I put these in the front doors and some NVX 6x9s in the rear deck on a Cobalt to replace blown factory speakers. They were just running off the (extremely weak) factory GM radio.
I was very, very impressed with their performance for a budget speaker. The tweeters were bright without being too harsh, and the bass response was unreal for the tiny amount of power they were getting from the headunit. Now, they didn't slam like subs or anything, but it was solid bass.
I think it was