Sub cuts out if I turn up the volume
 

Ok, so I bought this car from my brother in law, who got it from someone else - long story short, it came with an amp and a 1200 watt sub. Everything works great - bass is nice and clear, not a hint of distortion....until I turn up the volume. Then the sub just cuts out. When I look in the trunk, the amp's protect light comes on when it is at a higher volume. And I don't mean irritate the neighbors loud, it's at the point where you can have a conversation without raising your voice to the passenger at all, then the bass just goes away. The strange thing is, when the amp doesn't go into protect mode in time, the bass delivers nicely. I have no clue what I am doing, so any help is appreciated. If everything is fried, I won't be upset. I just hate having the bass, then all of a sudden not having it

what model amp and sub is it?

It is an Ultimate T2 5450. Sorry for the late reply, not on the computer much

I'll need to know the make and model # of the subwoofer as well. you may have to pull it out of the box to get it.

What size power wire is going to the amp? Good battery? Most common is having a poor power supply to the amp and the amp is starving, then goes into protect mode. What's the sub ohms?

It may be that your impedance is too low. When a 2 channel amp says it's 2 ohm stable, that means 2 ohm stereo. when you bridge a 2ch amp, each channel sees 1/2 the impedance. So if you bridge it at 2 ohms, the amp is actually seeing a 1 ohm load per channel.

A few things I would check is.. first power, put a multi meter on the amp's power terminal and set it to DC voltage and play the bass till it shuts off. if the voltage goes below 11volts on a strong bass note then the power from the battery is an issue. it could be a bad fuse as well. second, check the woofer's impedance.. some amp don't like 2ohm in bridged mode etc. or it could be a bad output transistor.. which could cause the amp to run hotter then normal and would go in protection or the amp's power supply might be bad.