I use an Rpi3, Hifiberry Amp2 and HifiBerry OS to play my music (radio or AirPlay, 320 kpb MP3's).
The amp2 can be used for 4 and 8 ohm speakers, mine are 8 ohm. They're capable of 250 Watt, the amp2 can deliver 60 Watt I think.
The sound is good, very rich and clear, I'm suprised I can hear stereo-effects much better. So I'm very happy :-).
I'm trying to learn what all the audio specifics mean, so I duckduckgo a lot and sometimes read that using a not-powerfull enough amplifier can damage my speakers (especially the tweeters, apparently).
Is there reason to worry? Is my setup a good idea, or would it be better to use smaller speakers?