I have a set of JBL P9650C component set hooked up to an Alpine V-Power MRP F450. Originally I had each set bridged at 4ohms to 140WRMS. Everything worked fine until I was cruising to an appt and I noticed it sounded like my left speaker wasn't hooked up. Once I finished my appt I put my head to the speaker, and found out it was in fact making noise, but VERY quiet. The next weekend I went ahead and started trying to figure out what the issue was. List the steps I tried so far

1) Switch around, try new, switch pre-outs on the back of the HU -> nothing changed at all no matter what i did with the RCAs

2) Tried wiring the speaker to a single channel, to the ch the other speaker was working on, and then finally straight to the head unit. -> no change

3) Pulled apart my door panel, checked all the connections from the amp - x-over - to each speaker. Reseated everything, checked everything in x-over (everything looked fine), and then hooked up the speaker straight ot the amp with a short pair of speaker wire (possibly wiring issue running through to car was my thought) -> Nothing changes

4) the cone on the speaker feels fine when I depress it, doesn't seem stiff or make ANY noises. Finally just put it back together and am now posting on here for help. I'm sure I"ve eliminated amp, HU, and wiring as any issues.

Here's the weird part though, one day I turned my car on and both started working. Next time I started it up, speaker went incredibly quiet again. Did this a couple of times so far too. But only briefly, before it'll go back to the original problem. I'm going to replace them, unless someone has any ideas? Any help would be much appreciated. Thanks