| Model | QT400-A |
| Nominal Basket Diameter | 123 mm (4.5 in) |
| No Voice Coil Diameter | 25 mm |
| Nominal Impedance | 8Ω |
| Sensitivity | 90 dB |
| Usable Frequency Range | 156Hz-14KHz |
| Rated Power | 40 W |
| MAX Power | 80 W |
| Resonant Frequency (fs) | 156 Hz |
| DC Resistance (Re) | 7.2Ω |
| Mechanical Q (Qms) | 4.63 |
| Electromagnetic Q (Qes) | 1.38 |
| Total Q (Qts) | 1.06 |
| Efficiency | 0.55% |
| Installation Dimensions | |
| (Overall Diameter) | 114 mm |
| (Mounting Holes B.C.D) | 119.5 mm |
| (Baffle Hole Diameter) | 105 mm |
| (The full height) | 63 mm |
| (Edge thickness) | 5 mm |
| (Net Weight) | Kg |
