Shure PA821B — Eight-Channel Antenna Combiner (470-865 MHz)

The Shure PA821B is an eight-channel active antenna combiner for in-ear monitor (IEM) systems, covering the 470–865 MHz range. It combines the RF output of up to 8 wireless transmitters (like PSM300/PSM900/PSM1000 IEM transmitters) into a single antenna feed — the essential backbone for any multi-channel in-ear monitoring rig.

Why a combiner matters for IEM systems: Just as a wireless microphone system needs an antenna distributor on the receive side, an in-ear monitor system needs a combiner on the transmit side. Without it, 8 IEM transmitters would need 8 separate antennas, all radiating in the same space and interfering with each other. The PA821B combines all 8 transmitter outputs into one antenna, dramatically cleaning up the RF environment and simplifying rack wiring.

Specifications:

• Channels: combines up to 8 transmitters
• Frequency range: 470–865 MHz
• Active combining with amplification to compensate for combining loss
• Cascadable for larger systems
• Rack-mountable
• Compatible with Shure PSM300, PSM900, PSM1000 transmitters

Ideal for: Touring sound companies, large houses of worship, theaters, and any venue running 4+ in-ear monitor channels. AV integrators specifying professional multi-channel IEM infrastructure.