Remember that a radio transmitter is modulating a carrier frequency with baseband audio, using the modulated RF as the transmission medium to be demodulated by the distant receiver. So, the RF is always harmonically coupled to the baseband signal at much higher frequency. The RF can therefore ring the baseband audio, creating RF feedback. That is hearable when the RF signal is demodulated by the receiver. Effort is therefore made to keep RF away from the audio input.
An audio amplifier is not modulating on a carrier, but is rather just increasing the amplitude of the baseband signal to send to speakers. So, frequencies are the same and one does not modulate the other with stray RF, at least in theory. Class D amps do have switching at RF frequencies, but the speakers attenuate that—there is no receiver trying to demodulate that radio frequency signal.
Rick “fun with the frequency domain” Denney
An audio amplifier is not modulating on a carrier, but is rather just increasing the amplitude of the baseband signal to send to speakers. So, frequencies are the same and one does not modulate the other with stray RF, at least in theory. Class D amps do have switching at RF frequencies, but the speakers attenuate that—there is no receiver trying to demodulate that radio frequency signal.
Rick “fun with the frequency domain” Denney