[ForShure]

I didn't know where to post this but Sound Science seemed like a good place. Looking around at higher end headphones I see many have a huge frequency range all the way up to 48,000Hz. If human hearing is at best only 20-20,00Hz what is the point of having headphones that go way beyond that? It's not like my cat is going to be listening to them.

 

[mikeaj]

It's mostly meaningless marketing, for those who don't know better.  They rarely specify the relative loudness at the extremes of the range they're quoting.  How many dB down is that, anyway?  (not that it matters if it's 48 kHz...)
 
That said, some design that can output higher frequencies might also be able to be more even or have less rolloff in the actual audible frequencies.  The ultrasonic extension could be some side effect of an actual design goal, if you will.

 

[ultrabike]

Like Mikeaj said, manufacturers seldom provide what it's meant by frequency range. Currently available headphones, including high end ones, are not perfect, specially in the frequencies north of 1kHz.
 
Consider the
LCD3: http://www.innerfidelity.com/images/AudezeLCD3Rev2sn2613375circa2012.pdf
SR009: http://www.innerfidelity.com/images/StaxSR009.pdf
HE-6: http://www.innerfidelity.com/images/HiFiMANHE6.pdf
HD-800: http://www.innerfidelity.com/images/SennheiserHD800.pdf
 
On the positive side I believe our auditive system sort of averages null and notches in the high frequency range. There is also quite a bit of debate regarding frequency response compensation curves due to HRTF and other stuff.
 
Certain high end headphones tend to exhibit low distortion. Also, well regarded headphones tend to have relatively smoother, balanced, and matched (left and right channels) FR behavior than under-performers. All of this is difficult to achieve in the < 20 kHz frequency range, and IMO maters more than having magic mountain FR all the way up to 48 kHz.

 

[ForShure]

Thanks, these answers make more sense than other ones I've heard. Somebody was trying to tell me that even though the human ear can't hear those frequencies the presence of them still effects the brain and I was like

 

[chewy4]

Well, the sound pressure of inaudible frequencies can still have an effect, at least in extreme circumstances. But this effect would not be a good thing.

 

[Roly1650]

Well, the sound pressure of inaudible frequencies can still have an effect, at least in extreme circumstances. But this effect would not be a good thing.

There have been studies which suggest the opposite of what you're saying, ie: if inaudible LF frequencies are missing, the brain can sense they are missing and percieve the reproduction to be incomplete and can have effects in the audio band. I've heard these "missing" frequencies referred to as "floor noises". The one study I can recall, but can't find at the moment, was a paper presented to the AES back in the late '70's/early '80's by Laurie Fincham, the then Technical Director of KEF Electronics. KEF used BBC KM1 Monitors equalized flat to 5 Hz for the study iirc.

Of course the study concerned loudspeakers and not headphones, but the average manufacturers spec for louspeakers is as loose as that for phones.

 

[chewy4]

Quote:

There have been studies which suggest the opposite of what you're saying, ie: if inaudible LF frequencies are missing, the brain can sense they are missing and percieve the reproduction to be incomplete and can have effects in the audio band. I've heard these "missing" frequencies referred to as "floor noises". The one study I can recall, but can't find at the moment, was a paper presented to the AES back in the late '70's/early '80's by Laurie Fincham, the then Technical Director of KEF Electronics. KEF used BBC KM1 Monitors equalized flat to 5 Hz for the study iirc.

Of course the study concerned loudspeakers and not headphones, but the average manufacturers spec for louspeakers is as loose as that for phones.

Well I was more referring to cases where it's pumped up enough to cause discomfort/pain. Like in that one episode of Star Trek where the space hippies transmit a high frequency noise through the PA system that nobody(except for Spock) can hear but it knocks them all unconscious.
 
But for a more realistic example any listening test at the frequencies on the edge of audibility will tell you not to keep turning up your volume until you can hear them as the sound pressure can cause damage.
 
I'd be interested in seeing that paper... not many systems can exactly reproduce 5Hz well(except for this:http://www.eminent-tech.com/rwbrochure.htm). Even if it's true for low frequencies I doubt this would apply to the high frequencies since you can throw a 17kHz lowpass filter on most music without being able to tell the difference. But I could see low frequencies causing some sort of perceivable ambience. 

 

[Roly1650]

Quote:

Well I was more referring to cases where it's pumped up enough to cause discomfort/pain. Like in that one episode of Star Trek where the space hippies transmit a high frequency noise through the PA system that nobody(except for Spock) can hear but it knocks them all unconscious.
 
But for a more realistic example any listening test at the frequencies on the edge of audibility will tell you not to keep turning up your volume until you can hear them as the sound pressure can cause damage.
 
I'd be interested in seeing that paper... not many systems can exactly reproduce 5Hz well(except for this:http://www.eminent-tech.com/rwbrochure.htm). Even if it's true for low frequencies I doubt this would apply to the high frequencies since you can throw a 17kHz lowpass filter on most music without being able to tell the difference. But I could see low frequencies causing some sort of perceivable ambience. 

Not a Star Trek fan so don't know the episode you refer to, but I get the idea and I guess it's possible.
Sorry, I can't find the link to the AES paper, but I know I'm not imagining it, it's out there somewhere.
 
 
 
 
 
 
 
 
 
 
 
 
 
to measure free field bass response,