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Vinyl and digital
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Old 7th September 2014
  #1
Here for the gear
 
🎧 5 years
Vinyl and digital

Hey, so I just got bullied off another forum (I probably should have just hung out here, those guys weren't very nice and they didn't seem to understand the audio world outside of the theoretical) and I had some questions about what we were discussing; The quality of digital vs. the quality of vinyl.
Hope I put this under the right tab, the only other place to put it that made sense was beginner questions but this seems a bit advanced compared to the other questions there and I'll be asking for in-depth answers rather than basic explanations.

Here's the first thing I've been having trouble with. I've always thought of vinyl as a continuous flow of audio information. Then I had a long discussion with a family friend who has an electrical engineering degree and he related digital audio to digital pictures; Analog pictures have a little silver or chrome molecules that are chemically being changed color when exposed to light to create the image. Digital pictures have surpassed analog because we can actually have pixels smaller than the silver or chrome molecule. I'm oversimplifying our discussion, but that's the general idea he told me.
Similarly, he told me that with vinyl the needle is reading grooves that are made up of vinyl molecules (whatever that chemical equation is) and that the resolution of vinyl has a sample rate and bit depth equivalent as defined by how small the vinyl molecules can become.
So I went out and was researching what these numbers would be, and I found (including on the forum mentioned) the number 44k and 12bit used everywhere.
My first question would be if my friend is right about vinyl having sample rate and bit depth equivalents and if this number is correct.
If this is all wrong, can you explain why vinyl is continuous audio (or whatever is actually going on here).
My basic understanding is that since the needle flows continuously over the vinyl it produces an average between the gaps in the molecules. But my question would be (if my last statement was right) is whether or not a high quality DAC would do the same basic thing?

I also found on several different sources that vinyl has a frequency response drop-off after about 17k. Is this true? If it is true, is it dependent on the quality of vinyl disk?

My other question is this; I always thought that a sample was an exact point in time, or it was a single measurement of the electrical signal with no width.
What someone in my audio class said (who I think is also an electrical engineer going for a 3rd or 4th hobby degree) is that every other sample is an on command and an off command, basically meaning that the audio between the first two samples was captured and that the audio between the next two samples was not (and alternating on until the recording stops). This seemed to be completely twisted backwards. What is right here, what is a sample and what precisely does it do?

Now I want to ask about some specific things these "electrical engineers" on the other forum said.
I got a warning for making the claim that lossy file types such as MP3 won't sound as good as WAV files because I didn't provide files for comparison. I thought it was common knowledge that the MP3 (and AAC for that matter) encoder dropped bits of information that the decoder can't make up again. They argued that lossy file types aren't a problem for quality at all.
I tested this in iTunes (which doesn't have good encoders or decoders from my impression) and burned a CD to AAC. Then I burned it to WAV and did a listen comparison. The WAV had a noticeable improvement in quality.
Even if I had noticed the improvement in quality, I noticed that the WAV CD took up nearly 5 times the storage space.
So my question is how much of the information is being lost and if the casual listener would even notice. I heard things in the WAV like definition in the reverb that I just couldn't hear in the AAC file.

They also made the claim that DACs have been a stable technology for the last 25 years (which seemed like a silly claim considering digital audio was only really released to the market 25 years ago). I think my professor who's been using Pro Tools since it was Sound Tools would tell me that they weren't what he'd call stable until the last decade or so.
I got warned for saying that most USB interfaces will sound better than the built in DACs on laptops, all in one PCs, and MP3 players including phones.
I also got warned for saying that Apogee DACs will sound better than PreSonus DACs.
So what's the deal here; I thought better DACs will smooth over the audio by averaging between the samples. Is that true?
Also, aren't there several other factors used to discern the quality of a DAC, most importantly including signal to noise ration, harmonic distortion, and highest sample rate (dithering too, but I didn't mention that)? Shouldn't it be common knowledge that my Behringer UCA222 or MOTU 828 MKII would sound better than the DAC built into my iMac or Macbook Pro?
Isn't it just common sense that the last generation of Pro Tools HD interfaces will have better DACs than my Galaxy S4?
I think the answer is obvious, I just don't feel comfortable making assumptions after the way I was treated over there.
So assuming that the professional quality DACs like PreSonus or even Apogee are better sounding than my phone DAC;
Will the DAC built into my MacBook Pro, iMac, or Galaxy S4 faithfully reproduce the sound? Will they be good enough quality to replace vinyl? Will they be good enough quality to mix or master on? If they don't reproduce the sound faithfully, what makes them inferior to the pro grade DACs?


One of the other things I got in trouble for saying is that DSP has not yet surpassed the quality of analog processing. I went on to describe how studios are using analog boards to record and mix to Pro Tools HD, so obviously I'm talking about the high end gear. Specifically, I said how you won't see Chris Lord Algae selling his LA-2A when he made the CLA-2A plugin. Even the Black Keys (who are the only pros I know of actually using UAD which has always been in my mind the cream of the crop among DSP) would probably argue that UAD is passible, not better than the real deal.
So, is there anyone out there who thinks the digital modeled plugins are better? And have mathematics replaced the tube and Fet transformer?

I'm concerned, because these guys are claiming to be Electrical Engineers and they seem to think that the knowledge I've acquired from years and years of working in the industry, education, and reading books, blogs and magazines is all wrong. This is my career path and if I'm being naive with my understanding of digital audio I really want to understand the real science behind my art.
Old 7th September 2014
  #2
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JohnRoberts's Avatar
 
🎧 10 years
I didn't hear a question in that, but i admit I was having trouble following.

