How Many Bits in Infinity?

Why are 24-bit digital recordings the benchmark for capturing live sound?

It has to do with our limited ability to measure physical phenomena. Experiencing and recording sound is essentially measuring pressure over time.

Regardless of whether you are measuring continuously or sampling at intervals, at any instant you are trying to capture the magnitude of a phenomenon, or signal, that exists as a real number — arbitrarily scaled to lie in the closed interval [0,1] — and its direction. Real numbers cannot (all) be represented exactly.

The set of real numbers has infinite size. The set is so big, the real numbers are not even countably infinite, like the integers. While there are an infinite number of integers, there are a finite number between any two of them, so that the set of integers in a closed interval has a known size N. A set of size N can be represented using b bits, where b is the smallest whole number such that N ≤ 2^b. Between any two real numbers are an infinite number of real numbers. How many bits in infinity?

Thus, our ability to record physical phenomena is defined by our ability to quantize it. Quantization maps infinite sets of real values to single values, to create a finite set of approximation sample values ("words") large enough both to have high dynamic range (DR), the maximum decibel (dB) level of a signal minus the aveage noise level, and have an acceptable error factor (inversely proportional to the size of the quantized set).

How big is an accurate quantization set and how many bits are needed to represent its members? Each bit added to the sample word accomplishes three important things:

1. Doubles the size of the quantized value set it can represent;
2. Cuts quantization error by half;
3. Adds 6 dB of DR.

There is a well-known term for this — exponential growth. Not only does the sample set expand as you add bits, the rate of that expansion accelerates. Every added bit is more significant than all the bits that came before it, up to a point. When does adding bits stop adding information?

Since the threshold of hearing is near 0 dB SPL, and since the "threshold of pain" is often defined as 120 dB SPL, it is said that the DR of human hearing is approximately 120 dB. Thus, 24 bits is the first natural computer word size (divisible by 8) that offers a DR geater than that of human hearing. Larger word sizes, while greater precision for other kinds of measurements, don't add meaningful information for sound. 24 bits is the right combination of precision and practicality.

Anything less than 24-bit digital audio has been a compromise. 16-bit samples were chosen for CD audio due both to the requirement to store more than 70 minutes of audio on a disc and to the limited space offered by optical disc technology in the 1970's. Lossy compressed audio was a concession to the covenience of being able to store a lot of songs on the low-capacity flash memory devices that were the first generation of portable digital music players. Now there is sufficient storage space and wireless bandwidth inside our homes to make 24-bit studio master recordings the de facto standard for digital music acquisiton and playback.

The reproduction is never going to be the original perfomance; or, as Alfred Korzybski said, "The map is not the territory." But a richly detailed map is better than the back of a napkin drawing. To paraphrase one of my design heroes Edward Tufte, summaries can emerge from high-information sources, but there is nowhere to go if we begin with a low-information source. A 24-bit studio master recording is a richly detailed map. Why settle for a summary?

             Vinyl-to-Digital Restoration #9            

Title: Desperado

Artist: Eagles
Genre: Rock
Year: 1973

When I bought my first CD player c. 1985, I already had an extensive album collection. Never the record labels' dream consumer, I rarely re-purchased on CD material I had on vinyl. For years, my turntable and CD player peacefully co-existed. So my Eagles albums went silent when I retired the turntable in the mid-90s (before the vinyl revival) for lack of space and a general frustration that an artist shuffle is not possible when the material is spread over seven LPs. It's nice to have the band back together after converting all that physcial media to weightless 24-bit digital. Hell Freezes Over, anyone?

© 2012 Thomas G. Dennehy. All rights reserved.

The Social Bandwagon: Everyone {Likes, Re-Tweets, +1's} a Winner

Mumford & Sons released their 2nd album Babel a few weeks ago. It's hard to know what any listeners think of it. But one thing we all seem to know — Babel sold 600,000 copies in its first week. That statistic was re-blogged and re-tweeted thousands of times, blindly hailing "the best debut of 2012." Everyone "shares" a winner.

Does a splashy debut lose significance as the music industry transitions from physical media to weightless digital? We'll get to that later. In any case, debut has replaced legacy as a benchmark of worth.

Artistic works that build their audience slowly and sustain it for long periods are becoming rare. Most works live and die with their debut. Go big or enjoy staying under the radar. In music, Adele's 21 is the outlier. No one saw it coming, and then nothing could displace it for more than a year.

Hollywood has known this for a long time. Cast, director, genre, story, and production values are irrelevant. The only thing that can predict the long-term box office success of a film is its opening weekend numbers. Big hits that opened small — My Big Fat Greek Wedding and Slumdog Millionaire, for two in recent memory  — are the outliers. To generate buzz, a film has to be able to trumpet an immediate historic feat, whether it be the best opening weekend (of ...), or opening night, or midnight debut, or whatever. Get people on the bandwagon before the next big thing comes along, because it's right behind you, already working the hype machine.

At the polar opposite of the sustained hit is what I'll call the hit-and-run, designed to open big and disappear fast before anyone can know how mediocre it might be. This applies equally to music, movies and books. Frozen Heat by Richard Castle debuted at #7 on the 30-September-2012 New York Times Fiction Best Seller List for combined print and e-book sales, dropping Mitch Albom's The Time Keeper from #6 to #8. The next week, it was gone.

