Focal SUB 25 KXS a profondità poco profonda da 25 cm
Best box: 18.0 L sealed · Fc 49.5 Hz · F3 40.7 Hz
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Comparable 10.0" Drivers
Drivers with similar piston area, resonance and Qts — useful alternatives when the Focal SUB 25 KXS a profondità poco profonda da 25 cm 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
- Straight vent would be 176.9 cm long: not physically buildable as a simple tube. Use a passive radiator, a folded slot port or model a 3D folded duct in Load Forge Studio.
Textbook Bass Reflex — not recommended
PORT NOT BUILDABLE| Net Box Volume (Vb) | 14.4 Liters |
| Tuning Frequency (Fb) | 29.8 Hz |
| F3 (-3 dB Cutoff) | 43.3 Hz |
| F6 / F10 Extension | 36.3 Hz / 28.2 Hz |
| Port Inner Diameter | Ø 10.0 cm |
| Port Physical Length | 176.9 cm |
| First Pipe Resonance | 97.0 Hz |
| Estimated MOL @ F3 | 107.2 dB SPL |
Sealed (Acoustic Suspension) — compromise
SUITS INFINITE / OPEN BAFFLEWith Qts 0.8 a Butterworth (Qtc 0.707) box would be many times Vas. A box equal to Vas reaches Qtc 1.131; for a flat response this driver is better used on an infinite (IB) or open baffle.
| Net Box Volume (Vb) | 18.0 Liters |
| System Q (Qtc) | 1.131 (above Butterworth: Qtc cannot fall below Qts (0.80)) |
| System Resonance (Fc) | 49.5 Hz |
| F3 (-3 dB Cutoff) | 40.7 Hz |
| F6 / F10 Extension | 34.0 Hz / 27.5 Hz |
| Air Spring Linearity | High (Zero port compression) |
Thiele/Small Parameters
| Resonance (Fs) | 35.0 Hz |
| Total Q (Qts) | 0.8 |
| Electrical Q (Qes) | 0.952 |
| Mechanical Q (Qms) | 5.0 |
| Equivalent Volume (Vas) | 18.0 Liters |
| Diaphragm Area (Sd) | 327.0 cm² |
| DC Resistance (Re) | 3.2 Ω |
| Efficiency Bandwidth Product (EBP) | 36.8 |
| Linear Excursion (Xmax) | 14.0 mm |
| Thermal Power (Pe) | 350.0 W |
| Nominal Diameter | 10.0" |
| Catalog Source | Load Forge catalog (manufacturer datasheets and retailer listings) |
Frequently Asked Questions
What is the recommended ported (bass reflex) box volume for Focal SUB 25 KXS a profondità poco profonda da 25 cm?
A simple ported box is not recommended for Focal SUB 25 KXS a profondità poco profonda da 25 cm: the textbook alignment (14.4 liters tuned to 29.8 Hz) needs a 176.9 cm port, and no nearby retune stays buildable without a bass hump. A sealed box, a passive radiator or a folded duct is the practical choice.
Can Focal SUB 25 KXS a profondità poco profonda da 25 cm be used in a sealed box?
Yes. In a sealed (acoustic suspension) enclosure of 18.0 liters with a Qtc of 1.131 (above Butterworth: Qtc cannot fall below Qts (0.80)), the system exhibits an F3 of 40.7 Hz.
What port dimensions should be used for Focal SUB 25 KXS a profondità poco profonda da 25 cm to avoid port chuffing?
A straight 10.0 cm port would need 176.9 cm of length, which does not fit a practical cabinet. Use a passive radiator or a folded/3D duct instead of a straight tube.
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