Audio-video receivers for amplifying, pre-amplifying, enhancing, processing, and converting audio signals, and routing audio and video signals between components of audiovisual entertainment systems such as music players, speakers, and subwoofers; Analog and digital sound enhancing apparatus, namely, preamplifiers for use in processing, recording, reproduction, streaming, and transmission of electronic or digital audio signals; Downloadable computer programs for generating, processing, measuring, analyzing, recording, amplifying, enhancing, reproducing, transmitting, controlling, testing, receiving and playing audio signals; Downloadable computer firmware for generating, processing, measuring, analyzing, recording, amplifying, enhancing, reproducing, transmitting, controlling, testing, receiving and playing audio signals
Electrical and Scientific Apparatus