Reflex Optimized
SB Acoustics SB36WBAC21-4
Complete Thiele/Small parameters, optimized ported (bass reflex) and sealed enclosure designs, F3/F6/F10 cutoffs, and vent turbulence analysis calculated by Load Forge.
⚠️ Engineering Notice for Builders
- Limited linear excursion (Xmax: 1.75 mm); set a high-pass subsonic filter at 25–30 Hz when driven with high power.
Recommended Bass Reflex (Vented)
OPTIMIZED EXTENSION| Net Box Volume (Vb) | 1.5 Liters |
| Tuning Frequency (Fb) | 187.4 Hz |
| F3 (-3 dB Cutoff) | 177.7 Hz |
| F6 / F10 Extension | 171.1 Hz / 161.9 Hz |
| Port Inner Diameter | Ø 5.0 cm |
| Port Physical Length | 7.6 cm |
| First Pipe Resonance | 2264.0 Hz |
| Estimated MOL @ F3 | 86.8 dB SPL |
Recommended Sealed (Acoustic Suspension)
MAX TRANSIENT DAMPING| Net Box Volume (Vb) | 0.1 Liters |
| System Q (Qtc) | 0.489 (Butterworth Q=0.707) |
| System Resonance (Fc) | 237.6 Hz |
| F3 (-3 dB Cutoff) | 152.5 Hz |
| F6 / F10 Extension | 120.8 Hz / 91.4 Hz |
| Air Spring Linearity | High (Zero port compression) |
Verified Thiele/Small Parameters
| Resonance (Fs) | 200.0 Hz |
| Total Q (Qts) | 0.41 |
| Electrical Q (Qes) | 1.033 |
| Mechanical Q (Qms) | 0.68 |
| Equivalent Volume (Vas) | 0.0 Liters |
| Diaphragm Area (Sd) | 4.2 cm² |
| DC Resistance (Re) | 3.4 Ω |
| Efficiency Bandwidth Product (EBP) | 193.7 |
| Linear Excursion (Xmax) | 1.8 mm |
| Thermal Power (Pe) | 5.0 W |
| Nominal Diameter | 1.0" |
| Catalog Source | Manufacturer Official Datasheet |
Shareable Acoustic Card for Forums & Social Media
Embed this verified design card on DIYAudio, AVSForum, Reddit, or Facebook. Includes verified F3, MOL, and box parameters.
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