[sovietdoc]

I thought I understood frequency response, although not from a deep technical level.  If headphones were rated 5Hz-50kHz they were better than the ones rated 20-20k.  I am now researching on a next phone to buy, and I am reading reviews of MrSpeakers' Ether phones that cap out at 20khz. 
 
While a LOT cheaper phones out there have a lot higher response from lower lows to higher highs.  My question is this, how come everyone says are nearly the best sounding phones if from the specs their frequency response is barely on par with 200 dollar cans?
 
Thank you!

 

[ClieOS]

  I thought I understood frequency response, although not from a deep technical level.  If headphones were rated 5Hz-50kHz they were better than the ones rated 20-20k.  I am now researching on a next phone to buy, and I am reading reviews of MrSpeakers' Ether phones that cap out at 20khz. 
 
While a LOT cheaper phones out there have a lot higher response from lower lows to higher highs.  My question is this, how come everyone says are nearly the best sounding phones if from the specs their frequency response is barely on par with 200 dollar cans?
 
Thank you!

 
The assumption on top is wrong - most listed FR number by manufacturer are completely useless. Many only serve to misled the consumer to believe bigger number is better while some only list some 'me too' basic 20Hz~20kHz number because that's what the customers are expecting to see. Therefore you question below is invalid, since you are trying to compare some useless numbers and try to draw a useful conclusion out of them.
 
Read this: http://www.ecoustics.com/articles/understanding-speaker-frequency-response/

 

[ProtegeManiac]

Quote:

Originally Posted by sovietdoc /img/forum/go_quote.gif

I thought I understood frequency response, although not from a deep technical level.  If headphones were rated 5Hz-50kHz they were better than the ones rated 20-20k.  I am now researching on a next phone to buy, and I am reading reviews of MrSpeakers' Ether phones that cap out at 20khz. 

 

While a LOT cheaper phones out there have a lot higher response from lower lows to higher highs.  My question is this, how come everyone says are nearly the best sounding phones if from the specs their frequency response is barely on par with 200 dollar cans?

 

First off, the range itself is effectively useless - human ears can only hear roughly around 20hz to 20000hz, maybe a little bit under and over for the healthiest ears. For this reason the shape of the response curve within that range is much more important than the overall response.

 

At best, a wide range is only correlative to a smooth response, but not all the time. For example electrostats can extend up to 100,000hz, planars can go down from 1000hz all the way down to 5hz, and in both cases they have a very flat curve, but it isn't the range that makes them flatter or smoother in that range of the curve. Rather, the driver design allows for a very smooth response all the way down or up whichever range. Even then what's really important still is how smooth they are at 20hz to 20000hz. 

 

In some cases the wider range a headphone has to play might affect how the drivers behave that may make them more prone to distortion and driver break-up, but there are barely any recordings that would go beyond the 20hz to 20000hz range anyway. Basically, you'll only get this with huge orchestras, and sometimes movie scores (which are basically the same kind of music) and SFX, but really as far as movies are concerned these are hard to appreciate in headphones, but in speaker systems they're fantastic. Like how the HT subs will vibrate the room more if they're playing below 20hz; in some horror movies for example they actually have an ambient infrasound track (that to begin with you'd need 15in subwoofers for) where you can't hear the bass as far as your ears are concerned, but the vibration adds to the feeling of dread right before the jump scare (if you don't have an HT, always best to watch these in a good cinema with the right kind of audio system). 

 

[sovietdoc]

Okay, absolutely awesome info.  All cleared up now, thank you :0
 
So in general the massive frequency response ranges are much of a marketing hype.

 

[gregorio]

I agree with the basic point you've made but just to be a pedant

 
Quote:

 

.. human ears can only hear roughly around 20hz to 20000hz, maybe a little bit under and over for the healthiest ears.

 
I would say; even the healthiest ears are very unlikely to be able to hear 20kHz, let alone beyond.
 
