Summary: I bought these speakers for my wife and her 'soccer Mom cruiser'. Speakers are matched with the Kenwood KFC-X173 6-3/4" speakers in the front doors, Kenwood DDX-470 head and Clarion XC1410 amp. I installed the speakers before adding the head and amp and gave them a try, what a difference over the factory speakers. Well worth the cost.
Summary: Installing these replacements in a 1996 Volvo 960 (rear deck) and fading the sound system a few notches to the rear made even the older OEM speakers in front sound better. Far less trouble to install (but yes, the back seat does have to come out of this vehicle) than a full component set (involving doors and dash as well), and the rear deck only option provides really good sound across the entire range.
Pros: Very clean sound across the range; suitability of fit for my application
Conclusion: I have 2 sets of these. One set in my escape running 100 rms off Memphis 2 channel. Sounds great. Highs very clear, bass is 8/10 at best, mids 7/10. My other set is running about 75 rms off vibe death box 4 channel and they sound average. I do believe that amp is not up to par so its being returned. They are also set up in both vehicles with alpine spr-69c's as other 2 door speakers. The alpine's are just in a different class. Worth the money to me.
Conclusion: I have these speakers put in the back of my 2007 grand prix. They provide good sound and alright bass. The only issue i have is i cant hear them over my stock speakers i have up front which in my opinion have better sound and bass than the kenwoods. I bought a 350w amp with them which will get the best sound out of the speakers. On a positive note though these babies are loud.
Summary: Put a pair of these in Datsun 280Z rear because there's not a lot of options for locations. Have one of the vintage look head units for power. Sound quality is pretty darn good. Much better than anticipated.
Pros: Good deep sound, lot of speaker for the money.