Some amps will not power up internally if u donot have remote wire. Also if u connect power then remote wire it will not power up until u reconnect in correct order. But if all that is ok. Than u have a bad amp
Disconnect the speakers one at a time and see if it comes back. If it does not then it is either being over driven by the head unit or it has an internal problem.
Bass knobs are just Rheostat "switches" run to a 2.5mm jack.
They are all essentially universal, and you can find them for very cheap, typically around what it would cost to build one.
Here's a few things you can do to find out what's wrong ,first make sure you have 12volt on your batt lead and your remote turn on and make sure you have good ground.Take an ohm meter or a 9volt battery and put across/momentary the voice coil on your good sub should read somewhere between 2-8 ohms,if using a battery speaker should pop.if ohms check out or speaker pops your good connect it to your amps output.Next make sure you have a signal to the amp,if you have multiple amps use the rca cable from amp that's working for testing purpose.if all that checks out you'll need to have your amp check by professional
