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post #1 of 93 Old 03-18-2016, 12:25 PM - Thread Starter
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Test Your Ability to Hear High-Res Audio

Many people believe that high-resolution audio (HRA) offers the potential for better sound quality than CDs by using higher sampling rates and greater bit depths—typically 96 kHz or more and 24 bits compared with CD's 44.1 kHz and 16 bits. A higher sampling rate can represent a wider range of frequencies extending into the ultrasonic region, while a greater bit depth can represent a dynamic range beyond the 90 dB practical range of CDs.

The big question is, can humans actually perceive the higher frequencies and wider dynamic range offered by HRA? Bob Schulein, a long-time audio-industry consultant, and Dan Mapes-Riordan, an expert in psychoacoustics—both founding partners at ImmersAV Technology—have developed three sets of audio files that allow anyone to explore this question for themselves.

The Recordings

One set of files is used to determine the dynamic range you can perceive. They are based on a clip from "Straighten Up and Fly Right," performed by Linda Ronstadt and the Nelson Riddle Orchestra. It was imported from a CD into the editing program Audacity at 44.1 kHz/24 bits.

Since the purpose of these files is to test dynamic range, not frequency response, it was unnecessary to use a recording at a higher sampling rate. And although the original source file did not have 24-bit precision, adding eight more bits allows the level to be adjusted with greater precision than the original file. The final sample was also normalized to the maximum amplitude without clipping.

To test high-frequency perception, they recorded one swipe across a set of Latin Percussion chimes using a GRAS 46BL measurement microphone and 26CS preamp with an on-axis frequency response out to 40 kHz (+3 dB). The mic signal was recorded on a Tascam DR-100 at 96 kHz/24 bits and normalized in Audacity. The chimes have plenty of energy above 20 kHz, making the sound ideal for testing high-frequency acuity.


In this graph, you can see the spectrum of the chimes recording as measured from the output of the Tascam recorder and the amplifier.

The Tests

Each file in the dynamic-range test suite consists of a 20-second clip of the music played first at "reference" level, then at a reduced level, and finally again at reference level. This sequence is repeated in 19 separate files, and the level of the second clip is reduced in increments of 5 dB in each one, all the way down to -90 dB. As you listen to the files in order (put them in a playlist), note in which one the second clip becomes inaudible to you. Obviously, you'll need to listen at the highest tolerable reference level in order to measure the maximum dynamic range you can perceive.


The dynamic-range test files attenuate the clip in 5 dB increments from one to the next.

You might wonder why the attenuation stops at "only" 90 dB, which CDs are capable of. Why not go down 100 dB or more? According to Bob, "This was my original goal, but when I exported files with as much as 100 dB attenuation, I found a practical lower level, beyond which the analog output of the three players I measured could not faithfully track the 5 dB steps of attenuation.

"I used pink noise to take the measurements of the players' outputs. The players I measured were a Tascam DR-100, a Sony NWZ-A17, and a Pono Player. These devices have an analog output stage with a noise floor that eventually dominates the situation and doesn't let you go below -90 dB. There might be some players with a better noise floor, but I have yet to find one. And there is little chance that one would be quiet enough to track the full dynamic range of a 24-bit actual signal. From our testing to date, no one has been able to hear anything below 85 dB attenuation."

"The point is that dynamic-range specifications associated with 24-bit words are meaningful as long as you stay in the digital domain. But once you play the file back through a DAC [digital-to-analog converter], there is a practical noise floor that you can't go below. When someone takes the test, they start to become calibrated as to what a 60 or 70 dB signal-to-noise ratio sounds like—it gets pretty darn quiet, to the point that there is very little of interest down that low, even when listening with insert earphones in a quiet space."

To which Dan added, "It will be interesting if we get reports of people reaching 90 dB attenuation and still being able to hear the signal. This will require a very high-quality DAC analog stage and a quiet environment. We can easily amend the files to include more attenuation steps if necessary."

