Avatar XBR-513
Best box: 11.4 L bass reflex tuned to 119.0 Hz · F3 124.6 Hz
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Comparable 12.0" Drivers
Drivers with similar piston area, resonance and Qts — useful alternatives when the Avatar XBR-513 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 (11.4 L at 68.0 Hz) would need a 89.8 cm port; the recommendation is retuned to 11.4 L at 119.0 Hz so the port can be built.
Recommended Bass Reflex (Vented)
PORT BUILDABLE| Net Box Volume (Vb) | 11.4 Liters |
| Tuning Frequency (Fb) | 119.0 Hz |
| F3 (-3 dB Cutoff) | 124.6 Hz |
| F6 / F10 Extension | 112.2 Hz / 97.5 Hz |
| Port Inner Diameter | Ø 20.0 cm |
| Port Physical Length | 44.0 cm |
| First Pipe Resonance | 391.0 Hz |
| Estimated MOL @ F3 | 112.4 dB SPL |
Sealed (Acoustic Suspension) — compromise
SUITS INFINITE / OPEN BAFFLEWith Qts 0.65 a Butterworth (Qtc 0.707) box would be many times Vas. A box equal to Vas reaches Qtc 0.919; for a flat response this driver is better used on an infinite (IB) or open baffle.
| Net Box Volume (Vb) | 14.2 Liters |
| System Q (Qtc) | 0.919 (above Butterworth) |
| System Resonance (Fc) | 113.1 Hz |
| F3 (-3 dB Cutoff) | 96.7 Hz |
| F6 / F10 Extension | 78.4 Hz / 62.0 Hz |
| Air Spring Linearity | High (Zero port compression) |
Thiele/Small Parameters
| Resonance (Fs) | 80.0 Hz |
| Total Q (Qts) | 0.65 |
| Electrical Q (Qes) | 0.728 |
| Mechanical Q (Qms) | 6.07 |
| Equivalent Volume (Vas) | 14.2 Liters |
| Diaphragm Area (Sd) | 530.0 cm² |
| DC Resistance (Re) | 3.4 Ω |
| Efficiency Bandwidth Product (EBP) | 109.9 |
| Linear Excursion (Xmax) | 10.0 mm |
| Thermal Power (Pe) | 40.0 W |
| Nominal Diameter | 12.0" |
| Catalog Source | Load Forge catalog (manufacturer datasheets and retailer listings) |
Frequently Asked Questions
What is the recommended ported (bass reflex) box volume for Avatar XBR-513?
Load Forge's calculated alignment puts Avatar XBR-513 in a 11.4 liter vented enclosure tuned to 119.0 Hz, reaching an F3 cutoff of approximately 124.6 Hz.
Can Avatar XBR-513 be used in a sealed box?
Yes. In a sealed (acoustic suspension) enclosure of 14.2 liters with a Qtc of 0.919 (above Butterworth), the system exhibits an F3 of 96.7 Hz.
What port dimensions should be used for Avatar XBR-513 to avoid port chuffing?
Sized from cone displacement (Sd × Xmax), a minimum port diameter of 20.0 cm with a length of 44.0 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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