If a built-in loudspeaker causes the adjoining components or surrounds to vibrate, this often causes unwanted noise. The Rattle & Noise Check loudspeaker testing device (RNC) controls any loudspeaker in a specific frequency range and at the correct level. This allows the loudspeaker and its installation environment to be checked for resonance and noise in the early stages of development.

A major advantage of the RNC is that it is transportable.
As such it can be used with little effort in development and service departments to gain initial insights into the behavior of the loudspeaker and its environment.

During the test phase, using a correctly pre-configured storage medium, the loudspeaker testing device outputs exactly the test signals that are equivalent to the signal that the loudspeaker receives from the amplifier in real operation. This ensures testing is conducted within the specified and non-destructive range of the loudspeaker. The testing device only accepts SD cards as storage media. These can be exchanged in the testing device and are protected against change and overwriting.