I had an RE SR 15" in a 2.65Ft^3 enclosure tuned to 35Hz, and it was loud & clear. I even put about 800WRMS to it. I wish I would never traded it for the prefab box. //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif Oh well. I say go with it. I have no idea what the IDQ sounds like, nor the price of it, so I can't do a comparison.