Jensen C 8 R
Best box: 18.2 L bass reflex tuned to 64.3 Hz · F3 130.1 Hz
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Comparable 8.0" Drivers
Drivers with similar piston area, resonance and Qts — useful alternatives when the Jensen C 8 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
- The textbook alignment (9.1 L at 107.1 Hz) would need a 5.6 cm port; the recommendation is retuned to 18.2 L at 64.3 Hz so the port can be built.
- 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.
Recommended Bass Reflex (Vented)
PORT BUILDABLE| Net Box Volume (Vb) | 18.2 Liters |
| Tuning Frequency (Fb) | 64.3 Hz |
| F3 (-3 dB Cutoff) | 130.1 Hz |
| F6 / F10 Extension | 115.0 Hz / 95.6 Hz |
| Port Inner Diameter ESTIMATED | Ø 10.0 cm |
| Port Physical Length | 24.1 cm |
| First Pipe Resonance | 713.0 Hz |
| Estimated MOL @ F3 | 109.7 dB SPL |
Sealed (Acoustic Suspension) — compromise
SUITS INFINITE / OPEN BAFFLEWith Qts 1.8 a Butterworth (Qtc 0.707) box would be many times Vas. A box equal to Vas reaches Qtc 2.546; for a flat response this driver is better used on an infinite (IB) or open baffle.
| Net Box Volume (Vb) | 11.4 Liters |
| System Q (Qtc) | 2.546 (above Butterworth: Qtc cannot fall below Qts (1.80)) |
| System Resonance (Fc) | 178.2 Hz |
| F3 (-3 dB Cutoff) | 142.7 Hz |
| F6 / F10 Extension | 128.7 Hz / 111.7 Hz |
| Air Spring Linearity | High (Zero port compression) |
Thiele/Small Parameters
| Resonance (Fs) | 126.0 Hz |
| Total Q (Qts) | 1.8 |
| Electrical Q (Qes) | 2.182 |
| Mechanical Q (Qms) | 10.29 |
| Equivalent Volume (Vas) | 11.4 Liters |
| Diaphragm Area (Sd) | 213.8 cm² |
| DC Resistance (Re) | 6.73 Ω |
| Efficiency Bandwidth Product (EBP) | 57.8 |
| Linear Excursion (Xmax) | N/A mm |
| Thermal Power (Pe) | 25.0 W |
| Nominal Diameter | 8.0" |
| 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 8 R?
Load Forge's calculated alignment puts Jensen C 8 R in a 18.2 liter vented enclosure tuned to 64.3 Hz, reaching an F3 cutoff of approximately 130.1 Hz.
Can Jensen C 8 R be used in a sealed box?
Yes. In a sealed (acoustic suspension) enclosure of 11.4 liters with a Qtc of 2.546 (above Butterworth: Qtc cannot fall below Qts (1.80)), the system exhibits an F3 of 142.7 Hz.
What port dimensions should be used for Jensen C 8 R to avoid port chuffing?
Xmax is not published for Jensen C 8 R, so the port is an empirical estimate: a 10.0 cm diameter with a length of 24.1 cm (area at least 12 in² per ft³ of net volume). Check the air velocity at your power level in Load Forge Studio.
Shareable Acoustic Card for Forums & Social Media
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