Quote:

 

... but there are barely any recordings that would go beyond the 20hz to 20000hz range anyway. Basically, you'll only get this with huge orchestras, and sometimes movie scores (which are basically the same kind of music) and SFX, but really as far as movies are concerned these are hard to appreciate in headphones, but in speaker systems they're fantastic. Like how the HT subs will vibrate the room more if they're playing below 20hz; in some horror movies for example they actually have an ambient infrasound track (that to begin with you'd need 15in subwoofers for) where you can't hear the bass as far as your ears are concerned, but the vibration adds to the feeling of dread right before the jump scare (if you don't have an HT, always best to watch these in a good cinema with the right kind of audio system).

 
The lowest fundamental of any instrument in the orchestra equates to about 33Hz. Anything below that is effectively unintentional/spurious mic rumble.
 
Cinema systems are generally rated to around 18kHz. Obviously they don't just stop beyond 18kHz, that's just their basic usable range, beyond which they roll-off steeply. In a "huge orchestral" movie score there's effectively nothing which can be heard in a cinema at 20kHz, let alone beyond 20kHz. The same is true of SFX.
 
At the bottom end, theatrical subs usually have 18in drivers and are usually rated from anywhere between 19Hz-28Hz up to varying limits although the sub (LFE) channel itself is limited to a high of 120Hz. Theatrical mixing convention is therefore to avoid anything intentional below about 25Hz. In other words, there is no "ambient infrasound track" in film! Of course there is often content below 25Hz in practice, because we commonly use rumbles in the LFE channel rather than a pure sine wave and generally don't deliberately apply a HPF. Human hearing starts rolling-off from around 200Hz, by the time we're down below about 30Hz we've got to use huge amounts of energy just to make it audible. These large amounts of energy, along with the freq absorption and resonance characteristics of relatively small rooms is why rooms vibrate, not specifically because of infrasonic content. BTW, (properly) constructed cinemas are specifically designed not to vibrate, home cinemas vibrate because they are not cinemas! The common intention of LFE use is to give the audience a physical sensation of being hit by the pressure wave/s that many thousands, even tens of thousands of watts of very low freq energy can induce. You might like the feeling of your room vibrating but that's not the intention of the content creators.
 
G

 

[serman005]

Thank you for that detailed explanation--I learned something!

 

[MF Kitten]

I think you'd be surprised by how high your hearing extends. There are many misunderstandings about human hearing. Your ears pick up frequencies way above and beyond the 20-20.000 range, but that's the PERCEIVED range of hearing, where you HEAR it. "Hearing" meanig you are aware of it and notice it. Your brain receives information way higher and lower than that, but it doesn't use it for "hearing".

I tested my own hearing, and found that it extends up to 25khz. And that's not really unusual. Human bodies aren't made to precise numbers and measurements, which means there are random little differences. 20hz-20.000 is an averaged range, and there are no hard cutoffs. Hell, there might be a dip where you think you reached the highest frequency you can hear, but then there's another little bump where you can hear another little range above that. Hearing is NOT exact or linear or anything like that.

 

[gregorio]

I think you'd be surprised by how high your hearing extends.

 
I very much doubt that, in fact, I think you'd be surprised at how limited your hearing is! When I was a lecturer we routinely (informally) tested new students over about a 5 year period. The vast majority of the roughly 1,500 we tested were 18-21 year olds. Only once did we find a student able to reliably hear 19kHz, no one ever managed to hear 20kHz and the vast majority max'ed out between 16kHz-17kHz. At one stage the course leader felt there must be a problem with the testing as he was a bit fixated on the published 20kHz figure. He did eventually manage to get a class to perceive 20kHz but unfortunately, it was with their eyes, not their ears. He kept increasing the output level until eventually the tweeters melted and started smoking, at which point the students noticed!
 
Quote:

There are many misunderstandings about human hearing. Your ears pick up frequencies way above and beyond the 20-20.000 range ...

 
You do of course have some reliable evidence you can provide, to back up your extraordinary claim? By reliable, I mean tests which haven't later been proved incorrect, of which there are several which were later proven to be IMD and well within the range of human hearing.
 

I tested my own hearing, and found that it extends up to 25khz. And that's not really unusual.

