AM, FM and SiriusXM aren’t nearly high enough quality to get the full potential out of the Alpnie or HK systems. A high quality source like Apple Music, Spotify, etc. Are the way to go.
I think my HK system sounds amazing and could actually use much much more base on certain tracks, all of my passengers think it sounds amazing aswell. This is with the bass set at +5 and sound deadening installed in all four doors and on the rear of the cab.
Sound quality is going to vary between stations aswell, my local FM rock station sounds like crap and is all bass so maybe that’s where people are having issues?