Visaton WSP 21 S 8 OHM
Best box: 31.1 L bass reflex tuned to 38.9 Hz · F3 40.4 Hz
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Comparable 8.0" Drivers
Drivers with similar piston area, resonance and Qts — useful alternatives when the Visaton WSP 21 S 8 OHM does not fit your target box volume or tuning. Each entry links to its full enclosure design and Thiele/Small parameters.
⚠️ Engineering Notice for Builders
- The textbook alignment (31.1 L at 37.0 Hz) would need a 48.1 cm port; the recommendation is retuned to 31.1 L at 38.9 Hz so the port can be built.
Recommended Bass Reflex (Vented)
PORT BUILDABLE| Net Box Volume (Vb) | 31.1 Liters |
| Tuning Frequency (Fb) | 38.9 Hz |
| F3 (-3 dB Cutoff) | 40.4 Hz |
| F6 / F10 Extension | 35.5 Hz / 30.9 Hz |
| Port Inner Diameter | Ø 10.0 cm |
| Port Physical Length | 42.9 cm |
| First Pipe Resonance | 401.0 Hz |
| Estimated MOL @ F3 | 106.0 dB SPL |
Recommended Sealed (Acoustic Suspension)
MAX TRANSIENT DAMPING| Net Box Volume (Vb) | 14.9 Liters |
| System Q (Qtc) | 0.707 (Butterworth) |
| System Resonance (Fc) | 68.6 Hz |
| F3 (-3 dB Cutoff) | 70.4 Hz |
| F6 / F10 Extension | 52.7 Hz / 39.6 Hz |
| Air Spring Linearity | High (Zero port compression) |
Thiele/Small Parameters
| Resonance (Fs) | 28.0 Hz |
| Total Q (Qts) | 0.28 |
| Electrical Q (Qes) | 0.302 |
| Mechanical Q (Qms) | 3.86 |
| Equivalent Volume (Vas) | 80.0 Liters |
| Diaphragm Area (Sd) | 213.0 cm² |
| DC Resistance (Re) | 5.7 Ω |
| Efficiency Bandwidth Product (EBP) | 92.7 |
| Linear Excursion (Xmax) | 19.0 mm |
| Thermal Power (Pe) | 100.0 W |
| Nominal Diameter | 8.0" |
| Catalog Source | Load Forge catalog (manufacturer datasheets and retailer listings) |
Frequently Asked Questions
What is the recommended ported (bass reflex) box volume for Visaton WSP 21 S 8 OHM?
Load Forge's calculated alignment puts Visaton WSP 21 S 8 OHM in a 31.1 liter vented enclosure tuned to 38.9 Hz, reaching an F3 cutoff of approximately 40.4 Hz.
Can Visaton WSP 21 S 8 OHM be used in a sealed box?
Yes. In a sealed (acoustic suspension) enclosure of 14.9 liters with a Qtc of 0.707 (Butterworth), the system exhibits an F3 of 70.4 Hz.
What port dimensions should be used for Visaton WSP 21 S 8 OHM to avoid port chuffing?
Sized from cone displacement (Sd × Xmax), a minimum port diameter of 10.0 cm with a length of 42.9 cm is suggested; check the port air velocity at your drive level in the Load Forge Studio.
Shareable Acoustic Card for Forums & Social Media
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