| Model ID | U-4iA |
| Form Factor | Floorstanding |
| Signal Path | Passive Hardware |
| Dimensions | 63.5 × 142.2 × 14 cm (W × H × D) |
| Weight | 152lbs |
| Power | 117/220VAC, 50/60Hz, 2W |
| Frequency Response | 32Hz-20kHz ±3dB |
| Driver | 870in² Electrostatic Diaphragm |
| Sensitivity | 86dB/2.83V/m |
| Impedance (Nominal) | 8Ω |
| Horizontal Dispersion | 45° |
| Recommended Power | >50W |
| Power Handling | 600W |
| Finish | Black |
| MSRP (2017) | $21,300 |
| Connections | - Input · Binding Post (Universal)
|
| Controls | - Bass Level · Rotary Switch · 4 Positions in 3dB Steps
- Midrange Level · Rotary Switch · 4 Positions in 3dB Steps
- Treble Level · Rotary Pot
- DC Bias · Rotary Pot
|
| Notes | Short lived model introduced in November 2016 and renamed the Ultimate 545 by mid-2017. |
