Hi David,
I've used that little awful-sounding amp/speaker for many years for signal tracing when I'm "out in the field".
It has a very tinny, shrill, shrieking sound quality. Something like a very cheap AM radio. It drives an external larger speaker very well and sounds much better.
As a joke I powered a large very efficient high-quality theater speaker with one of these little amps in the showroom of the speaker manufacturer. Their manager couldn't believe the quality and amount of sound that this little amp produced!
Then I unplugged his big speaker and let him hear this little guy shriek. :lol: