human hearing 20HZ to 20kHz !!

Quote:

Originally Posted by alz3abi 

i wonder why High end headphone have frequency range below 20HZ and Above 20khz,

 

for example Headphone Frequancy range 10hz~39kHz.

 

 

if the human can hear from 20hz to 20khz then why do i need or why the company manfuacture bigger frequancy range?

It sells more headphones to people who look at specs like they mean much?

I can't hear above 19khz myself. But I can hear 10hz, or should I say, feel it perhaps.

Very best,

Published frequency range is highly exaggerated and, so long as it's 20-20 or greater, the last thing you should look at when considering a headphone.

Well you're supposed to feel bass below 20Hz in your body and when you're really young you supposedly can be hear about 20KHz otherwise most people don't that they can't hear things before 20Hz and above 20KHz so they just pick up whatever has the smallest/biggest number. In my pre-audiophile days I certainly had a tendency to do that.

The limits aren't strict like that, it was just convenient to talk about 20Hz - 20kHz I suppose. It varies from people to people, some young people with excellent hearing can hear a little past 20kHz. Could be a headphone limitation but I hear up to around 18kHz or so with my headphones which has a bit rolled off highs (perhaps would need some better highs extension to find out my true limit) but I can hear down to 15Hz (no not feel and not hearing the distortions/harmonics but the low steady humming bassnote but it's very faint/barely audible over natural background noise at that point and 14Hz only makes some harmonic "flip-flop" sound which isn't 14Hz, this whit a fixed "normal" listening volume at least).

20/20 is the music standards for the last 20 years. The hps with the FR range of 10hz~39kHz will smooth out the sound for you, meaning better sound resolution.

Quote:

Originally Posted by alz3abi 

i wonder why High end headphone have frequency range below 20HZ and Above 20khz,

 

for example Headphone Frequancy range 10hz~39kHz.

 

 

if the human can hear from 20hz to 20khz then why do i need or why the company manfuacture bigger frequancy range?

A great question.

Not only do many headphones reproduce frequencies above 20 kHz,

many if not most audio electronics do so as well.  Sometimes well above 100 kHz.  And higher.

Why?

Much work has been done in this area (ultrasonics) by individuals

with a deep interest in music reproduction.  And who possess the time, resources,

capacity, money, and general wherewithal to do so. 

And thus there's a great deal of authoritative literature on the subject.

For example, recent research indicates that humans detect information above 20 kHz.

But not with our ears.

One well known research paper discusses bone-conducted ultrasonic hearing, and the involvement of

the saccule - an otolithic organ which has neural connections with the cochlea (of the inner ear).

That paper - There's Life Above 20 KiloHertz - was written by James Boyk in 2000.

At the time he was a Lecturer, Director of the Music Lab, and Pianist in Residence

at the California Institute of Technology ("Caltech") - one of the top technical universities in the world.

(http://www.cco.caltech.edu/~boyk/spectra/spectra.htm)

____________________

"TO FULLY MEET the requirements of human auditory perception I believe that a sound system must cover the frequency range of about 15Hz to at least 40kHz (some say 80kHz or more) with over 120dB dynamic range to properly handle transient peaks and with a transient time accuracy of a few microseconds at high frequencies and 1°-2° phase accuracy down to 30Hz."

That was the conclusion of David A. Blackmer, an audio engineer who attended MIT and Harvard, and who founded

dbx Corporation (which produced amazing and unique audio gear). 

(There's more here: http://recordinghacks.com/articles/the-world-beyond-20khz/)

As mentioned, much work has been done and much has been written on the topic.

I've summarized only some of it above.

You need headphones that go below 10hz if you want to find the "brown note"!!  

harmonics and sub pressure?