(under subclass 230) Subject matter including significant details of means whereby a part of the frequency range of the low frequency signals in an audio frequency amplifier of a receiver is emphasized or attenuated to produce a desired bass or treble effect thereby obtaining a quality more pleasing to the ear of a listener when the signals are reproduced.
(1) Note. Where the claimed subject matter comprises significant details of some specific control means other than tone control with tone control means claimed broadly, classification will be in the appropriate subclass for such other control means with an official cross-reference in this subclass.
SEE OR SEARCH CLASS
84, Music,
622, for electronic musical instruments with tone generation and/or control of tone partials.
330, Amplifiers, appropriate subclasses for amplifiers with equalizing or tone control networks.
333, Wave Transmission Lines and Networks,
28+, for equalizing networks of the passive type including tone controls which vary the signal attenuation characteristics over a range of frequencies.
