Can I add more speakers to my XP40iw?

You can get an XP40iw and add an XP40i and connect them with a 1/4” cable via the LINK. You could also get a second XP40iw on a different channel and connect them via the LINK so you can have two microphones. You can purchase multiple XP40iw's all on the same channel and use one Microphone the signal will be picked by all of the receivers.