Speakers not worse than ones built into PSR SX-900

[Elia]

I have a PSR-SX900 at home and I love the sound of its built-in speakers. I like it so much that I end up using the instrument as speakers (via BT or AUX in) to listen to music. I never owned really beefy expensive speakers, so these are literally the best I've heard.
So, I'm looking for a set of speakers for listening to music (not studio monitors), which are at least the same quality as the ones on SX900. What price range should I be looking at? What characteristics? What brands?
I must mention that I never set the sound over the half of the volume knob, it's 9 o'clock most of the time, so I won't probably benefit from very loud ones, but I don't want the sound to be clipped either.