Comparison Novation Impulse 49 vs Novation Impulse 25

The total number of keys on the keyboard.

The more keys provided in the design, the wider the instrument's own range, the more notes it can play without resorting to octave shift or transposition. On the other hand, this characteristic directly affects the dimensions and cost, and an extensive range is not required so often. Therefore, 88 -key instruments corresponding to a full-size classical piano keyboard are quite rare. But compact models with only 25 keys(2 octaves), on the contrary, are popular: for the purposes for which MIDI keyboards are used, this is often quite enough. Other common options are the 49 -key (4 octave) and 61 -key (5 octave) models; somewhat less common are 32 and 37 keys.

The number of faders provided in the design of the keyboard.

A fader is a slider control. The simplest kind of such controls is the volume setting; if there is one fader in the design, most likely it is responsible for the volume. If there are more controls, other functions can be tied to them, respectively — in particular, changing the settings in the recording programme on the computer to which the keyboard is connected.