 
1. It's literally unbelievably unusual! Again, what actual evidence have you got to support this claim? Through countless formal tests of many thousands of subjects over the last century, I've (personally) never seen documented any repeatable evidence of anyone hearing 25kHz reliably. For something to be "not really unusual" you're going to need 20% or so of people to be able to do it. Currently there's no evidence that even 0.01% of people can. So even if there is someone or even a few who can hear up to 25kHz, it would be far beyond any sensible definition of "unusual".
 
2. What is it you expect to hear? The violin is the highest pitched string instrument in the orchestra but it's highest fundamental note is only about 4kHz, beyond that it's only diminishing harmonics. Only 4% of the energy a violin produces is at or beyond 20kHz. Even if you could hear to 25kHz, I hope you're not trying to say that you hear up to that freq linearly, without a severe roll-off? So, not only is your hearing sensitivity at least greatly reduced at 20kHz but so is the actual amount of audio energy being produced. Add these two elements together and, what do you think is beyond 20kHz which can be heard, even if you were able to?
 
3. I've heard a number of audiophiles over several decades claim to have super-human hearing, to be able to hear well beyond 20kHz. I've never heard of one who was able to substantiate that claim though! On those occasions when their claims have been tested, the results have always demonstrated entirely normal/ordinary hearing response and their perception of hearing higher freqs either being due to IMD or more commonly, just wishful thinking or poor testing + wishful thinking!
 

Human bodies aren't made to precise numbers and measurements, which means there are random little differences. 20hz-20.000 is an averaged range ...

 
No it's not! No one has ever said that the range of hearing for every human being is 20Hz-20kHz. The averaged range would probably be somewhere around an upper limit of 14-15kHz. Experimental evidence, from nearly a century of testing, has lead to the obvious conclusion that 20kHz is the maximum upper limit of human hearing, not the average. Of course not every single human being has been tested so we can't prove absolutely that no one can hear above 20kHz. However, the conclusion of all these studies and experimental data is absolutely supported by the anatomical evidence, that there is no physical mechanism within the human ear capable of responding to freqs higher than 20kHz.
 
Your claims are not absolutely impossible but close enough to still be fairly preposterous. To stand any chance of being taken seriously, you are going to have to provide some truly exceptional evidence!!
 
G

 

[MF Kitten]

You provide good evidence, I've probably read and been told bad information! I also probably thought my hearing was pretty regular. I've done sine wave tests with very good tweeters, and I started at 30.000hz and let it very slowly sweep downwards. With my eyes closed, I clicked the "stop" button the second I heard something. Every time I did so, it was right around 25khz. I've confirmed through measurements that my tweeters can play that high too, so I'm pretty certain that it's correct.

Sorry for the totally misinformed post!

 

[gregorio]

Sorry for the totally misinformed post!

 
No problem. Sorry if I was a bit too harsh in my response. In my defence, I come across a lot of misinformation about hearing, often intentional misinformation designed to fool the unwary and support the buying of some snake oil product.
 

I've done sine wave tests with very good tweeters, and I started at 30.000hz and let it very slowly sweep downwards. With my eyes closed, I clicked the "stop" button the second I heard something. Every time I did so, it was right around 25khz.

 
I'm not saying absolutely that you can't hear 25kHz, I'm just pointing out that the chances that you are able to, are infinitely small. If you are actually able to hear 25kHz, you should get yourself off to a university. Pretty much any uni on the planet would pay good money to have access to a test subject who could hear 25kHz. Outside of discovering a completely new phenomena or supportable theory, scientists like nothing better than disproving an existing theory. Scientists in the field have been looking for people who are able to substantially (and reliably) break the accepted limits for decades, finding such a person would change the scientific field and make them famous!
 
The chances of you being such a person are absolutely minute. In fact, after so many years of looking, it's a pretty safe bet that such a person has ever existed. There are various explanations for your test result which don't require you to be able to hear above the normal range, each of which are, unfortunately, many orders of magnitude more likely. Intermodulation distortion (IMD) is a distinct possibility, as is the chance that the 25kHz sine wave is exciting something in your room which is resonating at a related freq (say an octave lower). There are other more likely possibilities as well.
 
