The Lowdown on Downloads

Three years ago I posted the entry in this blog called Listening to Tomorrow.  I wrote about the wonders I experienced after loading my music library onto a computer hard drive and using the computer as a “music server.”  Since then, the idea of music existing as computer files—as opposed to physical discs one loads into a player—has expanded.

Today, there are a myriad of music server applications for the various computer operating systems.  For those who want to take the fidelity beyond the capabilities of their computer’s sound card, there are countless external digital-to-analog converters (DACs) to choose from.  There are also numerous online sources for downloading music.  Some still offer the data-reduced formats such as mp3.  Others now tout “full CD quality”—in some quarters, an oxymoron.  And some offer extended-resolution and high-resolution files.  (For more information on the different formats, see the blog entry cited above.)

My music server has become the way I listen, whether via Wi-Fi feeding smaller systems in the house, or via direct connection to the music library drive when listening on the main system.  Yet for several reasons, as a consumer I have been hesitant to purchase downloads.  Early experiences with more than one provider were disturbing in that what was often sold as “high resolution” turned out to be upsampled Redbook—in other words, plain old CD sound, in a high res “package”—sold at a high res price.  Whatever the reason (or reasons), this was so rampant I feared the fledgling market might never get off the ground.

I was also not enamored of the .flac format in which the vendors delivered their downloads.  While called a “lossless” way to reduce file size, making for convenient, faster download times, the results were not so lossless according to everyone participating in the comparison tests we ran in my studio.  (Based on what I see on the Internet and in many printed audio journals, it seems many listeners are not bothered by flac.  In our tests however, the results were unanimous—everyone heard a difference between the source .aif masters and the .flac files created from them.)

In time I was glad to see some vendors offer what appeared to be the raw PCM formats I prefer, such as .aif and .wav.  These are the formats used to make the recordings.  However, it turned out that at least with some of the vendors, what was being delivered to the customer was still a .flac file.  The “download manager” software the vendors provided for use on the customer’s computer expanded the file back to .aif or .wav.  For my own purchases, I avoided the downloads and stayed with CDs or with the high resolution files-on-DVD versions that some of the vendors sold.  When the discs arrived, I’d extract the files—this is called “ripping” a disc—and add them to the server myself.  For all the files on my server I chose the uncompressed .aif format—the same format I use to make and master recordings.

As the owner of the Soundkeeper Recordings label, I stayed away from offering downloads for several reasons, even though many folks have requested them over the years.  The prime reason is that I seek to deliver our recordings to our customers with nothing less than the very best sonics, and from my perspective the download schemes I’ve seen involve compromises.

A full album at high resolution (24-bit/192 kHz sampling rate) can be larger than four Gigabytes in size.  Where others reduce file size—and by that means shorten download times—by utilizing so-called “lossless” compression formats (such as .flac or .alac), to my ears these result in subtle alterations of the sound, hence I don’t consider them lossless.  Trading fidelity for convenience is not what Soundkeeper wants to offer our customers.

Another common approach taken with downloads, is to break albums up into “singles”.  Our artists go to considerable efforts to create whole albums, so this is the only way we want to deliver their work to our customers.

It took a while for the answer to come but I believe there is another way.  Soundkeeper Recordings will soon offer downloads without any of the compromises cited above.  How to deliver full albums at up to 24/192 resolution?  Fans of the so-called “lossless” formats compare them to zipping a word processor file.  Yes, the zipped words come back intact, even though I can’t say I find the same to be true of flac’d music.

So what about zipped music?  We’ve used zipped music files before, such as those on the Format Comparison page of the Soundkeeper Recordings website.  And when unzipped, no one who participated in our tests could differentiate between the source file and the copy that had been zipped.

What about file size?  Converting an .aif or .wav file to a .zip file does not reduce the size to any significant degree.  It does make for simple downloads though, without exacting a sonic price.  When the files have been downloaded, the user unzips the file and simply drags the tracks into the server application of their choice (iTunes, Amarra, etc.).

One of the reasons I prefer .aif format for my music files is that the files can contain metadata (artist, album title, track title, composer, album cover art, etc.).  This metadata becomes part of the file.  The .wav format does not support metadata, so when the user adds this information in their music application, it resides in the application and not in the file.  If the file is moved out of the application, the metadata is lost.  In contrast, move an .aif file and the metadata travels with it.  The .aif file downloads from Soundkeeper Recordings will have the full metadata in them when they arrive on the customer’s machine.

