Okay, so this is a problem we were having with my friend's truck. The subwoofer is good, I tested it in my car and it works normal. I'm not testing the amp in my car because I have my amp pretty hidden and that would be a real pain the *** to unhook it just to test this other amp.


We have it wired up correctly, but when we turn on the stereo or turn the car on, the amp gets power, but the subwoofer just sits there and starts sucking the cone in, and holds it in place sucked in until you turn the stereo back off.

Anyone know anything about this?

 

the first thing that I would do would be to find somewhere to test his amp. If its something wrong with the amp, then testing it would save you a ton of troubleshooting time.

if it works, or if you don't want to test it, I would start by unplugging the rca cables from the amp and see if still does the same thing. doing this would narrow it down to being the Radio/RCAs or the Amp/wiring. and then go from there.

 

Putting another amp in the car solves the problem. I guess it's the amp. We're heading to the pawn shop today to see if they have anything decent.

 

Unplug the inputs to the amp and power it up. Measure the DC voltage between the output terminals. If more than about 0.1 volt, amp is bad. Applying DC to a speaker will cause the cone to pull in or out from it's normal centered position.

 

Alright. I'll do that when he gets here.

 

well if it stays sucked in then something is wrong with the amplifier and its giving power to the sub! not good.
if it just sucks it in for a second and goes right back and plays good then thats just a typical turn on thump from a cheap amplifier.

but to check his amplifier just run some speaker wires from his setup to your sub speaker wires. thats how i tested friends systems along time ago.
but if his sub sounds fine with your amplifier then most likely its just his amp that is bad or maybe his rca wires are shorted out somewhere. so another thing to test would be get some rca cables and run them from his rca ends and run them to your amplifier for a quick test. if the audio goes jacked then his rcas are bad.
commonly damaged when reinstalling trim pieces after running them.