The HDA-4100 is the entry point into URC's HDA audio distribution platform and the one that fits most houses and small commercial spaces. Four RCA sources feed four stereo zones or up to eight mono zones, driven at 100 watts per channel into 8 ohms or 200 watts into 4 ohms, and the whole system streams 96 kHz / 24-bit audio over the network rather than analog runs. Digital inputs also handle Dolby and DTS 5.1 downmixing.

What separates it from a plain multi-zone amp is the per-zone processing. Every zone gets high pass and low pass filters and a full 5-band parametric EQ, so an in-ceiling pair in a kitchen and a set of outdoor rocks can be tuned independently. A ducking input handles paging or a doorbell, and each chassis stores up to ten .WAV files for chime and alert playback. Two assignable pre-amp outputs and two 12V triggers cover the rest of the rack. HDA amplifiers connect over gigabit Ethernet on an AVB network switch and expand to 32 sources by 32 zones as the system grows.

Configuration	4 sources to 4 stereo zones or up to 8 mono zones
Power Output	100W per channel at 8 ohms; 200W per channel at 4 ohms
Audio Quality	96 kHz / 24-bit high resolution streaming; Dolby and DTS 5.1 downmix on digital inputs
Inputs	(4) RCA analog inputs
Outputs	4 stereo / 8 mono amplifier channels, (2) assignable pre-amp outputs, (2) 12V triggers
Per-Zone DSP	High pass and low pass filters, 5-band parametric EQ, ducking input
Network	Ethernet RJ45 1 Gbps full duplex; requires gigabit AVB network switch
Expansion	Up to 32 sources x 32 zones with multiple amplifiers
Dimensions / Weight	17.125 in W x 3.875 in H x 11.94 in D; 11.9 lbs