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Audio frequency range of LP vs. CD

I could not find any direct comparison of the above subject here. I did find this: https://www.youtube.com/watch?v=4eC6L3_k_48 .
I would like to hear from scientific minded and others' comments and whether we can have a "Binary" answer Yes/No to LP frequency range is higher than CD.
Good Music on 2-Channel
Fight the "loudness" war.
William

Re: Audio frequency range of LP vs. CD

Reply #1
I could not find any direct comparison of the above subject here. I did find this: https://www.youtube.com/watch?v=4eC6L3_k_48 .
I would like to hear from scientific minded and others' comments and whether we can have a "Binary" answer Yes/No to LP frequency range is higher than CD.
How about "Both exceed the range of human hearing".

Re: Audio frequency range of LP vs. CD

Reply #2
"Binary" answer: yes. Well-known and generally accepted. However, the question asked is too simplistic if you want a meaningful answer, i.e. one relevant to the real world. Additionally, the video linked to shows a "proof" that is so full of holes it resembles a sieve.

Re: Audio frequency range of LP vs. CD

Reply #3
CDs have a fairly hard cut-off around 20k, but essentially constant noise over the whole frequency range.  LPs can record and reproduce much higher frequencies, but noise becomes an issue both at the low and high end.

The video is something of a joke, just someone with more equipment than brain cells.  It shows there is something from the LP at very high frequencies, but fails to mention the quantity or quality of that something.  See if you can see the y-axis scale on the scope, then imagine noise comparable to the signal level.

Re: Audio frequency range of LP vs. CD

Reply #4
Noise and distortion.

If the frequencies are so high that they cannot be heard, can you still call them "audio"?
Is 24-bit/192kHz good enough for your lo-fi vinyl, or do you need 32/384?

Re: Audio frequency range of LP vs. CD

Reply #5
Noise and distortion.

If the frequencies are so high that they cannot be heard, can you still call them "audio"?
ah the philosophical question ;-)

sound = yes
audio/music = probably not

Re: Audio frequency range of LP vs. CD

Reply #6
If the frequencies are so high that they cannot be heard, can you still call them "audio"?
Good question. What about frequencies that are inaudible by themselves, but harmful?
Memento: this is Hydrogenaudio. Do not assume good faith.

Re: Audio frequency range of LP vs. CD

Reply #7
What about frequencies that are inaudible by themselves, but harmful?
Harmful.
Is 24-bit/192kHz good enough for your lo-fi vinyl, or do you need 32/384?

Re: Audio frequency range of LP vs. CD

Reply #8
Quote
I would like to hear from scientific minded and others' comments and whether we can have a "Binary" answer Yes/No to LP frequency range is higher than CD.

Well, my AT micro-line Shibata cartridge can pick up things well beyond 20kHz.  However, I recently digitized an old recording (Heifetz--Scottish Fantasy) that was first recorded in 1937 and then released as a hi-fi mono "remaster" in 1961.  The recording techniques of the day were limited to 6 kHz at the very most and this recording has a pretty hard roll off over 4 k.  Nonetheless, my faithful hi-tech player shows 'stuff' well into the 30-40 kHz range, although at a fairly low level.  What do you suppose that 'stuff' is?

One early form of quadraphonic recording used the ultrasonic region--cartridges like mine were needed--and even had a pilot tone at something like 30 kHz.  So your binary answer is YES.  Understanding what that means takes a bit more detail.  Hearing it takes either special decoding equipment that has been obsolete for 40 years or a trained bat.

Re: Audio frequency range of LP vs. CD

Reply #9
Well, my AT micro-line Shibata cartridge can pick up things well beyond 20kHz.  However, I recently digitized an old recording (Heifetz--Scottish Fantasy) that was first recorded in 1937 and then released as a hi-fi mono "remaster" in 1961.  The recording techniques of the day were limited to 6 kHz at the very most and this recording has a pretty hard roll off over 4 k.  Nonetheless, my faithful hi-tech player shows 'stuff' well into the 30-40 kHz range, although at a fairly low level.  What do you suppose that 'stuff' is?

Most likely distortion from how it was produced or stemming from your playback equipment or both.  I don't think anything above 6 KHz is worth even looking at with that kind of source (1930's recording on a fragile shellac disc record or cylinder) as it's often unintentionally added and the engineers themselves wouldn't have been able to hear it.  At best it's probably some tape bias from the master tape itself (at least with my understanding of how 1960's records were made), at worst it's just simply distortion.