The other two sets of files test the limits of your ability to hear high frequencies using the recording of the chimes. In one set, a highpass filter with a slope of 192 dB/octave is applied to the recording—the sample is played at full bandwidth, then with the filter applied, and finally at full bandwidth again. The filter cutoff starts at 1 kHz and increases in 1 kHz increments in each subsequent file, all the way up to 30 kHz. As you play the files in order, note at what point you can no longer hear the second sample.


A highpass filter is applied to the second sample, increasing its cutoff frequency in 1 kHz increments from one file to the next.

In the other set of bandwidth-test files, a lowpass filter with a slope of 192 dB/octave is applied to the chimes recording. In this case, a full-bandwidth sample is followed by a lowpass-filtered sample, ending with the full-bandwidth sample again. The lowpass cutoff frequency starts at 2 kHz and increases in each successive file in 1 kHz increments up to 30 kHz. As you listen to the sequence of files, note at what point the full-bandwidth and lowpass-filtered samples sound the same. As the cutoff frequency continues to increase from that point, the three samples should all sound the same and you get no further benefit from the additional higher frequencies.


A lowpass filter is applied to the second sample, increasing its cutoff frequency in 1 kHz increments from one file to the next.

Because of a psychoacoustical phenomenon called masking, the high-frequency limit you note from the lowpass-filter test will likely be lower than the result from the highpass-filter test. The lower frequencies in the recording mask the higher frequencies, whereas in the highpass-filter test, there are no lower frequencies. As you might surmise, the lowpass-filter test is more closely related to real-world content, which typically has a wide range of frequencies.

The Test System

Of course, you can use whatever audio-playback system you have, and doing so will address the question, "What happens when I use my existing gear to play HRA files?" But to test the limits of your hearing acuity, you need equipment that can reproduce everything in these files. So you need to start with a high-resolution audio player, such as the Sony NWZ-A17 or Pono player that can play uncompressed 96 kHz/24-bit files; Bob has measured both and found them to be sufficient.

The dynamic-range test can be played on any reasonably high-quality audio system. Using headphones—especially inserted earbuds with excellent sealing capabilities—will give the best result because they block ambient noise from reaching your ears.

The high-frequency tests are more system-dependent, since they rely on the ability to reproduce frequencies above 20 kHz. If you have headphones with a useful frequency response out to 30 kHz, you can connect them directly to the player. However, most headphones and earbuds do not exhibit smooth response that high, as seen in the following measurements by Bob:


Bob Schulein measured the frequency response of circumaural and in-ear headphones using a tiny microphone placed next to his eardrum.

To use a speaker, you need an amplifier with bandwidth out to at least 30 kHz. Bob recommends the Dayton Audio DTA-120 class-T amp with 60 watts/channel, which is available from Parts Express for under $90. He also notes that this amp's signal-to-noise ratio (SNR) is not sufficient to conduct the dynamic-range test, but it's well-suited for the high-frequency tests.


To conduct the tests for yourself under the most optimum conditions, you need a high-res audio player, a wideband amplifier, a wideband speaker for the high-frequency tests, and insert earbuds for the dynamic-range test.

For the speaker, Bob built a custom rig using a Tymphany XT25SC90-04 tweeter, also from Parts Express, mounted in a 90° curved PVC joint. This tweeter has the necessary bandwidth and output level to conduct the high-frequency tests, and the whole thing costs very little.


Constructing a wideband tweeter is not difficult or expensive.


The two tweeters Bob built exhibit excellent frequency response out to 40 kHz.


In this graph, you can see the spectrum of the chimes recording as measured from the output of the Tascam recorder and the speaker; notice how similar the speaker graph is to the recorder's output above 1 kHz.

Bob recommends placing the speaker about eight inches from and pointed directly at your ear. Using an SPL meter, set the output level to about 90 dB SPL as measured from where your ear will be.



