Okay so after reading countless threads I'm starting to get a handle on the science that is car audio. I have an 07 AC, and here is a basic outline for my first upgrade.
Front - Hertz ESK 165 Components (6.5")
Rear - Hertz ECX 165 Coaxial (6.5")
Possibly a JL 10" sub that I can plug and play when needed.
Question I have is do I really need a high frequency sound source in the rear? I ask this because Hertz also offers the EV 165L 6.5" woofer which claims "powerful, solid bass, even without a subwoofer". If I could get away without having a sub taking up valuable room I would. Having said that, would I sense a sound imbalance with the highs up front and only lows in the rear?
Replacing the HU is out of the question, at least for now...