2 DJ/PA mixer setup with passive mid/high speakers & 1 MCM custom audio $99, 18" subwoofer

Here I use a Rockville RPM45 powered mixer, power to passive Electro-Voice ELX200-12inch 300watt speakers. This is a basic PA mixer with 4 channels for mics/line in, & RCA inputs to CD/tape input on rear, controlled on the front. Now that I picked up 2 MCM custom audio, 18", $99 passive subwoofers built in China, I will add 1 to my small PA. I use RCA to RCA from the REC out next to the input on the rear of the RPM45, & take them to the front of the Phonic 620plus, powered mixer into the front "tape in". I then set the lower frequencies on the left side of the equalizer on the phonics 620 to replicate lower frequencies & remove higher frequencies. take a speaker cord out of the back of the van akin to the sub and use the main and too thin to control the sound volume. I put mine speaker into the single "bridge" output on the rear & switched the "amp mode" to "bridge".