So your best reference for the last octave "not mattering" is the research done for MP3 encoding ? Hardly a glowing endorsement of 10-20Khz not mattering
If you're happy with the conclusions reached by that research you should be perfectly happy listening to MP3's, right ?
It's many years since I've read the fraunhoffer papers on MP3 but you are misinterpreting their conclusions - the conclusions are not that the high treble frequencies don't matter, simply that they can't be encoded very efficiently when the available bit-rate is low.
With constrained bit-rate (for example 128kbit) it is found that low pass filtering the high treble content that is inaudible or marginally audible to most people (over about 17Khz) allows bits that would have otherwise been "wasted" on more accurately encoding the high end treble to be re-allocated to better encoding lower frequencies, and that the overall subjective quality is improved - since less bits are required to encode the low frequencies better use can be made of the available bits.
This is similar to applying de-noising algorithms to digitised film stock before compressing with MPEG2 or H.264 codecs - otherwise accurately encoding the film grain (essentially high frequency noise) wastes a lot of bits that could be better spent elsewhere, for example on better encoding motion.
The research says nothing about high frequencies not mattering, its simply about achieving the best overall quality tradeoff when bit-rates are very constrained, but at those low bit-rates quality has already been thrown out the window and you're just trying to make the best of a bad situation.
Because of this, low bitrate MP3s are inevitably brick wall low pass filtered at about 17Khz before being encoded - something that is both very easy to see on a spectrum display, and audible.
At higher bit-rates like 256kbit and above such tradeoffs are not necessary and aren't used. (At least on newer encoders)
To me one of the biggest shortcomings of MP3's in the early days of 128kbit and poor encoders was the treble, so bad in some cases (swishy artefacts, lack of crispness etc) that it was very easy to tell apart a WAV file and MP3 version of the same song in a blind test.
Encoders have improved and bit-rates have increased so its much harder to tell an MP3 from the original but its by no means indistinguishable with careful listening on good equipment.
So no, I don't accept the research on the tradeoffs made in the design of MP3 encoders as any sort of proof that the top octave doesn't matter, in fact I see it as the opposite - the tradeoffs made in the high treble during low bit-rate encoding was one of the main reasons why MP3 encoding caused such audible degradation of the sound quality.
(Joint stereo encoding destroying the background ambience in the recording being another)
So in blind studies people can't tell if the 10-20Khz octave is missing or greatly attenuated ? I have to call BS on that. What studies ? I can easily distinguish a 1dB shelf attenuation from 10-20Khz with a blind test.
No, I won't always pick it up immediately with a few seconds of listening to one song, but after listening to 2-3 familiar songs with good high frequency content I can get it right every time, the perceived difference is a difference in imaging. To suggest that people (with normal hearing) simply can't tell if the frequencies above 10Khz are missing is ludicrous.
Again I couldn't disagree more strongly. The frequencies around 10Khz and just above have a critical effect on imaging and the focus of the image, and are just as important as the lower treble.
What makes you think that we haven't already worried about the rest of the spectrum and got it sorted out ? Nobody is saying focus on the treble and ignore the rest...
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I still find the 15.75Khz flyback transformer on a CRT TV very audible and annoying, so much so that I'll turn the TV off if I'm doing critical music listening as it's quite a distraction...(and I can tell if the TV is turned on with the volume down from the next room...)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..
Simon
I was never talking about MP3 only the research behind it, and yes, it is valid support for my position. I don't like MP3, I see no poiont in it for my situation - lossless coding works just fine. But that does not discount the research as supporting evidence.
I am not going to respond to anything els since you are taking everything that I say to an extreme and implying things that I never said. As someone else said believe what you want to believe. Above 10 kHz just is not that important, period.
And please everyone, detecting 15 kHz has nothing to do with its importance in music.
I was never talking about MP3 only the research behind it, and yes, it is valid support for my position. I don't like MP3, I see no poiont in it for my situation - lossless coding works just fine. But that does not discount the research as supporting evidence.
I am not going to respond to anything els since you are taking everything that I say to an extreme and implying things that I never said. As someone else said believe what you want to believe. Above 10 kHz just is not that important, period.
And please everyone, detecting 15 kHz has nothing to do with its importance in music.
