most likely the speaker is shot, to be honest it's not a brand I would touch, but are cheap enough to replace. If all you did was replace the speakers and did a decent job wiring the speaker should be fine my guess is it would be the speaker itself. I would check to see if you have the wires backwards first to solve any quick issues. hope this helps.
2006 Mustang GT Premium Satin Silver Metallic | 5 Speed Manual | Hurst Short Shifter | K&N CAI | JSR Strut Brace, FLCA Brace, Rear Shock Tower Brace | Flowmaster Axle Backs | Ford K Springs | JM Trackbar | 93 Bama Performance Tune