If your only trying, not buying, go ahead, it won't kill you. I've always felt it best to leave the whole frequency range in the hands of the speaker designer. IMHO, it is very difficult to blend a sub with speakers on music successfully. I've heard a lot of attempts, but subs should be left to HT use, again that's just my opinion. If it won't cost you anything, it wouldn't hurt to 'play' around with it a little. I would recommend using the lowest crossover level possible.
John
John