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Post by Boomzilla on Oct 25, 2023 7:40:18 GMT -5
Actually, it seems that the human ear is less sensitive to distortion at both ends of the frequency spectrum. The classic Dahlquist DQ-10 speakers used a Motorola piezeoelectric super tweeter that was described as an ultra-high-frequency-noisemaker. Yet, it was one of the ONLY speakers of its generation that actually offered HF extension to 20Khz (albeit with tremendous distortion).
So, not only are our ears tolerant of bass distortion of up to 25%, but also of high treble distortion of similar magnitude.
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Post by ashrum on Oct 25, 2023 8:51:09 GMT -5
Actually, it seems that the human ear is less sensitive to distortion at both ends of the frequency spectrum. The classic Dahlquist DQ-10 speakers used a Motorola piezeoelectric super tweeter that was described as an ultra-high-frequency-noisemaker. Yet, it was one of the ONLY speakers of its generation that actually offered HF extension to 20Khz (albeit with tremendous distortion). So, not only are our ears tolerant of bass distortion of up to 25%, but also of high treble distortion of similar magnitude. Yes I would definitely agree with you analysis on higher frequency's, Especially since we start to loose the ability to hear higher frequencies as we age. Most people begin to lose the ability hear the edge of human hearing spectrum around the 20khz range by the age 8. You might find it interesting to play test tones starting at 10kz in increments of 1k and see how far you get till you stop hearing the tones. You would probably be surprised how far you get. I would bet most of us don't get past 15khz. |
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Post by monkumonku on Oct 25, 2023 10:03:25 GMT -5
Actually, it seems that the human ear is less sensitive to distortion at both ends of the frequency spectrum. The classic Dahlquist DQ-10 speakers used a Motorola piezeoelectric super tweeter that was described as an ultra-high-frequency-noisemaker. Yet, it was one of the ONLY speakers of its generation that actually offered HF extension to 20Khz (albeit with tremendous distortion). So, not only are our ears tolerant of bass distortion of up to 25%, but also of high treble distortion of similar magnitude. But what does the high frequency distortion curve look like? If the distortion level went up significantly in the upper ranges (towards 20Khz) then a lot of people wouldn't even be able to hear that, so whether it was clean and pure, or distorted, they wouldn't hear it anyway. In other words, if the distortion levels jumped at frequencies 15Khz and above, many ears wouldn't be capable of hearing it. Also have to consider how loud any signal like that would be on a recording. I think when it comes to bass distortion, it may be a matter of discernment rather than sensitivity. We just think the distortion is the actual signal since much of this depends on tactile response. |
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Post by leonski on Oct 25, 2023 12:28:24 GMT -5
The LAST TIME I know I could hear that high up was when I was about 10 years old. I was in a store with my DAD and I complained about a ringing noise I could hear.
Turning head and it changed, but was still present.
He asked a store guy....who said something about the Ultrasonic Burglar Alarm....I was the only one who could hear it....THAN......
And keep in mind that we in the 'WEST' have destroyed our hearing. A normal male of age 60 in say.....the Kalahari Desert hears better than ANY western male HALF his age.
Can perceive stuff coming FAR below the threshold of his guests who are clueless......and 'deaf' under those extremely quiet conditions.....
