Your head unit isn't going to play very well with that 5 channel amp.
Swap the positive and negative. Sometimes the adapters are reversed and the speaker is out of phase
Turn up the bass and turn up subwoofer in your settings
It's a free air subwoofer, it doesn't need as much power as one in a box
The signal the amp is send the factory subwoofer is the main reason you aren't getting much sound. It's crossed over very low so that it only hits on deep bass
https://www.autohack.org/
And
https://www.apkmirror.com/apk/team-dewitt/viper4android-fx/viper4android-fx-2-7-2-1-release
Viper4android has an EQ that can flatten your signal and kinda override the dumb factory crossover points
Is what most folks do to improve signal before you start having to spend a lot of money getting signal adapters and more amps and speakers
Good luck
That's just it came, it was like that in the pictures so I see nothing wrong. It's supposed to be a direct replacement after all.Why did your subwoofer come with wires attached to it? That should have set off all the alarms and sirens in your head telling you to return that used subwoofer
Wasn't used?So you bought a used subwoofer intentionally?
The whole problem was my audio cut out for no reason when I turned off and on my car one night, so I took it in to a place my grandpa recommended and they said it was my amp, so they got me a replacement stock amp from a 2017 SI, and it sounded a bit different, more notably my subwoofer, then they said it may be that my subwoofer is bad which made my amp go bad, so I got that subwoofer from the link above and I get little to no response from it from any song. So my neighbor who is hugely into car audio, recommends I get a 5-channel amp, so I go to a shop that HE recommends, and they say it will cost $1300 including wiring, parts, installation, and new door speakers which I need cause the stock ones will burn. I'm only upset because I just wanted my audio system to work like it did before, nothing else, and I got sucked into a hole of spending $1300+Ah i see, so its a kit that makes more sense now, should be fine im sure whoever put it together already did the homework to figure out the correct wiring. Make sure to set your eq and subwoofer level in the audio settings.