Small or large sub for music

For one thing we’re discussing subs, not full range. For another thing the reason you need a lot of power for many speakers to produce bass is that they are 3 dB or 6 dB or 9dB down at very low frequencies. Many speakers are more than 9 dB down 25 Hz. Which is why you sometimes need a sub in the first place. Hel-loo! If you need a lot of power to get decent bass you’re doing it all wrong. This ain’t rocket science, folks. 🚀

Why, it’s almost like you didn’t go to school. Oh, I almost forgot. You didn’t.

It depends on the power available and the efficiency of the subwoofer. And of course the capability of the subwoofer, Bass frequencies do not inherently require more power than any other frequencies. Other factors can be involved such as absorption of frequencies in a given room, standing waves, etc.