Thanks, that is reasonable data, albeit only a single expert listener and the signal source was not stated. I would certainly accept that 15 kHz is the limit of detection for any signal. That IMO would then make 10 kHz a reasoanble point above which the "importance" of the signal content on the sound quality is becoming negligable since by 15 kHz it is irrelavent. None of this is inconsistant with what I have been saying. "Detection" is not "importance" or "relavence".
But thanks for that, its good to see some "real" data and not all the conjecture.
There's a paper by Ashihara showing that humans are able to detect signals as high as 28 kHz. BUT the level at the entrance of the outer ear was about 110 dB SPL (they probable heard 28 kHz for the last time in their lives) and listener age from 19 to 25. As a rule of thumb I learned that the upper hearing threshold decreases by 2000 Hz every decade.
Best, Markus
I have a Sheffield Direct to Disc (Tower of Power) with a close miked horn fanfare that will wake one right up played through my 18khz responding horn HF. Somehow, I don't think the same effect will be given with a 10khz rolloff imposed in the signal path, especially a (blech) fourth order one.
I'm glad to say that my system is not 'bright'. However, neither is it at all forgiving or dull. It, including the two-way Iron Lawbreakers, excels at extracting subtle tonal information in recordings at all dynamic levels up to clipping (of my 60wpc OTL), which the pro sound drivers I'm using significantly enables. It also helps, IMO, that they have alnico magnets & underhung voice coils, and have maximum conversion efficiencies with a system efficiency of 99-100 db/w/m, thus giving many of the advantages of a fully horn loaded system in a 100 liter cabinet. The bass extension isn't too bad, either, being flat to 50-60hz and useable to 32hz, giving sufficient underpinnings for a convincing overall presentation.
I'm glad to say that my system is not 'bright'. However, neither is it at all forgiving or dull. It, including the two-way Iron Lawbreakers, excels at extracting subtle tonal information in recordings at all dynamic levels up to clipping (of my 60wpc OTL), which the pro sound drivers I'm using significantly enables. It also helps, IMO, that they have alnico magnets & underhung voice coils, and have maximum conversion efficiencies with a system efficiency of 99-100 db/w/m, thus giving many of the advantages of a fully horn loaded system in a 100 liter cabinet. The bass extension isn't too bad, either, being flat to 50-60hz and useable to 32hz, giving sufficient underpinnings for a convincing overall presentation.
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That might be true in that very special case but a speaker is no musical instrument. How sounds a virtual viola, close miked playing in a horn?
Best, Markus
"any particular artist you would recommend? I listen to jazz rarely and don't know any of the band names."
Dave Brubeck has ton of hights on all his recordings. There is significant signal all the way to 18kHz often reaching -3dB in some.
Ed
Dave Brubeck has ton of hights on all his recordings. There is significant signal all the way to 18kHz often reaching -3dB in some.
Ed
Yes they did. According to Greg Timbers himself, they added the supertweeter for the japanese market that wanted a "40khz" extension.
The 1.5" 476Be already goes up flat to 20khz with no issue (other than directivity), and the supertweeter is crossed over at that frequency (with no low pass on the 476Be I think).
But that has nothing to do with the debate at hand since that compression driver WAS able to go past 20khz anyway...
In fact they introduced the 045Be supertweeter for the K2 S9800, because the 435Be (476Be's little browser) could not reach the 20khz mark:
http://www.audioheritage.org/vbulletin/showthread.php?p=109787#post109787
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that data is consistent with my own experimentation ( not blind ) with a 36db/oct adjustable low pass filter. i could hear the difference in the way music sounded with the filter and without up to about 16 khz. i can hear sinewaves up to about 17 khz.
of course if the filter is shallow and you don't know what the music is supposed to sound in the first place you could probably be listening to a 10 khz low pass and think there is nothing wrong.
but if you A/B with a speaker that is flat to 20 khz the difference will be apparent.
it's all about what you expect to hear. if you expect to hear sizzling, shimmering heights - you will be disappointed. if you expect to hear something laid back and easy on the ears then you will not be.
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great link. let me paste some relevant parts of his post here:
so the Japanese requested 40 khz minimum and JBL developed a driver that goes to 40 khz off-axis, 60 khz on-axis. he agrees that this kind of extension is pointless although he will not say it out loud.
but he does at the same time say that it is valid engineering to address a driver that begins to have problems at 10 khz and dies by 15 khz.
he also admits that they could have used a much cheaper supertweeter to do the job but they didn't want to sacrifice the image of the product with a "toy" device.
i guess you can always put one of these:
http://www.madisound.com/catalog/product_info.php?cPath=45_229_246&products_id=293
on one of Geddes' speakers and fix it 🙂
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My JBL annular ring tweeters are good out to about 16kHz based on in room measurements, but really nose dive above this. More to the point my hearing nose dives around 12 - 13kHz so while I take your point, I suspect in my case at least I could not hear a difference solely attributable to FR above my range of hearing.
I've had my hearing tested a number of times and I can attest to what Gedlee states as being true in my case. Some of it is the inevitable effect of time on the clock, but some of it is probably not. We now live in a world of excessive and constant noise that we were NOT designed to handle on a continuing basis, this has to take a toll.
