Vented Specialist

HELIX C 6B

Best box: 18.6 L bass reflex tuned to 40.2 Hz · F3 43.5 Hz

Predicted SPL response of the HELIX C 6B in the recommended 18.6 L bass reflex box versus the alternative — open it in the simulator Open and tweak this box live ↗

Will it fit your requirements?

Check the HELIX C 6B against your space and targets — instant, no sign-up.

Design a box for this driver Box Design with the C 6B and its T/S already loaded Find alternatives Bass Match ranks similar drivers against the C 6B in the same box

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

⚠️ Engineering Notice for Builders

  • Limited linear excursion (Xmax: 3.0 mm); set a high-pass subsonic filter at 25–30 Hz when driven with high power.

Recommended Bass Reflex (Vented)

PORT BUILDABLE
Net Box Volume (Vb) 18.6 Liters
Tuning Frequency (Fb) 40.2 Hz
F3 (-3 dB Cutoff) 43.5 Hz
F6 / F10 Extension 34.9 Hz / 30.5 Hz
Port Inner Diameter Ø 5.0 cm
Port Physical Length 16.0 cm
First Pipe Resonance 1075.0 Hz
Estimated MOL @ F3 103.6 dB SPL
Simulate This Reflex Box in App →

Recommended Sealed (Acoustic Suspension)

MAX TRANSIENT DAMPING
Net Box Volume (Vb) 15.9 Liters
System Q (Qtc) 0.707 (Butterworth)
System Resonance (Fc) 70.5 Hz
F3 (-3 dB Cutoff) 71.8 Hz
F6 / F10 Extension 54.1 Hz / 40.8 Hz
Air Spring Linearity High (Zero port compression)
Simulate This Sealed Box in App →

Thiele/Small Parameters

Resonance (Fs) 54.0 Hz
Total Q (Qts) 0.53
Electrical Q (Qes) 0.557
Mechanical Q (Qms) 11.1
Equivalent Volume (Vas) 12.4 Liters
Diaphragm Area (Sd) 135.0 cm²
DC Resistance (Re) 3.4 Ω
Efficiency Bandwidth Product (EBP) 97.0
Linear Excursion (Xmax) 3.0 mm
Thermal Power (Pe) 150.0 W
Nominal Diameter 6.0"
Catalog Source Load Forge catalog (manufacturer datasheets and retailer listings)

Frequently Asked Questions

What is the recommended ported (bass reflex) box volume for HELIX C 6B?

Load Forge's calculated alignment puts HELIX C 6B in a 18.6 liter vented enclosure tuned to 40.2 Hz, reaching an F3 cutoff of approximately 43.5 Hz.

Can HELIX C 6B be used in a sealed box?

Yes. In a sealed (acoustic suspension) enclosure of 15.9 liters with a Qtc of 0.707 (Butterworth), the system exhibits an F3 of 71.8 Hz.

What port dimensions should be used for HELIX C 6B to avoid port chuffing?

Sized from cone displacement (Sd × Xmax), a minimum port diameter of 5.0 cm with a length of 16.0 cm is suggested; check the port air velocity at your drive level in the Load Forge Studio.

Shareable Acoustic Card for Forums & Social Media

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.

HELIX C 6B Enclosure Card
Download SVG Card 📥

Not sure if C 6B 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