The cone of a loudspeaker "breaks up" well below the frequency where it quits making sound. "Breaks up" means that different parts of the cone vibrate at frequencies that have more to do with the cone's mechanical caracteristics than the music. In other words, noise. This sound is undesirable, and should be eliminated by use of an electrical crossover of one kind or another. Output at the desired music frequencies aproaching breakup also exhibits large dips and spikes, also undesirable.
Some cone drivers are better than others. Exceptionally good ones are called "full range". They experience cone breakup too, but the spurious sound is of a pleasant nature that some people like.
Some cone drivers are better than others. Exceptionally good ones are called "full range". They experience cone breakup too, but the spurious sound is of a pleasant nature that some people like.