Yes, that is a pretty good analogy!
What is behind a "warm" or "vinyl"sound?
I found an interesting article in The Saturday Toronto Star's entertainment section on the resurgence of vinyl.
What I found most interesting in this article was a description of why people describe vinyl as "warm". Peter J Moore, the famous producer/mastering engineer of the legendary one microphone recording of the Cowboy Junkies' Trinity Sessions recording says it all comes down to the fact that humans do not like square waves - ie. when you go from super quiet to super loud at no time at all. He gives the example that if someone was to slap two pieces of wood together right beside your ear would be about the only time one would feel a square wave - and that would make you jump right out of your skin! He says digital, particularly MP3s reproduce square waves like crazy, which triggers fear which also produces fatigue. He says if those same two pieces of wood were slapped together across the room, the square wave would be rounded off by the time the sound reached our ears. Turntables cannot reproduce square waves due to through time it takes for sound to get though the length of wire and the magnet that the wire is wrapped around in the cartridge. By the time the signal gets through that the sharpness, he ugliness, has been rounded and that, he says, is what people are talking about when they describe vinyl as "warm" sounding. Interesting!
I find there are a bunch of digital manufacturers, like Lumin, that are striving for a vinyl sound. I wonder if they are somehow rounding off the square waves in the digital signal to do so? If this is the case, "perfect" reproduction may NOT actually be beneficial to the sound...at least for someone who really wants a vinyl sound experience. Better may not actually be better when it comes to digital sound reproduction!
What I found most interesting in this article was a description of why people describe vinyl as "warm". Peter J Moore, the famous producer/mastering engineer of the legendary one microphone recording of the Cowboy Junkies' Trinity Sessions recording says it all comes down to the fact that humans do not like square waves - ie. when you go from super quiet to super loud at no time at all. He gives the example that if someone was to slap two pieces of wood together right beside your ear would be about the only time one would feel a square wave - and that would make you jump right out of your skin! He says digital, particularly MP3s reproduce square waves like crazy, which triggers fear which also produces fatigue. He says if those same two pieces of wood were slapped together across the room, the square wave would be rounded off by the time the sound reached our ears. Turntables cannot reproduce square waves due to through time it takes for sound to get though the length of wire and the magnet that the wire is wrapped around in the cartridge. By the time the signal gets through that the sharpness, he ugliness, has been rounded and that, he says, is what people are talking about when they describe vinyl as "warm" sounding. Interesting!
I find there are a bunch of digital manufacturers, like Lumin, that are striving for a vinyl sound. I wonder if they are somehow rounding off the square waves in the digital signal to do so? If this is the case, "perfect" reproduction may NOT actually be beneficial to the sound...at least for someone who really wants a vinyl sound experience. Better may not actually be better when it comes to digital sound reproduction!
Showing 14 responses by mapman
"Interesting take on 'warm'. But, that does not explain why digital into tube amps produce 'warm'. Any thoughts on this?" TUbe amps, with their soft clipping nature and unique impedance characteristics among other things also tend to have a "rounding" effect compared to SS, much like vinyl versus digital. THat makes tubes an attractive ingredient to add into many audio soups to help take an edge off to various degrees when needed. The physics (heavily mass and inertia related) involved with a cart stylus and tonearm tracking a record is a big reason why vinyl sounds the way it does (rounded/smoother) compared to digital, where playback occurs exclusively in teh electronic domain with no physics of mass, inertia, etc. involved to inherently damp things from the start. |
I'm guessing digital done well in theory is better able to "pass a square wave" than vinyl, again due to the absence of natural physical damping factors like inertia, FWIW, similar to how wave bending (as opposed to pistonic motion solely as per most dynamic driver operations) in a pure Walsh driver has historically shown itself to lend itself well to the task, but just a guess. Maybe AL or some of our other trusted EEs out there can shed some light on that one? |
Here is what a square wave is and what used for: Square Wave Rise and fall time relate to attack and decay times, transient response, ringing and other aspects of accurate sound reproduction as well I am sure. |
