The problem is that we aren't comparing either medium to the mike feed. Which one more closely replicates it? Phono reproduction, even at its best, introduces all sorts of artifacts, some of which can be perceived as "improving" the sound. And the bandwidths for program (as opposed to noise) aren't really that much better.
The mike feed (or master tape) comparison is not something I've been able to do. But I have compared input versus output (level matched) of a 16 bit A/D-D/A system and couldn't hear a difference. Source was a first-gen tape at 30 ips (hmmm, how much ultrasonic do you think actually makes it onto an analog tape?). That comparison is one of the things that brought me around to an opinion that, issues of 'better' or 'worse' aside, digital reproduction was more accurate, band-limiting and all.
Joe D,JOE DIRT® said:
I routinely listen to my NAK recorded tapes and enjoy them very much (when my system is working). I recently spent $100 and waited 4 months to have a motor replaced in my BX300.
To be honest, I haven't heard the SACDs or DVD audio. There could very well be something there.sss said:
I must admit that my favorite LPs are direct-to-disc.SY said:
Typical cds just sound so sterile, sometimes to the point of sounding unnatural. This is a bias that was formed some years back. I need to come to speed on what is available in todays digital market. I think I could agree with a 44kHz Nyquist filter, but not the 22kHz that had been used.SY said:
>20kHz Is Not Desirable...
Hi Rodd,
I know the sound of live, and the sound of recorded with the live sound as reference, and in my view 20kHz BW digital audio is entirely adequate, and all that is required.
To my ear even very good phono systems are extremely coloured, and whilst enjoyable do not hold a candle to digital systems done correctly in terms of accuracy.
Very clean digital playback reveals characters in the source and recording equipment that are obscured and altered in phono systems.
I have heard modified microphones to sound magnitudes cleaner and more accurate than those that are typically used, and I find that I am consistently hearing bad microphone sounds in typical recordings.
To my ear a digital recording sourced from a nice microphone beats the pants off any phono system for cleanness and actual reality.
As an experiment I held my head so that my ear was at the modified microphone position and asked the female singer to repeat the just recorded passage whilst simultaneously listening to the just recorded passage.
The playback result was astoundingly close to the original acoustic sound, and even the female singer remarked on this and added 'Ooh, that makes my voice sound sexy".
In my experience, less than perfect digital playback sound is caused by digital systems revealling faults at the very source of the recording capture - ie the microphones.
Whilst phono systems can sound pleasing and comfortable, the air and ambience factors are actually artificial, and after comparing to much better record/playback systems, phono is revealled as artificial, noisy and inaccurate.
Eric.
Hi Rodd,
On very good systems, very good digital can sound unembellished - is this what you mean by 'sterile' ?.
I know the sound of live, and the sound of recorded with the live sound as reference, and in my view 20kHz BW digital audio is entirely adequate, and all that is required.
To my ear even very good phono systems are extremely coloured, and whilst enjoyable do not hold a candle to digital systems done correctly in terms of accuracy.
Very clean digital playback reveals characters in the source and recording equipment that are obscured and altered in phono systems.
I have heard modified microphones to sound magnitudes cleaner and more accurate than those that are typically used, and I find that I am consistently hearing bad microphone sounds in typical recordings.
To my ear a digital recording sourced from a nice microphone beats the pants off any phono system for cleanness and actual reality.
As an experiment I held my head so that my ear was at the modified microphone position and asked the female singer to repeat the just recorded passage whilst simultaneously listening to the just recorded passage.
The playback result was astoundingly close to the original acoustic sound, and even the female singer remarked on this and added 'Ooh, that makes my voice sound sexy".
In my experience, less than perfect digital playback sound is caused by digital systems revealling faults at the very source of the recording capture - ie the microphones.
Whilst phono systems can sound pleasing and comfortable, the air and ambience factors are actually artificial, and after comparing to much better record/playback systems, phono is revealled as artificial, noisy and inaccurate.
