Okay guys so firstly here's my car setup:
JBL GTO 938 (rear speakers)
Fusion EN-AM6004 600W Amp
Alpine CDE-9873 Head Unit
This is my first experience with car audio system. I got these components installed in my Coure from regal. The amp is 4 channel btw but I'm using 2 speakers only (rear). I asked the guy to connect the RCA cables on the left side as the amp setting was already done there, but after running it he said there's a problem on that side since only one speaker was working. So after playing around with the RCA connections he installed an extension which was connected to both sides, hence one speaker connected to front and the other to the rear terminal on the amp. Both speakers started working after that. Since I'm a noob in this I didn't know if this was done correctly, as long as it was working properly. Here's how it was done:
Didn't take a picture of the power cables that time.
For a month the system was working perfectly fine with good punchy bass and crisp clear sound. But then suddenly the sound level dropped and became distorted. I wasn't getting the same volume as I was before. So I went to get it checked from the same guy and after diagnosing he found out that the point where the RCA extension was connecting with the RCA cables from the head unit was being pressed under the amp hence the sound problem. He did move that joint further up where it wasn't being pressed and the sound was fine again as before. At least that's what we believed was the problem.
But then after 2 weeks when I was driving with the volume cranked up for about 20 min or so, I noticed some sound distortion and then suddenly the sound was killed. The head unit was on but I saw that the amp was shut down as the red light had turned on instead of the green one. Then I shut the system off for about 10-15 min and it started working after that. But again the same issue occurred so I thought maybe its because the amp is overheating and its going in protection mode. After the second shut down the sound quality wasn't as good and very less sound was coming now at the same volume level. I had to turn the volume way up to hear properly, meaning the amp wasn't working properly.
I went to the guy again and he did some tweaking with the power cables and the settings on the head unit. The sound was fine but then again the bass wasn't as punchy as before. I could "feel" the bass before at 10-15 volume level. One would say I didn't even need a woofer! Now even if I turn up the volume to 19-20, there is good bass, but the sound is loud only and the bass is not as punchy. I asked the guy to remove the extension and connect the RCA cables directly coming from the head unit. So he connected wires of both speakers to rear speaker terminals on the amp and switched sides of the RCA cables to the right completely. Now the setup is like this:
I've also noticed that the RCA cables were connected to the output terminals before, but now they are connected to input, which I believe is how it was supposed to be in the first place.
But to no avail, the sound is still the same. It IS crisp and clear, but the bass is not punchy as it was before. For an average or first time listener it is good. But for someone like me who has experienced a much better thing before, its just not the same feeling. The difference is huge. Plus I have to play a little louder now. The guy couldn't figure out the problem in 3 hours! I even tried playing around with the settings from the head unit but still nothing. I hadn't messed up with any settings before, the issue just appeared out of nowhere.
Anyone here has any idea what seems to be the problem or what I should do?
