SB Audience ROSSO-21SW800
Best box: 179.5 L bass reflex tuned to 32.3 Hz · F3 45.7 Hz
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Comparable 21.0" Drivers
Drivers with similar piston area, resonance and Qts — useful alternatives when the SB Audience ROSSO-21SW800 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
- Large enclosure volume (179.5 L) requires extensive internal matrix bracing to prevent panel resonance.
Recommended Bass Reflex (Vented)
PORT BUILDABLE| Net Box Volume (Vb) | 179.5 Liters |
| Tuning Frequency (Fb) | 32.3 Hz |
| F3 (-3 dB Cutoff) | 45.7 Hz |
| F6 / F10 Extension | 38.2 Hz / 29.6 Hz |
| Port Inner Diameter | Ø 20.0 cm |
| Port Physical Length | 36.0 cm |
| First Pipe Resonance | 478.0 Hz |
| Estimated MOL @ F3 | 123.0 dB SPL |
Sealed (Acoustic Suspension) — compromise
SUITS INFINITE / OPEN BAFFLEWith Qts 0.76 a Butterworth (Qtc 0.707) box would be many times Vas. A box equal to Vas reaches Qtc 1.075; for a flat response this driver is better used on an infinite (IB) or open baffle.
| Net Box Volume (Vb) | 224.4 Liters |
| System Q (Qtc) | 1.075 (above Butterworth: Qtc cannot fall below Qts (0.76)) |
| System Resonance (Fc) | 53.7 Hz |
| F3 (-3 dB Cutoff) | 43.4 Hz |
| F6 / F10 Extension | 36.1 Hz / 29.0 Hz |
| Air Spring Linearity | High (Zero port compression) |
Thiele/Small Parameters
| Resonance (Fs) | 38.0 Hz |
| Total Q (Qts) | 0.76 |
| Electrical Q (Qes) | 0.802 |
| Mechanical Q (Qms) | 14.41 |
| Equivalent Volume (Vas) | 224.4 Liters |
| Diaphragm Area (Sd) | 1661.9 cm² |
| DC Resistance (Re) | 6.4 Ω |
| Efficiency Bandwidth Product (EBP) | 47.4 |
| Linear Excursion (Xmax) | 11.4 mm |
| Thermal Power (Pe) | 800.0 W |
| Nominal Diameter | 21.0" |
| Catalog Source | Load Forge catalog (manufacturer datasheets and retailer listings) |
Frequently Asked Questions
What is the recommended ported (bass reflex) box volume for SB Audience ROSSO-21SW800?
Load Forge's calculated alignment puts SB Audience ROSSO-21SW800 in a 179.5 liter vented enclosure tuned to 32.3 Hz, reaching an F3 cutoff of approximately 45.7 Hz.
Can SB Audience ROSSO-21SW800 be used in a sealed box?
Yes. In a sealed (acoustic suspension) enclosure of 224.4 liters with a Qtc of 1.075 (above Butterworth: Qtc cannot fall below Qts (0.76)), the system exhibits an F3 of 43.4 Hz.
What port dimensions should be used for SB Audience ROSSO-21SW800 to avoid port chuffing?
Sized from cone displacement (Sd × Xmax), a minimum port diameter of 20.0 cm with a length of 36.0 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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