Hi friends, I am hoping you can help me with my first install. I have a pioneer HU (using their sync app / network mode / hardware as my crossover) going to a RD400/4 amp , powering 2 5.5 silverflutes and 2 seas prestige tweeters. My issue is confusing me a bit, my right midwoofer is producing no sound. Amp is set to 4 channel and stereo. If I take the left channel (working rca) and put it in the right channel amp instead of either sound or no sound, i continue to get sound out of the left woofer . (nothing is crossed, i thought maybe a terminal popped off but it doesnt make sense the right channel is getting a knowing working signal but still plays left). Things to note, amp I bought used, I have the main woofer rcas connected to HU but nothing connected to them on the other end yet. (bought a shallow 10" dayton that arrives tomorrow) . Thanks guys sorry for the beginner question.