I agree with Jaybo and Johnk. I currently use single driver speakers, have owned several others and heard many. Unless you are going to spend big money on a well designed and built example, you may be disappointed for your preference of music (classica/opera). Yes, an inexpensive SD speaker can play loud (Cycloneharry) or play well in a small room or near-field (Johnk), but it takes a seriously designed/built Single-Driver speaker to pull off Orchestral or Opera at concert volumes. All of the moderately prices SD speakers I've heard fail miserably at large scale classical music.
That said, for my music preference of small group jazz, folk rock, chamber music or even well recorded rock music, a simple AS single driver speaker can be a revelation in a smallish room and especially in the near-field.