- Yamaha Commercial Audio Systems announces the availability of the new IMX644 rack mount digital mixer. Developed for sound information applications such as conference rooms, banquet halls, lounges and restaurants, the IMX644 delivers excellent sound quality, is easy to install, and is available at a very competitive price point. The IMX644 features six Euroblock mono inputs each with individual +48V phantom power, four RCA stereo inputs, as well as an additional optical digital input. Outputs consist of two pair of stereo Euroblock connectors and two channels of mono outputs. RCA and optical digital outputs are also available for recording. The IMX644 will also compliment the successful Installation Series loudspeakers and have been designed for seamless compatibility with all 26 IS speakers.