In this clip from the D: Dive Into Media conference, Neil Young begins by saying ”My goal is to try to rescue the art form that I’ve been practicing for the past 50 years.” He goes on to talk about preserving the album format, how piracy is the new radio, and what Beats headphones bring to the back end of the donkey (more bottom end).
Neil wants to bring more attention to the front end: offering music in high-resolution formats, and making it available conveniently. That’s what we’re all about, and we will focus on this in the next installment of Hi-Fi 2.0. Let’s save the 95%!
MMT featured artist Andrew York wants to release his next recording without a label, and is using Kickstarter to make it happen. He set a modest goal, and after one day is more than half way there. Get a preview of the music below, where Andy explains his preparations and plans for the project.
Bust out your inner Cee Lo as the Executive Producer of Margot’s new CD
We first featured Margot MacDonald last December when she played a Christmas show at the Rock & Roll Hotel in DC. Christmas came early this year, and Margot is hoping for a little something from her fans to help complete her new recording. In return, you can score a pre-release download of the new album, a limited edition vinyl pressing, a live performance, or a stocking full of other goodies.
We wrote about her recording project here — and she’s almost half-way there — but time is running out. Visit IndieGoGo to hear Margot talk about her vision for the new album, and get more details on the available packages.
We are thrilled add Margot to the MMT Featured Artists roster, available from the dropdown list at the top of each page. Sample some performances and get more information from her Feature Artist page which is previewed below.
If you sign up for MOG or Spotify and leave everything at the default settings, you could be missing 50% or more of your music. That’s because Spotify defaults to ~96 kbps on mobile devices, and 160 kbps on the desktop. The settings outlined below will bring your Spotify mobile streams up to 160 kbps, and desktop streams up to 320 (for tracks available at the higher bit rate).
MOG on mobile starts out much worse (but gets much better). MOG defaults to an anemic 64 kbps for mobile streams, but can be kicked up to 320 kbps when using Wi-Fi.
NOTE: Information in this article is based on Mac desktops and iOS devices; your device may vary. You will need a premium account to get the 320 kbps streams from Spotify, and paid accounts to stream to mobile devices on either service. If you’re wondering why you should care about the kbps, check out part 3 of Hi-Fi 2.0: Let’s do the math!
Getting the most from Spotify
Spotify offers 320 kbps streams to premium subscribers, but will default to 160 kbps. From the desktop menu, select Spotify > Preferences. Under playback, check High quality streaming.
While you’re there, make sure Set the same volume level for all tracks is unchecked. This will let you hear the music’s full dynamic range.
Over on your iOS device, start up Spotify and press the Settings icon on the lower right. Next to Stream, select High Quality.
Next, go down to Sync, and select High Quality again.
Premium subscribers need to use the desktop app to get the higher-quality 320 kbps streams. If you want to send that audio to your home stereo and you’re not close enough to plug in, check out Airfoil from Rogue Amoeba. Airfoil will send audio from any desktop app to AirPort Express or AppleTV.
Oh, and now you’ll want a remote control for Spotify — try Remoteless.
Getting AirPlay going on the Spotify iOS app is much easier. Tap the info button while a song is playing. Then tap the AirPlay icon to the right of the volume slider and select an output.
Getting the most from MOG
Start up MOG on your iOS device, swipe to the second page, and select Settings. Next to High Quality Streaming, select ON.
Next, set High Quality Downloads to ON.
AirPlay is built-in the to the MOG desktop app for Mac, and the icon is always at the bottom right of the window, so that’s easy. Getting AirPlay blowing on the iOS app is a bit trickier. From any screen, press the volume + or – button on the side of your iThing. The AirPlay icon will reveal itself to the right of the volume slider — tap it and select an output.
For the very best sound (well, as good as you’re going to get from an MP3) use a dock that bypasses the low-quality DAC in your iPod, iPad, or iPhone. The MMT Editor’s choice is the iD100 from Cambridge Audio. [affiliate link] For more info, see Part 1 of Hi-Fi 2.0: Getting good audio in the iPod age.
Part 3 in a series: After decades of continual improvements in audio recording and playback technologies, the average 21st Century listener will hear most music at lower fidelity than before the millennium. How did this happen, and can anything be done about it?
In Part 1, we reviewed some of the reasons for the general decline in audio quality. Part 2 explored the differences between analog and digital audio. Now it’s time to take a closer look at the various digital formats, do some math, and find out what high fidelity means in the 21st century.
The resolution of a digital audio file is based on three factors: the sample rate, bit depth, and bit-rate.
Sampling Rate (sample rate, or sampling frequency) – the number of times audio is measured (or sampled) per second. The standard sampling rate for a CD is 44.1 kHz, which means that the audio is sampled 44,100 times per second.
