I assume this is for the sub which is a single mono signal. The Yamaha receiver has a sub out RCA jack. Plug a single rca cable into this. You can use one half of a pair. Plug the other end into the adaptor, and plug the adaptor into the carvin input #1. Depress the bridge switch. With this...
To beat the dead horse, 2 tweeters bad idea. They will step over each other, and even only one will already be too loud relative to the other drivers without padding. No upside at all to the second tweeter per cabinet. Do you have a plan to filter the signal to the woofer and midrange drivers...