This might be on the more portable and affordable end of your inquiry, but I bought my brother a Douni A5
($53 on Black Friday) for Christmas. He needed something small and portable with good sound to take with him on cruise ships (he plays in the band). I did a fair amount of research beforehand (although there are thousands of products). He really likes it.
Good bass. It's bass-rich to my ears at low volume (low-volume personal playback in a quiet bedroom) but once you get to mid-volume and higher, the treble and mids come out.
25W, which is rather powerful for this type/price of product. It gets pretty loud, but I can't comment on how it sounds behind the drone of a hot tub pump.
Powered or battery (battery life is good)
Build quality is good.
Good amount of weight for its size. I typically assimilate weight and quality for speakers.
Main: i5-3570K, ASRock Z77 Pro4-M, MSI RX480 8G, 500GB Crucial BX100, 2 TB Samsung EcoGreen F4, 16GB 1600MHz G.Skill @1.25V, EVGA 550-G2, Silverstone PS07B
HTPC: A8-5600K, MSI FM2-A75IA-E53, 4TB Seagate SSHD, 8GB 1866MHz G.Skill, Crosley D-25 Case Mod