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Author Topic: George....what's the resolution of analog?  (Read 56819 times)

Nika Aldrich

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Re: George....what's the resolution of analog?
« Reply #15 on: May 14, 2004, 04:39:51 pm »

raw-tracks wrote on Fri, 14 May 2004 21:16

I could be way off base here, but shouldn't the correct answer be that analog recording has INFINITE resolution.


Essentially, no.

The accuracy of an system has do with the relationship between the original signal and the amount of error imparted on the signal due to the recording/reproduction process.  Digital systems have far less error than pure analog systems.  Ergo, we would feign to say that analog systems have "infinite resolution" if digital systems are constrained.  Thus, the posts above are far more correct.

We would be better to phrase it in terms other than the nebulous term "resolution" and instead by the actual effects on the waveforms.  Digital systems are capable of error signals being pure noise at levels in the audible range of -120dB, complete phase accuracy for audible range signals, and distortion levels below the noise floor.

Analog systems have a tough time getting the distortion and noise levels below -80dB of peak signal, incur various phase distortions in the audible range, and have distortion that is audibly apparent as opposed to below the noisefloor.

For these reasons, digital audio is capable of far more accuracy than analog audio.  I would probably keep it in these terms and avoid the term "resolution."

Nika.
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david gregORIO

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Re: George....what's the resolution of analog?
« Reply #16 on: May 14, 2004, 04:54:31 pm »

From Mirriam-Webster online...
Resolution (noun)
1 : the act or process of reducing to simpler form: as a : the act of analyzing a complex notion into simpler ones b : the act of answering : SOLVING c : the act of determining

Digitization by nature depends on reducing a signal (or any information) to a form that a computer can process and store.

Analog Tape recording by nature requires that you add a bias signal which is the opposite of reducing the signal to a simpler form.

so, the answer is zero!.... or maybe.... infinity!

damn, I dunno what I'm talking about, maybe you should just ask George.



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raw-tracks

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Re: George....what's the resolution of analog?
« Reply #17 on: May 14, 2004, 04:56:48 pm »

By no means was I implying that analog is more accurate. As Nika pointed out, it is the term "resolution" that compelled me to post.
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Re: George....what's the resolution of analog?
« Reply #18 on: May 14, 2004, 10:13:33 pm »

Pretty straightforward answer.  The threshold of human hearing is in the 24-bit to 27-bit range (depending on the trained ears of the listener).  A 28-bit system (which equals 2 to the 28th power which equals 268,435,456 or 268,435,456 bitrate or 33554432 byterate) is beyond the range of human detection from all studies I have seen.  In this situation, all audible harmonics from a simple or complex source can be resolved within the ear.  

There is a similar analogue to vision.  The "resolution" of human eyesight is approximately 1400x1400 dots per inch (actually slightly skewed in the vertical direction like 1400x1398 due to the stereoscopy) at the focal length of our eyes, but can go higher for trained eyes.  

It's not rocket science.  Yes, analog has "infinite" resolution (but does it really because it is molecularly constrained to the nth molecule, electron, quark, etc., and are the "production" tape masters produced in a clean-room environment?), but the practical application is that if you attain 28-bit resolution, you are golden.  A 32-bit sound card on a computer refers to processing speed, not the signal path.  

When an analog harmonic takes place, the octave, octave-fifth, 2nd octave, etc. harmonics come into the spectrum until some nth divisor squeaks out, and we love it.  Digital is getting there, but not yet.  I have been "begging" sound processing companies for several years to develop 28-bit processors!  C'mon guys!  We're not that far away!  But even when we get there we'll need some clean, highly-controlled oscillations through our power sources, highly-shielded cables, etc.  Cold fusion, anyone?  

Here's a kicker: we hear in digital (the eardrum excites the cilia in our ears, which translate acoustical vibrations into electron flow within our neurotransmitters).  
The electron flow is represented by a series of moving charges, similar to a binary I/O DVD, CD, etc.  

Regards,
My World (yes, that's my name)
My World Studios
Los Angeles, CA
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Curve Dominant

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Re: George....what's the resolution of analog?
« Reply #19 on: May 15, 2004, 04:20:38 am »

Quote:

posted by My World:
analog has "infinite" resolution


This is an extremely misleading statement. Analog tape has nothing close to "infinite" representation.

This term "resolution" itself is for the realm of the amature. We really should not be throwing this word around so liberally on a professional audio forum.

