Has anyone heard their stuff? I heard a salesperson's system at goodguys the best SQ I've ever heard from car speakers. No distortion what so ever. Diamond audio rules. DiamondAudio.com
Everyone is entitled to their own opinion. Next time you see him ask if he has ever own a pair. I bet not, check out this web site for answers under the car audio http://www.decware.com.
I would have to say the mb quarts would be a better choice they have crystal clear output...well at least on my 6.5 in the doors. I havnt heard the diamond audio, but it hasnt been talked good about, plus the price is a bit much. I know there are better deals out there!!