SoundTube - IPD-EXT BOX - Extender Box Use up to 5 IPD-Hub 2 Amps per Extender Box SoundTube's new IPD Hub 2 Extender Box for adding onto a Hub 2 local system. Connect up to 5 IPD Hub 2 amplifiers to an extender box. The IPD Hub 2 utilizes a Dante infrastructure for flexible audio distribution. The amp is complete with local and Dante inputs and local and network control to address requirements for commercial audio connectivity in numerous scalable systems such as retail, bar, restaurants, hospitality, spas, education facilities, and more.