ND940 Driver
The ND940 is a ultra compact size, high performance, high power handling 4.0-inch diaphragm compression driver with a 1.4 inch exit throat. A thin copper ring is precision pressed on to the pole piece in order to modify and lower the inductance characteristics of the magnetic circuit and voice coil providing a controlled extension of the acoustic frequency response. The voice coil assembly is designed using a high strength, high temperature Kapton® voice coil former and edge wound copper clad aluminium wire directly joined to the diaphragm by RCF proprietary Direct Drive kapton technology. The ND940 features a 4-slot, optimised geometry, phase plug design. Extended computer assisted mathematical modelling and testing has resulted in a geometry that provides a balanced acoustic performance controlling and lowering air distortion and maximizing output.
Features
- 4.0 inch, Kapton former, edge wound aluminium voice coil
- 280W continuous program power handling
- Frequency range: 500Hz - 20kHz
- 4-slot optimized geometry phase plug
- Titanium diaphragm, Polyimide surround
Specifications
General specifications
| Exit Throat Diameter |
1.4 inch / 36 mm |
| Related Impedance |
8 ohm |
| Program Power (watt) |
280 W |
| Power handling capacity |
140 W |
| Sensitivity |
110 dB |
| Frequency range |
500 - 20000 Hz |
| Diaphragm Material |
Pure Titanium |
| Suspension Material |
Polyimide |
| Suspension Design |
Flat |
| Minimum Impedance (ohm) |
8.50 ohm |
| Voice Coil Diameter |
4.0 inch / 102 mm |
| Voice Coil Winding Material |
Edgewound Aluminum |
| Voice Coil Former Design |
Direct Drive Kapton |
| Number of layers |
1 |
| Kind of layers |
outside |
| Flux Density |
2.0 T |
| Phase Plug Design |
4 slot |
| Phase Plug Material |
Aluminum |
| Magnetics |
Neodymium |
| Voice Coil Demodulation Ring |
Copper |
Thiele - small parameters
| Bl factor (Bl) (T x m) |
17.60 T x m |
Mounting information
| Overall diameter |
140 mm / 5.51 inches |
| Overall height |
60 mm / 2.36 inches |
| Mounting |
4 x 6 mm threaded holes at 90° |
Standard compliance
| Safety agency |
CE compliant |
Size / Weight
Shipping information
| Package Height |
79 mm / 3.11 inches |
| Package Width |
169 mm / 6.65 inches |
| Package Depth |
171 mm / 6.73 inches |
| Package Weight |
2.87 kg / 6.33 lbs |
