Not hard at all
Try the same experiment with even half-decent headphones rather than speakers (any speakers). Or with classical or acoustic jazz music as the source. Or both together. What I hear is a halo of compression artefacts surrounding thin congested music. A bit like an audio equivalent of the visual artefacts you get if you overdo the processing of JPG images.
I've done this with several popular computer-based rip-compression programs (iTunes, WMP, VLC, etc) and with dedicated hardware (Brennan JB7). And at a range of bitrates. Uniformly horrible to my ears.
If you listen mainly to rock or pop over speakers you might get away with it. Those recordings usually start out compressed (in dynamic terms) anyway, though typically done with much more sophisticated kit/algorithms which produce fewer artefacts (or produce "desirable" side-effects such as punch).