Within the next week, we’ll begin offering downloads in six formats: 16/44, 24/96, and 24/192, .aif or .wav.  For those who prefer disc formats, we plan to continue offering these.  The downloads are just a long overdue addition that will please a different set of Soundkeeper listeners.

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The People’s System

(This entry was updated 10/29/17 with current models and prices.)

A year ago, the entry in this blog called Can you hear what you’re doing? was the first in a series written with the hope of helping musicians and other recordists who are interested, like myself, in studio setups that avoid superimposing their own sonic thumbprint on the signals they reproduce.  I hope these entries will also be of interest to any music and sound enthusiast who seeks a system capable of what I call “getting out of the way” in order to provide more direct access to the recordings in their music collection.

Previous entries have talked about monitoring system setup and room acoustics.  In the entry preceding this one, Magnificent Maggies, I spoke of a particular favorite speaker design, Jim Winey’s Magneplanars, and how I’ve found them to be exemplary in terms of stepping aside and allowing the listener to truly hear the input signal.

To be clear, not everyone really wants to hear the input signal unaltered.  Some folks like their systems to offer certain colors that please their ears.  While I would never argue with whatever brings anyone their listening pleasure, this entry is directed toward folks who want the colors to come from the music and not from the gear used to listen to it.

A system that gets out of the way is pivotal for those making records.  Unless they can be confident they are assessing the sound of the recording itself, they risk altering the sound to make inaccurate monitoring sound “right.”   If that happens, when they listen elsewhere they find that the recording itself doesn’t sound the way they intended it to sound.  Such a system is important to music lovers too because it reveals all the nuances contained in their music libraries.

I have often been asked to recommend a system for musician friends, clients, and other friends. In the majority of instances the recommendations have been very similar.  What I’m going to describe here is the least expensive system I would trust for monitoring recordings.  (I’ve heard systems costing considerably more that do not elicit the same confidence on my part.)  It is equally suitable for any music lover, whether as a starter system in a college dorm or as an ultimate system for folks who don’t seek anything more.  One can certainly spend less and have a very enjoyable system, but I would not recommend such for anyone who makes records or anyone who wants to hear the most from their music.

It is important to remember that the ideal recommended system will vary depending on the source of the recommendation.  I often say that if you ask three folks an audio question, you will receive at least four different answers.  I will report on a system I have experienced in many rooms and which has brought smiles to many musicians, recordists, and other music lovers I know.

For the purpose of this entry, I’m going to divide the music system into two parts: the front end and the back end.  The front end might be as simple as a CD or turntable, or it might be as elaborate as a computer feeding an external digital-to-analog converter (also known as a DAC).  The front end is the source from which recordings are played.  The back end is the monitoring which includes the loudspeakers and the electronics that drive the speakers.  The system I’m recommending here is built around the monitoring.

In the previous entry, I said that I often refer to Magnepan’s MMG (now MMGi) model ($650/pair) as “The People’s Speaker.”  To quote from that entry, “I’ve heard some $10,000 and $15,000 speakers that have so much ‘personality’ they end up exhausting the listener and engendering headaches.  MMGs, within their capabilities, just sound like what they are fed.  Properly set up, they are a joy that any music lover will intuitively recognize.”  The MMGis are the core of what I’ll call “The People’s System.”

What is needed now are associated components that will allow the MMGis to reveal their magic.  The speakers must be paired with an amplifier to drive them.  The most economical good match for the MMGis I’ve found so far is the RR-2160 stereo receiver ($799) from Outlaw Audio.  With sufficient power to drive the MMGis, the RR-2160 also serves as the control center for the system, where the input source can be selected and the playback volume adjusted, using either the front panel or the included remote.

While they are often overlooked when folks assemble audio systems, I’ve found the cables that connect all the individual pieces of gear to be critical in getting the best out of the whole.  In the entry called The High End Arrives, I recounted my earliest exposure to good cables.  It started with the loudspeaker cables.  From that entry: “…I already had ‘heavy gauge’ wires feeding the speakers.  Once the cable was sufficient to pass the requisite power to the loudspeakers, I wondered ‘how could cable make a difference?’  Once again I listened and once again I learned.  Where did all that musical information come from?  What was formerly just a guitar chord was now a set of individual strings sounding together to make that chord.  The room in which the musicians were playing was suddenly also much more clearly evident – both in recordings made in real rooms and those where a ‘room’ sound was added artificially via electronic reverberation.  Where cables had previously been not much more than an afterthought, required to get sound from one component in the chain to the next, I came to realize they are components in themselves and as with any chain, the weak link will determine the overall strength.”  I wrote more about the subject in the New Connections entry last year.

In my experience, the MMGis will easily reveal differences in cables and so I recommend using wires that are commensurate with the rest of the monitoring system we’re assembling here.  For this system, I recommend White Lightning speaker cables ($429/3-meter pair) from Nordost.  In order to connect a front end source component to one of the inputs on the Outlaw RR 2160, I recommend Nordost’s White Lightning interconnect cables ($195/1-meter pair).

Each of the cables is available with different types of connectors at each end.  I would choose Nordost’s “z-plug” banana connectors on their speaker cables, as these make for easy attachment at the amplifier and speaker ends.  Standard RCA connectors on the interconnect cables will work with the Outlaw RR-2160 and most source components.

Depending on the setup, shorter or longer speaker cables or interconnects may be desired.  In this example, I’ve chosen a 3-meter pair for the speaker cables and a 1-meter for the interconnects as good average lengths that work in most installations (and to “ballpark” the price).

So, excluding the front end source component(s), the system consists of:

Magnepan MMGi loudspeakers  $650
Outlaw Audio RR-2160 receiver  $799
Nordost White Lightning speaker cables  $429
Nordost White Lightning interconnects  $195

The total cost for this part of the system is $2073.  All that is needed now is the front end source or sources.  I’ve heard this system make mellifluous musical magic with inputs as simple as a $35 Sony DVD/CD player spinning a CD, or as complex as a computer-centered digital audio workstation in a studio feeding the system via an external DAC.

One thing that might surprise folks who are new to components like these is that wonderful as they sound fresh out of the box, all of them will improve considerably once they have played music for a while.  The cables and electronics get better over the first 100 hours of use, while the speakers can take as much as 400 hours of playing music to get to their best performance.  Extension in the bass as well as the treble, smoothness in the upper frequencies, “airiness”, and dynamic range all exhibit improvements.  The dimensions of the stereo soundstage expand and overall focus attains greater detail.  The system will sound fantastic immediately but will ultimately get even better.

While I could happily live with this system as described (and truly believe it tells a lot more sonic truth than I’ve heard in most studios), one of its beauties is that each of the various components will stand up to having any of the others upgraded within each respective brand.  For example, go up a model in the Magnepan line, and the RR-2160 and White Lightning will still deliver.  Go up to separate electronics, like Outlaw’s 2200 amplifiers, and the MMGis will respond to the increased power while the White Lightning will still faithfully render the signal from link to link in the component chain.  Go up to one of Nordost’s more elaborate cable designs, and the MMGis will reveal the increased performance.  These are all components that work superbly together, yet can also allow for growth.  And most importantly, the combination is true to the input signal.  Of course, models further up the Magnepan and Nordost lines will take the revelation level up accordingly.  (There are also some outstanding alternatives for more expensive electronics.)  But this system as it is, fits the goal mentioned at the start of this entry: It is capable of getting out of the way and providing more direct access to the music.  It gets my vote for The People’s System.

 

Pressing Matters

It is my sincere hope that this blog provides entries of interest to music lovers, musicians, and audio enthusiasts, as well as folks who make records.  A few previous entries, such as Can you hear what you’re doing? (Part 1) and Can you hear what you’re doing (Part 2), were aimed specifically at those setting up studios in order to make records, among whom there are a great many musicians.  Of course, it has been my hope that others would find these of interest as well.  So it is with the current entry.  While it is intended primarily for those who make records, if I’m lucky, those who purchase and listen to records will also find something of value herein.

With audio mastering completed for the new Work of Art album entitled Winds of Change (first mentioned in the August 22, 2014 entry of this blog, also called Winds of Change), and with the album artwork approved, it was time to contact the CD replicator in order to get the “pressed” versions manufactured.  Actually, CDs are not pressed like vinyl records.  They are made using an injection molding process, but the term pressing seems to have endured in common use.

Those familiar with my label, Soundkeeper Recordings, know that we release each album in several different formats.  In addition to the regular CD, we offer six custom burned formats, including CD-R and five formats with higher resolution than a CD can provide:
–   Music-only DVD-R with 24-bit, 96 kHz audio, playable in most regular DVD players
–   24-bit, 96 kHz .aif files-on-disc
–   24-bit, 96 kHz .wav files-on-disc
–   24-bit, 192 kHz .aif files-on-disc
–   24-bit, 192 kHz .wav files-on-disc

For more about the different resolutions, see the May 22, 2014 entry in this blog, Is “too much” not enough?

As far as standard, 16-bit, 44.1 kHz CD resolution, the reason Soundkeeper Recordings offers our releases in CD-R format, and the true subject of this entry, is something I’ve said since I heard the finished product for the very first CD I mastered, back in January of 1983—CDs made at different plants all sound different from each other and none sounds indistinguishable from the master used to make it.  This may sound strange in view of the marketing that has accompanied the CD format from the beginning, primarily in the form of the slogan “Perfect Sound Forever” and the widely accepted idea that nothing can change once the signal is in a digital format.

Imagine my surprise then, when I first started mastering CDs and found that the same digital U-Matic tape (the format used at the time to send CD masters to replication facilities) sounded different depending on which side of the Sony DAE-1100 editor I used to play it.  The DAE-1100 was commonly used at the time to assemble CD masters.  The unit controlled tape machines for the ¾” tape cartridges that comprised the U-Matic format.  One or two machines could be used on the Playback side and another machine was used on the Record side.  The CD master was assembled on a U-Matic tape in the machine connected to the Record side of the editor.

Early on in my experience with this system, I wanted to compare a tape that was copied from another, just to hear for myself that a digital copy was indistinguishable from the original, as we’d all been told.  Unfortunately, the test never got that far.  What I found was that the original tape, played from the Playback side of the editor sounded better than the copy.  Something was getting lost on the copy, as it seemed coarser and less well defined than the original.  I don’t recall what made me try it but I decided to swap the tapes, listening to the copy from the machine attached to Playback side of the editor and the original from the machine attached to the Record side.  To my surprise, now the copy sounded better (i.e., more like the analog source tape I was using) than the original digital conversion.  When heard from the Record side of the editor, the original digital tape now sounded coarser and less well defined than the copy!  Clearly, there was something else going on.

Perhaps it was this experience that diminished the surprise when the finished CDs for that first CD mastering project came in and I compared them with the CD master used to make those discs.  Here the coarseness was even greater than what I’d encountered on the different sides of the DAE-1100 editor.  The finished CDs almost sounded “out of focus” compared with the CD master, such was the extent of the loss of clarity and fine detail.

Things got more interesting when I created CD masters for albums where large sales were expected.  In those days, there were fewer CD plants than there are today and they were all working at capacity.  In order to accommodate expected demand for the big sellers, the CD master would be cloned and those clones were sent to multiple replicators in order to get back sufficient numbers of finished discs to meet the demand.  This was an education in that I discovered that CDs from different plants all sounded different from each other.  Sometimes CDs from different lines within the same plant sounded different from each other.

So much for “Perfect Sound Forever”.  The format has been claimed to deliver perfect copies of the master.  Logic would demand that if this is the case, all those perfect copies would sound indistinguishable from each other and they’d all sound indistinguishable from the masters from which they were made.  But they weren’t then and they still aren’t today.  (There is an exception that I’ll get to shortly.)

Having sent CD masters to plants all over the world and all over the USA, I’ve had the opportunity to compare a lot of finished product to the masters from which said product was made.  Happily, the days of U-Matic tapes are long gone and the advent (long ago) of computer workstations made for many improvements.  Still, even with the most sophisticated CD mastering tools, the reality from the replication facilities remains—the finished discs don’t sound like the masters.

In my experience, a slow-burned CD-R made directly from the computer-based CD master, sounds more like that master than any pressed CD, even the best in my experience.  This is why Soundkeeper Recordings offers our releases in CD-R format as well as replicated CDs.  But how then, to select a CD replicator?  If they all produce discs that sound different from the CD master, how does one find the most faithfully made discs?  This is the question that was on my mind when I started the label.  Knowing that a lot of folks just prefer a factory-made disc to a burned version, even if the latter is more faithful to the master, I needed to find a replicator for Soundkeeper CDs.  My whole reason for starting this label was to avoid the compromises I feel are too often part of the record making process.  I wanted a no-compromise replicator — if such a thing existed.

I reached out to contacts at most of the plants I’d sent masters to over the years.  I told them about my concept for the label and that I needed the most faithful to the master, highest quality discs.  All but one of them told me essentially the same thing.  They said their CDs were perfect replicas of the CD master.  Since my own experience consistently told me something quite different, I could only conclude they were not hearing it the same way I was.  Or they just weren’t listening and were simply repeating the received mantra.  I thanked each in turn and moved on to the next person on my list.

Out of all the replication facilities, only one person at one facility told me, with no prompting from me whatsoever, “Oh the finished CDs will never sound like the CD master.”  I wanted to hear more but knew by then that I’d found my CD replicator.  Here at last, was someone who appeared to actually be listening.  It turned out, this replicator took an unusual approach to making their finished CDs too.  Where many plants increased their throughput – and hence, their income – by speeding up the process, this plant kept with the slower methods.

The first step in manufacturing a CD involves cutting what is called the glass master.  The CD master from the mastering facility is fed into a Laser Beam Recorder (LBR), where a laser is used to create the pits in a photoresistant coating on a glass disc.  This disc is used in the subsequent steps of CD manufacturing.  Most plants cut the glass master at high speed.  Some will cut the glass master in real time, at additional cost.  Many folks have found real-time glass cutting to result in finished discs that sound closer to the original CD master.  The person at this plant told me they cut all their glass in real time, at no additional cost.  It is just how they do it.

In addition, most CD replicators have moved to shorter injection molding cycles.  The faster the cycle, the more finished discs that can be produced in a given day.  Typical injection molding cycles for CDs are now about 4 seconds long.  The person at this plant told me they use a slower cycle, closer to 9 seconds long.  This makes for better formed pits on the finished discs, making it easier for the laser in the CD player to read the discs and minimizing the incidence of playback errors.

Whether the real-time glass cutting and slower injection molding cycle are the reasons or whether some other factors might be involved, I don’t know.  What I do know is that when I master an album, I listen to it so many times that I become intimately familiar with all the details of its sound.  Often, when I hear the finished CD that comes back from the replicator, it takes only a few seconds to hear the typical loss of focus and fine detail.  Something like a chord strummed on an acoustic guitar becomes a loose mélange rather than the six discrete, individual string sounds heard on the CD master.  With CDs from this replicator, the sound is so much closer to the CD master, I need to synchronize playback of the finished disc with the CD master in order to discern the remaining differences.  (Still not as close to the master as the CD-R but closer by far than I’ve heard from other CD plants.)

Now earlier on in this entry, I mentioned an exception.  In fact, I wrote about this in the February 23, 2014 entry in this blog, entitled Listening to Tomorrow.  Basically, what I’ve found is that what I’ve written about in the current entry comes into play when the CD is played in a CD player or via a CD transport.  This has been my experience regardless of the player or transport, or its price.  However, when the CD is properly extracted to a computer, the audible differences do go away.  To date, after 31 years of the CD format, it is only via computer that I’ve heard the audio from a CD disc sound indistinguishable from the master used to create that CD.  Still, those listening to computer music servers with CD or better resolution (as opposed to mp3 or other reduced formats) are in the minority.

Most of the music lovers I know of who purchase CDs will listen to them in CD players or via a separate CD transport feeding an external digital-to-analog converter (DAC).  In order to provide these folks with a CD that truly represents the CD master approved by the artist and producer, selection of the replicator is critical.  To this end, I feel very lucky to have found Bryan Kelley and the folks at GrooveHouse Records, who I have been recommending to mastering clients since my first conversation with Bryan, and who, as far as I’m concerned, are the official CD replicators for Soundkeeper Recordings.

Is “too much” not enough?

As digital audio and the means of playing it back mature, there is an increasing divergence of perspectives to be found on the Internet.  Some revel in the sonics of music heard at high resolution, while others argue that the CD standard is not to be audibly improved upon and still others want even higher resolution.  All this while Joe and Jane Average download one song at a time at resolutions that throw away at least 75% of the information contained on a CD.

There are new efforts from some quarters to show Joe and Jane what they’re missing and to elevate what the download services offer.  The idea is to, at the very least, deliver 100% of what the CD offers and at best, deliver true high resolution.  Yet these efforts have spawned Internet “papers” and articles in effect, ridiculing the very idea of high resolution and arguing the supposed inaudibility of its benefits, or worse, suggesting that high resolution by definition will sound worse, not better.

I can’t speak for what others find but I can say that whatever these folks are reporting is quite the opposite of what I experience.  I’m hearing fidelity such as I’ve dreamed about for years and when I read those stories, they strike me much as though the authors are trying to convince me there are no colors in a rainbow.

The arrival of high resolution digital has the potential to fulfill the promise digital audio first made more than a quarter century ago.  Back then, astute listeners wondered at the marketing mantra “perfect sound forever” while cringing at the dry, bleached and airless sounds delivered by the first CD players.  While a great deal of progress has been made during the intervening years, the inherent limitations of the format remain.

Looked at in the most rudimentary fashion, the specifications for CD would, on the surface, appear to be all that is needed to perfectly reproduce anything that can be heard.  Human hearing is nominally sensitive to frequencies from 20 Hz through 20 kHz (i.e., 20 cycles per second through 20,000 cycles per second).  As we age, the top end limit decreases and most adults would be lucky to hear 15 kHz.  With CD, music is sampled 44,100 times per second.  That is, the digital recorder “looks at” the sound 44,100 times every second and captures a sample.  According to the theory, all frequencies below half the sample rate, (in this case, all frequencies below 22,050 cycles per second) will be captured accurately and since this is well beyond what most folks can hear, it all sounds quite neat.

These digital samples are each a series of digital bits, with each bit representing one of two binary states or values, often thought of as “ones and zeros”.  Each sample is stored in a digital word.  The CD standard uses 16-bit words, where each sample contains 16 values.  The particular combination of ones and zeros represents the level (i.e., volume) of each sample.  A series of 16 zeros (i.e., 0000000000000000) would be the lowest level that can be encoded and represents complete silence.  A 16-bit word representing an intermediate level might look like this: 0111011110101110.  The highest level would be 0111111111111111, a zero followed by 15 ones.  (For technical reasons which are beyond the scope of this entry, the loudest value is not a series of 16 ones.)

A word length of 16-bits allows up to 65,536 different levels to be represented.  The difference between the loudest sound that can be captured and the noise floor of the format is called the signal-to-noise ratio.  Signal-to-noise ratio is measured in units of loudness called decibels (dB).  For a 16-bit format like CD, the signal-to-noise ratio is approximately 96 dB, which means the noise floor (the inherent noise of the format) is 96 decibels below the loudest sound that can be captured.  This is much quieter than vinyl or analog tape.  Any hiss heard on a CD is captured from the source and is not inherent in the medium.  Many folks confuse the signal-to-noise ratio specification with dynamic range (the difference in level between the loudest possible sound and the lowest sound).  We’ll come back to this later and see why this is misguided.

The problems start when we move from the theoretical to the practical.  (Someone, perhaps it was Yogi Berra, once said “In theory, there is no difference between theory and practice, but in practice, there is.”)  When digital audio is recorded, any frequencies above half the sample rate can cause problems – they engender aliases or aliasing distortion, false frequencies that are not part of the program material.  In order to avoid aliasing, when digital audio is encoded, as well as when it is played back, most digital processors use a filter to ensure that no frequencies above half the sample rate can pass.  These anti-aliasing filters have audible side effects, manifesting in the time domain – the signal gets smeared in time.  Some designers will use gentler filters to minimize the time smear but in doing so, they cause the higher frequencies to fall off prematurely.  A number of modern playback devices have user-selectable filters where the listener can select between steep filtering and its associated time issues or gentler filtering and its associated frequency issues.

So, while CD can capture all the audible frequency range, the requisite filtering means the frequencies delivered to the listener are not all arriving on time or are not all arriving in the same proportion in which they were captured, or some combination of both of these.  One great advantage of the higher sample rates is that the anti-aliasing filter is moved far above the audible range.  This allows gentler filtering to be used without affecting the audible frequency range.

In recent years, thanks in no small part to formats like DVD and others, which are capable of storing more information than will fit on a CD, digital audio has grown up from the 16-bit words and 44.1 kHz sample rates by which sound is encoded for CD.  We’ve had 24-bit audio with sample rates of 96 kHz, 176.4 kHz and 192 kHz.  For reference, a 24/96 (24-bit, 96 kHz) version of a given recording contains more than three times the information contained in the same recording at 16/44 (16-bit, 44.1 kHz).  A 24/192 version contains more than six times the information.  And where a word length of 16-bits allows up to 65,536 different levels to be represented, going to 24-bits increases the dynamic resolution 256 times, allowing up to 16,777,216 different levels to be represented.

The widespread use of computers (and computing devices) for audio playback has enabled the proliferation of high resolution audio and emancipated music from the confines of silver discs and the limitations imposed by the process of retrieving music from these in real time.  (Separating the processing “overhead” from the playback will provide higher quality playback.)  Good as the best disc players and transports can be, my experience has been that there is invariably a loss of focus and fine detail, often subtle, sometimes not so subtle.  It is only via proper computer playback that I’ve heard results that I find indistinguishable from listening to the master used to create those silver discs.

This is good news, even for music at CD resolution, because the listener at home can now hear what is effectively the CD master itself.  However, while the limitations of playback from molded disc have been removed, the limitations of the format remain.  In addition to the frequency and time-related issues brought about by having the anti-aliasing filter just above the audible range, there are the consequences of inadequate word length.  Although the noise floor with a 16-bit medium like CD is 96 dB below the loudest possible sound that can be captured by the format, many often confuse this signal-to-noise ratio with dynamic range.  The assumption is that if the noise floor is 96 dB below the loudest sound, sounds just above the noise floor will be captured with the same fidelity, providing a range of dynamics as wide as the signal-to-noise ratio.  In fact, with a 16-bit medium, the fidelity plummets at lower levels.

The full resolution, in this case 16-bits, is only realized for sounds near the top of the volume range.  Each bit captures about 6 dB of the dynamic range (about 6.02 dB to be more precise but let’s use 6 in this example to keep things simple), so in a 16-bit system, sounds lower in level than 6 dB below the maximum will effectively be captured at less than 16-bit resolution.  To wit, if this lower level information is say, 12 dB lower in level, it will be encoded at what is effectively approximately 2 bits less than the full resolution of the format (i.e., 14 bits in a 16-bit recording, 22 bits in a 24-bit recording). If it is say, 36 dB lower in level, it will be encoded at what is effectively approximately 6 bits less resolution (i.e., 10 bits in a 16-bit recording, 18 bits in a 24-bit recording).

Some information, such as the trailing end of reverb as it fades away, or the higher harmonics of musical instruments, can be well more than that 36 dB lower in level than the loudest sounds and will be encoded with resolutions corresponding to fewer bits.  This results in the thinned, bleached and coarsened instrumental harmonics in even the best 16-bit recordings, as compared to a good 24-bit recording (or of course, the original sound in real life).  It also results in the defocusing of the spatial information and in the relative airlessness in the 16-bit recording compared to a good 24-bit recording (and real life).

While the level meter may show a peak on that 16-bit recording that is within the top 6 dB, this, like the waveform views shown by some computer software, is only a view of the “top” part of the musical waveform — the loudest part.  Sounds and components of sounds that are underneath the top part (i.e., in the background) are not captured as faithfully.  Accordingly,  when considering the dynamic range of the format, it is a good idea to take into account the relative distortion at different levels within the range.  If increasing distortion is not desirable, the real dynamic range potential is going to be considerably less than what the spec sheet might suggest (or is often echoed in the audio press and in some places on the Internet).  Note that even with low level information as in the examples above, a 24-bit recording still delivers more resolution than a 16-bit recording at its best.