There are a few popular videos floating around explaining sampling theory and other common misperceptions about analog vs digital.

JR

PS: analog is quantized by the individual holes and electrons, but that seems continuous to us humans since our auditory nerves fire when stimulus is above threshold and then our meat computer kind of samples and averages those nerve impulses to make sense of it all... Don't fixate too much on the minutiae.
Old 7th September 2014
  #3
Here for the gear
 
🎧 5 years
Well, I understand if you had problems following.

The questions were kind of at the end of every paragraph. I guess that was a long about way of asking:

Is there a sample rate and bit depth of vinyl as defined by how small the vinyl molecules can be?
If there is, what is it? If there isn't, how is vinyl continuous?
Does vinyl have a frequency drop-off at the high end and where does it happen? Does the drop-off (if it exists) change with the quality of Vinyl disk?

What is a sample and precisely how does it work?

How much does lossy compression effect the sound? A WAV file is roughly 4~5 times the size of the equivalent AAC, so what information is dropped?
Would the casual listener notice the difference between WAV and AAC?

DAC;
What specifications effect the DAC audio quality?
Do DACs built into Laptops, All-in-one computers, and phones or MP3 players reproduce the sound faithfully?
What separates the cheap DACs from the pro grade stuff?

DSP;
Does anyone actually like analog modeled plugins better than the real deal?
Can mathematics actually replace a tube of FET transformer?

I guess when I phrase it that way maybe it did belong in the beginner thread, I just want more in depth detail than I thought I'd get there. Sorry about the confusion, I guess this is what my original post should have looked like.
Old 7th September 2014
  #4
Lives for gear
 
🎧 10 years
Quote:
Originally Posted by cdroid ➡️
Hey, so I just got bullied off another forum (I probably should have just hung out here, those guys weren't very nice and they didn't seem to understand the audio world outside of the theoretical) ...
It's the same anywhere. Come in spouting a lot of half-understood dogma like it's gospel and you're bound to get grief. As you say, it would have been smarter to lurk for a bit, read the forum rules, and find out a bit about the inhabitants' credentials.

Quote:
Originally Posted by cdroid ➡️
... Here's the first thing I've been having trouble with. I've always thought of vinyl as a continuous flow of audio information. ...
Similarly, he told me that with vinyl the needle is reading grooves that are made up of vinyl molecules (whatever that chemical equation is) and that the resolution of vinyl has a sample rate and bit depth equivalent as defined by how small the vinyl molecules can become. ...
A University professor went to the trouble of explaining this:
https://www.st-andrews.ac.uk/~www_pa...t12/page2.html

Quote:
Originally Posted by cdroid ➡️
... So I went out and was researching what these numbers would be, and I found (including on the forum mentioned) the number 44k and 12bit used everywhere.

My first question would be if my friend is right about vinyl having sample rate and bit depth equivalents and if this number is correct. ...
It's in the right ballpark. You measure the frequency response and dynamic range of a typical LP playback system and relate that to the sample rate and bit depth that would be required to digitise that without losing any of it.

Quote:
Originally Posted by cdroid ➡️
... My basic understanding is that since the needle flows continuously over the vinyl it produces an average between the gaps in the molecules. But my question would be (if my last statement was right) is whether or not a high quality DAC would do the same basic thing?
Any competently designed DAC does the same basic thing. It produces a continuous analogue output that correctly matches the analogue voltage that was present between the digital samples taken at A-D time. Monty shows that quite clearly in the Youtube video you dismissed.

Quote:
Originally Posted by cdroid ➡️
I also found on several different sources that vinyl has a frequency response drop-off after about 17k. Is this true? If it is true, is it dependent on the quality of vinyl disk?
The answer is, "it depends". As you surmise, it does depend on the quality of the vinyl production process. It's possible to put more HF level and frequency extremes on an LP than can be reproduced by the majority of playback systems. Ditto at the LF end. But if you do, you're going to have a lot of unhappy customers and a lot of returns. Part of the art of vinyl mastering is to make a reliably playable LP that still sounds as close as possible to the artists' original intent.

Quote:
Originally Posted by cdroid ➡️
... My other question is this; I always thought that a sample was an exact point in time, or it was a single measurement of the electrical signal with no width.
What someone in my audio class said (who I think is also an electrical engineer going for a 3rd or 4th hobby degree) is that every other sample is an on command and an off command, basically meaning that the audio between the first two samples was captured and that the audio between the next two samples was not (and alternating on until the recording stops). This seemed to be completely twisted backwards. What is right here, what is a sample and what precisely does it do? ...
Your understanding is correct. Your classmate's understanding is incorrect. Again, Monty deals with that in his video. You could suggest your classmate watches it.

Quote:
Originally Posted by cdroid ➡️
Now I want to ask about some specific things these "electrical engineers" on the other forum said.
I got a warning for making the claim that lossy file types such as MP3 won't sound as good as WAV files because I didn't provide files for comparison. I thought it was common knowledge that the MP3 (and AAC for that matter) encoder dropped bits of information that the decoder can't make up again. They argued that lossy file types aren't a problem for quality at all. ...
Again, it depends. It may help to stop thinking of it as "missing bits". Perceptual coders discard signals which (hopefully) won't be missed. Think of a symphony orchestra in full crescendo. The 3rd violin misses a single note. Are you likely to notice its absence? If you carry this process to extremes, you will start noticing the missing notes, but the art of perceptual compression is in deciding which notes etc to leave out. By the time you get to 256Kb AAC or 320Kb MP3 it's getting pretty hard to tell if anything is being left out, even if you directly compare it with the original. You need to use "worst case" samples and know exactly what you're listening for.

