i bought 4 Alpine 170A speakers cuz I thought I needed 4. well i only ended up needing two. so im wondering how it sound if i pulled out the "sub" next to the rear seats, and put the other two alpines in there. than get a separate sub and maybe an amp for the hatch.

or should i just sell the other two speakers and replace the "subs" too?

i know absolutely nothing about car audio....

 

Sell or return the Alpine speakers. Then get an amp and sub to go along with your Alpines up front. Thats all you really need for good sound. You can always add rear speakers later if you want. Click on the link below to see my 3 speaker system.