Do not confuse "infinite" with "random."

And take note of the noise floor.

The noise floor in analog tape is indeed random (Gaussian). But it is still noise, and you can hear it.

The noise floor in digital is not AS random (Triangular), but it is much lower than in analog tape. Used properly, you cannot hear it.

So you are faced with the difference between truly random noise which you can hear, and somewhat more calculatedly random noise, which you cannot.

In either case, do not be fooled into thinking there is something resembling infiteness. There is no infinity in analog tape. Just because your computer moniter "shows" you the finiteness of digital audio doesn't make it "worse" than the finiteness of analog tape. On the contrary. If your analog tape machine could "show" you all of its anamolies, you would run to digital, pronto.

What this should tell you, is that there are some infinities that are bigger than others. How is that possible? Simple:

Take simple numbers. There are an infinte number of simple numbers, right? You start counting from one...and you can count onto infinity.

Now, take just the even numbers, and just count them exclusively. If you just count the even numbers...you can count them into infinity, right?

But when you compare the infinite numbers against the infinite even-only numbers, which is the greater infinity?

It's a brain-twister, right? Counter-intuitive as it is, it makes sense. Some infinities are indeed bigger than others.

And it tells you why people get so jammed on this analog/digital dilemma. You think you can "see" the finiteness of digital audio on your computer monitor. But that's not the whole picture. It's just a graphic representation of one part of the process.

Chuck

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analog = magnetic filed ; digital = square
« Reply #20 on: May 15, 2004, 08:26:47 am »

Hi there,,

every representation of analog is connected to the instance that the signal is at one or more points in the chain:

A magnetic field.

Examples: Microphones, tubes, transformers, tape heads, pickup-cartridges, loudspeakers.

When we listen to analog recordings, we could have the insight, that the better the recording, the more often the signal passed through as a field.

I you compare f.e. the Eagles records, you get a very good feeling for the decline of audio quality that has happened over the years.

The record Eagles from '72 sounds wonderful.
Desperado '73 very very good.
On the border '74 very good.
One of these nights '75, still good, but now it starts becoming flat.
Hotel California '76, well many think it sounds good, actually not far as good as the old ones.
The Long Run '79 has lost all of the original Eagles quality sound.

I have all those records and can clearly hear the decline in quality that I point down to the fact, that tube-equipment was replaced in favor of transistor equipment.

The effect is that many parts in the whole recording chain, where the signal originally passed as a magnetic field, now it just passes as electric current through silicon transistors.

Although as measurements suggest that devices operating on a field create distortion and transistors are much more accurate, we know that without those fields, we cannot enjoy music at all.

Look at todays desperate attempts to get that kind of magnetic field sound with digital means.

You can indeed say, that the resolution of a field is indeed infinite or at least: it cannot be captured with bits and sample-rates.

But this is not necessary, as the purpose of playback equipment is to reintroduce those subtle harmonic structures.

The problem of digital playback is just ONE:

Square Waves.

All that we try to capture are sinewaves, and all our converters put out are square waves.

As you all know, squares consist of odd harmonics alltogether, so the main job of digital reproduction is filtering out those high-order odd stuff.

You can imagine that the larger the squares, the more difficult it is to filter them into a round wave-form.

Now can you reduce the size of the squares by going from 16 to 20 or 24 bits ? Indeed not.

If you want to have smaller squares, you need to increase sampling rate.

Charles Smile

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Nika Aldrich

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Re: analog = magnetic filed ; digital = square
« Reply #21 on: May 15, 2004, 08:34:00 am »

Chuck wrote on Sat, 15 May 2004 13:26

You can imagine that the larger the squares, the more difficult it is to filter them into a round wave-form.


Chuck,

This is a completely erroneous and misleading statement.  

Nika.

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Chuck

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Re: analog = magnetic filed ; digital = square
« Reply #22 on: May 15, 2004, 09:03:42 am »

Nika Aldrich wrote on Sat, 15 May 2004 14:34

Chuck wrote on Sat, 15 May 2004 13:26

You can imagine that the larger the squares, the more difficult it is to filter them into a round wave-form.


Chuck,

This is a completely erroneous and misleading statement.  

Nika.




Hi Nika,,

Try to think about it again, but an octave higher.

