In our church, apart from the main church singers , a rented group also uses our mixers etc often causing issues. We are planning to add a new mixer which we do not wish the renters to use. So we were thinking of connecting all inputs to the mixer and the outputs from the mixer to speakers using Y connectors and locking the new mixer when we are not using it. Meaning only one mixer will be powered ON at a time. Will this work or any problems we might face? Please comment.