hello, my stock speakers blew out so I'm looking to replace them.

I been debating between, polk audio 6 x 9 & 4 x 6 or infinity's

I don't a head unit in my Alero ( 2001 )

and didn't plan on getting an amp unless I really do need to

wasn't really planning on subs either.

I mainly just want some speakers that sound decent and wont blow out when i play them loud

I don't know to much about car audio, do I need a head unit to have my speakers sound decent , or amp?

as of now I was only planning on spending $200 on speakers, can you guys give me some advise?

thanks alot