I would say its unscrupulous but probably not fraud although it depends. If they make actual factual representations about the goods that are in fact untrue then that would be fraud. But it could not be a subjective thing. Merely saying that the speakers are "great" when they are not would not cut it. For example the Virginia Consumer Protection Act has a laundry list of prohibited practices. Here are a few that could be applicable depending on the ad itself or what the salesman might say:
6. Misrepresenting that goods or services are of a particular standard, quality, grade, style, or model;
#6 is interesting.
If that is the case, how can anyone promote their product as the "best" or "finest"? That implies "sine qua non" AND absoluteness, not relativeness. So when my corner restaurant has "the best pizza in town" or a donut shop has the "world's finest coffee" when I'm certain that there are gourmet options which are certainly better.
FWIW, this seems to be only a tactic employed by small independents who aren't usually worth the effort to prosecute, as opposed to giant multinationals who have financial resources worth pursuing and the legal help to quash such claims before the litigation occurs...