Input (Load) Impedance refers to the impedance a device presents at its terminals. By this, we mean that we can imagine the device as a single resistor (or resistor in combination with an inductor and/or capacitor) and ignore the rest of the device. All things that can be plugged into some signal source present an input impedance.
Some common examples:
Microphone Input Impedance (on a sound console, for instance): > 100 kOhms
Line Level Input Impedance: > 10 kOhms
Speaker Input Impedance: 2-16 Ohms
RF Input Impedance: 50 or 75 Ohms
Some common examples:
Microphone Input Impedance (on a sound console, for instance): > 100 kOhms
Line Level Input Impedance: > 10 kOhms
Speaker Input Impedance: 2-16 Ohms
RF Input Impedance: 50 or 75 Ohms