I'm a big fan of adding subwoofers for music listening. Unless you have a big space and a big budget most unpowered towers can't manage more than the mid-30hz region before rolling off hard, and even then you're using almost all of your amp's power to handle the bass.
Using stand-mounts (or even towers) that are bass managed with a subwoofer or two eases the load on your amplifier and gives you much deeper and stronger bass than you'd get with any passive tower.
I'm a fan of using electronic bass management vs the passive high-level cable hookup that REL and Vandersteen use. Unfortunately it's not something found in most 2-channel processors or integrateds, but at least there are some nice options now, and most allow you to apply some room correction DSP to the lower frequencies (and the upper ones if you wish) to smooth out peaks so there's no boominess. The better systems, like Anthem's ARC will also pick the best crossover point and slope automatically so that you can get a seamless blend between your subwoofers and your mains.
Using stand-mounts (or even towers) that are bass managed with a subwoofer or two eases the load on your amplifier and gives you much deeper and stronger bass than you'd get with any passive tower.
I'm a fan of using electronic bass management vs the passive high-level cable hookup that REL and Vandersteen use. Unfortunately it's not something found in most 2-channel processors or integrateds, but at least there are some nice options now, and most allow you to apply some room correction DSP to the lower frequencies (and the upper ones if you wish) to smooth out peaks so there's no boominess. The better systems, like Anthem's ARC will also pick the best crossover point and slope automatically so that you can get a seamless blend between your subwoofers and your mains.