Re: Audio frequency range of LP vs. CD

Reply #10
The
Cardas Frequency Sweep and Burn-In Record
has sweep tones to 30kHz.  Using 88.2kHxz and 96kHz sample rates, I have recorded the entire 30kHz range
AND there are regular harmonics up to the cutoff frequency of either sample rate.

Those high frequencies are not possible with CD's 44.1kHz sample rate.

The only possible use I can think of is for a test tone if there is some use for a test tone to 30kHz+ but the point is that recording to and playing back of higher than CD frequencies is possible with LPs, using adequate equipment,

Re: Audio frequency range of LP vs. CD

Reply #11
And again ...:
It is possible to capture and playback way above 20 kHz on vinyl, AND some ears have detected 24 kHz and even 28 kHz ...
... at volumes so loud that they very quickly damage your hearing when played as pure tone beebs - then just imagine the damage if it were played loud enough to be audible in actual music.


Quoting myself (I):
Quote
I do not want to take a stand on how common it is, but here is a test with an 80s digital recording vs. an early 70's synth, made to address the claim that the ultrasound is merely distortion from the medium: https://www.youtube.com/watch?v=_DdxdBNd5Ew
There seems to be way more in the old recording than what can be explained by noise. So as long as the master tape does not limit it, and there is no low-pass filter applied in the cutting process ...

By the way: http://www.positive-feedback.com/Issue2/mastering.htm , catching a 122 kHz tone by cutting at half-speed.

Quoting myself (II):
Quote
As one should know on this forum, there are quite a few studies that indicate that some listeners do detect 24 kHz - and at least one that reports three 28 kHz-capable ears:
 
... at 100 dB (which means 98 dB over a 2 dB noise floor). Reference [38] in Reiss, open access: http://scitation.aip.org/content/asa/journal/jasa/122/3/10.1121/1.2761883

So if your favourite tune is a 100 dB pure-tone beep, then go ahead spend your golden ears on it. They won't last for too long.
(AFAIunderstand, Ashihara is mainly concerned about damage, not about pleasure.)
Memento: this is Hydrogenaudio. Do not assume good faith.

Re: Audio frequency range of LP vs. CD

Reply #12
can have a "Binary" answer Yes/No to LP frequency range is higher than CD.
Yes, LP can have FR beyond CD. No, not audible unless artifacts created by tweeter/supertweeter/electronics intermodulating down into audio band, aka CD range.
Yes, Youtube poster is a audiomoron, No denying.
Loudspeaker manufacturer

Re: Audio frequency range of LP vs. CD

Reply #13
can have a "Binary" answer Yes/No to LP frequency range is higher than CD.
Yes, LP can have FR beyond CD. No, not audible unless artifacts created by tweeter/supertweeter/electronics intermodulating down into audio band, aka CD range.
Yes, Youtube poster is a audiomoron, No denying.

I can agree with you -- I see anything above around 21kHz (actually less than that, but being conservative) is a nuisance.  Significant amounts of signal above 20kHz is just another opportunity for intermod -- esp when older electronics designs have to deal with the signal, and create more distortion (esp IMD) at higher frequencies.  Doesn't even have to be above 20kHz to be troublesome, but we have to pass up to at least 20kHz, and even 21kHz to make everyone happy.  I almost always use between 20.750kHz -> 21.50kHz as my HF goal.  I allow -6dB at 21.50kHz if 20kHz is essentially flat

An example nonsense being in recordings, even below the 20+kHz limit -- SuperTrouper from ABBA, even on disk, you can see an approx 19.2kHz (interesting frequency, huh?) signal tone, about 100Hz-200Hz wide, makes me think that it might even be modulated.  This is on VINYL.  On digital DolbyA encoded copies of those recordings, I usually carefully linear-phase notch or even just steep rolloff at 18.5kHz to nuke that -- almost looks like an ASCII data stream?  Weird frequency for sure  Some day, I might try to analyze the signal, but too busy for now..

Anyway -- stuff above 20kHz is problematical for a multitude of reasons, and offer little (NO) benefit unless being used for something other than baseband audio.  When doing audio processing with dynamic gain, I do everything that I can to avoid generating out-of-band IMD (or letting out of band signals cause in band IMD.)

