I am in complete agreement here.
I believe (but I cannot quote any) that many studies of the "last octave" 10-20 kHz were done when MP3 and the like were being developed. It takes much more data to represent this last octave and these studies found that it made vuirtually no perceptable difference. People think that it does and they think that they hear it, but in blind studies they cannot tell when its there and when its not.
The 5 kHz - 10 kHz octave is somewhat diferent in that 5 kHz is clearly in the range of importance for imaging and the like, but by 10 kHz the importance has gone almost to zero. So you cannot do without this octave, but its imporantance is no where near what the one below (2.5kHz - 5 kHz) is.
"Worry about the rest of the spectrum first" is good advice.
It does not surprise me in the least that audiophiles who have repeatedly exposed themselves deliberately to what are literally ear shattering sound levels can no longer hear sounds above 10 khz. For some of them it's surprising they can hear anything at all. How can I take such people seriously when they tell me one speaker, amplifier, etc. blows the competition away?
Perhaps one reason so few women are interested in audio equipment to the point where they become audiophiles is that their hearing at high frequencies starts out better than men's and stays better. Perhaps they find the shrillness of hi fi sound reproduction so irritating they instinctively avoid it.
Perhaps one reason so few women are interested in audio equipment to the point where they become audiophiles is that their hearing at high frequencies starts out better than men's and stays better. Perhaps they find the shrillness of hi fi sound reproduction so irritating they instinctively avoid it.
My GBP two pence worth is that I share Soundminded and DBMandrake's views, but different people have different priorities when it comes to juggling all the compromises.
We often forget that 99% of our hearing acuity is down to the phenomenally sophisticated brain processing we posses. We are tuned to respond to spatial cues which are strongest in the top octaves of our range where we localise sound. That's thanks to millions of years of fight or flight response, trying to eat or not get eaten.
Any discontinuities we hear which do not check out against expectation, referenced to the incredibly accurate model of the world we hold in our heads, are perceived as unnatural and we get confused: listening fatigue.
I have always found a high crossover point to be attractive but my experience is that its difficult to achieve really good integration, which in the end is more important. Everything starts working against you the higher up you go: controlling directivity, driver separation in Y and Z, it all makes bad phase matching and lobing really hard to avoid, all things that contribute to listening fatigue. If only it was easy!
We often forget that 99% of our hearing acuity is down to the phenomenally sophisticated brain processing we posses. We are tuned to respond to spatial cues which are strongest in the top octaves of our range where we localise sound. That's thanks to millions of years of fight or flight response, trying to eat or not get eaten.
Any discontinuities we hear which do not check out against expectation, referenced to the incredibly accurate model of the world we hold in our heads, are perceived as unnatural and we get confused: listening fatigue.
I have always found a high crossover point to be attractive but my experience is that its difficult to achieve really good integration, which in the end is more important. Everything starts working against you the higher up you go: controlling directivity, driver separation in Y and Z, it all makes bad phase matching and lobing really hard to avoid, all things that contribute to listening fatigue. If only it was easy!
If you want food or drink analogies, I like cappuccino; a tiny amount of chocolate on a great cappuccino makes it undrinkable for me. Just my sensitivity, which of course is probably different from yours.
Noise induced hearing loss is generally centered around the frequencies where our ears are most sensitive, 4kHz.
Age related hearing loss starts from the top and progresses downward.
Although I suffer from NIHL from power tool use and wind noise (and probably from some industrial strength concert tours) the age related hearing loss is a real drag, although I can still hear past 14K, it was not long ago that I could hear just above 16K.
Since I have much of the same genetics as my father, it is only a matter of time before the the ARHL closes in on the NIHL as it had for him when we last measured our hearing.
There have been some advances in treating hearing loss, hope they improve, I already miss the top half of the top octave.
I see a lot of audiograms, its what my wife does. In an amplifier we call its bandwidth its response out to its -3 dB point, with speakers it's about the same, but -6 dB is more likely (and sensible IMO). But very few people have a hearing response within 3 dB of flat at 10 kHz and no one at 20 kHz. People play these frequencies over their system and claim that they "hear" them, perhaps they do "sense" them, but in all likelihood the response is typically down 10-20 dB (or more) at 10 kHz. How can these frequencies not be masked?
Then there is the fact that in nature air absorption at 10 kHz is actually quite strong. This means that frequiencies of 10 kHz or higher do not propagate very far. Is it any wonder that out hearing has ceased to develop into a frequency range that did not even exist in our environment during its millions of years of development. In fact, how could our hearing ever have developed above 10 kHz given the almost complete lack of sound at these frequencies in our environment. (The evolutionary environment NOT our environment today.)
Now consider the cat. The cat lives in a world that is very close range when compared to ours. Its hearing goes well above 20 kHz, why? because it matters to the cat - these frequencies are present in its envoronment, but they are not present in ours.
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Did we not need to hear close up when evolving? I seem to remember seeing native peoples (Australian?) looking/listening for insects and grubs for food. Have I mis-remembered? Hissing or rustling of leaves? Also, does nature not sometimes throw in a mutation to see what happens? Perhaps some of us are mutants?
I would invest first in a hearing test which goes all the way to 20 kHz to see where you are at for hearing loss. My guess would be that you are not likely to hear much past 12-14 KHz or so. In that case you are really looking at improving the response in the 7-14 kHz range. I guess on the up side having a separate amp would allow you to boost volume as you age...
Mr. Geddes, if you wish to believe that most or all people do not hear above 10 khz or that those sounds if they exist or don't exist make no difference to their perception of music be my guest. My own experiments lead me to have concluded exactly the opposite. Looking at the Fletcher-Munsen curves is quite instructive about hearing sensitivity as a function of frequency. Among other things it shows why the spectral balance of electronically reproduced sound will not be perceived as accurate unless the loudness is correct. As for air absorption of high frequencies that is true depending on humidity however for the short distances between speaker and listener in a home listening environment it is negligable. If you wish to rationalize not building speakers that can reproduce the top octave of sound properly that's your prerogative. You wouldn't be the first. Edgar Villchur used something like that rationale to explain the rolloff of AR tweeters fifty years ago and BBC did the same for their designs about 25 years ago. Bose 901 strikes me as having almost no audible output in the top octave at all. Loudspeaker systems that cannot reproduce those frequencies don't seem to me to be accurate reproducers for music or speech. Additionally those that reproduce it poorly are worse than inadequate, they are often irritating. Among those I"ve encountered in recent years that sound badly distorted to me are full range electrostatic speakers. Awful, whether the $10,000 famous brand hybrid I heard in a store or the $30,000 monster panels I heard in someone's home. This was reason enough for me to design my own speaker systems based on my own analysis and engineering concepts.
BTW, my readings lead me to conclude that canines, felines, and primates including modern homo sapiens all evolved in the same environment in the Rift Valley region of Africa and confronted the same opportunities and threats affecting their survival.
BTW, my readings lead me to conclude that canines, felines, and primates including modern homo sapiens all evolved in the same environment in the Rift Valley region of Africa and confronted the same opportunities and threats affecting their survival.
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VHF exists in our environment, both in music and noise. The fact that we are unaware of much beyond 16-20 kHz (or an octave lower for geezers) does not make those frequencies unimportant, or nonexistent. Harmonic content differentiates instruments and voices, that content extends to 40 kHz in some instruments.
HF content that is above our hearing perception can still be perceived as beat frequencies (heterodyning) if it is reproduced properly.
A friend’s boy could hear a ribbon tweeter at 21 kHz, he had clear perception of sounds that his father and I were totally unaware of. He was able to hear the tone with his back to the speaker and the tone generator, reliably responding to when the tone was turned on or off.
HF air attenuation is not a problem given the proper receptors. Mammals such as bats, whales and dolphins use HF echolocation, bats can hear frequencies in the 100 kHz range through the background noise some 34 meters, 17 meters out and back.
Art
Not strictly true. I think the main distinction may well be the difference between hunter/gatherer and hunter only. Not much hearing acuity is required to harvest fruits and vegetables. Things like fire and weapons lessen the need for hearing predators creeping up, or seeing them in low light conditions.
Carry on... I've simply noted some misconceptions regarding evolution around the forum lately and can't always remain in spectator mode.
Carry on... I've simply noted some misconceptions regarding evolution around the forum lately and can't always remain in spectator mode.
Thank you, I will. And nothing stated here changes my opinion in any way.
Hearing a solo tone at some unknown level at 20 kHz in no way suggest that this has any importance or relavence to music. And personal subject tests are never going to sway me.
That some animals can hear VHF even over long distances when it is very much to their advantage to do so is also completly irrelavent for humans. SOunds above 10 kHz do fall off rapidly with distance, this is simply a fact.
