Software-Defined Radio for Modular Audio Mixers: Making Use of Market-Available Audio Consoles and Software-Defined Radio to Build Multiparty Audio-Mixing Systems

Simple and professional audio mixers can be built using a collection of software and hardware technology components. In this article, software-defined radio (SDR) is used to build a wireless microphone audio-mixing system in combination with a market-available audio console. The RTL-SDR is inexpensive and used to receive signals in the radio-frequency (RF) spectrum. Thus, as a professional solution, this article develops a standalone audio mixer either for wireless microphones or for working cooperatively with audio consoles. The universal serial bus (USB)-based SDR hardware component employs an SDR to perform personal computer (PC)-based computations, and the free open-source software (OSS) GNU radio companion (GRC) is chosen to build the block-diagram of the SDR application. Another combination employs the extensible messaging and presence protocol (XMPP) for voice-over Internet protocol (VoIP) audio chatting. Therefore, the following OSSs are employed: Jitsi for the XMPP client in a PC, Empathy for another client in a laptop, and Openfire for the XMPP server. The three technologies and the combination of hardware and software components were successfully tested in different scenarios and proved that this solution can provide inexpensive and various options for developers, audio technicians, musicians, and hobbyists.