Quote:
Originally Posted by cdroid ➡️
I tested this in iTunes (which doesn't have good encoders or decoders from my impression) and burned a CD to AAC. Then I burned it to WAV and did a listen comparison. The WAV had a noticeable improvement in quality.
I assume you mean you compared the original WAV against a WAV produced from the AAC. Did you know which was which when you were comparing? You should do some research into blind vs sighted testing. You need to set it up so that you don't know which WAV is which. For example, get a friend to burn you a disc (audio CD, not data) with several copies of each track in random order. Play the disc, write down a list of track numbers and whether you think each track is original or from AAC. Get your friend to score your answers. Provided the WAV-AAC-WAV conversion and disc production is competently done, I think you'll find it more difficult than you think.

Quote:
Originally Posted by cdroid ➡️
Even if I had noticed the improvement in quality, I noticed that the WAV CD took up nearly 5 times the storage space.
So my question is how much of the information is being lost and if the casual listener would even notice. I heard things in the WAV like definition in the reverb that I just couldn't hear in the AAC file.
There's a lot of redundancy (wasted space) in a WAV file. Compressing it with FLAC will typically reduce its size by 50% or more but not lose any information at all. AAC or MP3 compression isn't transparent under all circumstances, but it's "close enough for rock'n'roll". Which is basically what you've noticed.

Quote:
Originally Posted by cdroid ➡️
They also made the claim that DACs have been a stable technology for the last 25 years (which seemed like a silly claim considering digital audio was only really released to the market 25 years ago).
As was pointed out to you elsewhere, mass market consumer digital audio has been around since the early 80s and digital recording has been around since the early 70s. Digital audio in telecommunications goes back even further.

Quote:
Originally Posted by cdroid ➡️
... I got warned for saying that most USB interfaces will sound better than the built in DACs on laptops, all in one PCs, and MP3 players including phones.
I also got warned for saying that Apogee DACs will sound better than PreSonus DACs.
"It depends".

Quote:
Originally Posted by cdroid ➡️
So what's the deal here; I thought better DACs will smooth over the audio by averaging between the samples. Is that true?
All competently designed DACs, even the ones used in cell phones and PC/laptop chipsets, use reconstruction filters that reconstruct the parts of the waveform between the samples. Some of them do a better job than others, but even the cheap ones usually do an adequate job - see the RMAA tests you were pointed at.

Quote:
Originally Posted by cdroid ➡️
Also, aren't there several other factors used to discern the quality of a DAC, most importantly including signal to noise ration, harmonic distortion, and highest sample rate (dithering too, but I didn't mention that)? Shouldn't it be common knowledge that my Behringer UCA222 or MOTU 828 MKII would sound better than the DAC built into my iMac or Macbook Pro?
Isn't it just common sense that the last generation of Pro Tools HD interfaces will have better DACs than my Galaxy S4?
I think the answer is obvious, I just don't feel comfortable making assumptions after the way I was treated over there.
As a general rule, you're right, a DAC engineered to a higher price/performance will usually perform better than a DAC engineered to a low price point. But you're well up the curve of diminishng returns by that stage. You're getting into the personal preference and bragging rights area. DACs designed for the professional market also tend to have a different set of priorities (output levels, XLR vs RCA etc) than consumer DACs.

Quote:
Originally Posted by cdroid ➡️
So assuming that the professional quality DACs like PreSonus or even Apogee are better sounding than my phone DAC;
Will the DAC built into my MacBook Pro, iMac, or Galaxy S4 faithfully reproduce the sound? Will they be good enough quality to replace vinyl?
For most listening purposes, yes they will. It's a subject of considerable debate though, like a religious argument, between the analogue and digital audiophiles.

Quote:
Originally Posted by cdroid ➡️
Will they be good enough quality to mix or master on?
Again, it depends, for example it depends on the fidelity requirements of the music genre. But in general, no, because they are designed for a different purpose.

Quote:
Originally Posted by cdroid ➡️
If they don't reproduce the sound faithfully, what makes them inferior to the pro grade DACs?
They're as good as they need to be for the role they are intended for. It'd be a waste of money putting the guts of a Benchmark DAC-2 into an iPod dock or laptop.

Quote:
Originally Posted by cdroid ➡️
One of the other things I got in trouble for saying is that DSP has not yet surpassed the quality of analog processing. I went on to describe how studios are using analog boards to record and mix to Pro Tools HD, so obviously I'm talking about the high end gear.
Seeing "Pro Tools" and "high end" in the same sentence raised a smile.
For what it's worth, I agree with you, plugin quality can generally only asymptotically approach the sound of the hardware it is emulating.

Quote:
Originally Posted by cdroid ➡️
... Chris Lord Algae ...
That joke's getting old.

Quote:
Originally Posted by cdroid ➡️
I'm concerned, because these guys are claiming to be Electrical Engineers and they seem to think that the knowledge I've acquired from years and years of working in the industry, education, and reading books, blogs and magazines is all wrong. This is my career path and if I'm being naive with my understanding of digital audio I really want to understand the real science behind my art.
Your time hasn't been wasted, you don't have it all wrong. It just reads like you've spent more time on learning your craft (think car driver) than understanding the fundamentals (think car designer / manufacturer / mechanic). Your desire to learn the science is laudable, I think if you'd made that a bit clearer on your posts "over there" you'd have found people willing to explain things.