Our hearing is accute where it is for some very specific reasons - so as not to get eaten and to find something to eat. This is not close range (by then its either too late or the pray is too small). In the range of 1 kHz - 5 kHz sound travels very far and virtually all early warning indicates of preditors or prey will have significant content in this range. Our hearing is exceptionall accute in this range. Above that and the distances fall off quickly and below that the ambiguity of location rises quickly.
Not strictly true. I think the main distinction may well be the difference between hunter/gatherer and hunter only. Not much hearing acuity is required to harvest fruits and vegetables. Things like fire and weapons lessen the need for hearing predators creeping up, or seeing them in low light conditions.
Carry on... I've simply noted some misconceptions regarding evolution around the forum lately and can't always remain in spectator mode.
Both primates and felines are predators and predated. Lions will attack, kill, and eat cheetahs just as they will monkeys. Even herbivores need a keen sense of hearing to be aware of the presence of predators in order to increase their chances of survival. Natural selection favors those most quickly aware because they have the keenest senses including hearing.
The hearing FR of a mammal is probably related to its physical size, the tympanic membrane being largely resonant related to size and weight. Smaller animals like dogs and cats can hear to 40khz, even smaller animals like bats to 100 khz. And it's probably why adult women have better HF hearing than adult men.
Those of us old enough to remember vacuum tube television sets may like I do recall always hearing the high pitch of the 18 khz horizontal oscillator tube. As I posted earlier, despite my age, I can hear to at least 16 khz based on my own tests. I can also hear a 1 db adjustment to a 16 khz slider on a 10 band graphic equalizer. Whether you choose to believe it or not is not my concern, however don't expect me to even consider buying or recommending a loudspeaker that cannot reproduce the top octave of audible sound that I can hear.
Actually 15.734kHz for NTSC color, 15.75kHz for NTSC black & white. Just setting the record straight.
When in my early 20s I chose my first color TV very carefully as I found the flyback whine extremely annoying, although I still have and use an analog Sony color TV I am no longer annoyed by frequencies in this range as I am all done by 12 - 13kHz on a good day..
I cross from JBL 2440 (375) on 2392 horn/lens** assembly to JBL 075 at 8kHz.
** http://www.lansingheritage.org/images/jbl/specs/pro-comp/horns-lens/page3.jpg Don't confuse these with the current model bearing this part number.. Why does JBL do this?
Hard to say. It depends on the horn you are using now and your personal preference. Many people are quite happy letting a compression driver run out to it's top end and naturally roll off. I have 2 set-ups using the same 3" compression driver and have one where it runs out and rolls off naturally and another where I have a tweeter up top. I can listen to both all day long.
The main difference to me is better directivity control in the last 2 octaves on the system with the tweeter. In addition subjectively I think the upper octaves sound better in the system using the tweeter. FWIW my hearing runs out at about 13K using test tones. My tweeter systems crossover it at about 8K.
Rob
http://www.jblpro.com/pages/pub/components/2380a.pdf
I was a litle confused by the model number and the description of the unit as a "Bi-Radial". Looks to be a copy of the JBL 2380.
Yes the 2380 has flat d.i. to about 12kHz, so there would be no power response rolloff to that frequency if flat axial response is achieved. Response above 10kHz isn't perfect but you absolutely need to compare that to what you would get with a 7kHz crossover and a few degrees of listening axis error.
Will the units have a common baffle mounting (not a recessed tweeter)? If so then you will have considerable lobing through the crossover due to the depth of the mid horn and the time allignment error. If you recess the tweeter to try to get nominal time allignment then the drivers will still be 8 to 10" spread apart with a 7k crossover. Not the recipe for a wide polar at those frequencies.
Every time I see a horn 3 way with high crossover point the response is messy. I think some people like them because they can crank up the top octave and hear more "air".
Not sure it is accurate.
David S.
I was a litle confused by the model number and the description of the unit as a "Bi-Radial". Looks to be a copy of the JBL 2380.
Yes the 2380 has flat d.i. to about 12kHz, so there would be no power response rolloff to that frequency if flat axial response is achieved. Response above 10kHz isn't perfect but you absolutely need to compare that to what you would get with a 7kHz crossover and a few degrees of listening axis error.
Will the units have a common baffle mounting (not a recessed tweeter)? If so then you will have considerable lobing through the crossover due to the depth of the mid horn and the time allignment error. If you recess the tweeter to try to get nominal time allignment then the drivers will still be 8 to 10" spread apart with a 7k crossover. Not the recipe for a wide polar at those frequencies.
Every time I see a horn 3 way with high crossover point the response is messy. I think some people like them because they can crank up the top octave and hear more "air".
Not sure it is accurate.
David S.
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