In the digital domain, as long as one starts with high quality source material, almost anything can be made to sound like almost anything else relatively easily, if done well. Christy Brinkley is a beautiful woman still, but does she really look like that magazine cover photo in person? Inquiring minds want to know.... Analog is more limited in this regard, though anything is still usually possible. Where there is a will (and a budget), there is usually a way. Just look at what Ray Harryhousen was able to achieve! Still beats a lot of SOTA CGI effects in effectiveness, if not technical execution. |
A quick Google search shows some well documented cases and images of square wave tests with CD and the limitations there due to bandwidth, especially at higher frequencies. Can't find much at all for a similar phono test. Stereophile apparently had a test record with a square wave test signal once. How does that measure. Digital can do it better with greater bandwidth than redbook no doubt. How much does it matter practically though I wonder. Show me the perfect square wave audio reproduction system and I am there, dude. At least as fast as material becomes available and I can afford it. RTR tape maybe? I know the best RTR puts CD and vinyl to shame. No doubt there! |
"Digital does something to the sound of massed violins, a real acid test for sound reproduction, that can make them sound harsher and grittier than vinyl does. " YEs, has a lot to do with jitter though I suspect. The best massed violin CD reproduction I have heard came off DCS source equipment, which I consider to be pretty much SOTA. |
The massed strings off DCS source I heard on a standard issue Duetsche Gramophone CD was the closest to vinyl I have heard, I do not think I could have known it was CD in a blind test, whereas often not the case for me. Massed violins=digital acid test, no doubt. I've heard it done top notch though from CD, so I know it is possible. |
"10kHz signal also have not too many samples for sufficient signal resolution when decoded from the DAC. It's only roughly 2 samples per half-wave and this is perfectly audible frequency" I'm having trouble getting my arms around this one? Doesn't sound right, perhaps way off, based on Nyquist principle as I recall it but not sure. Better go break out my old digital audio book and study up.... |
Czar, CD is based on principles of Nyquist sampling theory. I have a lot of experience applying that in digital image processing and resampling. It works quite well in digital imaging. I ran a lot of test cases over the years on various forms of digital imagery that convinces me of that. Granted, it leaves little room for error, but it works pretty well when done right, even if not 100% perfectly in all cases. That jives with what my ears tell me these days. It's a fine line between good digital and poor, but luckily the technology used with the format has improved immensely over the years and most of the problems resolved. CDs still being as relevant as they are 30 years later and the lack of traction on any scale for high res audio formats these days despite the technology to enable it existing testifies to that. It is true that CD redbook spec has a fixed limit for dynamic range and more there is clearly possible with more bits, but the dynamic range possible already well exceeds what most consider safe levels for listening, and I have heard good CD format playback sound indistinguishable from good vinyl to me even with massed orchestral violins(though not as often as I'd like), so there you go. |
"To put things in perspective, it's perhaps worth noting that each of those increments is small enough to represent 0.0015 percent of the maximum possible ("full scale") amplitude. " Al, thanks for clarifying that! 2^16 is the correct number. Back to the massed violin acid test, I am sure jitter (and digital filtering effects) are factors there to deliver smooth rather than coarser tones often heard, but I do wonder how much a few more than 16 bits of resolution per sample might help. Still, I have heard it done as good as I have heard most anywhere with only 16 bits, so that tells me that it can be done if done right. The guys who created Redbook CD format did a smashup job I would say by any fair measure. Not to say that better is always possible when it comes to things digital. |
Its the discrete electronic equivalent of building with blocks that are all the same size and shape. Each block is conceptually a bit. Electronic signals, which are analog in nature, are "modulated" to form the electronic digital equivalent of blocks. To build the musical signal castle accurately, you need enough blocks and the ability to put them in place very accurately over a period of time. CD Redbook defines how many blocks you need and have to work with based on the Nyquist principle. Clearly, if the blocks you have are not assembled with great precision and accuracy, your castle may show defects. If you follow the instructions, and do it right, you are in good shape! Using more, smaller blocks alone may not get you any farther otherwise, and in fact will make things even harder to do right. Like doing a 5000 piece jigsaw puzzle compared to 1000 piece. |