Infinity Reference 51i Specification
| System type | 3-way |
| Enclosure type | Bass reflex |
| Frequency response ± 3dB | 38 - 25000 Hz |
| Nominal impedance | 6 Ohm |
| Amplifier Requirements | 25 - 150 W |
| Sensitivity (2.83V/1m) | 91 dB |
| Tweeter | 25 mm (1 inch) |
| Midrange | 130 mm (5.25 inch) |
| Woofer | 210 mm (8 inch) |
| Dimensions (H x W x D) | 890 x 274 x 275 mm / 35 x 10.7 x 10.7 in. |
