Summary: I bought these to replace the stock speakers in my 2004 Chevy Trailblazer. The stock speakers have a much better sound. I'm not sure if the Kenwoods need more power to get a better sound, but the the factory Delco speakers made the Kenwoods look real bad.
Summary: The best thing I like about the speakers was it fit my European car without modification. I won't even mention the better sound quality... hint hint... The old speakers were actually 6.2 inches. Can't find them here. Anyway... I was prepared to make an adapter out of MDF but was curious to see how off it was. To my surprise... it wasn't. The only thing extra I had to do was get some foam rubber and put along the outside edge of the speaker.
Summary: These are what they are - a solid basic speaker for cheap. They can take a beating from a stock stereo. If you want high fidelity or fancy stuff, this isn't for you - and neither is anything in this price range - I paid $25 including shipping - but for that price, I got a speaker with high sensitivity to take most advantage of what little power my stock stereo has, decent bass for what it is, and a vast improvement over my 16 yr old blown out stock speakers.