sure, you can generalize that most of the time within a certain companies line of woofers the 15" is going to be louder and play lower than a 12", a 10", or an 8" of the same companies same line of product. and at the same time you can generalize that the smaller woofers are going to work in smaller boxes, work off of less power, and have a lower Qts. i mean hell, if they designed them all to have the exact same specs, lets face it, everyone would just make one size of woofer and be done with it. but they dont, because that would not be an ideal business model.