I think after four years of faithful service my Sub amp may have croaked. I originally had it wired high level to stock HU via the rear speakers and it has sounded GREAT since day one. I recently installed a new Pioneer 8000BT and wired it with RCA cables for better control and SQ. It worked great for a week. The other day, my wife disconnected the box for more cargo space and when she put it back in, this problem arose. The Amp is a Lightning Audio LA150.2 driving two ten inch Lightning Audio subs BRIDGED in a Q logic sealed box. I don't remember the specs on the subs. The amp never went into protect mode. The only thing it did was before I turned the gain down, the power light went out, yet the illumination still was on. I cycled the power and it came back on. As you can see in these videos, the volume on the receiver is low, yet the subs are at full blast with what I think might be some kind of feedback. Things I tried were: I wired up each sub individually both bridged and stereo and got the same results in both subs. I also disconnected the RCA cable and hooked my high level harness back up and I got the same result which I think rules out a bad RCA cable. Any suggestions before I scrap this amp? I know Lightning Audio is lower end, but this setup has been GREAT for almost five years. I had to trash it if its something I can fix on the cheap. http://www.youtube.com/watch?v=hQxTD2IY5OA http://www.youtube.com/watch?v=tI3BqcAtlbw http://www.youtube.com/watch?v=3k-oVqb6hLs
Wow, man, that sucks! Something's definitely awry. Have you checked the output on the amp's speaker terminals with a DMM or oscilloscope? You may also want to check the RCA's & high-level-input's connector-to-pcb grounds inside the amp. Do you have another car you can check the amp in, or another amp you can check in your car to rule out problems with the HU? Maybe it's time for your wife to buy you another amp.
Might take it somewhre, or if you can do it yourself......bench test it to be absolutely sure its the amp and not an issue with it in the car...... A bad ground, a loose power wire, a crap audio interconnects...lots of potential issues....try a bench test and see what happens.....this is the first step...if you are happy with it then why buy a new amp if it aint bad?????
Is that noise not desirable? Oh, THAT noise! I thought you were talking about the RAP. Seriously, try this test: Unplug the inputs Measure voltage across power & ground at the amp Turn amp on while still measuring voltage Did voltage remain about the same? Is the noise still there? If the answer to both questions is "YES", I'd say "Bad amp". If one or more answers is "NO", I'd look further.
I solved the problem It turned out to be a short in the RCA cables. I didn't think at first that they'd be the problem cause I did try to re-hook up the high level harness and I had the same problem. Turned out that the high level harness ground worked loose as well!! I tested out my amp with my new 25ft. RG-6 Sub cable(mono) and its working fine now. Since I'm going to have to buy a new cable, should I get a 12ft. RCA cable or buy a shorter RG-6 sub cable? I've only used patch cables for my amps, but since its a 2 ch amp(bridged), is there a reason not to use a Sub cable? Is the signal to the amp stronger if I use a stereo RCA cable even though its output will be mono??
