I think theyre pretty good. I have a 96 Ford Explorer, and I have 4- 6x8" Roadmasters in the doors, and a custom install of 4-4" Roadmasters in the trunk in the side panels. I've had them in there for about 2 1/2 years and never had a problem! They shake my doors, they shake the front seats when youre sitting in em. Im powering the 6x8s with a Dual XDVD710 (head unit) and the 4"s with a VR3 200 Watt amp (also great!) and it matches the RMS with the deck, so its perfect. I can easily max out the volume on my headunit and they dont get that distorted! And like I said, I push my stuff to the max all the time for 2 1/2 years now, and these roadmasters haven't blown. I have posted a vid on youtube of my setup from about a year ago, the link is
http://www.youtube.com/watch?v=jncGo7OSu3A
