If you want to use the PX system with up to five people simultaneously, and you’re able to work with the same three signals from the soundboard or other audio source/s, you can upgrade your system with a PX-H 5-channel hub, and up to four additional PX-A mixer/preamps and EC25 Cat 5 cables. All connected PX units are powered by one 9V/2A power supply connected to a PX-B that feeds audio and power to the hub!