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KeithL
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Post by KeithL on Oct 25, 2023 14:24:27 GMT -5
That is quite true... but it goes even beyond what you think... The reality is that we rarely encounter low frequencies that don't already have lots of harmonic and other content. You just don't find things that produce a clean 30 Hz sine wave... except electronically generated tones. And most instruments produce a rather rich set of harmonics... so you often won't notice if their relative levels are a tiny bit off... The situation at high frequencies is even more interesting... Let's look at a 12 kHz tone - which is pretty high. What amount of THD would you expect to be able to hear at 12 kHz? In case you hadn't realized that's a trick question. The second harmonic of 12 kHz is 24 kHz. And nobody I know can hear ANY AMOUNT of 24 kHz. (So, in effect, at 12 kHz, there is pretty much no amount of 2nd harmonic distortion that you're going to hear.) Now add to that the fact that most instruments that make lots of high frequencies, like cymbals, also make massive amounts of disorderly harmonics. So, as long as you've got more or less the right amount of high frequency stuff, a cymbal will sound OK. (You can take white noise, shape its spectrum to be about right, and it will sound a lot like a real cymbal.) So, essentially, at frequencies above 10 kHz, the THD almost doesn't matter at all. Most of what you're likely to hear and notice are non-harmonic distortion products... And significant amounts of THD where the harmonics fall in the range of frequencies we're sensitive to... (around 300 Hz - 3 kHz)... So, for example, second and third harmonics on an otherwise clean 440 Hz bell tone... And, of course, changes in the pitch of that bell tone... But, while those can happen with tape, and to a lesser degree with vinyl, you just don't get those with digital content... And, of course, unrelated noise or "random contributions" in that highly audible range will be quite obvious as well... Actually, it seems that the human ear is less sensitive to distortion at both ends of the frequency spectrum. The classic Dahlquist DQ-10 speakers used a Motorola piezeoelectric super tweeter that was described as an ultra-high-frequency-noisemaker. Yet, it was one of the ONLY speakers of its generation that actually offered HF extension to 20Khz (albeit with tremendous distortion). So, not only are our ears tolerant of bass distortion of up to 25%, but also of high treble distortion of similar magnitude. |
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Post by leonski on Oct 25, 2023 17:21:58 GMT -5
That is quite true... but it goes even beyond what you think... The reality is that we rarely encounter low frequencies that don't already have lots of harmonic and other content. You just don't find things that produce a clean 30 Hz sine wave... except electronically generated tones. And most instruments produce a rather rich set of harmonics... so you often won't notice if their relative levels are a tiny bit off... The situation at high frequencies is even more interesting... Let's look at a 12 kHz tone - which is pretty high. What amount of THD would you expect to be able to hear at 12 kHz? In case you hadn't realized that's a trick question. The second harmonic of 12 kHz is 24 kHz. And nobody I know can hear ANY AMOUNT of 24 kHz. (So, in effect, at 12 kHz, there is pretty much no amount of 2nd harmonic distortion that you're going to hear.) Now add to that the fact that most instruments that make lots of high frequencies, like cymbals, also make massive amounts of disorderly harmonics. So, as long as you've got more or less the right amount of high frequency stuff, a cymbal will sound OK. (You can take white noise, shape its spectrum to be about right, and it will sound a lot like a real cymbal.) So, essentially, at frequencies above 10 kHz, the THD almost doesn't matter at all. Most of what you're likely to hear and notice are non-harmonic distortion products... And significant amounts of THD where the harmonics fall in the range of frequencies we're sensitive to... (around 300 Hz - 3 kHz)... So, for example, second and third harmonics on an otherwise clean 440 Hz bell tone... And, of course, changes in the pitch of that bell tone... But, while those can happen with tape, and to a lesser degree with vinyl, you just don't get those with digital content... And, of course, unrelated noise or "random contributions" in that highly audible range will be quite obvious as well... Actually, it seems that the human ear is less sensitive to distortion at both ends of the frequency spectrum. The classic Dahlquist DQ-10 speakers used a Motorola piezeoelectric super tweeter that was described as an ultra-high-frequency-noisemaker. Yet, it was one of the ONLY speakers of its generation that actually offered HF extension to 20Khz (albeit with tremendous distortion). So, not only are our ears tolerant of bass distortion of up to 25%, but also of high treble distortion of similar magnitude. I' ve PROVEN that with my sub. Shut off sub and image collapses inward. Crossover of the sub is 24db / octave and set about 40hz to 45hz.......So 24db DOWN at 90hz......GIVE or take... To complete the test? I'd have to RE-Enable the full range signal to the mains....which are low cut 5hz to 10hz above the subs