The Test Results

Bob brought the test files, player, amp, and tweeter rig to the 139th AES (Audio Engineering Society) convention and a meeting of the Chicago section of AES, both in November 2015. In total, about 30 people took the tests, with the following results:


No one was able to discern a dynamic range greater than 85 dB or high frequencies above 20 kHz, and the averages were less than that.

The Files

Here are links to the test files developed by Bob and Dan. You can download each set of files separately or combined into one large file.

Dynamic Range Tests
High-Frequency Tests Using Highpass Filter
High-Frequency Tests Using Lowpass Filter
Combined HRA Test Files

In addition to representing higher frequencies and wider dynamic range than CD, the sound quality of HRA is affected by the lowpass filters used during recording and playback, which can introduce audible artifacts within the normal hearing band. This aspect of HRA is not addressed in these tests. Bob and Dan are working on ways to test for such artifacts, and I am eager to see what they come up with.

For more about this project, check out the video made by Bob Schulein:


Bob and Dan recently appeared on the Home Theater Geeks podcast to talk about the project. Also, the ImmersAV Technology website is full of interesting info.

I encourage you to post your results in the comments! But please do not quote this entire article when you post a comment. If you want to respond to something specific in the article, feel free to quote just that portion, but the whole thing is way too long to wade through in the comments section. Thanks!

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post #2 of 93 Old 03-18-2016, 02:26 PM
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This is great, and I have everything I need to do these tests over the weekend. I'll be back...

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post #3 of 93 Old 03-18-2016, 02:36 PM
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Linda Ronstadt??? Does anyone else find it ironic that those who claim to care the most about audio purity, use their expensive equipment to listen to the WORST music ever recorded?
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post #4 of 93 Old 03-18-2016, 03:09 PM
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Linda Ronstadt??? Does anyone else find it ironic that those who claim to care the most about audio purity, use their expensive equipment to listen to the WORST music ever recorded?
Thanks. Can you back that statement with fact(s) or is that just your personal opinion?


My goodness.
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post #5 of 93 Old 03-18-2016, 04:30 PM
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ok

What are the age range for those 30 testers. Do younger people hear more?
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post #6 of 93 Old 03-18-2016, 05:37 PM - Thread Starter
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What are the age range for those 30 testers. Do younger people hear more?
I don't know the age range of the AES participants, but I imagine the median is well over 30. Younger people with normal hearing will most likely hear a lot more.
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post #7 of 93 Old 03-18-2016, 08:30 PM
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Originally Posted by Scott Wilkinson View Post
I don't know the age range of the AES participants, but I imagine the median is well over 30. Younger people with normal hearing will most likely hear a lot more.
ironic that when you CAN hear, you can only afford mp3's, and when you can afford high-res audio you can no longer hear it...

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post #8 of 93 Old 03-18-2016, 09:42 PM
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Originally Posted by Scott Wilkinson View Post

One set of files is used to determine the dynamic range you can perceive. They are based on a clip from "Straighten Up and Fly Right," performed by Linda Ronstadt and the Nelson Riddle Orchestra. It was imported from a CD into the editing program Audacity at 44.1 kHz/24 bits.

Since the purpose of these files is to test dynamic range, not frequency response, it was unnecessary to use a recording at a higher sampling rate. And although the original source file did not have 24-bit precision, adding eight more bits allows the level to be adjusted with greater precision than the original file. The final sample was also normalized to the maximum amplitude without clipping.












Those two statements discredited the whole experiment.


With the huge, fast drives available nowadays, there is no reason any pro engineer wouldn't be tracking, mixing and mastering at 32 bit float, and then ONLY dithering down for certain types of media.


That the sample track was a 16/44 polished up (using which algorithm?...I must've missed that) to 24 bit has a greater chance of throwing things wonky than it does smoothing it out.

Why, if the experiment were to prove something or not, would it not have used the highest rez file available, dithered down, and THEN measured if there is a difference that could be accounted for?


I can confidently say from experience behind the console that there is a HUGE difference between 16, 24, and 32, especially when stacking 20 plus tracks and under heavy 2 bus compression (though you need a lightning fast system to do that in 32).