Regards...
Old 7th September 2014
  #5
Here for the gear
 
🎧 5 years
Hey thanks Don, that helped clear quite a bit up. Especially the link, it confirmed my suspicions about vinyl and helped me understand that science. I really appreciate your thoughtful response.

I really don't feel like I'd gone in spouting audiophile lore as if it was fact (I'm still not sure if anything I had said in my first post was inaccurate, only simplified and I had a specific focus).

I actually wanted to ask about what you had said about MP3 compression. Can you describe it to me on terms of samples and bits what's happening? Maybe you can describe to me what it would look like if I zoom in to the samples on the waveform? I mean no offense, but your explanation didn't really give me any further insight to the tech behind MP3 compression.
I'll consider what you've said about the blind test, but I feel like I wasn't being biased. One of the albums I did this with was Avril Lavigne Let Go and I admit that I didn't hear much of a difference for the most part. Then I added a pop-rap (I'm not sure what genre I want to put them in) album from Karmin - Pulses - and I noticed a huge difference on the songs with heavy reverb and other detailed effects as well as the intro. On songs like the title song Pulses I barely noticed anything at all. I'm about to go test an orchestral CD (I'll probably choose Star Trek First Contact) when I'm done here. I didn't listen on high quality speakers though, but I still feel like I'd have a good understanding of how the WAV-AAC file formats affect the sound. (on a side note I just realized that I have been using the words effect and affect wrong the last couple days)

So I understand when you say that laptop - phone or whatever shabby DACs will be good enough for most purposes, but that's not my point of discussing this. I'm talking about DAC quality partly for my own enjoyment. I've been mixing audio for over 9 years now, and I've been playing music even longer than that including marching band all through high school. For the last 2 years I've been taking ear training classes in college for music theory and reading ear training books (with CDs) aimed at techies. When I'm asking if it's good enough, I'm not concerned with the general use. Part of what I want to discuss is whether or not those DACs will make the listening experience complete - as good as it gets from the source. I understand that even my ears may not be able to tell the difference (I don't say I've been doing this for 9 years to brag or qualify myself as a genius, I just want to point out that my ears will be well beyond the average listener) but part of the reason I want to know these things is because I'll have piece of mind when I know my listening experience can't get any better with that source. I just like to know that there's one piece of the audio chain to my ears isn't the limiting factor, you know?

So I didn't mean that I thought Pro Tools was high end. What I was saying is people said they doubted DSP hadn't already surpassed analog signal processing. What I was trying to say is that since I was talking about Pro Tools HD systems in pro studios, people in the thread ought to have deducted that I wasn't talking about comparing the Dyn3-compressor from Pro Tools to a 266 DBX analog processor. They should have deducted that I was talking about Waves plugins or UAD plugins compared to the real thing. That's what I meant by high end. I'm actually not a huge fan of the Pro Tools HD systems (let me interject "For the cost" here because this doesn't go to say I don't like the Pro Tools HD systems) and I think that the Digico live sound boards have a better sound. For in the studio I thought that one of the Apogee units I've used sounded better than the Pro Tools HD (and it's around half the cost not including the core system). I also thought that Studio One sounded better than Pro Tools 10 (I should really compare 2.5 to 11). I don't know if the digital summing algorithms are any different/better in Studio One but I did suspect that part of my experience there was expectation (what you were talking about with blind tests).

To your last section there:
I really think that some people on some forums are just jerks because give a man a mask and he'll call you names. When I was younger I would look up tech support issues on forums much more often, and routinely I'd do a Google search and find a thread where the op had the same exact problem I did and the first response is calling him a noob including a snarky "Let me google that for you" link. Almost invariably, the first result from the "Let me google that for you" search would be the forum I just came from. The next page or two would be forums with almost the exact same scenario. And I'm one of the guys who uses google as though if something I need isn't on the first page then I need to try a different search. I can't remember the last time I got past the second page of google results.
So in this example, I was on that forum with a post that was partially an opinion post using (what I thought was) common knowledge and people started weighing in with pretty vicious comments with wrong information. One of the guys tried telling me how the phone DAC is every bit as good as the Pro Tools HD DAC and I think we all know that has to be wrong.

At any rate, I think I've seen enough to call shenanigans on the people in the other forum I was on but I'm still a bit fuzzy on some of the specifics for my own personal use.
Old 7th September 2014
  #6
Here for the gear
 
🎧 5 years
Algae... I just caught that. I'm sorry, that wasn't meant to be funny, I just wasn't paying attention to what I was typing.
Old 7th September 2014 | Show parent
  #7
Lives for gear
 
🎧 10 years
Quote:
Originally Posted by cdroid ➡️
...
I really don't feel like I'd gone in spouting audiophile lore as if it was fact (I'm still not sure if anything I had said in my first post was inaccurate, only simplified and I had a specific focus).
It's the impression you gave, though, hence the responses you received. Anyway, moving on:

Quote:
Originally Posted by cdroid ➡️
I actually wanted to ask about what you had said about MP3 compression. Can you describe it to me on terms of samples and bits what's happening? Maybe you can describe to me what it would look like if I zoom in to the samples on the waveform? I mean no offense, but your explanation didn't really give me any further insight to the tech behind MP3 compression. ...
Don't think of it in terms of samples and bits.
A greatly simplified explanation:
Take the input and divide it into short segments. Run each segment through a Fourier transform, the output of which is a list of the frequencies present in the segment and their amplitudes. Write the lists out to a file. To play it back, perform the inverse transform on each list and write the segments out as a WAV file.
The above is a lossless process, but can result in a space saving because simple (or no) signals result in simple lists. The clever part is that once you have the lists, you can apply "perceptual masking" techniques. This involves making use of the way the human auditory system works. Basically, any sound that you're unlikely to hear because it's masked by other sounds, gets encoded less accurately or even left out entirely. For example, a loud sound at one frequency can mask a somewhat quieter sound at a slightly different frequency. If you can't perceive it, why bother listing it?

