| Power Handling | 150W |
| Finish | Walnut |
| MSRP (1975) | $74.50 |