Originally Posted by chetlanin
Apart from that I wonder what different people mean by “mids”. Big difference if we talk about the 500Hz to 1kHz area or if we talk about the 2k to 3k area.
A propos: The other day I saw a fellow talk about 5k as “mids”.
Musically speaking (at least) 5k is far into the treble. The highest tone one can squeeze out of a violin -the main treble instrument of the orchestra- is about 3k. Also the working span of most treble units is typically from 2k and upwards, and they are very often used with crossover freq of between 2k and 3k. (They produce treble, if you wondered). Has the 5k guy ever heard an isolated 5k tone, one may asks.
Some misunderstanding may come from the FR charts, who knows. The tonally insignificant octave between 10 k and 20k takes up much space on paper. But those frequences are not “treble”, rather mostly “air” (of course).
Main thing, the rightly placed upper and lower bumps gives excitement.
There are frequencies charts that do not seem to agree entirely on what is an exact range of the middle frequencies, the studio audio engineers and the musicians seem to have different ideas about that. For us on head-fi dealing with headphones I would suggest as the fundamental untouchable area of the middle frequencies to be the full range of the men's and women's voices, the range of 50 Hz to 1000 Hz. I mean untouchable to the headphones frequencies response + deciBel tuning that results in headphones having the recessed mids. Any headphones that significantly lower the volume of the sound with the vocals, in any part of 50 Hz to 1000 Hz range, are to be designated as defective headphones not fit for the humans. Very good headphones [like T1 or W3000ANV] have full volume presentation extended to 2000 Hz, that means no big drops of volume up to 2000 Hz. 50 to 2000 Hz covers all the fundamental tones of the men's and the women's voices plus all of the first harmonic series overtones, [plus the second series of harmonic overtones of the frequencies 16 to 670 Hz and the third series from 16 Hz to 500 Hz - the more series of harmonic overtones the better, the tonality of instruments and voices is more full and pleasant ]. http://en.wikipedia.org/wiki/Harmonic . Broadly speaking for the world of headphones the middle frequencies region has an upper useful limit of 3500 Hz. At around this frequency, depending on an individual and his or her ears, the human ear tends to be very sensitive to the shrill resonances. The good headphone manufacturers try to lower the headphones volume output in the frequencies around 3500 Hz.
Useful charts, I include the one referenced previously by another member of head-fi. All in one place.
1 - http://www.independentrecording.net/irn/resources/freqchart/main_display.htm
2 - http://baovocreative.com/wp-content/uploads/2013/08/frequency-chart-2013.pdf
3 - http://solomonsmusic.net/insrange.htm
4 - http://www.listenhear.co.uk/general_acoustics.htm [Edit - well, this one did not work, just click on the link]
5 - http://www.reverse-engineering.info/Audio/bwl_eq_info.pdf
6 - https://app.box.com/shared/npn8une6lf [you'll have to enlarge the image - With this chart you can find what is wrong with any headphones, which part of the FR spectrum has an unnatural peak or dip]
Edited by zorin - 1/8/14 at 5:35pm