Eric.
I thought I had seen somewhere that vinyl had a narrower bandwidth than redbook. I thought it was down to something like 11khz when you got to the inside grooves. Does anyone know off the top of their head? Otherwise I'll look it up.
Chris
Re: >20kHz Is Not Desirable...
i agree with u , i dont like phono playback ,it adds "things" to the original sound , but digital recording is not perfec eather - noise . The problem is that we dont have a good analog recording media and i think there wount be anny .
mrfeedback said:
i agree with u , i dont like phono playback ,it adds "things" to the original sound , but digital recording is not perfec eather - noise . The problem is that we dont have a good analog recording media and i think there wount be anny .
Re: >20kHz Is Not Desirable...
We've hadn't had an exchange in some time. Always a pleasure.
By "sterile" I mean that it is detailed, but it sounds lifeless, without air and ambience compared to a well recorded LP.
Certianly there are poorly recorded LPs as well as poorly recorded CDs. I admit, it takes the best that the vinyl world can offer to top a well recorded CD, and the system to play it back on. I further admit that I've tweaked my vinyl system for 25 years where the CD/DVD player came from Best Buys. I know, taint fair... that just how it is today. I don't plan to go after digital until they get rid of the 20kHz brick wall filter. Now, it's my understanding that DAT is a step above the typical CD.
I know that back in the 70's there was an invention called Quadraphonic. They made Quad LPs that would play back on a quad system (with a conventional turntable but smaller stylis tip). The quad decoding for the rear channels used playback frequencies as high as 50kHz from the vinyl LPs. That not to say that there were not some cheap, poorly recorded LPs that were BW limited to 11kHz, I'm sure there were. Bell Labs achived 10kHz from vinyl in 1936, with 60db of dynamic range.
Hi Eric,mrfeedback said:
We've hadn't had an exchange in some time. Always a pleasure.
By "sterile" I mean that it is detailed, but it sounds lifeless, without air and ambience compared to a well recorded LP.
Certianly there are poorly recorded LPs as well as poorly recorded CDs. I admit, it takes the best that the vinyl world can offer to top a well recorded CD, and the system to play it back on. I further admit that I've tweaked my vinyl system for 25 years where the CD/DVD player came from Best Buys. I know, taint fair... that just how it is today. I don't plan to go after digital until they get rid of the 20kHz brick wall filter. Now, it's my understanding that DAT is a step above the typical CD.
Hi Chris,Christopher said:
I know that back in the 70's there was an invention called Quadraphonic. They made Quad LPs that would play back on a quad system (with a conventional turntable but smaller stylis tip). The quad decoding for the rear channels used playback frequencies as high as 50kHz from the vinyl LPs. That not to say that there were not some cheap, poorly recorded LPs that were BW limited to 11kHz, I'm sure there were. Bell Labs achived 10kHz from vinyl in 1936, with 60db of dynamic range.
I think the reson the idea failed technically was that the 50kHz decoding signal wore awayafter a few playings. Some of the quad recordings have been re-released as DTS CDs. Not too bad although I sometimes catch a hind of tape hiss.
roddyama said:
In the absence of any nonlinearity in the system, there are no actual lower frequency tones being generated - a standard IMD test adds two high frequencies together and checks for an absence of signal at the beat frequency.
So, here's a proposition: we know human ears generate distortion; certainly within the normal frequency range they will generate IMD products. If the mechanisms which generate this distortion are still working above 20Khz, we will be able to detect the IMD products even if we can't hear the original tones. (In fact, we will hear only IMD products).
Has anybody tested this idea? There's no particular reason to suppose the distortion-generating mechanisms stop at exactly the same frequency as the detection mechanisms.
Cheers
IH
Hi Ian,
I haven't found the actual paper yet.