Importance in music is a hard term to define. Important to the essence of melody and the musical line? Probably not. But if the frequencies are audible then we should strive to maximize the fidelity of their reproduction. Certainly significant response errors above 10kHz are audible by most of us and typically show real differences between the sound of one dome tweeter and the next, for example.
I would agree that frequencies above the typical audible range are neither important or required. I don't know of any studies that show that they are. The arguement about beat tones is irrelevant since beats will only come about as a result of nonlinearity. If they existed in the performance then the audible effects would exist and should be recorded. After the original performance they have no place. A system that reveals supersonic frequencies via sonic beats is exhibiting an undesrable distortion artifact (and would be better served with a restricted bandwidth input).
As to bandwidth studies, the old RCA Olson experiements are interesting. In the 30's there was a debate where some thought that narrower bandwidth was preferred and better than wide bandwidth. RCA conducted studies with wide, narrow and medium bandwidth systems (4k, 7k and 10k bandwidth) and most listeners preferred narrower to wider reproduction.
Since the result was a bit unexpected they looked into the possibility that distortion was a factor. Speech and music were fed to triode and pentode amplifiers (4 combinations) and distortion was turned up until it was determined to be in turn: perceptable, tolerable, and objectionable.
Finally, the bandwith was varied to see at what average distortion level the 3 judgements were made. Bandwidths tested were 4k, 6k, 8k, 10k, and about 16k (the unfiltered case). Results were that wider bandwith always was found objectionable (or tolerable or perceptable) at a lower percentage of distortion. To our discussion, there was a significant difference in perception of distortion between the unfiltered and 10k filter case. In other words the listeners perceived distortion above 10kHz. (and tolerated progressively greater distortion percentages as bandwidth was diminished.
Since this implied that the previous preference for narrow bandwidth was possibly due to distortion, RCA repeated those tests with a small orchestra in a room with an open/shut acoustical low pass filter. A multilayer acoustical filter, composed of turnable curtain slats, could be opened and shut. It filtered at 4-5kHz. In this test there was a strong preference for full bandwidth rather than filtered.
Regards,
David
I would agree that frequencies above the typical audible range are neither important or required. I don't know of any studies that show that they are. The arguement about beat tones is irrelevant since beats will only come about as a result of nonlinearity. If they existed in the performance then the audible effects would exist and should be recorded. After the original performance they have no place. A system that reveals supersonic frequencies via sonic beats is exhibiting an undesrable distortion artifact (and would be better served with a restricted bandwidth input).
As to bandwidth studies, the old RCA Olson experiements are interesting. In the 30's there was a debate where some thought that narrower bandwidth was preferred and better than wide bandwidth. RCA conducted studies with wide, narrow and medium bandwidth systems (4k, 7k and 10k bandwidth) and most listeners preferred narrower to wider reproduction.
Since the result was a bit unexpected they looked into the possibility that distortion was a factor. Speech and music were fed to triode and pentode amplifiers (4 combinations) and distortion was turned up until it was determined to be in turn: perceptable, tolerable, and objectionable.
Finally, the bandwith was varied to see at what average distortion level the 3 judgements were made. Bandwidths tested were 4k, 6k, 8k, 10k, and about 16k (the unfiltered case). Results were that wider bandwith always was found objectionable (or tolerable or perceptable) at a lower percentage of distortion. To our discussion, there was a significant difference in perception of distortion between the unfiltered and 10k filter case. In other words the listeners perceived distortion above 10kHz. (and tolerated progressively greater distortion percentages as bandwidth was diminished.
Since this implied that the previous preference for narrow bandwidth was possibly due to distortion, RCA repeated those tests with a small orchestra in a room with an open/shut acoustical low pass filter. A multilayer acoustical filter, composed of turnable curtain slats, could be opened and shut. It filtered at 4-5kHz. In this test there was a strong preference for full bandwidth rather than filtered.
Regards,
David
I find it unceasingly funny that the most important measure of hearing acuity is "how high can you hear?". This seems like nothing but a numbers game to me. Can't hear above 10K? Oh, then your hearing is no good 'cause I understand what the bats are saying! Whoopee! What about thresholds, lack of FR holes in your hearing, the ability to recognize pitch or amplitude, a sensitivity to harmonics, etc? They don't seem to matter. Just "I can hear 22Khz." Yeah, so what? Why is that so important?
