Have a look for some used Polk RT-15's on ebay. Superb small speaker. Not quite as compact as the Alpha B1, but it's a great way to get fine sound from a small and inexpensive speaker. Easily my favorite Polk speaker. Actually out-performs the more expensive RT-25. The RT-15 has a very even balance of sound. There are much bigger, louder, bass-heavier Polk speakers, but the RT-15 gets a lot right and very little wrong. I know of few other Polk speakers I can say the same of.

Best stay clear from the matching PSB Alpha sub. It sounds to me like an empty cereal box being struck by a spoon.

Sig' begineth here: