@rhatten5 you need to check the wiring to the speaker that is not working properly. Depending on which side, it may be the crossover cable or the wiring right on the speaker. Yes you can replace it but you need to find a replacement which is not always easy. At this point I would check the wiring first. Post some images of what your speakers etc. Look like so we can see what you see. iFixitでの質問に画像を追加する方法
Check this video to get to your speakers etc.
Use a multimeter and check to see if there is continuity from the plug/board to your speaker. If not then it is the crossover cable. If there is then the issue is with/on the speaker.