G

 

[dprimary]

I think you'd be surprised by how high your hearing extends. There are many misunderstandings about human hearing. Your ears pick up frequencies way above and beyond the 20-20.000 range, but that's the PERCEIVED range of hearing, where you HEAR it. "Hearing" meanig you are aware of it and notice it. Your brain receives information way higher and lower than that, but it doesn't use it for "hearing".

I tested my own hearing, and found that it extends up to 25khz. And that's not really unusual. Human bodies aren't made to precise numbers and measurements, which means there are random little differences. 20hz-20.000 is an averaged range, and there are no hard cutoffs. Hell, there might be a dip where you think you reached the highest frequency you can hear, but then there's another little bump where you can hear another little range above that. Hearing is NOT exact or linear or anything like that.

You might have a lag between the sweep you are playing and the frequency readout you are looking at, or you are playing it at extreme and dangerously high levels. 20k is known the to be the extreme limit not an average. Typical for 16k would be 60dB down from 4k
 
If you can hear 25k life must be very unpleasant for you since there is so many devices producing ultrasonic tones and noise.

 

[spruce music]

There have been tests and some 1 to 2% of people under 30 years of age can hear above 20 khz.  It drops precipitously above 23 khz.  Though a few reaching near 25 khz might be possible.  Those who have been tested have extremely high thresholds like above 100 db for those above 20 khz signals.  So usually for purposes like listening to music very little music has such high levels at those upper frequencies. 
 
It also is possible your tweeters have a resonance near that range and emit some IMD down into a lower frequency during a sweep.  You could check that with spot tones rather than sweeps.  Or using a very slow sweep might make it a lesser issue.  Of course you may be one of the lucky few with such hearing response.  It isn't normal though.  Count yourself lucky.  Protect that great hearing when engaging in loud activities.

 

[castleofargh]

yup, hearing goes down with age and abuse, and like vision, we're not all born equals. but noticing a sound when playing a 25khz tone isn't evidence that one can hear 25khz even if it can happen for a few youngsters. hearing matters at normal usual listening levels, I can hear 19khz if I push the volume up to very unreasonable levels. but if I was playing music instead of a single tone, the audible range would be way too loud for me. I couldn't stand it, and if I could, it would probably still mask the higher treble sounds somehow. plus the fact that the sound engineer most likely couldn't hear the ultrasounds so he wouldn't know how to set the levels and mix correctly in that range. plus the fact that not all mics are great in the ultrasounds. it really makes the all affair very uninteresting from a musical point of view.
and as mentioned, there is the very serious possibility that a sound system creates some rather audible distortions, again it only comes down to how loud was the sound for it to be audible or not. so all this can be very misleading, and many audiophiles believe they have extraordinary hearing simply because they tested some tones at a way too loud sound level(remember that you can ruin your ears with loud ultrasounds even if you can't hear them, as long as your sound system can output them loud, the danger is very real).
 
hearing tests must be done at average listening levels, if you go to an audiologist to test your hearing, they go from reasonably calm, to very quiet with each tone. but they usually don't bother testing high frequencies, my last hearing test stopped at 8khz 

I was pretty bummed out not to be tested for high frequencies. and when I asked about some audiophiles saying they were hearing ultrasounds and noticing the difference in music, he just laughed saying he didn't know babies were that much into HIFI...

 

[Samueru Sama]

I'm able to hear up to 20.5 KHz, but I have to turn the volume up to 109 dB SPL xd. 

 

[sonitus mirus]

  I'm able to hear up to 20.5 KHz, but I have to turn the volume up to 109 dB SPL xd. 

 
That is highly unlikely.  I'm sure you were hearing something, though I doubt it was a fundamental frequency at 20.5kHz.  I'd be inclined to believe a person survived without water for 30 days before I'd believe this one, that is how unlikely it seems to me.  Increasing the volume level in order to hear higher frequencies can be potentially hazardous to your hearing, and I would strongly suggest that you never attempt this again.