Thiele-Small Parameters
Table A.9: Typical T/S Parameter Ranges
| Driver Type | Fs (Hz) | Qts | Vas (L) | Xmax (mm) | Sensitivity (dB) |
|---|---|---|---|---|---|
| Subwoofers: | |||||
| Small sealed | 35-45 | 0.6-0.9 | 15-35 | 8-15 | 84-87 |
| Ported bass | 28-38 | 0.3-0.5 | 40-80 | 12-20 | 86-89 |
| Competition SPL | 35-50 | 0.3-0.5 | 60-150 | 20-35 | 90-95 |
| Midbass: | |||||
| 6.5" sealed | 50-80 | 0.5-0.8 | 8-18 | 6-10 | 88-91 |
| 8" sealed | 40-60 | 0.4-0.7 | 18-35 | 8-14 | 89-92 |
| Midrange: | |||||
| 3-4" dome | 80-150 | 0.5-1.0 | 1-5 | 3-6 | 87-90 |
| 4-5" cone | 60-120 | 0.4-0.8 | 3-12 | 4-8 | 88-91 |
Table A.10: Enclosure Type Selection by Qts
| Qts Range | Best Enclosure Type | Characteristics |
|---|---|---|
| < 0.3 | Ported, Bandpass | Very efficient, boomy without proper design |
| 0.3-0.4 | Ported optimal | Excellent for ported enclosures |
| 0.4-0.5 | Ported or Sealed | Works well in either |
| 0.5-0.7 | Sealed optimal | Good transient response, tight bass |
| 0.7-1.0 | Sealed only | Poor in ported, good sealed |
| > 1.0 | Sealed small box | Limited output, very tight bass |