Fostex FW405N
Best box: 186.5 L bass reflex tuned to 26.4 Hz · F3 28.7 Hz
Open and tweak this box live ↗
Will it fit your requirements?
Check the Fostex FW405N against your space and targets — instant, no sign-up.
Estimated retail 590.00 EUR · Check price & availability ↗
Free, no sign-up to simulate · a free account saves your design
Comparable 15.0" Drivers
Drivers with similar piston area, resonance and Qts — useful alternatives when the Fostex FW405N 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
- Large enclosure volume (186.5 L) requires extensive internal matrix bracing to prevent panel resonance.
Recommended Bass Reflex (Vented)
PORT BUILDABLE| Net Box Volume (Vb) | 186.5 Liters |
| Tuning Frequency (Fb) | 26.4 Hz |
| F3 (-3 dB Cutoff) | 28.7 Hz |
| F6 / F10 Extension | 24.8 Hz / 21.4 Hz |
| Port Inner Diameter | Ø 12.5 cm |
| Port Physical Length | 19.4 cm |
| First Pipe Resonance | 888.0 Hz |
| Estimated MOL @ F3 | 115.0 dB SPL |
Recommended Sealed (Acoustic Suspension)
MAX TRANSIENT DAMPING| Net Box Volume (Vb) | 89.3 Liters |
| System Q (Qtc) | 0.707 (Butterworth) |
| System Resonance (Fc) | 48.3 Hz |
| F3 (-3 dB Cutoff) | 50.0 Hz |
| F6 / F10 Extension | 37.5 Hz / 28.2 Hz |
| Air Spring Linearity | High (Zero port compression) |
Thiele/Small Parameters
| Resonance (Fs) | 20.0 Hz |
| Total Q (Qts) | 0.28 |
| Electrical Q (Qes) | 0.293 |
| Mechanical Q (Qms) | 6.5 |
| Equivalent Volume (Vas) | 480.0 Liters |
| Diaphragm Area (Sd) | 855.0 cm² |
| DC Resistance (Re) | 6.8 Ω |
| Efficiency Bandwidth Product (EBP) | 68.4 |
| Linear Excursion (Xmax) | 10.0 mm |
| Thermal Power (Pe) | 350.0 W |
| Nominal Diameter | 15.0" |
| Catalog Source | Load Forge catalog (manufacturer datasheets and retailer listings) |
Frequently Asked Questions
What is the recommended ported (bass reflex) box volume for Fostex FW405N?
Load Forge's calculated alignment puts Fostex FW405N in a 186.5 liter vented enclosure tuned to 26.4 Hz, reaching an F3 cutoff of approximately 28.7 Hz.
Can Fostex FW405N be used in a sealed box?
Yes. In a sealed (acoustic suspension) enclosure of 89.3 liters with a Qtc of 0.707 (Butterworth), the system exhibits an F3 of 50.0 Hz.
What port dimensions should be used for Fostex FW405N to avoid port chuffing?
Sized from cone displacement (Sd × Xmax), a minimum port diameter of 12.5 cm with a length of 19.4 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.
Not sure if FW405N 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