distortion in one speaker only

Hey everybody. well for a while now my system has had no issues. WHICH IS GREAT. so the other day out of the blue my front right (driver side) speaker started to distort, like it had blown or just crakling hisssing noise... Thought it could be the speaker.. changed it and yet it stil is going on. HERE IS THE KICKER, when i initially start my car this happens and then goes away after about 15-20mins. its just weird!!!!  I own a chrysler 300 2006- avic n2 head unit, i changed my door speakers above noted to kicker 6x9's and it is powered by a power acoustic 4 channel amp. so what gives guys? anything? Thank you all.

On another note, ive had some grounding issues with my head unit in the past AS YOU ALL KNOW damn pioneer's NEVER AGAIN!!! i had to ground all the rca plugs to the chassis of the head unit

Make sure you don't have the speaker wire next to a power wire etc.. if so run it cross them at a 90* angle...Haha J/k.

Is the speaker wiring upgraded or is it oem? Have you checked it entirely for damage/grounding out, maybe pinched off by a panel?

Sounds like an amp problem to me.  But there are 2 things you need to do to verify this.  You need to do them one at a time.  First you need to swap the speaker wires at your amp.  Connect front right wire to front left channel of amp.  And front left wire to front right of the amp.  If the problem stays on the same speaker, you have a speaker or wiring problem from amp to speaker.  If the problem moves to the other speaker, you have an amp/headunit problem.  If it moved to the other speaker, connect the wires back to the correct channels.

To find out if it is your amp or your signal source, you will need to swap your RCA's  left rca to right input of the amp and right cable to left input.  If the problem stays on the same speaker you have amplifier issues. If it moves you have radio/processor issues.