cutoff...... Those pesky overtones or harmonics sure do matter! I don't worry TOO much about wow and flutter content causing 'warble tone' frequency shifts since I'm in a pure digital domain. No warped record HUGE bass bumps (ever see a woofer cone 'breathe') phenom, either. My NAD1700 tuner preamp had an infrasonic (subsonic) filter which pretty much fixed the 'woofer breathing' situation.... AND? One other related but not very germain observation. ELEPHANTS create Infrasonic sounds which can be heard for MILES and located by others of the species. www.thecareprojectfoundation.org/a-secret-language-infrasonic-communication-in-elephants/#:~:text=Scientists%20speculate%20that%20infrasound%20production,%2C%20producing%20low%2Dfrequency%20sound. I wonder how THEY can locate such a sound while human response is generally considered direction free below about 80hz. Would that change OUTDOORS and at a distance? THAT can be tested, as well..... |
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KeithL
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Post by KeithL on Oct 26, 2023 13:35:59 GMT -5
All species have evolved to be good at hearing the sounds that are useful for their survival. In general that means "sounds made by things you eat", "sounds made by things that can eat you", and "sounds made by members of your own species. Elephants are big, and range over long distances, so it makes sense that they would evolve the equipment to both produce and hear low tones that travel over long distances. (They're also physically large enough to carry around the necessary equipment... generally lower pitched sounds require larger hardware to produce and detect efficiently.) The generally accepted limit of 80-100 Hz for humans really does sort of apply indoors - and more specifically in relatively small rooms. That's why, for example, Dolby only uses a single LFE channel for home content, but they DO use multiple subwoofer zones in large theaters. (There's also the issue of quantity... but they do use separate channels rather than a single common channel.) In a very large room, under some circumstances, you can get some localization out of lower frequencies. (I'm sure there's research out there somewhere on this.) There are also several other things to bear in mind... For example, even with a "sharp" 24 dB/octave crossover, set to 80 Hz, response will only be down about -27 dB at 160 Hz. And, if you include both distortion, port noise, and incidental room vibration, subs do still somewhat tend to "telegraph their location". This is why, while a sub, pretty well anywhere, works well for those scenes where everything rattles... But, if there really is a situation where the thing is supposed to be in one specific spot, location does matter - at least a little bit. Usually, in situations like that, the sound itself includes higher harmonics, which come from the main speaker... And these act as strong cues to "pin" the sound to its intended source location... and override weaker conflicting cues. Another interesting fact about critters... including humans... We humans cannot actually HEAR what direction a sound is coming from. Our ear holes are not directional... and our ear mechanism only analyzes "what sound is arriving at our eardrum at the bottom of the hole". While we can figure out what direction a sound is coming from we cannot directly detect that information. Our BRAIN figures out the direction of the source based on things like arrival time, and phase, and head-related-transfer-function. (How the sound is altered by having to wrap around your head, and around the various parts of your ear, on its way into your ear... ) HOWEVER, from what I've read, the "audio gear" on some insects actually CAN detect the direction in which sound waves are travelling. So they can hear sound direction directly. (Insects don't have ears... they use things like little hairs on their legs to detect sound waves.) I' ve PROVEN that with my sub. Shut off sub and image collapses inward. Crossover of the sub is 24db / octave and set about 40hz to 45hz.......So 24db DOWN at 90hz......GIVE or take... To complete the test? I'd have to RE-Enable the full range signal to the mains....which are low cut 5hz to 10hz above the subs cutoff...... Those pesky overtones or harmonics sure do matter! I don't worry TOO much about wow and flutter content causing 'warble tone' frequency shifts since I'm in a pure digital domain. No warped record HUGE bass bumps (ever see a woofer cone 'breathe') phenom, either. My NAD1700 tuner preamp had an infrasonic (subsonic) filter which pretty much fixed the 'woofer breathing' situation.... AND? One other related but not very germain observation. ELEPHANTS create Infrasonic sounds which can be heard for MILES and located by others of the species. www.thecareprojectfoundation.org/a-secret-language-infrasonic-communication-in-elephants/#:~:text=Scientists%20speculate%20that%20infrasound%20production,%2C%20producing%20low%2Dfrequency%20sound. I wonder how THEY can locate such a sound while human response is generally considered direction free below about 80hz. Would that change OUTDOORS and at a distance? THAT can be tested, as well..... |
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Post by leonski on Oct 26, 2023 17:30:47 GMT -5
When peope talk crossover point, the IMPLICATION is that it is a brick wall....which it is NOT......
