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Propeller Head Plaza Technical and scientific discussion of amps, cables and other topics. |
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Propeller Head Plaza Technical and scientific discussion of amps, cables and other topics. |
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In Reply to: Yer Right............... posted by Todd Krieger on May 19, 2009 at 18:48:29:
"It's not 640,000 cycles per second...... You're mixing bitrate (actually half the Redbook bitrate, roughly) with frequency response."
I'm calculating the number of bits the stylus would have to test in order to read the appropriate digital signal to get a 20 Khz frequency response.
Assume a sampling rate of 40k, in order to get the 20khz response the stylus would have to respond to 40,000 * 16 (for each word) = 640K bits per second.
It's not that complicated I'm actually considering the requirements needed for a stylus to process a digital signal encoded on vinyl.
That's what they are doing on hydrogen.
"Heck, if 256 kbps MP3 equated to 128,000 cycles per second, you could argue that MP3 is more-resolute than vinyl......."
Who said that? But I doubt one could encrypt the digital bits into vinyl and expect the stylus to be able to reproduce a digital signal even at that low resolution.
"I wouldn't *want* to make a claim like that for vinyl..... Trying to equate bitrate with an analog signal is like trying to nail jello to a wall......"
Well by golly you might possibly get the point of the original OP then. As my effort is no different than the effort being made over on the hydrogen site.
We could take 640 K samples per 1/2 revolution (assume 30 rpm for convenience) and then calculate the width required to store a single digital bit on a vinyl LP. Of course it will be different depending on how far we are from the center hole of the disk.
Let's do it briefly and see how close we come to what they got over on hydrogen. Assume a 5 inch radius for convenience. That gives about 16.5 inches per 1/2 revolution and the 16.5/640000 inches per bit. That's .0000258 inches per bit or .0000655 cm per bit. I think that comes out to be about 6550 angstroms. For 24 bit digital I come up with a bit more than 1700 angroms.
I can't comment on the material properties as they do in hydrogen post but surely a stylus isn't going to track this kind of stuff anyways.
"For a long time, the digital advocates **accepted** that vinyl had more resolution- Their argument was that our hearing wasn't capable of resolving the reduced resolution of Redbook CD......"
I think the digital recordist makes a big difference. I think subtle dynamicism comes through much more often on vinyl. Not sure if digital is handicapped but it seems very reasonable to assume that if a recordist isn't making full use of all 16 bits of resolution something is going to get lost is the process.
"Words? I didn't know Evelyn Wood had "speed listening" courses...... [-;"
It's a digital thing - 16 bits makes a word. You know what I'm talking about I hope.
"If this is how we do math these days, our education system *is* in trouble......"
You've failed to show me anything wrong with my approach to the same topic presented on hydrogen.
You don't get it? Be a little bit more specific and I can help you out.
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Follow Ups
- RE: Yer Right............... - Don Till 05/19/0920:45:41 05/19/09 (0)
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