That link could get the thread bounced to $ & c
here's a picture found by googling "pioneer speaker plugs", and clicking on images
and there will be a few vendors that pop up, some are expen$ive!!
then there's a way to get cinch inline connectors, cut off one of the three pins and use it as well:
(from electronicplus.com , part # P303CCT @ $4.95 ea no affiliation)