That's why my very low sub crossover is important to me AND renders the sub 'invisible'.....
Imagine the 'hardware' of Blue Whales which can hear one another maybe thousands of miles away......
Humpbacks are aparently good to as far as 5000 miles. Of course, water is a better material than
air for such vibrations.....
And the human SOSUS system used to detect submarines which I'm certain HEARD the recent
Titanic Submersible disaster.....But couldn't report all the details because of 'security' / 'intel' .......
Humans are VERY good at diretiontion of sound.
Factors?
Time of arrival at each ear. Spectral Content compared.....
The ability is software AND hardware....driven.
That phenon is part of what Carver and Polk used for the speakers or external systems used to
improve stereo....
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Post by leonski on Dec 27, 2023 17:54:00 GMT -5
For Keith?
I was a Golf Caddy back in the late 60s.......What does that have to do with ANYTHING?
Well, I read some golf magazines, one of which claimed the MOST IMPORTANT 6 inches in golf
was the distance between your EARS. As it turns out? The SAME 6 inches used for the hardware
part of audio direction finding and spectral content.
Of course, the golf magazine was talking about YOUR BRAIN. In my coaching of golfers, I realized
they were ALL headcases and would have benefitted from a good beating with a stick....
Hardcore golfers are even MORE phobic and superstitious than ANY high-end audio guys I've ever met.
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Post by Boomzilla on Dec 27, 2023 19:16:32 GMT -5
Fair is fair - I'm NOT the "average" listener. Why? First, I don't listen loudly. Apparently, the majority of listeners like to annoy their neighbors. I don't. The majority of my listening is done at amplifier power outputs of less than one watt. So how an amplifier sounds at five, 10, or more watts is something that I don't care about at all.
It's also fair to say that the dynamics of many amplifiers (and speakers) vary wildly between "less than one watt" and "more than one watt." So an amplifier (or speaker) that might "come alive" at higher volumes (Magnepan speakers come to mind) may sound significantly less dynamic unless you crank them up.
So, unless your speakers are higher sensitivity (as mine are) and unless you listen only at lower volumes (as I do), we aren't hearing the same things out of our amplifiers. I've owned a LOT of Emotiva amplifiers (Generation 1 X-series, Generation 2 X-series, Generation 3 X-series, R-series reference amps, PA-1 series "pro" amps, and BasX series amps). For my "first watt" listening, I rate the Generation 2 X-series, the PA-1 series, and the BasX series as the "best sounding." The rest lag behind in sound quality, to my ears.
The folks who listen at higher outputs (due either to higher volume preferences or because they own less sensitive speakers) seem to find any and all of the Emotiva amplifier products roughly equivalent. I won't argue with them - apples & oranges. So don't take my criticism of the Generation 3 X-series amplifiers too seriously - we're likely listening very differently.
Cordially - Boomzilla
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ttocs
Global Moderator
I always have a wonderful time, wherever I am, whomever I'm with. (Elwood P Dowd)
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Post by ttocs on Dec 27, 2023 20:27:53 GMT -5
I'm with ^^^^that guy.
