I always used to say only 18's sound like 18's. There is just something so etheral and effortless about them. They only have to work half as hard to do the same job as a 15 incher. If you want to add something in the mid-bass region run some 8 or 10 inchers as mid-bass drivers along with 15's or 18's. 10's are really too small to go real low, though they do OK especially in small spaces like Ranger cabs.