If a sub sounds thick then it's crossover is too high. There is no such thing as fast bass. If the bass is fast, it is not bass. The ability to blend with smaller speakers is the job of a good crossover and room setup. Have you ever seen a small bass drum? A small sub, in order to move as much air as a large sub, has to move further than a large sub. Therefore a small sub cannot be any faster than a large sub when making the same amount of bass.