The only reason things like this are even debated is because 99.99999% of music listeners haven't heard proper examples in controlled environments.

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post #9 of 93 Old 03-18-2016, 09:55 PM
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Don't get me wrong I'm not a big fan of Hi res music but I thought the whole idea behind oversampling is to digitally represent the audio frequency more accurately, 96KHz or 192KHz are not meant to be heard, they are used to represent the wave form in the range of 20Hz-20KHz more accurately as a curved waveform not square waveform, Think of it as frequency carrier for a carried signal such as satellite, the higher the frequency carrier the smoother and closer to the original signal to be carried. I can see the purpose of the bit depth test but I see no raison behind the high frequency test, most of the high end equipment work in the range of 15Hz-25KHz anyway.

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post #10 of 93 Old 03-18-2016, 11:25 PM
 
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This thread is for young ears.

The older we get the farther away we are from a hobby we believe we still master. ...It's similar to playing football; when you get passed a certain age you can only talk about the older days of past and most obsolete techniques, or watch the younger generations perform the latest chops on TV.
Older people's performance years and ears are gone; they're the talkers now in a world they can't hear anymore.
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post #11 of 93 Old 03-19-2016, 04:50 AM
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Do we really need to test this over and over?
No one can hear past 20kHz and it lowers with age.
24bit is dynamic range or noise floor, even the best amps in the world can barely reach 16bit noise floor.
Our ear don't like too dynamic sounds, above about 20db of dynamics sound becomes too disturbing and not musical, try to listen to 96db of dynamic range and tell me it's pleasant...

The workflow in the studio is another matter, but for the final product nobody needs or can hear anything above 44khz 16bit, GET OVER IT!
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post #12 of 93 Old 03-19-2016, 05:04 AM
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Originally Posted by latreche34 View Post
Don't get me wrong I'm not a big fan of Hi res music but I thought the whole idea behind oversampling is to digitally represent the audio frequency more accurately, 96KHz or 192KHz are not meant to be heard, they are used to represent the wave form in the range of 20Hz-20KHz more accurately as a curved waveform not square waveform, Think of it as frequency carrier for a carried signal such as satellite, the higher the frequency carrier the smoother and closer to the original signal to be carried. I can see the purpose of the bit depth test but I see no raison behind the high frequency test, most of the high end equipment work in the range of 15Hz-25KHz anyway.
No, Doubling the sample rate is equivalent to adding one bit. The jump from 16 bit to 24 bit (practically 19 or 20 bit effective) gives a far greater accuracy.


And no you should not see the waveform as steps (square). The samples are pulses and when filtered the original sampled waveform is what comes out of it.
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post #13 of 93 Old 03-19-2016, 05:25 AM
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I tested it years ago. Can't hear it because it isn't audibly different.
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post #14 of 93 Old 03-19-2016, 05:55 AM
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I don't buy high-res audio because I think I'll hear more than a CD could render; I buy a particular high-res release when it's been tested to have a higher dynamic range than the CD version. The recording industry is calculating that audiophiles will pay more for product that sounds better. 24-bit depth and higher sampling rates are the marketing, but in most cases the perceptible difference is just the rendered dynamic range, which could be delivered on a CD or in a 16/44.1 or 24/44.1 release.
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post #15 of 93 Old 03-19-2016, 06:07 AM
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Originally Posted by aharden View Post
I don't buy high-res audio because I think I'll hear more than a CD could render; I buy a particular high-res release when it's been tested to have a higher dynamic range than the CD version. The recording industry is calculating that audiophiles will pay more for product that sounds better. 24-bit depth and higher sampling rates are the marketing, but in most cases the perceptible difference is just the rendered dynamic range, which could be delivered on a CD or in a 16/44.1 or 24/44.1 release.
Yes, that's even done with vinyl records (that have notably less dynamic range than 16/44.1)
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post #16 of 93 Old 03-19-2016, 06:27 AM
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Such pity that CD is synonym with "super compressed brickwalled dynamic-less crap", so we have to pay more for "premium product" with the industry devised money sucking plan of "Hi-Rez" or a lesser quality container like vinyl hoping for a better mix.
A better mix.....
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post #17 of 93 Old 03-19-2016, 06:45 AM
 
