What speakers would work good with factory system headunit without a amp I am just looking to add speakers now I need all 4ohm 6.5 in doors and 3.5 in dash I was looking at JLs or focalbut crutch goes told me that I need an amp to run a JL speaker and the focal speakers are fine but I'm not sure about them just wanna get some opinions my current thoughts are focal in the doors and infinity in the dash what do you guys think?