IX
| Brand | ESS |
| Manufacturer | Electrostatic Sound Systems, Inc. |
| Function | Speaker |
| Produced | 1972-1975 |
| Country | United States |
| Form Factor | Bookshelf / Stand Mounted |
| Signal Path | Passive Hardware |
| Dimensions | 40.6 × 68.6 × 31.1 cm (W × H × D) |
| Frequency Response | 35Hz-20kHz ±3.5dB |
| Treble | 2.25" Paper Cone |
| Midrange | 5" Paper Cone |
| Bass | 12" Paper Cone |
| THD (80Hz-20kHz, 90dB) | <1.5% |
| Recommended Amplifier Power (RMS) | >25W |
| Power Handling (Peak) | 450W |
| Enclosure Type | Bass Reflex |
| Enclosure Construction | Particleboard |
| Finish | Oiled Walnut, Rosewood |
| MSRP (1973) | $189 |