FWIW, I think most tweeters suck. And I have since I was a young whipper-snapper who could hear >16Khz. Very few sound natural to me, they don't sound like what I hear in natural sounds. I'd rather not have the content up there than the artificial sizzle that most speakers provide. Is it the tweeters themselves or the implementation? I dunno, but I don't like most of them - they sound fake. They sound like tweeters.
I have a problem similar to the OP. My Altec 288 drivers need help about about 7Khz. Getting that to sound right is extremely frustrating. Using crossover tricks to make them play to about 14K usually sounds a lot more natural than adding a tweeter. Doesn't mean I've given up, tho.
FWIW, I think most tweeters suck. And I have since I was a young whipper-snapper who could hear >16Khz. Very few sound natural to me, they don't sound like what I hear in natural sounds. I'd rather not have the content up there than the artificial sizzle that most speakers provide. Is it the tweeters themselves or the implementation? I dunno, but I don't like most of them - they sound fake. They sound like tweeters.
I have a problem similar to the OP. My Altec 288 drivers need help about about 7Khz. Getting that to sound right is extremely frustrating. Using crossover tricks to make them play to about 14K usually sounds a lot more natural than adding a tweeter. Doesn't mean I've given up, tho.
I find it unceasingly funny that the most important measure of hearing acuity is "how high can you hear?". This seems like nothing but a numbers game to me. Can't hear above 10K? Oh, then your hearing is no good 'cause I understand what the bats are saying! Whoopee! What about thresholds, lack of FR holes in your hearing, the ability to recognize pitch or amplitude, a sensitivity to harmonics, etc? They don't seem to matter. Just "I can hear 22Khz." Yeah, so what? Why is that so important?
FWIW, I think most tweeters suck. And I have since I was a young whipper-snapper who could hear >16Khz. Very few sound natural to me, they don't sound like what I hear in natural sounds. I'd rather not have the content up there than the artificial sizzle that most speakers provide. Is it the tweeters themselves or the implementation? I dunno, but I don't like most of them - they sound fake. They sound like tweeters.
I have a problem similar to the OP. My Altec 288 drivers need help about about 7Khz. Getting that to sound right is extremely frustrating. Using crossover tricks to make them play to about 14K usually sounds a lot more natural than adding a tweeter. Doesn't mean I've given up, tho.
Pano: You are a breath of fresh air!
BTW, I enjoyed your "how much voltage/wattage" thread. I am sorry for those that did not understand it.
I find it unceasingly funny that the most important measure of hearing acuity is "how high can you hear?". This seems like nothing but a numbers game to me. Can't hear above 10K? Oh, then your hearing is no good 'cause I understand what the bats are saying! Whoopee! What about thresholds, lack of FR holes in your hearing, the ability to recognize pitch or amplitude, a sensitivity to harmonics, etc? They don't seem to matter. Just "I can hear 22Khz." Yeah, so what? Why is that so important?
FWIW, I think most tweeters suck. And I have since I was a young whipper-snapper who could hear >16Khz. Very few sound natural to me, they don't sound like what I hear in natural sounds. I'd rather not have the content up there than the artificial sizzle that most speakers provide. Is it the tweeters themselves or the implementation? I dunno, but I don't like most of them - they sound fake. They sound like tweeters.
I have a problem similar to the OP. My Altec 288 drivers need help about about 7Khz. Getting that to sound right is extremely frustrating. Using crossover tricks to make them play to about 14K usually sounds a lot more natural than adding a tweeter. Doesn't mean I've given up, tho.
My impression of what your saying, if it were me, would make me ask the following.
1) Could the harshness you hear be caused by something in the electronic chain (ie source, pre-amp, power amp, etc)
2) Could it be the quality of the media which your source plays (for instance later CD remasters with compression and smiley faced eq'ing)
3) Could it be your room environment (believe it or not , I had an ongoing harshness problem that turned out to be a reflection in the room)
4) What tweeters in what environment do you like? (this leads to can you obtain these tweeters yourself)
Good questions Jim. I'll try to answer, but it's valid for me only, of course.
Thanks for asking.
Yes, could be and probably often is. But not always. Since I hear it on so many different systems, I suppose it's just me and tweeters don't get along.
