Why the obsession with the lowest octave

Martykl, not referring to you earlier. Someone else linked T. Rex foot falls and human hearing. BTW, I think your 1/21 post is very accurate.

Why the obsession? Everything discussed in this forum is about obsession.

I like deep, but not too deep bass. In fact I like to have a upward tilt in frequency response below 40Hz. It sounds good to me. But what I have discovered from looking at countless spectrograms of popular music recordings is that there really isn't that much information below about 40-60Hz. As long as the harmonics are present, the ear/brain fills in the "missing" fundamental. However, if the recording actually has true low frequency content, then I like to hear it.

My system goes down to 25Hz and then steeply drops off. Are some people saying that there's musical info below 20Hz?

One last point, humans had not evolved when dinosaurs existed. Human hearing is not at all sensitive to low frequencies, witness the Fletcher-Munson curves. Humans are most sensitive to upper midrange sounds. Think about it.

Where are people getting this sub-harmonic talk. Yes, string instruments can produce sub-harmonic sounds, but it is not a commonly used technique and it's virtually never written into compositions. Harmonic overtones are always present in acoustic music, sub-harmonics are not.

"Grandma's Hands" was recorded on a suspended wooden floor which is being excited by the foot tapping of the singers. It's a common effect in recorded gospel music. It's debatable if those sounds are part of the performance or are they in the class of falling mic stands, A/C rush, passing subways, page turning and fret scrapping, in other word noise. Although on tunes like the Supremes "Where Did Our Love Go" the floor effect is prominently featured as part of the rhythm track.

So Dan_Ed, how about an explanation of your mathematically derived harmonic content?

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.