Im going to be using a Hifinics 1606D (1600RMS) on a Pioneer Premier 3002SPL. Im getting Polk Speakers for my insides with a Crunch 4channel amp (400RMS). My headunit is a pioneer 5900ib. Do I need a upgraded amp and a Kinetik battery? Or should I get a capacitor?
If you can keep the volume down, then no upgrade is required. However, if you must listen loud, upgrade the alternator first, then the big 3. Battery is not a must unless it's dying now.
set your gain right and check your voltage, also look and see if your lights dim and stay dimmed, if so do the big 3 and check again, then get a bigger alt if needed.
Unless you've got a big stock electrical system I would expect an alternator upgrade is in your future. 1700-1800w is a lot of power for even the biggest stock set ups.