|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
64.122.72.31
In Reply to: RE: Beware of false information posted by J. Phelan on April 15, 2017 at 16:54:24
Any LP system has bandwidth to at least 35KHz. Stock cutter systems designed in the late 1950s went to over 50KHz and were usually bandwidth limited at about 40-45KHz; ours is set at 42KHz).
This bandwidth exists in playback- we can easily cut a 35KHz signal and play it back on very modest equipment without distortion.
The second thing is a type of distortion that the digital industry does not like to talk about! This is known in several guises: 'Inharmonic distortion, which is in this case a form of IMD where the spurious tones generated are related to intermodulations between the scan frequency and the actual fundamental tone.
The digital industry does not like to admit to distortion so they call this 'aliasing'. The problem with it is not detectable unless you use an analog source. This is because digital algorithms are designed to avoid the problem!
To easily hear the issue, use an analog sweep generator and set up a slow rising tone from 20Hz to 20Khz. Record; in playback you will hear the spurious intermodulations as 'birdies' (the term coined by the radio industry decades ago).
These spurious tones only occur in analog systems with a serious malfunction!
Since the music usually played by audiophiles is not sweep tones, the spurious tones are not audible as tones- the ear converts them though to the brightness for which digital is traditionally known.
Analog lacks such brightness or any tonality for that matter (those being properties of some recordings but not others- clearly an issue of recording gear, its use and that of the playback as well). Its biggest problem is noise floor, but if set up correctly and if the LP is mastered and pressed with care it has no problem being quieter than the electronics used to play it back.
That does not sound like digital is 'better' to me, the suggestion of such sounds like an opinion that really isn't based on a sound understanding of the issues.
Follow Ups:
A subjective proof of a medium's faithfulness to any signal, is given by a generation loss test as was normal to do in the days of audio tape.
The argument being the more faithful the process was to the original signal, the more generations the music could survive without transmogrification.
Since the errors accumulate with each generation one gets a caricature of "what's wrong" and at work, this proved to be a useful tool developing loudspeakers.
My point is, here is a way to prove your argument subjectively.
For instance one could do a low respolution digital copy of an analog tape recording and on the first pass lose an aweful lot of audible information. But...one can also take that low res digital copy and do a thousand generational copies with zero degradation. OTOH in the analog domain one can do a one to one copy on analog tape and have the first generation be virtually indistiguishable from the original but if one were to make a thousand generations of that original recording in analog you'd have an end copy that was far far more degraded than the low res digital copy. This test just doesn't hold up when condiering digital media. different rules
I don't think so.
Here's the problem, which has nothing to do with how media has or has not generation loss:
The human ear/brain system converts all forms of distortion into tonality. It only detects distortion as such when it predominates, such as clipping in an amplifier.
Otherwise what the ear does is assign tonality; in most cases this usually results in the playback being "brighter" than the original (as an example, the 2nd harmonic often associated with tubes causes 'warmth' or 'lush' qualities).
However if one were to measure the frequency response, the 'brightness' would not show up in the frequency response test. That is because its not the result of a frequency response error!
The reason it won't show up is that the additional harmonics (or inharmonics) only need to be in trace amounts. This is because the human ear is tuned to birdsong frequencies and also because higher ordered harmonics are used by the ear/brain system to gauge sound pressure. As a result, in this regard the ear is more sensitive than the best test equipment.
The audio industry in general likes to ignore this fact; this is why most audio systems sound like audio systems rather than real music.
So 'A subjective proof of a medium's faithfulness to any signal' has nothing at all to do with generation loss, and everything to do with not making distortion. It does not matter if you can duplicate endlessly if the master recording is distorted. Right now the LP does that better than digital...
In a nutshell, this is the cutting edge of digital technology. We are pushing of course for greater scan frequencies and more bits, but if the basic problem of inharmonic distortion is not solved, then analog will continue to be around. That's the bringing home the bacon aspect that digital has not solved.
Mind you, its a lot better now than it was! So I have hope for the future, but from what I've seen of the industry so far, it regards this matter as trivial because its pulled the wool over its own eyes.
I am not sure that there would be any kind of alteration to the signal, that would not be captured and then when fed back as the input signal on the next generation, accumulate.
The ONLY thing that doesn't accumulate is the original unaltered signal. The result is a caricature of what's wrong with the original signal.
In an old days analogue tape system, each generation accumulated noise and whatever distortion present was also made more obvious each pass. Digital is not immune to generation loss if even one bit or timing is altered.
Fwiw, back when CD's were first introduced, at least at the studio level, they were intentionally made a bit brighter to drive home that they were "clearer" and "better" than lp's.
I think one can see this in the tests Floyd Toole did which shows what the listener preffered loudspeaker response shape is and guess what it is, about a -1 dB /oct roll off broad band (which over the entire band would imply a -10dB reduction at 20Khz) compared to "Flat response " which used to be the target in analogue days.
