Thanks for the question.
We do not recommend changing the speakers from the VI300 kit, as doing so could damage the VI300 receiver module. Changing the speakers could draw too much power from the module.
If you have any other questions, please let us know.
Brandon - Community Support
Thanks for replying!
As Brandon was mentioning, the VI300s were designed to work with what came in the speaker kit. The 591s will draw too much power as it's rated to work with a dedicated amplifier like an SA-5.