Friends in the Navy in the past have told me that they are having a great deal of difficulty find young men with sufficient hearing acuity for training as sonar operators. No computer has yet been developed that does this job better than a seasoned human. The problem seems to be the loud world most youth live in today - the problem started to appear about 20yrs ago shortly after the incidence of devices like the Sony Walkman.
I've noticed the most perceptive rarely make much noise their sensory acuity or lack thereof, you simply come to realize that they can "hear" through the occasional well placed comment relating to some aspect of sound reproduction you are working on. One of the most perceptive people I know has told me that he cannot hear beyond 8kHz in one of his ears, but he notices everything. Clearly an ability to listen critically plays a big role here.
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I think that you have a misunderstanding. My speakers go to 15-18 kHz. What you see in the data is the anti-aliasing filter. My point is that I do nothing above 10kHz in the design, because it is so unimportant. I could boost the heck out of the response and get above 20 kHz, but that would simply be the wrong thing to do just to be able to say that I can. Lets not get these things mixed up.
The JBL driver is a bigger throat and will have a great deal more trouble that the 1" throat at those frequencies. I have yet to see a 2" throat driver that can even get to 10 kHz on a CD horn, usually about 7-8 kHz and its suffering. The ones that show that high a response do so only on axis because of serious beaming in the diffraction horn. The 1.5" dies about 10-12 kHz and the 1" can get to 18 -20 kHz, which is IMO just fine.
What is not being considered or understood here is the vast difference in sound quality between CD at 10 kHz and the typical beaming at this frequency.
Quite correct, hearing loss is becoming endemic. And loss does not mean low abilty to hear and judge. They are entirely different things.
And since there are no accepted techniques for assesing hearing loss above 8 kHz, those people who claim that they can are simply guessing. They could be down by 30-40 dB - they just turn up the signal loud enough to detect it and claim hearing ability to 17 kHz - nonsense! And it could be distortion or noise or God knows what else.
Yes they do:
An externally hosted image should be here but it was not working when we last tested it.
Nathan in-room response (Impulse response 642ms)
Best, Markus
well i am 28 years old. i started wearing earplugs to protect my hearing when i was approximately 20. but i still got way too much exposure to loud noise. i am not 100% sure but i think i used to hear to 19 - 20 khz when i was in high school. but the 17 khz that i hear today is without any boosting.
at 1 khz i start at about the volume that most people watch TV on and then i increase the frequency without increasing the level. as the frequency is increased the sound becomes subjectively louder then it starts becoming painful then it turns almost into nothing but pain at around 16 khz and then at around 17 khz it abruptly cuts out.
This is so very true. I know a few guys like that.
The Air Force tested my ears when I was 18. My hearing was literally off the chart. Not in frequency response, but in threshold. Because my ears were so good? Not really. Because I paid attention, that's all. I had been taught to hear and listen by my father. Anyone else with normal hearing could have done as well, with a little practice.
We seem so mesmerized by the numbers. "I can hear 20KHz!" "I can hear 24KHz!" "I hear bats and alarms!" OK, great. But can you tell me what note or frequency this is? Or the dB difference between these two tones? Or where the spike is in a certain FR? Or phase? Tonal balance? Some people can. (Lynn Olsen is a good example).
What this has to do with the topic of the thread is beyond me, tho.
What about a simple constant amplitude sine sweep through your speakers at say 70-75db?? Providing you have measurements on your speakers that's an easy way to see where your hearing drops off the cliff. Just becasue there is no stardardized hearing test doesn't mean you can't come up with something simple and meaningful.
Rob🙂
people don't seem to be concerned about damage that accumulates slowly.
they're afraid of things like cocaine because you could overdose and be dead in minutes.
but they think its OK to smoke or drink because you don't get liver cirrhosis or lung cancer overnight.
yet in the long term smoking or drinking is probably more damaging than cocaine. but this just doesn't register with people's heads.
i have yet to meet a single individual in person who is even concerned about hearing damage. most people don't know anything about it but those that do know - do not care.
i would always come to work in earplugs ( for the subway train ) and people would look at me like i needed to be put on medication. then one day the girl that worked next to me says she saw an article in the newspaper saying that research found that some train station has unsafe sound levels and that i wasn't in fact crazy like everybody thought.
for real ? is it really that hard to correlate excruciating pain with damage ? do you need to read about it in a newspaper ?
i also heard kids bragging on the bus how they got "used to it" and the band in which they play "doesn't hurt their ears ANY MORE"
for a moment there i wanted to tell them that they simply became deaf but then i decided they weren't worth my time ...
Americans don't seem to have any concept of what pain actually is. They think that pain is something you take pills for. They don't understand the very basic idea that pain is a signal informing you that damage is occuring. You're not supposed to endure pain or take pills for it - you should stop the damage. Americans simply don't understand this.
When i first came to America we used to laugh at American commercials for pain medications. We thought the commericals were absurd. I did not know then that television is the foundation of American thinking and that Americans think that what they see on TV is real.
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Why not post your measurements up past 20KHz showing on and off axis response with THD?
Maybe frequency isn't the "right" variable for the listener?
Measuring the frequency response means nothing in terms of musical performance. It's measuring what doesn't happen!
Otherwise you would be able to make precise correlations. Even the most critical person - with the highest technical skills - can't tell the difference between two different loudspeakers with same FR in the same room without listening.
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