That doesn't look like the stock speaker to me, not sure where it is from. A good aftermarket head unit can put out 40+ a channel so it would explain why they sounded bad. How was wiring the tweeter? Can be a pain to feed it down imo.

Also, remember if the speaker you bought is a coaxial the lower speaker will have a tweeter as well.

Sent from my ASUS_Z00TD using Tapatalk