Jensen C 12 R
Best box: 37.5 L sealed · Fc 124.9 Hz · F3 101.6 Hz
Open and tweak this box live ↗
Will it fit your requirements?
Check the Jensen C 12 R against your space and targets — instant, no sign-up.
Estimated retail 63.00 EUR · Check price & availability ↗
Free, no sign-up to simulate · a free account saves your design
Comparable 12.0" Drivers
Drivers with similar piston area, resonance and Qts — useful alternatives when the Jensen C 12 R 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
- 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 (3.7 dB bass hump)
PORT BUILDABLE| Net Box Volume (Vb) | 30.0 Liters |
| Tuning Frequency (Fb) | 75.1 Hz |
| F3 (-3 dB Cutoff) | 120.1 Hz |
| F6 / F10 Extension | 110.5 Hz / 97.1 Hz |
| Port Inner Diameter ESTIMATED | Ø 12.5 cm |
| Port Physical Length | 12.8 cm |
| First Pipe Resonance | 1343.0 Hz |
| Estimated MOL @ F3 | 113.3 dB SPL |
Sealed (Acoustic Suspension) — compromise
SUITS INFINITE / OPEN BAFFLEWith Qts 2.47 a Butterworth (Qtc 0.707) box would be many times Vas. A box equal to Vas reaches Qtc 3.493; for a flat response this driver is better used on an infinite (IB) or open baffle.
| Net Box Volume (Vb) | 37.5 Liters |
| System Q (Qtc) | 3.493 (above Butterworth: Qtc cannot fall below Qts (2.47)) |
| System Resonance (Fc) | 124.9 Hz |
| F3 (-3 dB Cutoff) | 101.6 Hz |
| F6 / F10 Extension | 93.4 Hz / 82.8 Hz |
| Air Spring Linearity | High (Zero port compression) |
Thiele/Small Parameters
| Resonance (Fs) | 88.3 Hz |
| Total Q (Qts) | 2.47 |
| Electrical Q (Qes) | 2.85 |
| Mechanical Q (Qms) | 18.52 |
| Equivalent Volume (Vas) | 37.5 Liters |
| Diaphragm Area (Sd) | 490.9 cm² |
| DC Resistance (Re) | 6.7 Ω |
| Efficiency Bandwidth Product (EBP) | 31.0 |
| Linear Excursion (Xmax) | N/A mm |
| Thermal Power (Pe) | 25.0 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 R?
A simple ported box is not recommended for Jensen C 12 R: the textbook alignment (30.0 liters tuned to 75.1 Hz) needs a 12.8 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 R be used in a sealed box?
Yes. In a sealed (acoustic suspension) enclosure of 37.5 liters with a Qtc of 3.493 (above Butterworth: Qtc cannot fall below Qts (2.47)), the system exhibits an F3 of 101.6 Hz.
What port dimensions should be used for Jensen C 12 R to avoid port chuffing?
A straight 12.5 cm port would need 12.8 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.
Not sure if C 12 R 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