MTX Thunder x504 RCA Craziness

[ninjasword71]

First of I have a new JVC deck with two sets of RCA outs. One set says it runs the front and other the rear/sub. The deck runs the front two factory speakers directly while the mtx amp runs middle and rear speakers via rca cables in my Yukon. The rear/sub outputs from the deck are used directly to channel 1 and 2 on the amp which run four 6.5" speakers. 2 in rear door and 2 on back roof. Everything worked great for a week when all the rear speakers had no sound suddenly. I played around and found that by unplugging Chanel 2 rca from the amp made the four speakers work again. The rear door speakers are wired into the first channel using two positive and two negative. The rears are wired using a single speaker wire joining both speakers. I want to add a self powered sub this month. How can unplugging channel 2 make all the speakers work suddenly and how can I add the sub now? I know the speaker hookup is wrong but with only 4 outputs on the head, not sure what to do.

Click to read more...

 

[ninjasword71]

Basically just wondering why disconnecting 1 RCA lead would make all 4 speakers work. 2 speakers per channel. It worked for a week with both RCA leads (channel 1 and 2). Anyone? Hope this is not too stupid a question....