A Hifi Berry [1] plus a speaker. The Hifi Berry is a Raspberry Pi hat. There are hats for digital output, analog output, and one with amplified analog output th

A Hifi Berry [1] plus a speaker. The Hifi Berry is a Raspberry Pi hat. There are hats for digital output, analog output, and one with amplified analog output that can drive a 4ohm speaker quite respectably. I have some old Cambridge Soundworks speakers outside that I drove from a HifiBerry Amp2 hat for a while. Not quite enough power for outside so I switched to a Hifiberry DAC Pro and a pretty capable amp off eBay. The sub to go with them uses a HifiBerry DAC too. My main listening speakers are active digital speakers, with SPDIF inputs, and Hifi Berry Digi+. The HifiBerry has a RPi build you can just stick on a card, though I now use dietpi as it survives power loss better. Once that's done you can connect over wifi or wired, using Airplay, Roon, bunch of other things I forget. Basically you can run any music server on it, because linux. With Airplay or Roon (and probably others) you can make all the speakers in the house play the same music, which is awesome for parties. There's a bunch of manufacturers that make wifi/wired active speakers. Bluesound. KEF make some nice ones for $2000. Not portable, mind you. [1] https://www.hifiberry.com https://www.hifiberry.com