Although, I do listen at various volume levels based upon mood which will dictate the tunes played. But at any volume I'm hearing what I like, but I don't listen at EAR SPLITTING volume levels, even though I could. Lately in fact, in the last couple weeks, I've been listening at very low volume levels for long hours.
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Post by leonski on Dec 27, 2023 20:52:21 GMT -5
At only about 1000 watts available for my panels and sub, I really CAN'T get it all that loud.
There is a 'sweet spot' which is louder than TV level. Certainly more than Boom's 'one watt' but certainly not as loud as double digits per speaker......
Those panels consume power like I own stock in SEMPRA.....
And for sure, in a quiet or subdued environment? A softly playing system will lack dynamics. The quietest passages may simply disappear....
Material may lack harmonics (always lower in level) or lack 'realism'.....
As for annoying neighbors? The trick is to CONVINCE THEM that you are DEAF. Or at least hard of hearing. Playing that card reasonably (not too late....or early) is fine.
For some reason? Nobody ever thinks to question a hard-of-hearing Audiophile......Just never comes up.
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Post by Boomzilla on Dec 28, 2023 7:47:52 GMT -5
...And for sure, in a quiet or subdued environment? A softly playing system will lack dynamics. The quietest passages may simply disappear.... Material may lack harmonics (always lower in level) or lack 'realism'..... This is particularly true with low-sensitivity speakers. They often have a "loudness threshold" above which, the speakers come alive dynamically. But generally, the more sensitive the speaker, the lower that threshold. Highly sensitive speakers (Klipschorns and La Scalas come to mind), the threshold is so low that even at whisper levels, the music's dynamics are still retained. BECAUSE I like to listen at low volumes, I've always had a preference for high-sensitivity speakers. That said... I've owned at least one system that had VERY low sensitivity speakers, but that still had low-volume dynamics. But to get that, I had to have insane power to drive the speakers. The system was Dahlquist DQ-10 speakers driven by an Adcom GFA-1 power cube. It was one of the best-sounding systems I've ever owned! Would any other amp of similar power capabilities have driven the Dahlquists so well at such low volumes? I don't know. Would any other speaker of similarly low sensitivity have sounded so dynamic at such low volumes? I don't know. Perhaps that system just had synergy... |
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Post by leonski on Dec 28, 2023 20:25:53 GMT -5
Talk about QUIET in an enviroment.
We had a major power fail in Southern California in 2011, lasting about 12 hours or so....
As quiet as I've ever experienced in this area. Near-Zero traffic. No loud engines / noises / music.
I did some shortwave listening and tried some DX of commercial AM. A real special couple hours.
I got woken up about 0330 or so when the lights came back ON......
Someone had tripped on the extension cord from Arizona.....
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Post by vcautokid on Dec 30, 2023 17:36:26 GMT -5
When people talk crossover point, the IMPLICATION is that it is a brick wall....which it is NOT...... All of my digital Computer or as I call them Confuser buddies would think this way. Leonski, thanks for that post. Put a smile on face.
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Post by leonski on Dec 30, 2023 21:41:24 GMT -5
Thanks mucho,
I've been fighting the 'brick wall' issue for years.
But one more thing? A major Powerfail here in SoCal is a rarity in the extreme. Florida, OTOH? A regular seasonal event with
some amazing lightining displays.....which I've seen from literally miles away as the horizon lit up. Call it 30 or 40 miles East of Tampa
on my way back to school....
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Post by vcautokid on Dec 31, 2023 9:41:28 GMT -5
Boy this ASR dude sure does get allot of press. Ultimately your bank account does not tie in with his distortion analyzer, or O scope and so on does it? He is just a dude measuring schiit right? Thousands everyday measure schiit.
In the end, you buy what YOU LIKE. Yeah try to measure that ASR! A human feeling.
Nice to know that a rat fart might be .000000000034 and potentially upset you? Why? Would it invalidate your choice that much?
I haven't been to his site in forever because the dude does not enjoy the listen other than how loud it can go before his ears bleed.
ASR is a non factor to me. You might think otherwise. That is fine.
But in the long run, you're gonna do what YOU want to do. Not somebody elsewhere in the world who doesn't know you!
You know YOU!
Your money! It is data. How useful? Don't know. Besides I am not in the market for a rat. But to me it is more internet fodder, no more, no less. Keep buying what makes you happy. Ultimately what, you're gonna do no matter what goes.
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Post by leonski on Dec 31, 2023 17:35:45 GMT -5
Some 'tube reviews strike me the same way. Crying into a half full glass of beer......or whatever.
But it IS true, that historically, much gear which measured really good also simply came and went. while much gear which
simply didn't measure as well has very good resale and in some cases, a 'following'.
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KeithL
Administrator
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Post by KeithL on Jan 1, 2024 2:56:28 GMT -5
Crossover points, and crossover slopes, are an excellent example of things that audiophiles like to obsess over...
Yet many don't actually understand very well.
For example... how much difference does it actually make whether you set your Bass Management to 70 Hz or 80 Hz. (And could it possibly matter if you had the granularity to set it in increments of 1 Hz or 5 Hz instead of 10 Hz ?)
If you look at it from the perspective of: "At what frequency will it start to roll off?" Then the difference is not really that big a percentage
If you look at it from the perspective of: "How much attenuation will I have at a given frequency?" You will also see that there isn't much difference there either. Changing the crossover POINT from 70 Hz to 80 Hz won't change the ATTENUATION at 160 Hz by much at all.
(In other words the actual effect it has on what you hear is FAR LESS than you might expect.)
In fact, if you want far sharper attenuation, you want to switch from a 12 dB / octave to a 24 dB / octave filter. That will give you FAR more attenuation at any point significantly past the turnover point.
Also, when you think about these numbers, keep in mind that the uncorrected response in a typical room could vary by +/- 10 dB... or more...
And, compared to that, the difference of a few dB of attenuation at a certain frequency just disappears into the proverbial background noise... (And, to be quite blunt, we humans aren't all that sensitive to accurate levels of very low frequency content anyway.)
I also have a bit of an editorial comment here... about crossovers... specifically for subs... There has been a gradual shift in how sub crossovers and room correction are viewed by folks... Back when subs became a thing they were considered to be a sort of separate delivery vector for their part of the audio spectrum... The subwoofer was: "The new extra speaker that filled in that important missing bottom octave of the audio spectrum"... And notice that we STILL think of the subwoofer as a separate FUNCTION.
There are at least two big companies who sell large speakers with: "built in powered subwoofers". Wouldn't it make more sense for them to say that: "they make a true full-range speakers that DOESN'T NEED a subwoofer"?
My point here is that, historically, little consideration was given to achieving a smooth transition between your sub and mains. (It's as if, back then, we thought of subs like we think of Butt Shakers today, as "an extra special effect" rather than "part of the AUDIO system".)
Just a thought...
But I suspect this is why, the further back you look... - the more emphasis you find on "sharp cutoff" - and the less emphasis on smooth transitions and things like impulse response
Thanks mucho, I've been fighting the 'brick wall' issue for years. But one more thing? A major Powerfail here in SoCal is a rarity in the extreme. Florida, OTOH? A regular seasonal event with some amazing lightining displays.....which I've seen from literally miles away as the horizon lit up. Call it 30 or 40 miles East of Tampa on my way back to school.... |
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Post by leonski on Jan 1, 2024 21:29:11 GMT -5
Exactly WHY I configured my system as it sits today.
Basically, I think of it as a 3-way system.....2-way panels and THAN the sub as the '3rd way'......
I set the low cut to the mains ABOVE the high cut to the sub......far enough that the slopes tend to SUM FLAT
thru the passband....that region from the LF to the HF turnover. Sub is 24db / octave so by 2x the turnover, it is down a LOT.....
And the mains roll off already so I don't feel bad using the 12db / octave of the preamp......
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