REDCATT 18NPW
Best box: 80.5 L bass reflex tuned to 47.9 Hz · F3 51.6 Hz
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Comparable 18.0" Drivers
Drivers with similar piston area, resonance and Qts — useful alternatives when the REDCATT 18NPW does not fit your target box volume or tuning. Each entry links to its full enclosure design and Thiele/Small parameters.
Recommended Bass Reflex (Vented)
PORT BUILDABLE| Net Box Volume (Vb) | 80.5 Liters |
| Tuning Frequency (Fb) | 47.9 Hz |
| F3 (-3 dB Cutoff) | 51.6 Hz |
| F6 / F10 Extension | 44.8 Hz / 38.5 Hz |
| Port Inner Diameter | Ø 12.5 cm |
| Port Physical Length | 11.0 cm |
| First Pipe Resonance | 1567.0 Hz |
| Estimated MOL @ F3 | 127.1 dB SPL |
Recommended Sealed (Acoustic Suspension)
MAX TRANSIENT DAMPING| Net Box Volume (Vb) | 38.7 Liters |
| System Q (Qtc) | 0.707 (Butterworth) |
| System Resonance (Fc) | 86.8 Hz |
| F3 (-3 dB Cutoff) | 84.3 Hz |
| F6 / F10 Extension | 65.1 Hz / 49.8 Hz |
| Air Spring Linearity | High (Zero port compression) |
Thiele/Small Parameters
| Resonance (Fs) | 36.0 Hz |
| Total Q (Qts) | 0.278 |
| Electrical Q (Qes) | 0.288 |
| Mechanical Q (Qms) | 8.39 |
| Equivalent Volume (Vas) | 211.5 Liters |
| Diaphragm Area (Sd) | 1257.0 cm² |
| DC Resistance (Re) | 5.1 Ω |
| Efficiency Bandwidth Product (EBP) | 125.2 |
| Linear Excursion (Xmax) | 4.8 mm |
| Thermal Power (Pe) | 2400.0 W |
| Nominal Diameter | 18.0" |
| Catalog Source | Load Forge catalog (manufacturer datasheets and retailer listings) |
Frequently Asked Questions
What is the recommended ported (bass reflex) box volume for REDCATT 18NPW?
Load Forge's calculated alignment puts REDCATT 18NPW in a 80.5 liter vented enclosure tuned to 47.9 Hz, reaching an F3 cutoff of approximately 51.6 Hz.
Can REDCATT 18NPW be used in a sealed box?
Yes. In a sealed (acoustic suspension) enclosure of 38.7 liters with a Qtc of 0.707 (Butterworth), the system exhibits an F3 of 84.3 Hz.
What port dimensions should be used for REDCATT 18NPW to avoid port chuffing?
Sized from cone displacement (Sd × Xmax), a minimum port diameter of 12.5 cm with a length of 11.0 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.
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