An analog signal (light bue) measured over time at a fixed sampling rate (red).
The sampling rate determines the frequency response — the range of sounds from low to high that a file is capable of reproducing.
Imagine a felt hammer striking a piano string. A string that is thinner, shorter, or under more tension will vibrate more rapidly, producing a higher frequency or pitch.
The lowest note on a piano (A0) has a frequency of 27.5 Hz, and the A above middle-C (A4) has a frequency of 440 Hz, or 440 cycles per second. The highest note on a piano is C8, at 4186.01 Hz, and the normal range for human hearing is from 20 Hz to 20,000 Hz.
According to the Nyquist-Shannon sampling theorem, a sampling rate needs to be twice the frequency of the signal being sampled in order to accurately capture the sound. So the 44.1 kHz sampling rate used for CDs should be sufficient to capture audio frequencies up to 22,050 Hz, beyond the range of human hearing.
However, some maintain that inaudible frequencies above 22,000 Hz can “color” the sound and affect the lower-range frequencies we do hear. And the digital recording process can produce distortion through the aliasing of these higher frequencies that requires filtering to correct.
There is no theoretical frequency limit for an analog signal, but the physics of audio reproduction place a practical limit on what can be achieved. Testing on some analog systems has shown evidence of frequencies up to about 50,000 Hz.
Most professional digital recordings are made at a sampling rate of 96 kHz, so they can capture the high-end audio frequencies that might be found in an analog recording but would be missing from a CD. And if you absolutely must go higher, you can use a sampling rate of 192 kHz. At this rate, you are slicing each second of audio into 192,000 pieces, and capturing frequencies up to 96,000 Hz (ouch!).
Bit-Depth -the number of bits used to record each slice of audio. Think of this as the number of levels available to capture each slice. Every bit doubles the number of levels: the resolution for 16-bit audio is calculated as 216, giving you 65,536 possible levels. 24-bit audio is calculated as 224, providing over 16 million levels.
Most professionally-recorded digital audio is 24-bit. Recording at a higher resolution allows for a greater dynamic range (the difference between the softest and the loudest sounds in a recording) and a better signal-to-noise (S/N) ratio (i.e., more signal, less noise).
Sound levels are commonly measured in decibels (dB), and the normal range of human hearing is from 0 dB (threshhold) to 120 dB (hearing damage). The dynamic range for 16-bit digital audio is 96 dB, and the range for 24-bit audio is around 144 dB. The best most analog formats can offer is a dynamic range of around 60 dB, and there will almost always be more noise present.
By the time all of these calculations end up as air moving from your speakers, compression may have obliterated some of the differences in dynamic range between the formats. A lot depends on the type of music you listen to — look for an update on the “Loudness War” in an upcoming article.
Bit rate – the number of bits processed per unit of playback time. For an uncompressed digital audio file, this can be calculated as:
Sample Rate x Bit-Depth x Number of Channels = Bit Rate
Let’s do the math for a CD: 44,100 x 16 x 2 = 1,411,200 bits per second (or 1411 kbps, or 1.4 Mbps). Compressed audio, such as an MP3 file, is a different story. The sampling rate for an MP3 file can vary, and there is no equivalent bit-depth, so the bit rate is an indicator of how much compression was applied to the original signal. A higher bit rate results in a larger file size and greater fidelity to the original sound. Since a CD has about 11 times the bit rate of an MP3 file, does that mean it sounds eleven times better?
How high is up?
Let’s think about this for a minute. Higher sample rates and greater bit-depth will result in more information being captured for each sound. Higher resolution means better sound, but there are limits. Our ears impose limits: the highest frequencies we can hear drop with age, and some ears are better-trained and more discerning than others.
The recording method and storage media impose another set of limits. And the playback system comprises a long chain of limiting factors: the playback unit, audio circuitry, DAC, amplifier, wiring, speakers, and more. The rooms we listen in, and where we sit in those rooms can have a dramatic impact 0n the quality and accuracy of the music we hear.
T Bone Burnett prefers analog, but maintains that if we have to listen to digital audio, we should do so at a minimum resolution of 96 kHz/24-bit. There is a fair amount of controversy over sampling at higher rates, with some engineers and audiophiles claiming that 192 kHz audio is a gimmick, overkill, or “just stupid”. From one detractor:
Sampling audio signals at 192KHz is about 3 times faster than the optimal rate. It compromises the accuracy which ends up as audio distortions. There is an inescapable tradeoff between faster sampling on one hand and a loss of accuracy, increased data size and much additional processing requirement on the other hand.
