@gregjacob Its actually a myth that a speaker can be good for one genre of music (rock) and not another. If your speakers aren't good for rock, then they are likely weak with jazz and classical too. Put another way, no-one has ever figured out a way to design any electronics (including speakers) to favor a certain genre.
Put yet another way, what makes a speaker good for rock should make it good for classical, jazz and folk just as well. If it isn't, its not that good for rock either, which is simply to say its not that good.
Now it might be that you want more sound pressure or more bass. That will benefit classical recordings too. The thing is, humans all use the same hearing rules, so classical, jazz, folk, electronia, whatever- all has the same energy spread across the frequency range. So it takes more power in the bass and almost none at very high frequencies.