mijostyn
Undertones don't typically exist in music or nature. You might want to consider the undertones you're having in relation to your woofer flapping problem.
It is not an undertone cleeds. It is another low frequency sound that accompanies the note.Here's what you wrote:
You have to forget about fundamentals. Things like the thumb striking low E produce a thump that is below the fundamental. Percussion will do this also.A note related to but lower in pitch than the fundamental is an undertone. A note related to but higher in pitch than the fundamental is an overtone. There is no gray area. The transient effect of percussion is higher in pitch than the LF fundamental. (That's why it is so readily localizeable.)
Undertones don't typically exist in music or nature. You might want to consider the undertones you're having in relation to your woofer flapping problem.