Hot rear speakers and amp

[Julioengineer]

I finally got my car (2014 Ford Focus ST) to sound just the way I like it but now the rear speakers get hot and smell like they're cooking, the fronts are fine and don't smell or get hot at all. Funny thing is the rears still play. I am using the factory My Ford Touch premium system and I originally had JBL speakers and the rear tweets cooked. I am now running Alpine SPS-610C's in the front and SPS-610's for the rear since I didnt want tweeters right by my ears. I have since added an LC7i and it solved my amp shutting off problem but the rear speakers still get hot and smell. The amp also gets very hot and eventually shuts off for a few minutes while it cools. The LC7i is set to less than half on the main and rear outputs and I have these summed to get the full range audio to the JBL GTO5-EZ amp. The sub output is a little louder but that's because the signal is lower from the factory amp. I'm using a 2013 Sony amp and not the one that came with my 2014 ST so there shouldn't be a load issue. I am a little frustrated because now the car sounds great but my rear speakers smell. Anyone that has had this problem and can guide me in the right direction, I would really appreciate your help. Maybe you know an installer who has worked with these new amps because every time I call JBL for tech support I get someone in India who then transfers me to some kid working out of his house with no real knowledge about the amps. Thank all of you in advance for any help you can offer. I really want to solve this issue before I fry some speakers. I realize I am probably asking a lot as a newbie to this forum but I am desperate.

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[Jeffdachef 5,000+ posts]

Monitor your system voltage at full blast. If its dropping really low, then you are either clipping or needing electrical upgrades such

as "the big 3"

lower the gain on the rear or raise your high pass filter or back off the bass. You might be clipping the rears. Especially with a line out converter, there's two gain knobs in the equation now, they act like multipliers so you can have a clipped/distorted signal a lot easier. You cannot guesstimate this, might want to rent an O-scope from an electronics store to set the gains on your LC7 and your amp properly. Even if your ears cannot hear distortion it may already be happening.

Also check your grounds/redo your grounds, might not be a good spot or you need to sand it down to bare metal. Amp might be clipping due to resistance. Use a digital multi-meter to check the impedance at each ground/connection.

 

[Julioengineer]

Jeffdachef thank you very much for the help. After reading your post I went back to see the video from audio control on how to adjust gains and I checked my voltage as you recommended. Fortunately there was no current drop and the ground was solid. I turned down all the gain on the amp and adjusted the LC7i as per specs and viola, no more burnt smell and the amp is running warm and not hot to the touch. Now I just need to tweet the sub channel to get the nice well rounded sound I like and I'll be done. Maybe I canalso tweet a little more volume if I need to. Once again thanks for your help. I imagine from your user name that your a chef, maybe we can talk food one day since I like to do some cooking myself.