Rock Speaker 8 Ohm Bridged Speaker Connection Mono Audio?

I have a garden rock speaker 8 ohm that I want to send mono audio so I don’t have to buy/connect/place 2 speakers in a small garden to support stereo audio. I want to bridge either the A50 or SA100 depending on whether an A50 bridged speaker out will drive an 8 ohm speaker or is the A50 limited to a 4 ohm speaker impedance? First, will either the A50 or SA100 accept a bridged speaker out connection to create mono audio (left positive / right negative connection)? Second, if I use the SA100, it appears I need to switch to the load to an 8 ohm impedance configuration. Will the SA100 mono output then be 100 watts mono audio into an 8 ohm speaker? Thanks