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I buy a particular high-res release when it's been tested to have a higher dynamic range than the CD version.
Maybe you're too young to remember, but one of the selling points of CD when they came out was their higher potential dynamic range than vinyl. That potential was never really capitalized upon, because right around the same time period producers became more and more compression happy. Not so much as today, but still much more so than previously. It doesn't matter what the capability of the playback media is, you can only put on it what's present on the master.
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post #18 of 93 Old 03-19-2016, 07:16 AM
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I'm not surprised at the results. I have tested my hearing as a 37-yr-old man that has been exposed to concerts, gun ranges, etc. My hearing starts to fall off at 14kHz and becomes nearly inaudible above 16kHz.

That said, some of these high res audio products (not all, and in fact not many), such as SACDs sound a little bit better because the goal was high quality audio. When we care about the best quality, and we think through it from start to finish, it can often sound better. But it can sound better regardless of the medium if this approach is taken.

All in all, the quest to determine what we can hear and what we cannot hear just gets us closer to a better overall solution. So for that, I appreciate this test and for sharing the results.
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ironic that when you CAN hear, you can only afford mp3's, and when you can afford high-res audio you can no longer hear it...
I could afford CDs when I was young, and basically only listened to classical / jazz. MP3s are only about the convenience of downloading songs that you didn't pay for and the sound quality didn't matter all that much because the only time you'd otherwise listen to new music (for free) was over the radio. That, and the fact that most esoteric / rare CDs of good remastered recordings were often not available on Napster / DirectConnect at the time, meant that actually buying your own CD collection made sense. The problem with CDs was getting scratched / banged up. Young people are often careless with their gear, and CDs were quite fragile.

What's really frightening is the sheer level of ignorance frankly, of people who actually think that vinyl is a good sound medium, against all the empirical and scientific evidence to the contrary. True audiophiles need to stop focusing on pushing high bit rate audio (which is completely worthless on the consumer end), and focus mostly on educating people about dynamic range, noise floors, etc, and why they should be listening to FLAC and nothing else.

16/44 is all you will ever need and this is what we need to hammer into people's heads, hard. From a scientific point of view, that is the end of the discussion. No point in going further than CD, but also no point in going below it either.
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post #20 of 93 Old 03-19-2016, 12:41 PM
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I could afford CDs when I was young, and basically only listened to classical / jazz. MP3s are only about the convenience of downloading songs that you didn't pay for and the sound quality didn't matter all that much because the only time you'd otherwise listen to new music (for free) was over the radio. That, and the fact that most esoteric / rare CDs of good remastered recordings were often not available on Napster / DirectConnect at the time, meant that actually buying your own CD collection made sense. The problem with CDs was getting scratched / banged up. Young people are often careless with their gear, and CDs were quite fragile.

What's really frightening is the sheer level of ignorance frankly, of people who actually think that vinyl is a good sound medium, against all the empirical and scientific evidence to the contrary. True audiophiles need to stop focusing on pushing high bit rate audio (which is completely worthless on the consumer end), and focus mostly on educating people about dynamic range, noise floors, etc, and why they should be listening to FLAC and nothing else.

16/44 is all you will ever need and this is what we need to hammer into people's heads, hard. From a scientific point of view, that is the end of the discussion. No point in going further than CD, but also no point in going below it either.

