Why the obsession with the lowest octave

FWIW, I'll share my experience on this.

I once heard a demo at a local shop. It was a recording of an acoustic guitar. Nothing else. Don't remember exactly what speakers I was listening to. I listened for a while, it sounded very nice. The dealer then said," I'm going to switch things up a bit and let you listen to the same recording, same speakers, same amp. Tell me what you think". I listened again, wow! It sounded more real, deeper soundstage, more immediate, etc. Like the notes were floating out there instead of coming from the speakers. I asked if he switched cd players? "Nope", he said, "I turned on the REL sub in the corner over there".

There's definitely information that we process, even if we don't exactly "hear" it.

On 1/21 Dan_Ed wrote:

To ignore the range from 20 to 40 Hz is to deny the FACT that there are harmonics down in that range that do affect realistic music reproduction.

and on 1/22 Arj wrote:

adding on to Dan_ed's post, from what i could figure out the fundamental at 40 Hz has a subharmonic at 20 Hz as well as overtones at 80 /160

If I understand these statements correctly, then a harmonic overtone series is produced both upwards and downwards in frequency from the fundamental frequency. That's just not my understanding of harmonic overtones. With very rare exceptions acoustic instruments produce only higher frequency overtones. Am I wrong? Can someone please explain the math.

Dan_Ed, good point about cymbal and bass content. Large cymbals are basically enharmonic and their frequency spectrum can go from 30Hz to 60+kHz. The bass content shouldn't be that surprising since the cymbals in question are 11" diameter and greater. They are the size of large woofers.

Onhwy61... Two signals, one at 30 Hz and the other at 20 Hz will yield a "beat" at 10 Hz.

Yeah, and a snare drum whack is maybe an even better example of the very complex sounds we listen to.

I think what sometimes happens is we read the definition where is says that the harmonics are "integer multiples" but we forget that there is a negative integer series that fills in below the fundamental and we get that bell curve shape around the fundamental. This is in the frequency domain.

Dan_ed... I don't believe that you can call modulation below the fundamental a "harmonic".

Consider a violin string. It is fixed at each end. and sounds a fundamental tone. But, by soft placement of a finger in the middle of the string you can immobilize that point of the string so that each section (end-to-middle and middle-to-other-end vibrate at a higher frequency because the length of sting is shorter. I don't see any way to make the string vibrate at a lower frequency (other than by loosening it up).