Short answer is that as many as needed. Each AES67 audio-over-IP stream received by the loudspeaker can contain up to 8 channels of audio, and you can run an unlimited number of parallel streams. AES67 uses precision time protocol (PTP) version 2 clocking and this ensures complete synchronisation of all parallel streams - so your channel count is not really limited. Very high channel count Dante streams can also be configured and received by Smart IP loudspeakers. Each loudspeaker outputs one of the audio channels in a stream, or the sum of two selected audio channels.