The ST-HP3 is the ideal choice where line-level audio filtering needs to be provided at the input of a power amplifier for protection of public address horns against damage from low frequencies. The ST-HP3 has one input and two filtered outputs: 300 Hz high pass and 500 Hz high pass. Both the input and output are balanced, and each may be wired unbalanced if required. The input accepts line-level (+4 dBu nominal) audio. The module operates at unity gain (balanced input and output). The two outputs may be used simultaneously. The ST-HP3 features RDL's SupplyFlex power input configuration for operation directly from ground-referenced, floating or bipolar 24 Vdc power.