GRS 5-1/4" Woofer Surface Mount Poly Cone 4 Ohm 5SMP-4
Best box: 9.0 L bass reflex tuned to 45.3 Hz · F3 49.5 Hz
Open and tweak this box live ↗
Will it fit your requirements?
Check the GRS 5-1/4" Woofer Surface Mount Poly Cone 4 Ohm 5SMP-4 against your space and targets — instant, no sign-up.
Estimated retail 29.95 EUR · Check price & availability ↗
Free, no sign-up to simulate · a free account saves your design
Comparable 5.25" Drivers
Drivers with similar piston area, resonance and Qts — useful alternatives when the GRS 5-1/4" Woofer Surface Mount Poly Cone 4 Ohm 5SMP-4 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
- Limited linear excursion (Xmax: 2.0 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) | 9.0 Liters |
| Tuning Frequency (Fb) | 45.3 Hz |
| F3 (-3 dB Cutoff) | 49.5 Hz |
| F6 / F10 Extension | 39.2 Hz / 34.3 Hz |
| Port Inner Diameter | Ø 5.0 cm |
| Port Physical Length | 28.3 cm |
| First Pipe Resonance | 608.0 Hz |
| Estimated MOL @ F3 | 97.1 dB SPL |
Recommended Sealed (Acoustic Suspension)
MAX TRANSIENT DAMPING| Net Box Volume (Vb) | 8.4 Liters |
| System Q (Qtc) | 0.707 (Butterworth) |
| System Resonance (Fc) | 79.8 Hz |
| F3 (-3 dB Cutoff) | 80.1 Hz |
| F6 / F10 Extension | 60.5 Hz / 45.7 Hz |
| Air Spring Linearity | High (Zero port compression) |
Thiele/Small Parameters
| Resonance (Fs) | 62.0 Hz |
| Total Q (Qts) | 0.54 |
| Electrical Q (Qes) | 0.619 |
| Mechanical Q (Qms) | 4.21 |
| Equivalent Volume (Vas) | 6.0 Liters |
| Diaphragm Area (Sd) | 80.0 cm² |
| DC Resistance (Re) | 3.7 Ω |
| Efficiency Bandwidth Product (EBP) | 100.1 |
| Linear Excursion (Xmax) | 2.0 mm |
| Thermal Power (Pe) | 35.0 W |
| Nominal Diameter | 5.25" |
| Catalog Source | Load Forge catalog (manufacturer datasheets and retailer listings) |
Frequently Asked Questions
What is the recommended ported (bass reflex) box volume for GRS 5-1/4" Woofer Surface Mount Poly Cone 4 Ohm 5SMP-4?
Load Forge's calculated alignment puts GRS 5-1/4" Woofer Surface Mount Poly Cone 4 Ohm 5SMP-4 in a 9.0 liter vented enclosure tuned to 45.3 Hz, reaching an F3 cutoff of approximately 49.5 Hz.
Can GRS 5-1/4" Woofer Surface Mount Poly Cone 4 Ohm 5SMP-4 be used in a sealed box?
Yes. In a sealed (acoustic suspension) enclosure of 8.4 liters with a Qtc of 0.707 (Butterworth), the system exhibits an F3 of 80.1 Hz.
What port dimensions should be used for GRS 5-1/4" Woofer Surface Mount Poly Cone 4 Ohm 5SMP-4 to avoid port chuffing?
Sized from cone displacement (Sd × Xmax), a minimum port diameter of 5.0 cm with a length of 28.3 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 5-1/4" Woofer Surface Mount Poly Cone 4 Ohm 5SMP-4 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