The optimal sample rate should be largely based on the required signal bandwidth. Audio industry salesman have been promoting faster than optimal rates. The promotion of such ideas is based on the fallacy that faster rates yield more accuracy and/or more detail. Whether motivated by profit or ignorance, the promoters, leading the industry in the wrong direction, are stating the opposite of what is true.
While looking at the above chart, remember that we are comparing apples (uncompressed audio files such as those on a CD) and oranges (compressed files). While a CD track may contain 11 times the information in a 128 kbps MP3 file, it’s not really a fair comparison. The compression algorithm is designed to throw away the unimportant and mostly inaudible parts of the music, it doesn’t just randomly remove 90% of the data.
What is HD Audio, and how do I get it?
So the CD might not sound 11 times better, but it definitely sounds better — MP3 files are a step backwards from CD-quality audio. There are a few competing definitions and formats, but for our purposes, High-Definition (HD) audio will be defined as audio formats that exceed the sampling rate and bit-depth (44.1/16) of the Red Book CD Standard.
There is a high-definition audio specification from Intel for PC audio up to 192 kHz/32-bit for two channels, and 96 kHz/32-bit for as many as eight channels. But this spec supports sample rates as low as 6 kHz, as well as 8 and 16-bit audio, so it falls outside of our definition. Oh, and then there’s HD Radio, which has nothing to do with high-definition audio. HD originally stood for “Hybrid Digital”, and now is just part of the HD Radio trademark and stands for nothing.
We will take a deeper dive into the competing formats for HD Audio in our next installment, and look at the various ways and means to get high-fidelity in the 21st century. Onward!
Part 2 in a series: After decades of continual improvements in audio recording and playback technologies, the average 21st Century listener will hear most music at lower fidelity than before the millennium. How did this happen, and can anything be done about it?
In Part 1, we reviewed some of the reasons for the general decline in audio quality. Here we will explore the differences between analog and digital audio and sort out the winners and losers. Let’s start with the basics: what is the difference between analog and digital audio?
The analog world is built from atoms, and the digital world is composed of bits. This distinction plays out when music is recorded, stored, distributed, and played back.
Recording
All sound waves are analog: an instrument or voice produces a disturbance that moves atoms through a medium. Here on Earth, that medium is usually air.
In an analog recording, these waves are typically picked up by a microphone that converts them into an electrical signal. Variations in the voltage of the signal are then converted into a continuous physical representation of the sound on lacquer or magnetic tape.
For digital recordings, an analog-to-digital converter (ADC) samples the signal at a specified frequency, and converts the results into bits ( a series of ones and zeroes). The bits are recorded onto a digital storage medium, usually a computer disk. Most professional studios record digital audio at 96 kHz, or 96,000 samples per second. When transferred to a CD, the rate is reduced to 44,100 samples per second.
Storage
Analog recordings are most often captured on tape. They are then transferred to another physical medium such as vinyl for distribution and storage. (They can of course be transferred to a CD, at which point they are no longer analog.) Digital recordings are usually captured on a computer disk, and stored on a CD, DVD, or in a computer file.
Distribution
There’s no way around it: tapes and vinyl records have to be shipped and then carried into your home. Digital recordings can be distributed in a similar manner by CD or DVD, but can also be transferred as files around the globe at the speed of light.
Playback
Analog recordings can be played back on tape or vinyl. In a reversal of the recording process, a tonearm moves a needle along the grooves of a record, and sends the signal through analog cables to an amplifier. The amp powers speakers that disturb the air to reproduce the sound waves. It’s atoms all the way through.
Digital recordings require an extra step for playback. A digital-to-analog converter (DAC) takes the bits from the file and turns them back into an analog electrical signal. This conversion can take place at the source (e.g., CD or MP3 player), within the amplifier, or in an outboard device that sits between them. After conversion, the signal is amplified and sent through the speakers.
In practice, the analog and digital realms are almost always intermixed. Vocals may be sent through a digital signal processor (DSP) before they are recorded on an analog tape deck. Digital recordings might be mixed on an analog console and then converted back to digital for mastering.
Prior to the introduction of digital recording equipment, all recordings were “pure” analog. When compact discs (CDs) first became available, they were often labeled with a three-letter SPARS code using A (analog) and D (digital) to indicate the type of equipment used for recording, mixing, and mastering.
So theoretically, a DDD disc would be “all digital”. This system has been largely abandoned because of the confusion caused by overlapping technologies at various stages of the recording process. It’s worth noting that there was at least one quadruple D disc. The 25th Anniversary Edition of Switched on Bach* from Wendy Carlos was labeled DDDD, since the sounds were produced by a digital instrument and then digitally recorded, mixed, and mastered.
Do CDs sound better or worse than the LPs they replaced?
Yes. As should be obvious by now, there are a lot of variables going into the signal that ends up as sound waves emanating from your speakers. How well was the original recording engineered? How carefully was it mixed, mastered, and pressed? After that, there are even more obstacles to high-fidelity: how good is your your turntable or CD player? What about your amplifier and speakers?
The LP was introduced in 1948, so the art of analog recording had matured considerably by the time the CD was introduced in 1982. The digital arts were in their infancy, and CDs created a huge spike in demand for catalog titles that resulted in thousands of discs being quickly, and sometimes carelessly, mastered.
Some early CD releases sound just awful compared to their analog predecessors — I know, I bought them (many for the third time: LP, cassette, CD). There were a few cases where CDs sounded harsh because the master tapes had already been equalized for vinyl, and others where the wrong (i.e., inferior) master tape was used.1 Over time, digital techniques and equipment matured and sound quality improved dramatically.
With well-produced source material, you can get excellent sound out of either a digital or analog system. The digital system will probably be less expensive, and digital formats are more portable, less prone to degradation, and easier to distribute. The advantages of analog are harder to quantify, and advocates usually end up making emotional appeals instead of technical arguments.
Broadcasting from his basement, BadEditPro concedes that a CD “smokes” the LP in just about every specification that can be measured, but prefers LPs because of their “warmth, crispness, and depth, and reality...you feel like you are listening to the artist and not a representation of what the artist recorded in a recording studio.” The typical arguments are nicely summed up by the writers below:
When I get a chance to hear vinyl after long bouts with zeros and ones analog always surprises me. It just sounds better–nicer–and more, well, musical. You folks who love music and have never experienced vinyl, you literally don’t know what you’re missing. No one’s saying analog’s perfect, there are distortions, scratches, noise, and dirt that dig-o-philes never deal with. It’s just that digital seems to miss the natural warmth that analog seems to capture so well. Maybe we’re “designed” for analog and digital is just too unnatural to fully enjoy.
Hey, it’s one thing to subjectively prefer vinyl’s “warmth” and “richer sound” (what others might call “muddy bass” and “rolled-off highs”) to CDs. But that subjective judgment shouldn’t be equated with better “audio quality,” which implies a more rigorous technical standard of measurement.
Everything else being equal – and admittedly, that isn’t always the case – I know of no technical criterion where vinyl is in any way superior to CD (with the possible exception of upper frequency range, but only in some special cases). This of course doesn’t suggest that all CDs sound better than all LPs, or vice versa, or that CDs are perfect – only that CDs offer a (far) greater potential for accurate sound reproduction.
It’s hard to call this fight, and the results of most listening tests seem to be inconclusive. Of course, when there is a conclusion, the losing side will claim that the test was biased, or flawed. Digital may be a winner on paper, but analog has won many a heart. And there is something appealing about natural sound waves creating analogous grooves that are used to recreate the same waves in another space and time. It’s, well…groovy.
Here’s a theory. We know that sound doesn’t exist in a vacuum. In fact, since we read MMT we know that it can’t exist because there is no medium for its transmission. Do you remember the first time you used a digital voice circuit and there was a pause in the conversation? It sounded funny, right? Like, um, dead. Maybe it’s the imperfections in analog audio reproduction: the wow, the flutter — the hiss, crackle and pop that make it sound more “real” and “warm” and “life-like” to us.
But just because analog is our friend, we don’t need to make digital our enemy. One thing’s for sure: digital is here to stay. In part 3, we’ll take a closer look at the various digital formats, do some math, and find out what high fidelity means in the 21st century.
In the meantime, check out what it takes to cut and press a vinyl record below, and get the full story here.
Sign up at IndieGoGo to support Margot MacDonald’s next release Margot MacDonald has been performing for over 10 years and released three CDs, but none of her recordings to date truly reflect the breadth and depth of her talents. She aims to fix that with her next release, and wants your help to make it [...]
Brooklyn’s Ambassadors of Love serve up 18 new songs – No waiting! TMBG’s new release Join Us is available from their site in either MP3 or FLAC (lossless) format for one low price of $9.99. (Vinyl available for one low price of $15.) MMT is pleased to see bands such as TMBG and OK Go [...]
Among the influences listed on Atomic Tom’s Facebook page are The Cure, The Smiths, and New Order (twice). The UK Pop/Rock sound of the 80′s comes through on many of the cuts from their first full-length record, The Moment. Recorded not in a home studio, but in an apartment studio in Brooklyn, The Moment explores [...]
* from Wendy Carlos was labeled DDDD, since the sounds were produced by a digital instrument and then digitally recorded, mixed, and mastered.
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