Charles Smile
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Former Oceanway drone

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Re: George....what's the resolution of analog?
« Reply #23 on: May 15, 2004, 11:17:51 am »

Chuck wrote:

"I you compare f.e. the Eagles records, you get a very good feeling for the decline of audio quality that has happened over the years.

The record Eagles from '72 sounds wonderful.
Desperado '73 very very good.
On the border '74 very good.
One of these nights '75, still good, but now it starts becoming flat.
Hotel California '76, well many think it sounds good, actually not far as good as the old ones.
The Long Run '79 has lost all of the original Eagles quality sound."


I certainly have opinions about analog vs. digital and I have no intention of talking about them right now. That said, I do have a problem with Chuck's connecting the declining recording quality of Eagles albums with a "decline" in analog.

First, and more importantly, the first two Eagles albums were recorded by Glyn Johns. An engineer who aside from having great ears, also tended to record things simply, but with very good gear. After that Bill Szymzyck took over and started using MCI inline consoles, which, while quite versatile, can not be easily confused for Neves.

Second, Ampex ATR-124s came out at the beginning of the 1980s and can in no way be connected with the "decline" of analog. Indeed I would argue that it symbolized the apex of the analog tape machine. More generally, some amazing analog recordings came out in the early 1980s (e.g. Joni Mitchell "Wild Things Run Fast"; Dire Straits "Love Over Gold"; etc.

I disagree fundamentally with the premise that analog got worse over time.

Cheers,

Alan Tomlinson
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Curve Dominant

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Re: George....what's the resolution of analog?
« Reply #24 on: May 15, 2004, 12:24:26 pm »

Quote:

posted by Charles:
Nika Aldrich wrote on Sat, 15 May 2004 14:34
Chuck wrote on Sat, 15 May 2004 13:26

You can imagine that the larger the squares, the more difficult it is to filter them into a round wave-form.

Chuck,

This is a completely erroneous and misleading statement.

Nika.



Hi Nika,,

Try to think about it again, but an octave higher.

Charles



Nika,

I got your message yesterday.

Good lord, no wonder you're exhausted. It seems they have us outnumbered.

David Bock

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Re: George....what's the resolution of analog?
« Reply #25 on: May 15, 2004, 12:35:30 pm »

"In any way you care to measure, even a $25 SoundBlaster sound card beats pretty much any analog tape recorder."
Wow, I thought it was pretty well known that we did not have, as of yet, a real complete set of tools to measure things we can hear (including compensation for the dramatic non-linearities of each person's hearing). Yes, we have many tests (measurements) that are useful and give some indications of device behavior, but they are simply "easiest path" devices, that is, measurements we CAN make but not really all the measurements we would WANT to make. So knowing that mankind's AVAILABLE audio measurement systems crudely scratch the surface of audio behaviour, one would then have to factor in one's experience to assist them in navigating the darkness of the audio jungle. My experience has shown:
Vinyl records (good & bad): more fun than CD's
Multitrack tapedeck: always elicits shock and awe from daw fed engineers
Musicians: very sensitive, and are responding to the awesome editing power of daw with some of the most uninteresting music ever.
Regards,
David Bock


Chuck

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Re: George....what's the resolution of analog?
« Reply #26 on: May 15, 2004, 12:43:45 pm »

Former Oceanway drone wrote on Sat, 15 May 2004 17:17


I certainly have opinions about analog vs. digital and I have no intention of talking about them right now. That said, I do have a problem with Chuck's connecting the declining recording quality of Eagles albums with a "decline" in analog.



Hi Alan,,

thanks for filling in the info on recording gear and engineers.

Of course there are great recordings being made after the 70's.

I did not want to say that available analog equipment is getting worse over time.

But in general terms, while cruising through my record collection, I am expecting good sound from late 60's to late 70's some to '82, then it appears to become increasingly difficult to obtain that rich hi-fidelity sound quality.

Btw. I also have the early Eagles records on CD with a sticker on them that says:"digitally remastered", and if you know and have the records, I would say the CDs are just unlistenable.

I don't blame it on digital or the CD format. But actually, I don't know who or what I would want to blame for it. For me, subjectively, it is just a decline in audio quality.

I have Joni Mitchell Hejira on vinyl, and I have the Travelogue album on CD. Both excellent, really very very good.

Lately I bought Joni Mitchell 'Both sides now' as 24/96 DVD-A. As I have Chesky 24/96 DVDs that are really excellent, I expected something.

