Do I need an interface?
What wiring harness/adapter did you use or did you cut and splice? Double-check that everything is wired up correctly.
If you look by the spare tire do you see an amp?

Monsoon FAQ Sticky:
https://ls1tech.com/forums/stereo-el...nsoon-faq.html
Check your head unit for any settings that might affect bass output such a separate sub controls.