In an experiemental setting, this would be a valid assumption (requirement), but with the reproduction of music, who's to say what is distortion and what are the upper harmonics of other sources within the material.IanHarvey said:
We should hear them as they affect the audible frequencies.IanHarvey said:
Karou and Shogo “Detection of Threshold for tones above 22kHz.” – Convention paper 5401 presented at the 110th Convention, May 12-15 2001, Amsterdam.IanHarvey said:
I haven't found the actual paper yet.
roddyama said:
Here's the abstract:
To investigate audibility of ultrasounds contained in a complex tone, psychoacoustic experiments were designed. Human subjects were required to discriminate stimuli with and without components above 22 kHz. All subjects distinguished between sounds with and without ultrasounds only when the stimulus was presented through a single loudspeaker. When the stimulus was divided into six bands of frequencies and presented through 6 loudspeakers in order to reduce intermodulation distortions, no subject could detect any ultrasounds. It was concluded that addition of ultrasounds might affect sound impression by means of some non-linear interaction that might occur in the loudspeakers.
Seeing as Curl used a single driver, it's possible that the differences detected were due to intermodulation distortion. This may also have implications for Oohashi's results.
se
I was just about to post the text below. Seems you, and Karou and Shogo, have beaten me to it:
Cheers
IH
--------------------------
You get two supertweeters, driven off two amps and two signal sources. Put them close together and feed one 39Khz and the other 40Khz, at similar levels. What do you hear?
If the answer's "nothing" then my proposition is disproved. If the answer's "a 1Khz tone" then it has to come from some intermodulation mechanism within the ear itself, because that's the only place the signals mix. If so, it would explain why frequencies > 20Khz might under some circumstances be perceptible.
Cheers
IH
--------------------------
You get two supertweeters, driven off two amps and two signal sources. Put them close together and feed one 39Khz and the other 40Khz, at similar levels. What do you hear?
If the answer's "nothing" then my proposition is disproved. If the answer's "a 1Khz tone" then it has to come from some intermodulation mechanism within the ear itself, because that's the only place the signals mix. If so, it would explain why frequencies > 20Khz might under some circumstances be perceptible.
Quite. It should surprise no-one that if your amplifier output signal consists of the input signal plus, say, a couple of volts of 500Khz sine wave, it really sounds quite appalling. I don't think this is because you can hear 500Khz....
Cheers
IH
Cheers
IH
Well I haven't read the whole thing yet. but it appears the someone is already marketing and selling a "Directional Speaker". It suppose to work by using 2 ultrasonic transducers. One is a reference and the other is frequency modulated by the audio signal. The result is a directional audible reproduction of the original audio signal (ie. music, voice) using only ultrasonic transmission.
Here are the white papers:
http://www.atcsd.com/pdf/HSSWHTPAPERRevD.pdf
Here are the white papers:
http://www.atcsd.com/pdf/HSSWHTPAPERRevD.pdf
IanHarvey said:
this may be true because your amp cant amplify that 500khz sine wave , instead you will see some kind of strange and distorted wave at the output that u may hear .
If u had a "super amp" that can amplify those hi-freq signals then imo there wount be no difference .
You might be interested in the published research of Dr. Bruce Dear (I hope I remembered this right) in which he shows that a bat was capable of discriminating high frequency phenomena way beyond the mechanical bandwidth of their ears.
Oh, great, now I have to explain to my wife that I'm in the garage trying to make my speakers more bat-compatible.
Nelson Pass said:
Yes. But so far it doesn't seem to have been shown that humans are capable of the same. In Oohashi's research, the high frequency content didn't seem to have any effect on its own. Only when it was combined with audio band frequencies. Suggesting that it only gets sensed by way of some form of intermodulation.
And Karou and Shogo's research seems to bear this out which indicates that it's a phenomenon brought about by the tranducers rather than the lack of sensory input (by whatever means) from the high frequencies themselves.
Perhaps a better approach would be to use some type of acoustic filtering to subtract the high frequency content so that the signal and tranducer side of the equation could remain constant rather than being the variable.
se
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