Here's a good explanation, as part of a paper on designing a perceptual coder:

"An Experimental High Fidelity Perceptual Audio Coder
Project in MUS420 Win 97"
https://ccrma.stanford.edu/~bosse/proj/proj.html

Searching for "perceptual masking" using your preferred search engine should turn up any number of similar hits. There's also Wikipedia, for example:
http://en.wikipedia.org/wiki/Auditory_masking

Getting back to what the resulting waveform should look like, the answer is "very similar to the original". A common procedure for measuring differences is to invert the result waveform and null it against the original. Any residual is the difference. This works quite well for classic differences such as those caused by frequency response changes and distortion, but doesn't work so well for testing what a perceptual coder has left out. The residual doesn't really sound anything like what you would expect.

Quote:
Originally Posted by cdroid ➡️
I'll consider what you've said about the blind test, but I feel like I wasn't being biased. ...
If you knew which was which, you were hopelessly biased, regardless of your feeling. I'm not being smart, it's a stone cold fact. I suggest you look right here on GS for posts by user j_j.

Search --> Advanced Search --> posts by user j_j --> List by threads

For example, there's this one:
ABX, Blind testing methods

And this one:
Everyone should watch this - Audio Myths

Watch the video referenced in the first post of that thread, then go to the site JJ references in post 12 and read the suggested papers:
PowerPoint Presentations from recent (or not so recent) meetings.

Listen and read very carefully. JJ arguably knows more than anyone else alive about perceptual coding and blind testing. His credentials:
https://home.comcast.net/~retired_old_jj/

Regards...
Old 7th September 2014
  #8
Lives for gear
 
🎧 15 years
Hi
Interesting and thought provoking discussion so far.
Taking only a tiny extract:
[ One of the guys tried telling me how the phone DAC is every bit as good as the Pro Tools HD DAC and I think we all know that has to be wrong. ]
The basic DAC chip MIGHT be as good (or even the same) but the use in a phone or other small device puts it into a lousy 'environment'.
A DAC chip can cost a few Dollars but it is the surrounding chips and whatever that really determine the ultimate 'quality'.
Another thread was mentioning 'mastering for Tape, Vinyl, CD and 'HD CD' as the requirements are different.
This will affect the overall sound tremendously as it is 'working around' inherent problems of each system.
Thus direct comparison is not so easy unless you know the provenance of each.
Matt S
Old 7th September 2014 | Show parent
  #9
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JohnRoberts's Avatar
 
🎧 10 years
Quote:
Originally Posted by cdroid ➡️
Well, I understand if you had problems following.

The questions were kind of at the end of every paragraph. I guess that was a long about way of asking:

Is there a sample rate and bit depth of vinyl as defined by how small the vinyl molecules can be?
If there is, what is it? If there isn't, how is vinyl continuous?
Wrong question, or comparison. Vinyl is an electro-mechanical system so limited by mechanical resonances, surface irregularities, turntable errors, etc. (only a partial list).
Quote:
Does vinyl have a frequency drop-off at the high end and where does it happen? Does the drop-off (if it exists) change with the quality of Vinyl disk?
The HF response is generally limited by playback cartridge, and lathe that cuts the record pressing masters. MC (moving coil) carts can have somewhat wider frequency response than MM (moving magnet). Back in the day some masters were cut at half speed, effectively doubling the cutting lathes HF response, other high end approaches were direct to disk eliminating interim tape storage.

Another limit in vinyl is that LF sounds need to be mono or panned center to prevent tracking problems.
Quote:
What is a sample and precisely how does it work?
Watch the videos
Quote:
How much does lossy compression effect the sound? A WAV file is roughly 4~5 times the size of the equivalent AAC, so what information is dropped?
Would the casual listener notice the difference between WAV and AAC?

DAC;
What specifications effect the DAC audio quality?
Do DACs built into Laptops, All-in-one computers, and phones or MP3 players reproduce the sound faithfully?
What separates the cheap DACs from the pro grade stuff?

DSP;
Does anyone actually like analog modeled plugins better than the real deal?
Can mathematics actually replace a tube of FET transformer?

I guess when I phrase it that way maybe it did belong in the beginner thread, I just want more in depth detail than I thought I'd get there. Sorry about the confusion, I guess this is what my original post should have looked like.
These are all old questions that have been answered and discussed many times. Consider doing a search.

JR
Old 7th September 2014 | Show parent
  #10
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JohnRoberts's Avatar
 
🎧 10 years
Quote:
Originally Posted by Matt Syson ➡️
Hi
Interesting and thought provoking discussion so far.
Taking only a tiny extract:
[ One of the guys tried telling me how the phone DAC is every bit as good as the Pro Tools HD DAC and I think we all know that has to be wrong. ]
The basic DAC chip MIGHT be as good (or even the same) but the use in a phone or other small device puts it into a lousy 'environment'.
A DAC chip can cost a few Dollars but it is the surrounding chips and whatever that really determine the ultimate 'quality'.
Another thread was mentioning 'mastering for Tape, Vinyl, CD and 'HD CD' as the requirements are different.
This will affect the overall sound tremendously as it is 'working around' inherent problems of each system.
Thus direct comparison is not so easy unless you know the provenance of each.
Matt S
Perhaps this is talking about the asymmetry in mobile codecs where the DAC is generally capable of playing back full range recordings, while the ADC side of the codec is scaled appropriate for capturing speech.

