Most material requires less than 1 or 2 watts most of the time. But low frequency sounds need more. Depending on your listening level and the bass content, you might be pushing into 30 watt levels on peaks. Although 60 watts only gets you 3 db more sound level, it does provide more headroom before clipping. Clipping can be quite harmful to speakers and should be avoided.
I would be OK with 30 watts if I expected never to play at higher volumes. Otherwise, stay with the speaker manufacturer's recommendation.
I would be OK with 30 watts if I expected never to play at higher volumes. Otherwise, stay with the speaker manufacturer's recommendation.