sub loses power

for some reason it seems like my sub will sound weak at times and them sound better. I thought it mightve been a bad ground connection since i didnt have the ground wire on bare metal. so i used a die grinder and cleaned it down. that didnt do anything.

im wondering if maybe i need a better alternator or a capicitor. or maybe even a new sub or amp, ive had them for almost 7 years. kept swithcing them out everytime i got a new vehicle.

 

No to the alternator or cap.
do you have a friend with another amp you can use to test? Or just hook up your sub to his amp? Find out the problem by narrowing it down.

 

honestly, im the only one out of my friends that has a sub and amp. im actually the only one that likes to do things to my vehicle. my friends just drive em, boring.

 

What equipment? (models not just brands)

 

i will have to look to get the models. i think the sub is 12in alpine type E. not sure about the amp. they were both hand-me-downs, so who knows how old they both are.

my older bros friend had them, then sold it to my bro, then gave it to me.