the pioneer 4in speakers i had in my W124 sucked imo! thats why i gave them to my dad
he has them in the dash of his W123 run by the radio's power with 6.5 dual's in the back. Sounds fine for everyday listening, not crazy like the setup in my W124
Go with 4in rockfords for the front they are good! those MB quarts need to be pushed with an amp.