So the DAC is quite good and probably a lot better than the phone electronics around it. There will be (better be) improvement in very expensive DACs but perhaps less than we might expect.

JR
Old 7th September 2014
  #11
Lives for gear
 
Richard Crowley's Avatar
 
🎧 15 years
Remember also that virtually all modern analog recordings ("vinyl" is only one distribution media) were originally recorded on analog magnetic tape. Mag tape has a form of "sampling" by virtue of the recording media. Mag tape is composed of millions of microscopic magnetic "dipoles". These dipoles individually "record" a "bit" of the waveform amplitude at that instantaneous moment. And then, the playback head gap determines the "resolution" of how finely you can "resolve" those magnetic dipoles and what magnetic field each of them have.

Those of us who grew up in the old analog era don't have the same fascination for that antique technology. IMHO good riddance. It was a deficient and fiddly makeshift system before the digital age. Is modern digital technology perfect? Of course not. But it is a far sight better than the old analog methods. Do people still use analog mag tape for "effect"? Sure, but it is just a form of artificial distortion that some people prefer the sound of (for whatever reason).
Old 7th September 2014
  #12
Lives for gear
 
🎧 15 years
Hi
What seems to have 'bypassed' all these 'audiophile' types is that the quality of sound reproduction does not have to be technically 'perfect' to thoroughly enjoy it.
Sound 'captured' by a microphone is 'imperfect' and from then on it is downhill all the way. The advent of 'digital processing' has 'flattened out' the degradation curve in the 'middle' somewhat (over full analogue which can be excellent) before it hits a new low in the speaker(s).
I was thinking of playing back a wav file from my phone and measuring it's performance, just not got around to it yet. I have a feeling the output sections on a phone may use class D amplifiers to reduce battery drain.
Matt S
Old 7th September 2014
  #13
Here for the gear
 
🎧 5 years
Matt, what's up with the mysterious quotations?

To all;
I wanted to spend a couple seconds refocusing future discussion; I read a lot of good input on the topic and I wanted to thank you for teaching me these concepts.
What I wanted to focus on however, is whether or not the digital storage medium was higher resolution and better quality than vinyl.
I understand that tape may be better quality or that many people wouldn't notice certain quality changes but that's beside the point I was asking.

So you might not think that the DSP discussion or DAC discussion is relevant, but it affects the ability for the digital file to be reproduced as analog sound. Same goes for the lossy or lossless audio file types.

Also I specifically left out discussion on amplifiers or speakers.

I'll watch the Monty videos someone mentioned before I join the conversation again, but did anyone else have any other videos I should be watching?

Thanks all for your input.
Old 7th September 2014 | Show parent
  #14
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JohnRoberts's Avatar
 
🎧 10 years
Quote:
Originally Posted by cdroid ➡️
What I wanted to focus on however, is whether or not the digital storage medium was higher resolution and better quality than vinyl.
Higher resolution suggests that a direct comparison of that specific property can be made, analog resolution is very different than digital resolution so not an appropriate reference quality to compare. ( A comparison of linearity where all errors or deviation from perfect are less than some tiny amount should suffice to demonstrate superior accuracy.)

IMO digital technology is capable of far superior performance to vinyl in pretty much every aspect that makes sense; S/N or dynamic range, frequency response (HF and LF), channel separation, linearity (distortion), etc.

This does not mean that every digital medium is better than the best vinyl, but IMO the best vinyl is not better than the best digital, and vinyl is systemically inferior in several aspects (but I already mentioned those in an earlier post).

JR
Old 7th September 2014 | Show parent
  #15
Lives for gear
 
🎧 10 years
Quote:
Originally Posted by cdroid ➡️
... What I wanted to focus on however, is whether or not the digital storage medium was higher resolution and better quality than vinyl. ...
As usual, the answer is "It depends".

It depends on the bit depth and sample rate of the digital system.
Pick the frequency response and dynamic range you deem significant for the vinyl system. Now pick the sample rate and bit depth that will comfortably contain them. Job done. 16 bits is enough for any real-world vinyl dynamic range. 44.1 KHz sample rate is a bit more arguable. Nowadays it's easy to avoid any argument and use 24/96.

One point you brought up in an earlier post was the audibility of reverb tails. Many people prefer vinyl because they say the reverb tails are better preserved than with digital. Some years back I listened carefully to some tails of the same music on both LP and CD and came to the conclusion that, for me, it's the vinyl noise level that makes the difference. A reverb tail on vinyl fades into audible noise. The noise gives the illusion that the tail goes on longer. On CD, it just "fades to black". (Strictly speaking, it fades into the dither noise, but it's down at an inaudible level, assuming you haven't cranked the gain to insane levels.)
At the time I didn't have the means to artificially increase the background noise of the CD version to that of the LP and see if it helped. Some day I ought to try it.
Old 9th September 2014 | Show parent
  #16
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Paul Gold's Avatar
 
8 Reviews written
🎧 15 years
Quote:
Originally Posted by cdroid ➡️
Matt, what's up with the mysterious quotations?
What I wanted to focus on however, is whether or not the digital storage medium was higher resolution and better quality than vinyl.
According to the specs it is. If so why do so many people like records? There is no way to do a direct fair comparison because each has it's own types of failure modes and issues.

