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DD Audio 812F D2

Best box: 28.4 L sealed · Fc 43.6 Hz · F3 44.3 Hz

Predicted SPL response of the DD Audio 812F D2 in the recommended 28.4 L sealed box versus the alternative — open it in the simulator Open and tweak this box live ↗

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⚠️ Engineering Notice for Builders

  • Straight vent would be 301.1 cm long: not physically buildable as a simple tube. Use a passive radiator, a folded slot port or model a 3D folded duct in Load Forge Studio.

Textbook Bass Reflex — not recommended

PORT NOT BUILDABLE
Net Box Volume (Vb) 28.3 Liters
Tuning Frequency (Fb) 24.5 Hz
F3 (-3 dB Cutoff) 29.6 Hz
F6 / F10 Extension 21.9 Hz / 18.7 Hz
Port Inner Diameter Ø 15.0 cm
Port Physical Length 301.1 cm
First Pipe Resonance 57.0 Hz
Estimated MOL @ F3 114.1 dB SPL
⚠️ Port feasibility: a straight tube would need 301.1 cm and cannot fit in a practical cabinet, and no nearby retune stays buildable without a bass hump. Prefer the sealed alignment, a passive radiator, or a 3D folded duct in Load Forge Studio.
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Recommended Sealed (Acoustic Suspension)

MAX TRANSIENT DAMPING
Net Box Volume (Vb) 28.4 Liters
System Q (Qtc) 0.707 (Butterworth)
System Resonance (Fc) 43.6 Hz
F3 (-3 dB Cutoff) 44.3 Hz
F6 / F10 Extension 33.5 Hz / 25.3 Hz
Air Spring Linearity High (Zero port compression)
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Thiele/Small Parameters

Resonance (Fs) 34.0 Hz
Total Q (Qts) 0.548
Electrical Q (Qes) 0.6
Mechanical Q (Qms) 6.28
Equivalent Volume (Vas) 18.8 Liters
Diaphragm Area (Sd) 532.4 cm²
DC Resistance (Re) 1.7 Ω
Efficiency Bandwidth Product (EBP) 56.6
Linear Excursion (Xmax) 31.0 mm
Thermal Power (Pe) 2500.0 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 DD Audio 812F D2?

A simple ported box is not recommended for DD Audio 812F D2: the textbook alignment (28.3 liters tuned to 24.5 Hz) needs a 301.1 cm port, and no nearby retune stays buildable without a bass hump. A sealed box, a passive radiator or a folded duct is the practical choice.

Can DD Audio 812F D2 be used in a sealed box?

Yes. In a sealed (acoustic suspension) enclosure of 28.4 liters with a Qtc of 0.707 (Butterworth), the system exhibits an F3 of 44.3 Hz.

What port dimensions should be used for DD Audio 812F D2 to avoid port chuffing?

A straight 15.0 cm port would need 301.1 cm of length, which does not fit a practical cabinet. Use a passive radiator or a folded/3D duct instead of a straight tube.

Shareable Acoustic Card for Forums & Social Media

Embed this design card on DIYAudio, AVSForum, Reddit, or Facebook. It shows the calculated F3, MOL (when the power rating is published) and box parameters.

DD Audio 812F D2 Enclosure Card
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