I have used them before for a loudringer/paging speaker. Its fairly straight forward with what is in the manual. You get the HESC-65A cable and are supposed to wire that into a biscuit jack and put a line cord from the biscuit jack to the BHEU. I just plugged the HESC into the BHEU and wired it straight into the BESCB1A. It took a little playing around with the wiring this way but I eventually got it to work. Then you wire the paging horn into the output and thats it.