Assertion: mpx filter | /r/HasProperty | mandatory
Facets:
value: for all cassette recorders
type: TRANSITIVE-OBJECT
Source sentences:
text: More importantly, the pilot tone interferes with the proper functioning of reciprocal noise reduction systems, causing audible artefacts such as breathing and pumping For this reason, the MPX filter is mandatory for all cassette recorders equipped with Dolby B and Dolby C systems.