MResist Metal Oxide
MResist Metal Oxide
No winding. No winding-related residual inductance.
The construction is based on a ceramic core as a dimensionally stable and temperature-resistant base. A metal oxide film is applied to it as the resistive element – so this is a film resistor without any wire winding. An additional cement or potting structure provides mechanical stabilization, effective damping, and uniform heat distribution. Axial lead wires ensure robust contacting and easy mounting.
Compared to classic wire-wound high-load resistors, metal oxide film resistors (MOX) behave particularly frequency-neutral because they are not built as a winding. As a result, no coil-like residual inductance arises – an advantage wherever impulse fidelity, clean transients, and a stable phase response are decisive.
Typical fields of application are loudspeaker crossovers in the midrange and treble branches, attenuation elements (L-pads), and matching and correction elements in which a resistor should, as far as possible, be “nothing but a resistor”.
Why MOX in the loudspeaker crossover?
Impulse Fidelity and Transients
In midrange and treble branches, parasitic effects become audible more quickly than in the bass. Metal oxide film resistors are often the preferred choice here because, without a wound construction, they introduce no additional coil effect into the network.
Minimal Residual Inductance
Wire-wound high-load resistors can have a residual inductive component. In filters, this can affect the impedance and phase response. MOX resistors reduce this side effect by design.
Power Handling Under Music Loads
The M-Resist MOX designs offered by Mundorf have a continuous power rating of 5 W or 10 W. In pulse operation, they can briefly handle significantly higher loads, because music signals consist of transients rather than constant continuous power.
Key Technical Data
- Type: metal oxide film resistor (MOX)
- Conductor material: metal oxide
- Core / potting: ceramic / cement
- Inductance: < 0.075 µH
- Temperature coefficient (TCR): ±300 ppm/°C
- Temperature range: -55 °C to +200 °C
- Voltage rating (depending on variant): 700–850 V AC
- Continuous power rating: 5 W / 10 W