Here is the user guide for the Amp: https://www.sonos.com/en-us/guides/amp

You can connect 4 - 8 ohm speakers to the Amp in parallel (+ to + and - to -) on each speaker. All the speakers will play at the same volume, so if you wanted to lower the volume on a specific pair of speakers, you would either need a speaker selector with volume controls, or a second Amp.

You might also look at a Sonos Port feeding a multi-channel amplifier for that many speakers. The right amplifier would give you more control over the speaker levels but you could only play one stream, where with two Amps you could play two.

If you used the Sonos by Sonance outdoor speakers you could put all six on a single Amp.

Hi @mojism, I concur with @Stanley_4: look at a multi-channel amplifier driven by a Sonos Port. I’m a big fan of separating the ‘streamer’ which needs to be updated more frequently from the amplifier which pretty much never needs to be updated.

I came back to add you could use more than one Port too, giving multiple independent streams if the Amp you select supports multiple inputs.

Thanks so much for all the advice here.