DS18 CF-65M
Best box: 16.0 L bass reflex tuned to 63.8 Hz · F3 93.0 Hz
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Comparable 6.5" Drivers
Drivers with similar piston area, resonance and Qts — useful alternatives when the DS18 CF-65M 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) | 16.0 Liters |
| Tuning Frequency (Fb) | 63.8 Hz |
| F3 (-3 dB Cutoff) | 93.0 Hz |
| F6 / F10 Extension | 79.7 Hz / 63.4 Hz |
| Port Inner Diameter | Ø 6.8 cm |
| Port Physical Length | 11.9 cm |
| First Pipe Resonance | 1451.0 Hz |
| Estimated MOL @ F3 | 112.5 dB SPL |
Sealed (Acoustic Suspension) — compromise
SUITS INFINITE / OPEN BAFFLEWith Qts 0.931 a Butterworth (Qtc 0.707) box would be many times Vas. A box equal to Vas reaches Qtc 1.317; for a flat response this driver is better used on an infinite (IB) or open baffle.
| Net Box Volume (Vb) | 20.0 Liters |
| System Q (Qtc) | 1.317 (above Butterworth: Qtc cannot fall below Qts (0.93)) |
| System Resonance (Fc) | 106.1 Hz |
| F3 (-3 dB Cutoff) | 83.5 Hz |
| F6 / F10 Extension | 71.2 Hz / 58.6 Hz |
| Air Spring Linearity | High (Zero port compression) |
Thiele/Small Parameters
| Resonance (Fs) | 75.0 Hz |
| Total Q (Qts) | 0.931 |
| Electrical Q (Qes) | 1.057 |
| Mechanical Q (Qms) | 7.82 |
| Equivalent Volume (Vas) | 20.0 Liters |
| Diaphragm Area (Sd) | 115.0 cm² |
| DC Resistance (Re) | 3.14 Ω |
| Efficiency Bandwidth Product (EBP) | 71.0 |
| Linear Excursion (Xmax) | 8.5 mm |
| Thermal Power (Pe) | 100.0 W |
| Nominal Diameter | 6.5" |
| Catalog Source | Load Forge catalog (manufacturer datasheets and retailer listings) |
Frequently Asked Questions
What is the recommended ported (bass reflex) box volume for DS18 CF-65M?
Load Forge's calculated alignment puts DS18 CF-65M in a 16.0 liter vented enclosure tuned to 63.8 Hz, reaching an F3 cutoff of approximately 93.0 Hz.
Can DS18 CF-65M be used in a sealed box?
Yes. In a sealed (acoustic suspension) enclosure of 20.0 liters with a Qtc of 1.317 (above Butterworth: Qtc cannot fall below Qts (0.93)), the system exhibits an F3 of 83.5 Hz.
What port dimensions should be used for DS18 CF-65M to avoid port chuffing?
Sized from cone displacement (Sd × Xmax), a minimum port diameter of 6.8 cm with a length of 11.9 cm is suggested; check the port air velocity at your drive level in the Load Forge Studio.
Shareable Acoustic Card for Forums & Social Media
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