I have a 2016 audi s3 and added a jl audio hd 600/4 and jl audio hd 750/1. The 600/4 is running the oem front end highs and mids while the 750 is running a single 10 h.o box from JL. Now the installers added a jl audio fix 82 for factory integration. Now the problem I'm having is the highs are too bright and not enough balance between highs and bass. Also I hear some crackling coming from rear passenger door speakers not always but at particular music notes. I also have the front drivers door sprakers cut in n out. But the worst part is today......while driving around 15-20min and listening to the stereo, I smelled a bad odour...now I thought it was coming from outside but when I pulled in my driveway and shut the car off, I noticed some smoke coming from the rear lid panel which houses the oem woofer. Not sure if other speakers are in that lid but I haven't touched it since. I do have an appointment with the installers to install an audio control unit to replace the fix 82.