I have Two 12" Type-R's, vented at 2.0Cube each chamber tuned at 34hz and they sound amazing. Sound Quality is superb, and loudness is plenty to satisfy anyone. "Well Almost anyone"!! //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif Compared to CVR's they provide much better sound quality. Just make sure they get enough power, and power them with something that will throw out the watts.