Do column speakers need a separate amplifier or can connect to DSP directly?

Good news — you do not need a separate power amplifier. The VISSONIC VIS-SPK series (including the 2×3 inch model) are full-frequency linear POE column speakers with a built-in amplifier.

Each speaker is powered directly over a single CAT5 network cable (PoE, compatible with 802.3af/802.3at), which carries both power and audio. So for a corridor install you simply run CAT5 from a PoE switch (or the VISSONIC conference controller) to each speaker — no local amplifier or mains wiring at the speaker position.

How it fits with the audio matrix

The dB-NET Digital DSP Audio Matrix (VIS-DAP84 / VIS-DAP88 / VIS-DAP1212 / VIS-DAP1616) routes and processes the audio signal, and the PoE column speakers connect on the network output side. If you ever need conventional passive speakers, that is when a VIS-AMD4300 power amplifier would come in.