OEM or replace HU and speakers

[familycar]

so did anyone do that test with the pink noise cd or whatever to find if it is neccessary to replace the HU with an aftermarket one. or put in a cleansweep. is the OEM HU junk with bad eq or is it ok to just replace the stock speakers with aftermarket ones and a sub. or do we all have to go all the way and replace evereything.