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!
camb

Showing 6 responses by czarivey

Sanity, cognitivity and normal desire to learn should definitely dominate "Someone said..." information to avoid this endless clownade and heresy.
MP3s reproduce square waves like crazy
if anyone thinks that they're listening to these "square waves", it's absolutely wrong.
square waves are generated to divide ("slice") recorded continuous analogue signal onto samples that represented with bits as an amplitude and samples or "square waves" per second as sampling frequency.

the digital playback has dac that decodes these "square waves" back to the analogue signal and as Steve N mentioned, most of successful digital playback depends on it. it also depends on sample frequency and number of bits per amplitude. the larger sampling frequency and resolution, the lower losses of information during an analogue conversion. 1 5min song 36bits/192kHz format may occupy the whole CD that can fit over 1hr of 16/41kHz of digital music.

in neither of cases we do not listen to any square waves and more over we do not "round" them too. all we do we convert the recorded digital information into continuous analogue signal.
the higher the frequency, the higher the error will be in digital playback.
in 44kHz sampling frequency 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 alais from 22kHz that is not audible at all.
Mapman,
Digital audio is very similar to the radio transmission where you have to have a frequency generator of waves that propagate through the air.
Same thing you do with digital audio. You divide your signal using a sample generator, the generator of so long discussed "square waves" that also someone clames to listening to them too much to the point of fatigue. So called "square waves" can be analogued to the carying frequency that will be decoded with appropriate device and brought as an analogue audio signal.

These square waves divide an input analogue signal and cary digital information about our original analogue signal that had been transfered from microphones and instrument sound pickups.

The red book CD sampling frequency is 44.1kHz and it does not change. It's almost like carying frequency in radio transmission only it's carried internally through the digital processors to be decoded at the end just like in radio receiver.

It clearly means that 1kHz frequency will have roughly 22 samples in positive half-wave and 22 samples in negative half-wave of the sin function totalling roughly 44 samples. In analogy, if the radio carying frequency 2mHz, than 200Hz signal will have 20,000 waves of the carying frequency...

2 kHz will have only roughly with 11 in positive and negative half-waves respective totally roughly 22 samples. etc...etc...etc...

The above two paragraphs give the horizontal axis picture.
With vertical axis not everything is perfect either. For red book CD we have 16-bits resolution. It tells you that maximum amplitude is 16 bits and the whole dynamic range is divided by 16 portions of the vertical axis.

When the signal is loud, we get maximum resolution and when the signal is quiet we may only use 1...2 bits, so mastering of the digital CDs does involve great deal of compression in order to be able to hear quiet pieces with minimal distortion.

On the 'receiving' end we have DAC that reads either each bit or reads whole digital word which is in case of red book CD 16bit. Each bit will cary a very simple information in terms of either 1's or 0's. DAC determines the absolute value of each bit and reads it either as 1 or zero and so generates an analogue bit-portion of the signal of certain fixed magnitude.
Steve,

It's not only modulated carrier frequency, but also could be modulated phase or amplitude (AM signal is Amplitude Modulated)
Most RF is really analog
Why most? Square waves cannot propagate through the air unless there's again carrying frequency and in case of digital encoding phase modulation is used to define 1 or 0 in the air.
In all of the cases mentioned above and even more than above of this post we deal and deal and deal with carying frequency
Digital is discrete states and levels
It's not what Al said or even books. It will never be discrete or sudden. Before it forms "square wave" there's a process and certainly components that build it step by step so nothing is discrete for sure.

Mapman,

My objective was not to critisize digital playback vs. an analogue, but to express points where digital playback is inferior to analogue. There are bunch of points where analogue playback is inferior to digital as well...
Technology grows and there are far better formats than red book CD as well and post Y2K CDs in vast cases sound substantially better, but taken that and consumed, still I can spin records whole day while even after 2...3 perfectly mastered and recorded CDs I have to dial 'Analogue' function on my recently purchased DAC-preamp(hoped to boost my poor digital collection, but it's huh still poor). I'm also glad that my record shop visit more and more of teens and students who may or maynot have the idea why analogue is so cool, but they certainly hit on great past music of our analogue 60's, 70's and 80's :-).
Steve,

It's not only modulated carrier frequency, but also could be modulated phase or amplitude (AM signal is Amplitude Modulated)
Most RF is really analog
Why most? Square waves cannot propagate through the air unless there's again carrying frequency and in case of digital encoding phase modulation is used to define 1 or 0 in the air.
In all of the cases mentioned above and even more than above of this post we deal and deal and deal with carying frequency
Digital is discrete states and levels
It's not what Al said or even books. It will never be discrete or sudden. Before it forms "square wave" there's a process and certainly components that build it step by step so nothing is discrete for sure.

Mapman,

My objective was not to critisize digital playback vs. an analogue, but to express points where digital playback is inferior to analogue. There are bunch of points where analogue playback is inferior to digital as well...
Technology grows and there are far better formats than red book CD as well and post Y2K CDs in vast cases sound substantially better, but taken that and consumed, still I can spin records whole day while even after 2...3 perfectly mastered and recorded CDs I have to dial 'Analogue' function on my recently purchased DAC-preamp(hoped to boost my poor digital collection, but it's huh still poor). I'm also glad that my record shop visit more and more of teens and students who may or maynot have the idea why analogue is so cool, but they certainly hit on great past music of our analogue 60's, 70's and 80's :-).