One thing that makes the >20kHz signal important is that some organizations use above 20kHz energy as an indication that it has 'high definition' or maximum bandwidth.  For that reason, my high-end audio processing software, very purposefully processes the audio up to a reasonable maximum frequency above 20kHz, then beyond that 'reasonable' processing frequency -- then the signal is passed with no modification.  So for my DHDA DolbyA compatible decoder, there are 4 visible audio processing bands:
LF: <20Hz->80Hz, MF: 80Hz-3kHz, HF0: 3kHz-9kHz, and HF1: 9kHz->20+kHz (the top two bands are sometimes as shown before, and are also sometimes 3k->20+kHz and 9k->20+kHz internally.)
When looking at the band with 20+kHz -- lets use the 9kHz band -- it really looks like this:
9kHz->21.5KHz, 21.5kHz-45kHz, 45kHz->0.46*Nyquist.
The bands 9k-21.5k and 21.5k-45k are gain controlled, while the 45k->0.46*Nyquist are passed unmolested. (at lower sample rates, this description is appropriately changed.)

I have been reconsidering the choice of 45k above, and possibly going to talk to my project partner about dropping it to 35kHz or even lower.  Gain controlling at such a high frequency is meaningless, and only widens the bandwidth for IMD to encroach into the audio band.  In fact, my design is very careful that the modulation products occuring in the 21.5k-45k band DO NOT encroach into the audible audio range.

Signals in NORMAL audio above 20k IS only trouble, and the only thing that I can see beneficial to passing above 20k (or, 21.5k) is for the time when 2nd, 3rd or 4th order IIR (analog style) filters are used to limit the bandwidth, and there will be some slop above the needed audio range.  I usually use linear phase FIR (overkill for a lot of applications), but I have my internal technical reasons, just like AT TIMES, I specifically use IIR filters for technical reasons.  And then, much of the time -- either style is usable, and it is a tradeoff of phase vs skirts vs. CPU usage at that point.
Anyway -- people who hear a 'difference' when there is a signal substantially above 20kHz, more often than not it is a distortion artifact -- mostly IMD or even troubles in properly handling nonlinearity mixed with sampling (in the case of sampled digital stuff.)
On the other hand -- if super wide bandwidh is desired, I am not going to claim that it is wrong, I don't understand the REAL purpose though.

CD DOES have a wider power bandwidth, BTW -- you can push a full strength 20kHz signal on a 16bit 44.1kHz .wav file, but doing that accurately on vinyl might be intersting, maybe even turning the cutter head red?   Likewise, I'd suspect that a CD can blow-away the low frequency dynamic range of a practically cut vinyl record also.

Arguments about low signal level dynamic range on CD -- about the stair stepping are, for most purposes, specious.  It is possible that 'stair stepping' can cause problems if ther e is no dithering, but if properly dithered, signals BELOW the level of one bit can be detected.  The cell systems in used today depend on that ability -- seeing below single bit signals -- all of the time.

So, WHEN DONE PROPERLY (that is a BIG, BIG if), a CD is a wonderful medium mostly blowing away vinyl for simple stereo recordings in ways of dynamic range and usable frequency/power response.  In the case of specialty signals -- vinyl might be better in corner cases (until the special information in the groove is worn away.)

ON THE OTHER HAND, if vinyl makes someone 'feel good', then it is wrong to take away that enjoyment!!!

YMMV.
John

Re: Audio frequency range of LP vs. CD

Reply #14
Quote "... if properly dithered, signals BELOW the level of one bit can be detected."

Here is an example of that for a programme of full audio, low bit depth and properly dithered,  resulting in just three levels -1 , zero and +1.
The file posted to the forum by member,  mjb2006, on 2014-08-08 13:10:38.

original
http://hyperreal.org/~mike/tmp/ha/dither/GoNogo-orig-16-to-24.wav

dithered bit depth reduction
http://hyperreal.org/~mike/tmp/ha/dither/GoNogo-16bit-dithered+60dB.wav


 

Re: Audio frequency range of LP vs. CD

Reply #15


Well, my AT micro-line Shibata cartridge can pick up things well beyond 20kHz.  However, I recently digitized an old recording (Heifetz--Scottish Fantasy) that was first recorded in 1937 and then released as a hi-fi mono "remaster" in 1961.  The recording techniques of the day were limited to 6 kHz at the very most and this recording has a pretty hard roll off over 4 k.  Nonetheless, my faithful hi-tech player shows 'stuff' well into the 30-40 kHz range, although at a fairly low level.  What do you suppose that 'stuff' is?

One early form of quadraphonic recording used the ultrasonic region--cartridges like mine were needed--and even had a pilot tone at something like 30 kHz.  So your binary answer is YES.  Understanding what that means takes a bit more detail.  Hearing it takes either special decoding equipment that has been obsolete for 40 years or a trained bat.


What is the sound of the content between 6khz to 20khz isolated and played back .

 
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