Let's take the 8 bit, 44k "equivalent" that a record is to PCM. You can't compare THD because on a record THD is frequency dependent. IN PCM it isn't. That makes it very difficult to measure dynamic range because how you define the distortion spec will greatly influence the result. Lastly in analog you can hear deep into the noise floor. In digital you can't. There is another strike against defining dynamic range in the same way. You can say that a record is equivalent to 8 bit 44k and it is true in a technical sense but the measurements do not describe the differences between a record and PCM accurately at all.
Old 9th September 2014 | Show parent
  #17
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JohnRoberts's Avatar
 
🎧 10 years
Quote:
Originally Posted by Paul Gold ➡️
According to the specs it is. If so why do so many people like records? There is no way to do a direct fair comparison because each has it's own types of failure modes and issues.
[edit] If there was a significant number of people still buying records, they would be a mass market medium and not eclipsed by digital media. In my judgement they are a low volume niche product. [/edit]

There are not obvious objective explanations for subjective preferences. Some people like old stuff just because it's old. Just like some people like new stuff, just because it is new. There are objective quantifiable differences between vinyl and modern digital.

BTW the customer is always right.... even when they are wrong.
Quote:
Let's take the 8 bit, 44k "equivalent" that a record is to PCM.
8-bit is only 48 dB or so... That is more like cassette tape dynamic range than vinyl.
Quote:
You can't compare THD because on a record THD is frequency dependent. IN PCM it isn't.
For high levels of distortion they are apples vs oranges, but for very low levels of distortion it does not matter (IMO).
Quote:
That makes it very difficult to measure dynamic range because how you define the distortion spec will greatly influence the result.
Dynamic range is loudest level vs noise floor,, only way distortion affects that is if you tolerate significant amounts of distortion to claim louder peak levels.
Quote:
Lastly in analog you can hear deep into the noise floor. In digital you can't.
Not exactly,,, perhaps true for early very old low bit rate digital where LSB was above the input noise floor, but for modern convertors when the LSB is dithered by input noise, signals can be heard in the noise floor below that LSB. (look up dithering)
Quote:
There is another strike against defining dynamic range in the same way. You can say that a record is equivalent to 8 bit 44k and it is true in a technical sense but the measurements do not describe the differences between a record and PCM accurately at all.
Again not sure where that 8 bit claim is coming from. In my experience records are much better than that, Just not as good as modern digital media.

For what its worth telephone system codecs ran at 8 bit and used a non-linear coding algorithm to deliver acceptable (for telephone) sound quality. Nobody considers telephone audio to be music quality. (Telephony also sampled at 8 kHz so less bandwidth too.)

Dynamic range is not the only compromised parameter for vinyl reproduction, but I am repeating myself. There will continue to be a market for vinyl among aficionados but I am not aware of any objective justification for this.

JR
Old 9th September 2014 | Show parent
  #18
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Paul Gold's Avatar
 
8 Reviews written
🎧 15 years
Quote:
Originally Posted by JohnRoberts ➡️

For high levels of distortion they are apples vs oranges, but for very low levels of distortion it does not matter (IMO).
I agree but measuring low level distortion in analog and digital will make analog look better. Measuring high level distortion will make digital look better. Not a particularly useful metric.

Quote:
Dynamic range is loudest level vs noise floor,, only way distortion affects that is if you tolerate significant amounts of distortion to claim louder peak levels.
Analog has a "soft top" better gear will preform better at the top of the dynamic range. Digital has a "hard top". What's "significant distortion", 0.1% 0.001%? At what frequency? It still seems very messy to me.


Quote:
Not exactly,,, perhaps true for early very old low bit rate digital where LSB was above the input noise floor, but for modern convertors when the LSB is dithered by input noise, signals can be heard in the noise floor below that LSB. (look up dithering)
I have done a lot of listening tests. Listening through dither is a wholly different experience IMO. Not comparable to gaussian hiss at all. God knows everyone has tried to make dither random. It hasn't worked.
Old 9th September 2014
  #19
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JohnRoberts's Avatar
 
🎧 10 years
Discussing audibility of signals below the noise floor is only marginally important if the noise floor of the medium is inadequate to capture the full signal dynamic range. In my experience modern digital noise floors are below the signal noise floors they are tasked with capturing, so the digital playback is dominated by the analog input noise floor.

Sorry for the veer and I am not trying to be argumentative, I've just listened to these arguments before and followed the incremental advancements to digital technology over several decades. Back in the '70s digital was pretty rough, but that was a long time ago. By the time they started making CDs they had it pretty well sorted, and since then it has just gotten better.

An unfortunate reality is consumers are not driven solely by performance or betamax would have beat VHS. Vinyl has it's fans and I wish you continued success with that.

JR
Old 9th September 2014
  #20
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AlexK's Avatar
 
🎧 10 years
The task of engineering audio for music lies between two (often completely opposed and conflicting) approaches and justifications. Half of your brain is that of an engineer; science, evidence, engineering, repeatability and understanding solid facts about the underlying principles of say a digital PCM recording system (like ProTools), or a class A amplifier design.

However, this is all in the name of art (which is what music is), and everything becomes far more complicated. This is where the other half of your brain has to be.

Some of the engineers who make the best sounding recordings (IMO) actually often have a somewhat patchy technical understanding, especially when it comes to the digital world.

