Or "combination tone"?
From what I read, it would seem to account for hearing frequencies lower than the fundamental but is believed to be most likely due to non linear inter-modulation distortion associated with how we hear more so than an aspect of actual sound per se, an "illusion" per se, so most likely not something that the speaker would play a role in producing assuming the speaker does in fact deliver the real instrument fundamental frequencies up to snuff.
From what I read, it would seem to account for hearing frequencies lower than the fundamental but is believed to be most likely due to non linear inter-modulation distortion associated with how we hear more so than an aspect of actual sound per se, an "illusion" per se, so most likely not something that the speaker would play a role in producing assuming the speaker does in fact deliver the real instrument fundamental frequencies up to snuff.