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post #21 of 93 Old 03-19-2016, 01:00 PM
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Originally Posted by latreche34 View Post
Don't get me wrong I'm not a big fan of Hi res music but I thought the whole idea behind oversampling is to digitally represent the audio frequency more accurately, 96KHz or 192KHz are not meant to be heard, they are used to represent the wave form in the range of 20Hz-20KHz more accurately as a curved waveform not square waveform, Think of it as frequency carrier for a carried signal such as satellite, the higher the frequency carrier the smoother and closer to the original signal to be carried. I can see the purpose of the bit depth test but I see no raison behind the high frequency test, most of the high end equipment work in the range of 15Hz-25KHz anyway.

This is a common misunderstanding based on the visual representation of sampling frequencies. In all cases, the digital data is turned back into a smooth sine wave output. The question then becomes whether the higher accuracy of the reproduced sine wave originating from a higher sampling rate is audible.
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The question then becomes whether the higher accuracy of the reproduced sine wave originating from a higher sampling rate is audible.
No there is no audible difference, I agree 100%, our ears don't sense the shape of the wave, it just sense the amplitude of the pulse and obviously its frequency of happening as long as it is within the audible range, That's why I'm not a big fan of anything more than 16/44.1 although I have a collection of FLAC just because it came from a better master.
And every time this subject brought up in the forums I tend to share this common link, So there it is:
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Originally Posted by latreche34 View Post
No there is no audible difference, I agree 100%, our ears don't sense the shape of the wave, it just sense the amplitude of the pulse and obviously its frequency of happening as long as it is within the audible range, That's why I'm not a big fan of anything more than 16/44.1 although I have a collection of FLAC just because it came from a better master.
And every time this subject brought up in the forums I tend to share this common link, So there it is:
https://www.youtube.com/watch?v=cIQ9IXSUzuM
Agreed - I buy from HDTracks because sometimes (though not always) they start from better masters.
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post #24 of 93 Old 03-19-2016, 03:47 PM
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is this the same as a diy hearing test? I get a free annual hearing test from a Dr every year and its not looking good....

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post #25 of 93 Old 03-19-2016, 07:23 PM
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Originally Posted by RLBURNSIDE View Post
I could afford CDs when I was young, and basically only listened to classical / jazz. MP3s are only about the convenience of downloading songs that you didn't pay for and the sound quality didn't matter all that much because the only time you'd otherwise listen to new music (for free) was over the radio. That, and the fact that most esoteric / rare CDs of good remastered recordings were often not available on Napster / DirectConnect at the time, meant that actually buying your own CD collection made sense. The problem with CDs was getting scratched / banged up. Young people are often careless with their gear, and CDs were quite fragile.

What's really frightening is the sheer level of ignorance frankly, of people who actually think that vinyl is a good sound medium, against all the empirical and scientific evidence to the contrary. True audiophiles need to stop focusing on pushing high bit rate audio (which is completely worthless on the consumer end), and focus mostly on educating people about dynamic range, noise floors, etc, and why they should be listening to FLAC and nothing else.

16/44 is all you will ever need and this is what we need to hammer into people's heads, hard. From a scientific point of view, that is the end of the discussion. No point in going further than CD, but also no point in going below it either.
the medium is not the cost, it's the hardware. i had plenty of cd's as well, and i listened to them on a $40 discman with the headphones that came with it, or a $200 dollar stereo. even though i could technically afford a higher end amp, headphones, SACD player or whatever, they would have been a very significant purchases(like the choice between those or a car). 'kids these days'(man do i hate saying that) are going to have a device that plays mp3's anyway, i mean i probably have 6 devices that play mp3's and i haven't bought any of them for that purpose. so it's essentially 'free' hardware for them.

no matter how you slice it, high end audio is pretty pricey, and most ppl have more money as an adult(over 30) than as a teenager.

there's a time and a place to care about FLAC, and honestly most ppl don't need it imo. driving in the car, no point. working out at the gym, no point. background music at a party, no point. the truth is music is rarely the focus anymore. it's usually just something in the background. don't get me wrong, i'm not saying quality doesn't matter at all, but you really need to pay attention to notice the difference between 320kbps mp3 and a cd. and you gotta be pretty into music to care enough to pay extra for it.