Record's have another thing CD's don't have, the cartridge on the record is also a microphone of sorts, it's picks up some amount of room sound while playing the record and that goes back for another pass through the system. It isn't much but you can hear it if you put one speaker in another room, put on an old record but not rotating and set the needle down on the lead in. Then turn the volume up to a normal level and have friends talk or the tv on so you can hear how much is coming out of the speaker in the other room. After doing this in the old days, I ended up putting the Thorens on a granite slab on springs and using a brass weight to keep the record down as much as possible.
Consider too that by any measure you choose, loudspeakers are by far the weak link so far as reaching realism, even when abundant in a recording. For example you can have two sets of loudspeakers with very similar frequency responses and yet with one pair, a mono phantom floats solidly in the center and you are not even aware of a right and left source. With the other, there is a phantom image if you're in exactly the right position and the right and left sources are obvious. What properties could be behind this kind of difference, one that has a profound effect on imaging and not on timbre or frequency response?
Record's [sic] have another thing CD's don't have, the cartridge on the record is also a microphone of sorts, it's picks up some amount of room sound while playing the record and that goes back for another pass through the system. It isn't much but you can hear it if you put one speaker in another room, put on an old record but not rotating and set the needle down on the lead in. Then turn the volume up to a normal level and have friends talk or the tv on so you can hear how much is coming out of the speaker in the other room. After doing this in the old days, I ended up putting the Thorens on a granite slab on springs and using a brass weight to keep the record down as much as possible.
That's not a fault of the media, its a fault of the playback apparatus, which clearly has problems! Its not that hard to solve that one BTW- my 'table has no issues with that at all.
Its the initial encoding of the audio which is an area where the problem exists. Once there, sure you can copy it endlessly (much to the dismay of the music industry) but the damage was done on the initial encoding and does not seem to be something that the consumer can fix with better gear (although that certainly helps).
Don't get me wrong- I'm not against digital. I want it to work. I'm just pointing out that when the industry does not think it has a problem, it won't do anything to fix it. That's the case and that is why no matter how much we talk about it, the LPs are still around decades on. They're old but not obsolete.
It was no contest, LP was better than digital in the 80s. But vinyl is still around due to a hobbyist movement. Digital sources, DSP crossovers, etc. are doing the real work and taking us closer to the elusive goal of a live mike-feed.Look at the measurements of LP -inc. speed stability and explain how this could be a high-resolution system. How about inner-groove distortion ?
Strange -as LP 'improved', here comes tape ! The reference (now) for some audio writers.
Even more scary was the finding that 45 and 78rpm records are better sounding than LP. Robert Harley and Jacob Heilbrunn (of TAS) wrote blogs on systems that used 45's (as a source), not LP. Herb Reichert recently made comments in line with these demos.
I had no idea analog recording/LP playback were that bad. Maybe I'm doing too much reading. But most reviewers have given up LP, so my findings can't be too far off...
Edits: 04/19/17 04/19/17 04/19/17 04/19/17 04/19/17
what the **** is that?
I believe the change is partly because so much of music is mixed to be played on ear buds and low rate mp3. The recording industry's loudness wars are responding to th every low dynamic range one has in the car or limited systems, they raise the average volume without raising the peak level with compression.
In other words, it is the companies who in effect decided and determine what is popular and implemented through mass marketing. The folks here are the 1% who have been known to sit down and listen as opposed to having musical background entertainment.
Anyone who is working in that direction gets my vote.
-
Re-written, but high end *is* a movement. Just has no name.
J. Gordon Holt thought of it as a movement, wanted accuracy and truth, and never listened to LP as such.
-
Read his interviews -he used tapes as a reference.
Ralph: Analog on playback is limited to 15-16 kHz, not 35 kHz.Digital brightness is gone and has been for years. (2) false things already.
The problems of analog are so large that no one serious in audio is using it. No classical recording labels, not Bob Ludwig, not anyone investigating (or producing) cutting-edge crossovers. In order to advance sound quality, XOs are going DSP.
Edits: 04/17/17 04/17/17
Analog on playback is limited to 15-16 kHz, not 35 kHz.
If that were true, the CD-4 records produced in the 70s would never have worked.
The second half of his statement, however, is true:
"Specifically, the frequency bandwidth of LPs and FM multiplex broadcasts were limited from 30 Hz to 15 KHz .
Yes, FM radio was limited by convention to that range. Why? Because, like the CD-4 recordings, the other channel rode on a higher frequency carrier. In the case of multiplexed FM, it is 19khz, while the back channels of CD-4 rode on a 30kHz carrier.
The poor man must be deaf. Here are some other *jewels*:
"192 KBPS is considered "CD quality." No human can hear any difference between an MP3 at that rate (or higher) and a CD. "
"CD quality is so accurate that you can't hear any difference between a properly-recorded CD and the original microphone feed."
Some 'false information' that is not just 'opinion'!
Took a while!
"Analog on playback is limited to 15-16 kHz, not 35 kHz. "
Where are you getting that information?
View YouTube Video
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
...Alex Jones has to say about this.
It ranges from 15-20 kHz. But not recommended over 15-16 kHz due to noise and distortion.
Edits: 04/17/17
The real reason that they posted that is they don't want to spend time with any given project.
