Thiele-Small Parameter Reference
[VISUAL PLACEHOLDER: TSParameterMeasurement_Diagram.png] Description: Impedance curve with TS parameters annotated: Fs at impedance peak, Re at lowest impedance, f1 and f2 at √(Re×Zmax) points for Q calculation, Zmax at peak
Complete parameter set:
| Parameter | Symbol | Units | Typical Range (subwoofer) |
|---|---|---|---|
| Free-air resonance | Fs | Hz | 20–50 Hz |
| DC voice coil resistance | Re | Ω | 2–8 Ω |
| Voice coil inductance | Le | mH | 0.5–8 mH |
| Electrical Q | Qes | — | 0.3–1.5 |
| Mechanical Q | Qms | — | 2–10 |
| Total Q | Qts | — | 0.2–1.2 |
| Compliance volume | Vas | L or ft³ | 20–200 L |
| Linear excursion | Xmax | mm | 5–30 mm |
| Effective piston area | Sd | cm² | 200–800 cm² |
| Sensitivity | SPL | dB/W/m | 83–97 dB |
| Power handling | Pe | W | 100–3000 W |
[VISUAL PLACEHOLDER: TSParameterDesign_Flowchart.png] Description: Flowchart from T/S parameters to enclosure recommendation: check Qts first → if <0.4 ported/bandpass; 0.4–0.7 either; >0.7 sealed; then Vas determines box volume, Fs determines tuning