i feel the same way with video. i mean i really 'demand' 1080p quality now, but that's because i watch most of my stuff in a theater environment, and pay full attention to it. the times that i just have the tv on in the background, i don't really care what quality is playing. and if i were to stream something on my phone, it doesn't even need to be HD.

so i can't blame somebody for not caring about high quality audio. in the situations they listen to it, i wouldn't care either. and i don't think there are a lot of younger people sitting in their rooms just listening to music anymore. they're listening to music, while playing a game on their phones, and checking their snap chats, while doing math homework...
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post #26 of 93 Old 03-19-2016, 11:49 PM
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What are the age range for those 30 testers. Do younger people hear more?
We had quite a range of test subjects. The youngest was 9 years old and the oldest in their mid 70's.
At the Shure presentation many were in the 25-40 age range.
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post #27 of 93 Old 03-19-2016, 11:54 PM
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I'm happy to see that we all unanimously agree that content above the hearing threshold is useless and has been proven to be so time and again by science.
CDs have tremendous dynamic range, good enough for you and your neighbor and your neighbors neighbor.
Now it's all about the customer making the industry understand that we don't want loud, we want quality.

@producer s
For the love of music, please let the consumer enjoy the mix before you send it to snotty kids to do the mastering.
If it's that important to release a loud master to the market please release an "audiophile" un-mastered version with it.
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post #28 of 93 Old 03-20-2016, 12:07 AM
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Do we really need to test this over and over?
No one can hear past 20kHz and it lowers with age.
You are wrong.

Through my mid-twenties I found myself quite irritated by "ultrasonic" vehicle presence detection devices at a couple of traffic lights in my neighborhood. And that's in spite of whatever damage NYC's subways must have been doing to my ears.

I surely can't be the only one.
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post #29 of 93 Old 03-20-2016, 12:19 AM
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Those two statements discredited the whole experiment.


With the huge, fast drives available nowadays, there is no reason any pro engineer wouldn't be tracking, mixing and mastering at 32 bit float, and then ONLY dithering down for certain types of media.


That the sample track was a 16/44 polished up (using which algorithm?...I must've missed that) to 24 bit has a greater chance of throwing things wonky than it does smoothing it out.

Why, if the experiment were to prove something or not, would it not have used the highest rez file available, dithered down, and THEN measured if there is a difference that could be accounted for?


I can confidently say from experience behind the console that there is a HUGE difference between 16, 24, and 32, especially when stacking 20 plus tracks and under heavy 2 bus compression (though you need a lightning fast system to do that in 32).


The only reason things like this are even debated is because 99.99999% of music listeners haven't heard proper examples in controlled environments.
Hi from Bob Schulein,
As to the dymanic range test, which was created using audacity, the validity of the test were confirmed by checking each level of attenuation for accuracy.
Two techniques were used; one was to re amplify each attenuated sample buy the amount of a attenuation and confirm that the level returned to the reference level, and the other was to use pink noise as the test file and confirm each drop in attenuation by a spectral measurement. Spectral measurements were made using the program Spectra Plus.
As stated in the descriptive Youtube video, these tests give one a number, which must be further interpreted by the test subject as it relates to their equipment, their hearing acuity, and any masking noise present when listening.
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post #30 of 93 Old 03-20-2016, 12:56 AM
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Originally Posted by Rectaltronics View Post
You are wrong.
Through my mid-twenties I found myself quite irritated by "ultrasonic" vehicle presence detection devices at a couple of traffic lights in my neighborhood. And that's in spite of whatever damage NYC's subways must have been doing to my ears.
I surely can't be the only one.
Ultrasonic sensors for traffic light are from around 38kHz to 43kHz, and they are very loud in terms of sound pressure level.
What you heard is in-band (below 20kHz) harmonics or distortion, and no, you are not special, many people hear that noise including me.

Last edited by James Freeman; 03-20-2016 at 01:01 AM.
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