It takes time and expertise to cut a good LP. If you want to avoid processing, you have to identify problem areas in the recording and then do test cuts to see if you can sort it out. That takes time.
When you're billing at $400/hour, taking time is not what the customer wants.
We do it by the LP side and spend the time to do a quality project. As a result we have no worries putting 35KHz+ in the cut, although there is nothing up there except harmonics. The main reason to have that bandwidth is not because there is signal, its to prevent phase shift which affects things like imaging.
This is one reason why an LP can have a better more 3-dimensional soundstage than a CD; there is less phase shift. The ear uses phase as part of its image locating mechanism.
More reading. Best part -a few paragraphs below '3 answers', (starts with) 'playing a vinyl 'LP'.Apparently, LP struggles with content over 10 kHz !!
Edits: 04/17/17 04/17/17
"Apparently, LP struggles with content over 10 kHz !!"
Yes, with a conical stylus.
You might want to look at the physics using a fine line stylus.
You seem have little understanding of the subject at hand.
Have a good day.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
The Dynavector 17D3 has a microridge stylus and short diamond cantilever and has a flat response to about 50Khz. The first resonanance is around 100Khz. That is probably the best example of a wide bandwidth cartridge that I know of. Many MCs have a resonance just below 20khz but not the Dynavector.
Analog master-engineers, what few remain, recommend a cut off at 15-16 kHz.
And the link I provided was in fact, physics. Have you read it ?
"Analog master-engineers, what few remain, recommend a cut off at 15-16 kHz."
Which ones? Certainy none of the top guys. Are you doing this on purpose? ya know, getting everything wrong? I am begining to wonder.....
-
...uh, the link I provided. But then, LP seems to struggle (mechanically) with frequencies over 10 kHz (other link).If anyone here thinks I'm wrong, prove it. I provided links - now it's your turn...
Edits: 04/17/17
http://www.recordtech.com/prodsounds.htm
I provided you with a link to a you tube video showing the FR from a crappy turntable well above 20kHz (all the way out to 60kHz). Just imagine how much better a hi-end turntable and cartridge would be.
Did you view it?
We can go back and forth on this but you need to do some studying and try to understand the issues at hand.
You clearly have very little knowledge.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
I'd prefer a study or an expert's opinion.
If you tube is the best you can do, then *you* have very little knowledge.
First of all, I am an expert.
To find out what the FR of a LP is one needs to measure it.
That is what the guy in the you tube video is doing.
What part of the video did you not understand?
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Tre':I respect you knowledge, I just thought a hard-paper would be better than you tube.
However, it's too confusing for the limits of LP. Search on chat rooms and you'll get all different answers -15, 18, 20 even 40 kHz. Then, is this musical content ? noise ? harmonics ? Can the stylus actually read signals that far up (without side effects) ?
The record-pressing site I linked was very clear: cut off at 16 kHz. Did you read this ?
The main concern here is overall sound quality: speed accuracy (belt LP gets an "F' here), inner-groove pressure -leading to distortion of our music, etc.
Edits: 04/18/17 04/18/17
Let's examine what you find in the link posted here.
" The high frequency response of vinyl depends on the cartridge. CD4 records contained frequencies up to 50 kHz, while some high-end turntable cartridges have frequency responses of 120 kHz while having flat frequency response over the audible band (e.g. 20 Hz to 15 kHz +/-0.3 dB).[5] In addition, frequencies of up to 122 kHz have been experimentally cut on LP records."
"Mechanically then, LPs cannot record much beyond 10 kHz without using a smaller-than-standard stylus. In fact the cutoff of frequencies recorded today is around 24 kHz ."
Note the qualification with this one. This refers to using a conical, not a multi-radial or Shibata stylus designed for higher frequency response.
Tre',
There's no sense in trying to debate a 'right fighter'. They'll dig themselves into a deeper and deeper hole in their futile attempts to prove themselves 'right'. Arguing with them is a fools errand. All it accomplishes is to provide them another platform for their madness. Put this guy on 'ignore' and you'll starve his never ending appetite for inane blather.
IOW - quit feeding the troll :-)
Cheers,
SB
-
.
Have Fun and Enjoy the Music
"Still Working the Problem"
If you prefer an expert opinion Ijust gave you one in another response. But speaking of expert opinions can you cite one actual cutting engineer who agrees with your assertions on the high frequency response of vinyl?
The (linked) vinyl-pressing website is one, Roger Sander's white paper is another. I trust Sanders because he's an industry veteran.The limit is dependent on many factors -it could be 15 to 25 kHz. The point is after 16 kHz, it's all noise and distortion. Let the mass-market listen to these -we're audiophiles, I thought.
Even though you're trying (hard) to prove I'm wrong, this is a minor issue. It's the sound quality of LP that matters. And it's doing TERRIBLE if we look at what classical labels use to record *and* what reviewers use for playback.
Edits: 04/18/17
Roger Sander's white paper is another...
You mean like his *interconnect test* ? :)
What actual real world records did he actually engineer? Kevin Gray, the mastering engineer I cited has a resume that is second to none. Did you read what he said about vinyl's frequency response?
"It must be true, I read it on the INTERNETS!"
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: