Post by AmonRa November 25, 2011 (211 of 424)
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Tubes and tape: two sources of added distortion. Which sometimes sounds nice, warm and smooth. If we strive for accuracy, no. In that respect digital has no rival in sight.
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Post by GregM November 25, 2011 (212 of 424)
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Edit: sorry for feeding the troll.
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Post by Ogrady November 26, 2011 (213 of 424)
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AmonRa said:
16/44.1 PCM digital audio exceeds the technical quality of even the best analog tape by a factor of 10 to 1000 times on all technical specs. In addition tape has about 1.5 octave less frequency range, there is built in compression at the top 12 dB of dynamic range, there is speed deviation, wow & flutter, print through etc. etc.
There seems to be some kind of misunderstanding that the word "analog" in "analog tape" somehow means it is truer to the original signal. It is not, it is just an ancient (and surprisingly good) attempt at preserving the audio waveform, which now can be done vastly better with digital means. Even the lowly CD.
Yep, as I suspected, NEVER HEARD an open real analog tape recorded with top gear.
You AmonRa, in your bucket list, need to put this on your list of need to experience.
I feel poorly taking advantage of someone who's 'come to gun fight with a flip out pocket knife' so I'll go easy on you... this once.
1.5 octave less frequency range... etc, really? Do do you think you're talking to school children who've never even seen a spool of tape? Oops, I digress, there's the real possibility... sorry.
Do yourself a favour, create a -60db 10khz 44.1/16bit pcm sinewave and expand the resultant waveform and look at it on your computer screen. While you're at it get yourself a bit meter and run this signal through it. Possibly you'll have a revelation as to the cherry picking of 44.1/16 pcm proponents who've expunged on such fantastic technical specs for 44.1/16 pcm through the decades.
You've been lied to! Or are you one of the creators?
This resultant -60db thing of a signal looks like a 3 step square block full negative to full positive deflection ridiculously poor impression of a sinewave. In fact, it's not recognizable as a sine wave at all. The number of bits that remain to describe this so called sine wave; about 7.
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Post by rammiepie November 26, 2011 (214 of 424)
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Ogrady, I'm still pretty astounded at what HDDT Tape Transfers does with '60s and '70s vintage Open Reel commercially duplicated reel to reel tapes! As played back on my Meridian 808 in 96/24 resolution, it rivals a lot of current fare.
I have a pretty significant collection of Open Reel tapes and they NEVER sounded that spectacular, Shows you what modern technology is really capable of.
AmonRa is too obsessive about specifications.......No doubt digital has amazing specs (and NO hiss) but maybe one day a cheap $25 plastic transport and an equally cheap DAC will equal the mega expensive gear one needs to decode 16/44.1.....PROPERLY!
But, Until that time..............
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Post by Ogrady November 26, 2011 (215 of 424)
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rammiepie said:
Ogrady, I'm still pretty astounded at what HDDT Tape Transfers does with '60s and '70s vintage Open Reel commercially duplicated reel to reel tapes! As played back on my Meridian 808 in 96/24 resolution, it rivals a lot of current fare.
I have a pretty significant collection of Open Reel tapes and they NEVER sounded that spectacular, Shows you what modern technology is really capable of.
I too have a bunch of safety masters, 15ips 2 track from the late 50's and 60's. I've been digitizing them and then remastering. I've also applied my same processes to Everest Stereo acetate commercial tapes.
It is amazing what is below the hiss on these 55 year old tapes when the hiss is gone.
Most hiss reduction software does major damage and their 'cure' is much worse than the disease, and then there's the odd piece of hiss/noise reduction software that does simply wonders.
I bet you would be astounded at what you have on those open reel tapes!
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Post by AmonRa November 26, 2011 (216 of 424)
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Ogrady said:
1.5 octave less frequency range... etc, really?
CD goes flat to 5 Hz, while the best tape machines start to roll off at 30 Hz. That is over 2 octaves missing right there.
I'll be back...
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Post by Ogrady November 27, 2011 (217 of 424)
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AmonRa said:
CD goes flat to 5 Hz, while the best tape machines start to roll off at 30 Hz. That is over 2 octaves missing right there.
I'll be back...
Funny, I have 2 consumer 1/4 inch decks personally that start their roll off at 15hz, (yes, I've personally run response curves). At the other end we see -2db out beyond 40khz, oh dear, that's about double CD's brickwall upper response.
Just so you know, I'm not getting sucked into the kind of back and forth that you appear to thrive on, that is throw something out there but not acknowledge a question with an answer.
Start by answering some questions, such as, what does that -60db signal look like, not anything resembling a sine wave is it, a tape deck has no problems reproducing a real sine wave at this level and yet CD quality fails miserably, could this effect the sound we hear from CD? One thing I'll give you right now, I don't ask questions unless I already know the answer.
Low level signal reproduction at a frequency we use for echo/sound source location is far more important than 5hz response unless you're in the habit of co-inhabiting with whales, then it's useful. Try a meaningful give and take next time.
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Post by AmonRa November 27, 2011 (218 of 424)
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You live with bats, I live with whales... At least people can hear and feel the low frequencies, but can not hear or feel the high ones. Guess which is more important for faithful reproduction of music?
If your tape has 15 Hz to 40 kHz range, and my CD 5 Hz to 22 kHz range, CD frequency range is still one octave bigger than tape. Or how do you do your math, new boy?
You need to use extremely sophisticated DIGITAL noise reduction solutions with your analog tape to get even near plain CD dynamic range. Tells something about the analog recording noise problems.
I can come up with a -60 dB 16/44.1 sine wave, can you come up with a picture of the same sine wave recorded with an analog tape machine at - 60 dB with all the analog gunk?
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AmonRa said:
If your tape has 15 Hz to 40 kHz range, and my CD 5 Hz to 22 kHz range,
Then CD lost. Period.
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Post by Ogrady November 27, 2011 (220 of 424)
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AmonRa said:
At least people can hear and feel the low frequencies, but can not hear or feel the high ones. Guess which is more important for faithful reproduction of music?
If your tape has 15 Hz to 40 kHz range, and my CD 5 Hz to 22 kHz range, CD frequency range is still one octave bigger than tape. Or how do you do your math, new boy?
You need to use extremely sophisticated DIGITAL noise reduction solutions with your analog tape to get even near plain CD dynamic range. Tells something about the analog recording noise problems.
I can come up with a -60 dB 16/44.1 sine wave, can you come up with a picture of the same sine wave recorded with an analog tape machine at - 60 dB with all the analog gunk?
Which is more important for faithful reproduction of music? Low or High frequency?
Got ya... HIGH FREQUENCY!!
I doubt that half the population in the world can hear beyond 15khz and yet response out to 30khz is PARAMOUNT for accurate music reproduction. How so?
Re-creation of the sound field with accurate pin point location of instruments is determined by the differences in time between receiving the sound to our ears. This is impulse response and these time differences are what the brain uses among other cues to figure out where a particular sound is coming from.
Impulse response describes what allows humans to locate objects in space and we can do so by separation of as little as 3 degrees, (a couple feet separation a hundred feet away) or a time resolution of 30 microseconds. A 30 microsecond time separation of the same sound coming from both left and right speakers is the limit of human hearing. So what is this in frequency, as in a tone? It's 33khz. We can't hear this frequency as a tone, but we can hear the change in location within a sound field so response beyond 20khz is very import in music reproduction.
44.1khz PCM has major problems with ringing on impulse signals. In fact, it actually rings BEFORE the sound arrives and continues ringing after the sound has left! Do you think this might impact our sense of sound field location?
Further, accurate reproduction of acoustic music requires the creation of a sound stage with its building low level echo and resonance all of which has to be recorded somehow and be reproduced accurately for our brain to reassemble a faithful simile of the actual performance. DSD, (SACD) is so far beyond 44.1khz PCM as to be another animal entirely in this capability. DSD DOES create an accurate soundscape, and along with analog, (tape) has zero issues in reproducing a 30 microsecond time delay with NO PRE-RINGING and thus allows our ears to perceive a much more accurate soundfield than the grung that is 44.1khz PCM.
Further answers to your questions;
1)I decided to retest the low end frequency response of a couple of my decks. The 15hz low end is not the lower limit, it's flat at 15hz, the -3db point is 9hz.
2) Indeed I had no problems recording and playing back a -60db, (using +12db as MOL) sine wave and viewing the result on my scope. Indeed, even a 3 3/4 ips recording can do this.
I tried this with 44.1khz PCM and had one hell of a time locking my scope on the signal, it's very noisy, as in not a pure tone which is what I'm trying to get you to realize.
Here's some 'lite' reading to enlighten you;
http://www.dspguide.com/ch22/1.htm
"If your tape has 15 Hz to 40 kHz range, and my CD 5 Hz to 22 kHz range, CD frequency range is still one octave bigger than tape. Or how do you do your math, new boy?"
I'm not getting under your skin am I? Your reference to me as 'new boy' does bring on this connotation. But I digress, on to your claim;
Really?... We're taking 'range' here, your sentence talks of 'range' 3 times, so indeed range must be what you're talking about as well, not lower frequency response limit. So 15hz to 40khz is a range of just short of 40khz, and 5hz to 22khz is a range of just short of 22khz. 40 khz is bigger than 22khz by close to double and thus has a much bigger frequency response range. If you're talking about octaves of range using the starting point of 5hz then you have a 6.1 or so octave range and tape using 15hz as the starting point, 3.85. Why not start from 0hz, then your octave range would be infinite? Yes, PCM has a lower frequency response capability, do your speakers reproduce 5hz?
You indeed do not need extremely sophisticated digital noise reduction solutions to get analog tape into the realm of plain CD dynamic range. Both DBX and Dolby SR handily hands 44.1khz PCM it's lunch on s/n performance and they're both good old analogue.
So, lastly, have you 'come up with a -60db 10khz 44.1khz PCM sine wave yet? Have you looked at it as I suggest?
Tape has no issues producing a -60db 10khz sine wave, it looks exactly like a sine wave, the PCM 44.1khz, no way.
Maybe it's time to enlighten yourself with where tape is in 2011 and not keep coming up with 1956 specs? You talk of the last 12db in tape being compressed. It is? The linear dynamic range, (plus/minus 0.3db) of ATR tape is 78db, implement Dolby SR and you're at 103db linear dynamic range. The peak range of ATR tape is 86db, gets you into the 110db range.
The point here though is with 78db of dynamic range where wavelength response is linear within plus/minus 0.3db who needs noise reduction? Remember, PCM is not remotely linear even at -60db, (go... go... go on, reproduce a -60db 10khz sinewave 44.1khz PCM tone and look at it) I challenge you.
Finally, to see how well echo location can work for us in the real world look what this blind 14 year old can do. Amazing stuff.
http://www.cbsnews.com/stories/2006/07/19/earlyshow/main1817689.shtml
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