Trouble is, while Mitch Albom is a real-life best-selling author — Tuesdays with Morrie spent more than 200 weeks on the best seller list — Richard Castle is a make-believe best-selling author (turned amateur cop) on an eponymous TV show. The release was a publicity stunt coinciding with the start of the new season. Hyperion Press published both books, and I think they owe Mr. Albom an apology.

A splashy book or music debut may be increasingly easy in the weightless digital world. Apple can't sell more iPhones than it can manufacture and distribute. A movie theater can't sell more tickets than it has seats. E-book and digital music sales make it possible to respond to demand instantly and infinitely, without having to plan, produce, ship and stock physical inventory. Bits are never sold out. Mumford & Sons fan base was ready for a new release and downloaded accordingly.

Less newsworthy was the fact that sales of Babel dropped 72% in week two (though still topping the charts). Social media had already moved on to tweeting the debut of a new album from Muse at #2.

            Vinyl-to-Digital Restoration #44             

Title: Voices Carry
Artist: 'Til Tuesday
Genre: Alternative
Year: 1985



If you read The Lefsetz Letter, you know that sales of Aimee Mann's album Charmer dropped 63% in its second week on the charts. If you're on social media, you probably know (and have re-tweeted) that the video for the single Labrador is a shot-for-shot remake, featuring Mad Men's Jon Hamm, of her iconic 80's video for the song Voices Carry. I know that I got my first CD player in mid-1985, and the album Voices Carry may be the last new title I have ever bought on vinyl.


© 2012 Thomas G. Dennehy. All rights reserved.

Would Pandora Survive Russian Winter?

If the world was fair, a new rival entering your market would have to compete head-to-head on features. Innovation would rule. But the world is not fair, and new rivals often enter your market specifically because they can win with inherent advantages that make head-to-head comparisons irrelevant. The software industry coined a term for this—Russian Winter. (Why?) And Pandora may be about to experience it.

Russian Winter has been a factor in the rise and fall of many products. Two examples:

• Mosaic, the first inernet browser, was invented at NCSA. Netscape commercialized Mosaic in 1994, and Netscape Navigator commanded 80% market share at its peak in 1996. Microsoft countered by introducing Internet Explorer. Whether or not it was a better browser than Netscape Navigator was irrelevant. As a stand-alone product, you can't compete with "pre-installed with Windows." Microsoft achieved 80% market share by 2000, 95% at its peak in 2002, completely defeating the invasion of its Desktop.

• Similarly, the market for simple chart-drawing software was once dominated by Visio and Autodesk Actrix. Feature-for-feature, you could make the case for either one. But when Microsoft bought Visio (the company) in 1999, the climate became much chillier. As a stand-alone product, you can't compete with "bundled in Office." Autodesk cancelled Actrix almost the same day, ceding the market to Microsoft.

In both cases, the victory virtually shut down disruptive innovation in these technology areas.

Pandora invented user-customized radio. You select a song and it will program a stream of more like this music based on its musical "genome." It now streams more than a billion user hours per month. Consumer awareness of Pandora is 50% among internet users, double that of its nearest competitors.

But a new competitor may be entering the market. The Wall Street Journal and New York Times reported that Apple is preparing an audio streaming service to compete with Pandora. How does Apple bring Russian Winter to the streaming audio market? Five things are immediately apparent:

1. Installed Base. You can't compete with "pre-installed on 365 million iOS devices."
2. Halo Effect. There is no brand loyalty like Apple brand loyalty. Not only will an Apple streaming service trigger an exodus of Pandora users who were there merely because there was no equivalent Apple service, the cool factor of Apple will bring many new users into the sector who were sitting on the sidelines. Pandora desperately needs these subscribers.
3. Lack of Transparency. Pandora is having trouble turning a profit, and has to say so every fiscal quarter in SEC filings, incurring negative brand image. Apple will bundle its streaming service with iTunes, burying the costs inside the rosy financials of the world's largest music retailer.
4. Leverage. The New York Post reported that Apple is negotiating directly with music labels for content, rather than adopt Pandora's disadvantageous statutory licensing model. Apple doesn't need Congressional support to make its business work.
5. Game-Changing Ability. Pandora's service defines user-customized radio. But, with more that $100B in cash and securities available, Apple could raise the stakes by introducing new capabilities requiring capital investment that Pandora couldn't match in its current financial condition. Or, taking another cue from the software industry, Apple could offer its service free to listeners. In August 2012, UK retailer Tesco announced that it was closing its MP3 store, citing the rising capital costs of trying to stay competitive with the big players, Apple and Amazon.

Could it be that the real target of Apple's ambitions is Amazon? By adding a streaming music service to iTunes, Apple would force Amazon to roll out a similar service to stay competitive. Being acquired by Amazon could be Pandora's way out of the cold.

            Vinyl-to-Digital Restoration #43             

Artist: Paul Winter Consort
Title: Earthdance
Genre: New Age
Year: 1977



I'll admit, I chose this library title for this piece because of the artist name. But The Paul Winter Consort is a foundation group in my collection, with metadata tentacles radiating through many other titles. Among the descendent links: the groups Oregon and Gallery, and the musicians Glen Moore, Paul McCandless, Collin Walcott (1945-1984), David Darling and Ralph Towner.

© 2012 Thomas G. Dennehy. All rights reserved.