o/t need help hooking up cb pa speaker
 

i hooked up a pa speaker to a cb and when i key up the mic to talk i get a squeeking feed back. what m i doing wrong? the cb has a plug in the back for the speaker, and has a pa mode built into the cb. im just getting to much feed back any sugestions? i tried moving the speaker as far away from the cb but that didnt help, i also tried turning down the volume, and the squelch control with no result.

by the way, the cb is installed in a piece of work equipment and not the p car just in case anyone was wondering.