Sealed Specialist

Jensen C 12 Q

Best box: 38.0 L sealed · Fc 123.7 Hz · F3 100.0 Hz

Predicted SPL response of the Jensen C 12 Q in the recommended 38.0 L sealed box versus the alternative — open it in the simulator Open and tweak this box live ↗

Will it fit your requirements?

Check the Jensen C 12 Q against your space and targets — instant, no sign-up.

Design a box for this driver Box Design with the C 12 Q and its T/S already loaded Find alternatives Bass Match ranks similar drivers against the C 12 Q in the same box

Estimated retail 70.35 EUR · Check price & availability ↗

Free, no sign-up to simulate · a free account saves your design

⚠️ Engineering Notice for Builders

  • Xmax is not published, so the port size is an empirical estimate (area ≥ 12 in² per ft³ of net volume, minimum by driver size), not a displacement calculation. Check air velocity in Load Forge Studio.

Textbook Bass Reflex — not recommended (3.3 dB bass hump)

PORT BUILDABLE
Net Box Volume (Vb) 30.4 Liters
Tuning Frequency (Fb) 74.4 Hz
F3 (-3 dB Cutoff) 118.2 Hz
F6 / F10 Extension 108.2 Hz / 94.5 Hz
Port Inner Diameter ESTIMATED Ø 12.5 cm
Port Physical Length 12.9 cm
First Pipe Resonance 1331.0 Hz
Estimated MOL @ F3 114.3 dB SPL
Simulate This Reflex Box in App →

Sealed (Acoustic Suspension) — compromise

SUITS INFINITE / OPEN BAFFLE

With Qts 2.23 a Butterworth (Qtc 0.707) box would be many times Vas. A box equal to Vas reaches Qtc 3.154; for a flat response this driver is better used on an infinite (IB) or open baffle.

Net Box Volume (Vb) 38.0 Liters
System Q (Qtc) 3.154 (above Butterworth: Qtc cannot fall below Qts (2.23))
System Resonance (Fc) 123.7 Hz
F3 (-3 dB Cutoff) 100.0 Hz
F6 / F10 Extension 91.5 Hz / 80.6 Hz
Air Spring Linearity High (Zero port compression)
Simulate This Sealed Box in App →

Thiele/Small Parameters

Resonance (Fs) 87.5 Hz
Total Q (Qts) 2.23
Electrical Q (Qes) 2.694
Mechanical Q (Qms) 12.95
Equivalent Volume (Vas) 38.0 Liters
Diaphragm Area (Sd) 490.9 cm²
DC Resistance (Re) 6.0 Ω
Efficiency Bandwidth Product (EBP) 32.5
Linear Excursion (Xmax) N/A mm
Thermal Power (Pe) 35.0 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 Jensen C 12 Q?

A simple ported box is not recommended for Jensen C 12 Q: the textbook alignment (30.4 liters tuned to 74.4 Hz) needs a 12.9 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 Jensen C 12 Q be used in a sealed box?

Yes. In a sealed (acoustic suspension) enclosure of 38.0 liters with a Qtc of 3.154 (above Butterworth: Qtc cannot fall below Qts (2.23)), the system exhibits an F3 of 100.0 Hz.

What port dimensions should be used for Jensen C 12 Q to avoid port chuffing?

A straight 12.5 cm port would need 12.9 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.

Jensen C 12 Q Enclosure Card
Download SVG Card 📥

Not sure if C 12 Q fits your physical space?

Don't force a driver into the wrong box. Use Bass Match to calculate which of 8,000+ catalog drivers delivers the highest SPL, lowest F3, and cleanest port air velocity for your exact trunk or room dimensions.

Run Bass Match for Your Space