So while it is good to know about these technologies and what their limitations are, I don't believe you can simply sit back and enjoy the CD over the vinyl because you know the CD is higher 'resolution' (I actually still don't understand what that refers to in the audio world). For a long time now, the technology we're using has not been the limitation of getting good quality sound when playing back audio, but more knowing how to apply it and use it correctly.

A beautifully executed recording on 256 kbps AAC will sound far, far better than a poorly produced or mixed, or mastered (or performed) recording on the best super-duper-9-billion-bit-DSD-analodigitalised-whatever.

I still love my vinyl, but also don't mind listening to digitised versions of my records (although I would rather listen to the vinyl because I have more fun in the process).
Old 10th September 2014 | Show parent
  #21
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Paul Gold's Avatar
 
8 Reviews written
🎧 15 years
Quote:
Originally Posted by JohnRoberts ➡️
By the time they started making CDs they had it pretty well sorted, and since then it has just gotten better.
I like CD's. I like digital recording. I think both sound good. I loved my MiniDisc recorder with Sony microphone and AGC.
Old 10th September 2014
  #22
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sameal's Avatar
Sciencesluts?

Hell if I know what any of it all means in the end. What I do know is they will have to pry my vinyl out of my cold dead hands.

More likely, it'll end up in a garage sale. Hey that's what happened to my parent's records and their parents records.

I commend those tape warriors of old. You fought the good fight. But Im pretty much on the good riddance wave.

Anyway, this wall of text could of been about 10 albums man.
Old 10th September 2014
  #23
Gear Head
 
🎧 15 years
As a general rule of thumb - vinyl sounds pretty crap!!!
Old 10th September 2014
  #24
Lives for gear
 
🎧 15 years
Hi
{As a general rule of thumb - vinyl sounds pretty crap!!! }

But some punters will pay mega bucks for these and the hardware to play them on. What is this saying about the 'Hi Fi' loving world?
Matt S
Old 10th September 2014
  #25
Lives for gear
 
sameal's Avatar
Well sure it does on paper, but cds break, scratch and backing peels even kept in a case, and hard drives die all the time.

Now I get vinyl can get ****ed up, but if you keep it flat and in it's case, you will have it for damn near ever, and rather then buying up the latest and greatest hardware player which changes every week, I have the same stereo I've had since high school.

No, I don't hate digital. I got cds and downloads, I just prefer vinyl because the upkeep is easy and I don't need to constantly buy new players and crap for it, leaving more cash for what I really want. More music.
Old 11th September 2014
  #26
Gear Maniac
 
telegramsam's Avatar
 
🎧 5 years
I listen to records for a couple of reasons:

1. I have mostly records.
2. I like the larger artwork
3. Longevity: I have records over 50 years old that play perfectly.
4. It fascinates me, that such a primitive technology can actually sound so good, at least most of the time.

Of course Specs do matter, but my Technics SL-1200 has only a small amount of wow & flutter at .0025 wrms and a s/n ration of 78db. Those are both arbitrarily low. Cartridges can make a huge difference too, as channel separation can be pretty poor on some. However the better cartridges are around 40 some db, which should not be much of a factor.

Also alignment is a big factor. A poorly aligned deck will sound pretty bad on certain selections and only mediocre most of the time. Some people do not have the stomach for this, but many folks here have aligned tape machines, so I can't think that's too much of a drawback.
Old 11th September 2014 | Show parent
  #27
Lives for gear
 
🎧 10 years
Quote:
Originally Posted by telegramsam ➡️
...
2. I like the larger artwork
..
4. It fascinates me, that such a primitive technology can actually sound so good, at least most of the time.
Those are my main reasons too.

Quote:
Originally Posted by telegramsam ➡️
Of course Specs do matter, but my Technics SL-1200 has only a small amount of wow & flutter at .0025 wrms and a s/n ration of 78db. Those are both arbitrarily low. ...
You might find this interesting...
Archimago's Musings: MEASUREMENTS: Technics SL-1200 M3D Wow & Flutter - PlatterSpeed + Dr. Feickert's Test LP...

"There are lies, damn lies, and manufacturer's specifications."
Old 11th September 2014
  #28
Gear Maniac
 
telegramsam's Avatar
 
🎧 5 years
Very interesting, indeed! Thanks for the link.

From my experience with a few different turntables, I have always like DD ones the best, however I don't think the drive system is important, so long as it turns the platter consistently.

I currently use the sl-1200, but have also used:
Kenwood KD-500
Dual 1219
Thorens TD-125
Linn LP12
Garrard Lab 60mkII

In the Garrard, I could hear the wow & flutter. The rest all sounded pretty decent to pretty good. I liked the Linn and Thorens, but they seemed more finicky to set up then the Technics and Kenwood, and did not sound noticeable better to my ears. These are all subjective impressions, as I did not listen back to back in any of these cases.

My point is simply that a quality turntable and a good pressing will not detract much if at all from the experience of listening.
Old 12th September 2014 | Show parent
  #29
Lives for gear
 
🎧 10 years
Quote:
Originally Posted by telegramsam ➡️
... My point is simply that a quality turntable and a good pressing will not detract much if at all from the experience of listening.
Agreed. It goes back to your earlier statement:
"It fascinates me, that such a primitive technology can actually sound so good, at least most of the time."

I have a party trick. I play a 1 KHz tone from a test LP. Then I play the same tone from a test CD. The differences are obvious. Then I point out that the problems they hear in the LP test tone are also present in the music from all LPs that they play...
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