As society and technology have moved on, everything has become smaller. Computers once filled a room; now they're small enough to carry in one hand. To listen to music, all you need now is your phone or MP3 player and a pair of headphones. Back in the 1980s - before even the humble CD had been invented - you needed a tape deck. Attach two speakers to that and haul it over your shoulder, and you could call it a boom box. They were the bane of public transport everywhere for over a decade.
Boom boxes were very loud and very portable - hence their name. Young people, in particular, were notorious for carrying them around everywhere they went, and annoying everyone they met by refusing to turn their favorite music off. Fortunately, the trend passed - but those who are yearning for their old boom box are willing to pay up to $1,600 for a genuine Ghetto Blaster.