But the Joni Mitchel DVD-A sounds like crap. I read the names Geoff Foster, Allen Sides and Bernie Grundman on the inlet. I don't know these guys personally, maybe you know them...

I have just no comprehension and no words for the decline in audio quality, that I have to face today.

I just wonder: "How did they manage to have that wonderful sound, almost half a century ago, and what are the reasons, that make it so difficult to achieve today ?"

Charles Smile
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ted nightshade

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Re: George....what's the resolution of analog?
« Reply #27 on: May 15, 2004, 12:54:41 pm »

I well believe that those pushing 192 as a *standard* have ulterior financial motives in doing so.

I also believe that many of those posting here are pleased to be able to prove on paper that theoretically the digital systems they have invested in are superior to any and all analong tape machines- this may well serve as a way of rationalizing not undertaking the pain in the ass that is analog tape recording. A pain in the ass, but with excellent machines and some work you can give a lot of your signal processors a rest and achieve qualities of sound very pleasant to humans- I can't help but notice there's a lot of wannabe analog systems available for digital these days...

I'm talking about tracking to analog, not dumping digital stuff onto analog tape as an effect. Actually I very much appreciate the relative transparency of exceptional digital recorders (no others need apply), to the extent that that transparency exists, when it comes to mixdown- one generation of analog tape suits me fine.

Anybody care to prove on paper that photography is superior to oil painting?
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chrisj

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Re: George....what's the resolution of analog?
« Reply #28 on: May 15, 2004, 02:32:46 pm »

Ethan Winer wrote on Fri, 14 May 2004 13:16


In any way you care to measure, even a $25 SoundBlaster sound card beats pretty much any analog tape recorder.


Um- I don't think so. I think perhaps what you mean is, <i>'with regard to the accuracy of continuous test tones over a frequency range of arguably 20-20K, a $25 SoundBlaster sound card beats pretty much any analog tape recorder.'</i>

You can measure truncation artifacts. You can measure jitter. You CAN measure some of the phenomena that are good at making digital audio unpleasant. For that matter, you can measure reconstruction filter 'ringing' (really the aftereffect of a brickwall filter, and not a resonance like other sorts of 'ringing') to the point where you can tell when it's going to distort the DAC. You can measure that down to ten decimal places for a given signal- and such signals are hardly impossible- modern pop and rock is loaded with that stuff thanks to overcompression and overlimiting.

I'm sorry, but there is no scientific basis for behaving like a Sound Blaster beats a Studer. You're looking at way too narrow a set of criteria. Hell, it's well known that inharmonic distortion is much easier to hear than harmonic distortion. Phenomena like the tape machine head bump the Studer would have is significant in frequency response terms, but extremely unobjectionable. What about the on-the-fly SRC built into some Sound Blaster Audigys? These things can be both measurable, and acutely unpleasant. Please don't behave like 10% of second harmonic distortion is more obnoxious than 5% of five and 3/8ths harmonic distortion- or a mathematically related, not harmonically related, distortion (akin to ring modulation)

As far as the resolution of analog- you can hear through noise, otherwise we'd be going constantly deaf everytime a car or airplane passed by. It's not so much about noise, still less about analog really delivering a wider frequency range. It's more about the KINDS of distortion analog is subject to, being a heck of a lot less objectionable than the KINDS of distortion even the best digital is subject to.

chrisj

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Re: analog = magnetic filed ; digital = square
« Reply #29 on: May 15, 2004, 02:40:53 pm »

Chuck wrote on Sat, 15 May 2004 08:26


All that we try to capture are sinewaves, and all our converters put out are square waves.
As you all know, squares consist of odd harmonics alltogether, so the main job of digital reproduction is filtering out those high-order odd stuff.



Mm. No. Let me put it this way:
There are no squares, really. You're looking at the visual representation of a bunch of numbers designed to tell the converter what kind of SINES to put out.
The only time you'd be hearing squares is if you were using one of those funky DACs with no reconstruction filter. And that's actually not technically correct, though there are some things about it that count as advantages...
The squares you're thinking of, you might be better served by thinking of them as lists of numbers, not as a waveform. Nothing is ever about trying to present that information as squares. The DAC wants to present it as sines again, that's what it's for. That's what a reconstruction filter is for.
What you should be looking into is not 'squares', not increasing frequency range (necessarily), but the types of harmonic and inharmonic distortion generated by each kind of recording.
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