okay, my friend and i just got done installing his jl audio e1200 amp pushing 2 10w0's in a sealed box.
anyway, when we turned his truck on, we heard a "pop" noise come from the speakers. we didnt think much of it at first... we looked at the amp to see if it was in protect, messed with the headunit for a sec... anyway, i had him turn the truck off, and i heard the pop again. we turned the box around so we could see the subs, and cut the truck on again, and the subs not only made a pop noise, but they stayed pushed out to their maximum excursion. so i immediately yelled for him to cut it off, but we were too late.
We took the speakers out of the box, amidst plumes of white smoke, and noticed that we had nicely melted the voicecoils. so i broke out the multimeter, and i measured 36 VDC coming from the amp when the truck was on. Thats pretty ridiculous and most definitely what fried those speakers.
I have done a few audio installations in the past, and i have never encountered anything like this before. Any help is greatly appreciated.
Whoa, if you're getting that much voltage at the speaker terminals, something's seriously shorting out. Check all your wires very carefully. Disconnect all rca wires. With the amp hooked up, connect the remote wire to the pos wire. This will turn on the amp by itself. Now measure the output terminals. If with no load, you're still getting 36v, then the amp is missed up. That happens sometimes, you do everything right and the amp blows. If the output stage looks okay, then connect one of the subs that's still working. It shouldn't cause any "popping" noise since there is no input load. Now connect the rca wire to the amp's input terminals. Touch one of the rca wires with your thumb, if you hear a hum, then that channel is fine. Test both. If the amp passes that test, then it's good. Now to test the amp with sound, find a portable cd player or iPod and connect the headphone's output jack to the amp's input rca via adapter. You should hear music as you increase the volume on the portable unit. You might want to also measure the HU's preouts just in case it's faulty. One more thing, make sure your gain/level is set correctly according to your HU's preout voltage.
oh yeah, by the way, we did disconnect the rca cables, and the dc voltage still comes through, the only thing we havent tried is the connecting the power to the remote wire, i'll give that a shot too. Since we did try it w/ the disconnected rca cables, and the problem still occured, do you think that it could be a faulty amplifier? And do you think that this will be covered by jl audios warranty
If the amp is under warranty, don't tell them anything. Just say it's defective amp. From what you described, it sure sounds like a defective amp. Stuffs like that happen. I had an amp that died for no reason. It's too bad that your friend lost the sub/subs due to a defective amp.
Anonymous
Posted on
hey isaac, or anyone else, could this happen from hooking the rca cables up before the ground wire?