Could be - but I don't think always is. See above.
Have heard the same in too many rooms over too many years, don't think that's it. Bigger, better rooms do tend to help some, but don't eliminate it.
Surprisingly (to me), some of the HiVi planar tweeters don't bother me, they just blend. Haven't heard enough of these to know if it's the technology or if they were just especially well implemented.
Thanks for asking.
Gee, thanks.
I don't won't to diss the folks who do hear up that high, a lot of "Hi-Fi" must be painful for them. Ultrasonic alarms bother some guys I know, sure glad I don't hear that stuff. Just wanted to point out that HF extension is far from the only, or even best, measure of hearing quality.
Loss of the ability to hear high frequencies is one sign of hearing impairment. Whether acquired or you're born with it, it's an indicator that you do not have the capacity to hear the full range of sounds most people are born with. It would be like being color blind or being unable to detect certain aromas. It is not proof that there are other kinds of hearing impairment in that person as well but it is suggestive of it. Interestingly I've observed that many people with hearing impairment are hyper-sensitive to even moderately loud sounds, they sometimes find them even more annoying than those with normal hearing do.
SoundMinded: Before you start giving a clinical diagnosis over the internet, please keep in mind that a hearing impairment or deficit does not mean you are entirely insensitive to high frequency sounds. It simply means that for weak signals you might need an extra 20 db (or whatever) before you can detect it. Once you have that extra amount of energy, you may be hearing what others also hear. It really depends on the nature of the deficit. Again, it may be a deficit and not a total loss.
If your going to speculate, then please label it as such and please do not start speculating and offering it as "clincal advice"
If your going to speculate, then please label it as such and please do not start speculating and offering it as "clincal advice"
Or of sound quality.
The position that "if its in the source then it has to be in the reproduction" is a weak argument and quite frankly a cop-out. The inability to prioritize what is important in audio reproduction is a serious failing of many audiophiles. It is not only reasonable but necessary to rank the importance of many aspects of sound reproduction and to focus on those that matter most and, if not ignore, certainly not prioritize those that don't.
Simply taking the position that you have to do it all is not very effective.
One of the four elements of music is tonality. The inability of this industry to produce a product that can reproduce the timbre of acoustic musical instruments accurately from recordings demonstrates that the basic science on which its products are designed is seriously lacking in one or more critical aspects. That is sufficient to call all of them not high fidelity. The failure to reproduce the highest overtones convincingly is just one of its failures. The industry nevertheless pursues the same design concepts ad nauseum because it doesn't know what else to do. Nobody has performed the research. The conclusion is that its products are by and large not worth anywhere near what many manufacturers charge for them. Audiophiles keep buying them but they can't be very satisfied as it seems to be an endless process for them of tweaking, experimenting, and then shopping for a replacement. At least DIY gives the tinkerer the opportunity to experiment and make his own mistakes usually at much lower cost than store bought equipment.
And exactly what advice did I give except to avoid exposure to loud noise? But don't take my word for it, here are some more authoritative sources;
Noise-Induced Hearing Loss
Dangerous Decibels Hearing Loss
Noise-Induced Hearing Loss and its Prevention by MedicineNet.com
Noise
Anyone who has ever worked in a factory or other job where there is exposure to loud noise knows that OSHA has standards too and employers are required to provide at no cost to the employee hearing protection equipment. One of the thresholds is 86 db exposure for 15 minutes. You can check out OSHA's web site for others. Hearing loss by exposure to loud noise is usually to one degree or another permanent.
Sorry if my "advice" comes too late. Many audiophiles have impaired their hearing though deliberate self exposure. I always thought it ironic that after Edgar Villchur sold Acoustic Research Inc which he founded, he went into the hearing aid business. I always wondered how many of his hearing aid customers became hearing impaired using his loudspeaker systems.
I no longer hear the flyback, (this set was chosen for its quiet) but I can hear quite low levels of audio/noise bleeding through, not to mention noise from the HT system it is connected to. So I turn it all off when I am going to listen to music.
I believe OSHA allows 85 dB(A) for 8 hours. Above that they trade 3dB increases for cutting exposure time in half (88 for 4 hours, etc). Louder than I would want to endure, but the long time exposure is a part of the equation.
David
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