Why then, would someone publish a “white paper” against higher resolution or declare that resolutions like 24/192 are “pointless” or worse?  A few possible reasons come to mind:

  1. The higher sample rates place significantly increased demands on the gear used to record and play them back.  For example, digital gear contains an internal clock to control the timing as the device encodes or decodes the stream of digital samples.  Spacing between the samples must be kept accurate or the reconstructed analog waveform that we hear will not have the correct shape and hence, will not provide the correct sound.  Irregularities in timing are referred to as jitter.  Higher sample rates also mean the analog stages of the gear must be able to perform at the wider bandwidths.  Perhaps the folks complaining about high resolution are using gear that does not have clocking that is up to the task and analog stages that can perform at high bandwidth.  Such will either not reveal any benefits or will actually sound worse than they do at the easier, lower rates like 24/96. (This is true of a number of “professional” units as well as those sold to audio enthusiasts.  A  built-in, $250 “soundcard” simply won’t do it, regardless of what the specs claim.  In today’s market, it may cost 10 times this amount for a device truly capable of revealing the potential of these sample rates.  Maybe it is no wonder these folks hear little or no difference.)
  2. It could be possible that the rest of the system these folks are using isn’t up to resolving a wide band recording.  Or it could be that these folks are just not sensitive to these particular differences.  I’ve always found that different folks have different sensitivities to different aspects of sound.
  3. Perhaps they believe CDs (or 24/96) already sound identical to the input signal.  If that is the case, I can understand that anything more would seem wasteful.

Sample rates like 176.4k and 192k don’t, as some have erroneously suggested “have more jitter”.  Sample rates don’t have jitter.  As stated above, higher sampling rates do place greater demands on clocking accuracy (just one reason why buying a DAC
(digital-to-analog converter) “by the chip” is at best a foolish enterprise).  They also place greater demands on the analog stages surrounding the digital stage.

Why some would see these characteristics as “flaws” (and write papers or articles on the subject), I don’t understand.  I’ve always gone with empirical evidence over theoretical analysis; that is, when “theory” and direct experience are at odds with each other, I’ll tend to seek a new theory.  (As I see it, theory should explain the experience, not the other way around.)

All this to say, when a firmware upgrade enabled 192k capability in the converters I use for my work, I approached it conservatively — even continuing to do a few recording sessions at 96k because I was familiar with it and could be confident in the results.  But then I started running tests at 192k and quite quickly found I had to get my jaw up off the floor: for the very first time in my experience, I was hearing (with this device anyway) a recording device “disappear”.  I had never heard that before, even with the best analog recorders and most certainly nothing close with the best digital recorders, even with this very device when used at 96k.

Now I felt a threshold had been crossed (I’ve read similar words since then from one of my favorite audio engineers, Keith Johnson).  The results no longer sounded like “great digital”; they no longer sounded “digital” at all.  They didn’t sound like “great analog” either.  The jump from 24/96 to 24/192, when done well, is to my ears a much more significant jump than the one from 16/44 to 24/96.  It’s all about that threshold; this is the promise digital made in 1983, finally and for real.  (While it certainly sounds more faithful to the input signal than 16/44 does, 24/96 doesn’t yet, to my ears, “get out of the way”.  Having the anti-aliasing filter moved well up and away from the audible range definitely helps but it is the rates like 176.4k and 192k where I find the threshold is crossed.  Interestingly, to me, while many speak of the treble response, I find some of the greatest benefits to be in how much more lifelike I find the bass.)  24/192 pointless?!?  Only if real progress in music reproduction is pointless.

While some decry the higher sample rates, either declaring them to offer no audible sonic differences from the lower ones or to offer inferior sonics (!) to the lower ones, other voices are talking even higher numbers.  We are seeing marketers talking 32-bits and sample rates like 384 kHz.  As long as there are customers who are taken in by sheer numbers, there will be those who see an opportunity for commerce, who will accommodate them with sheer numbers.

I get a chuckle out of these things because my experience has been that in reality (that is, with the hardware or software one can go out and buy today, as well as the recordings one can purchase to play on these), I see gear that isn’t particularly clean at 24-bits.  I see other gear which, when presented with 4x sample rates (176.4k or 192k), performs worse than it does at 2x rates (88.2k or 96k).  Yet the spec sheets and ads say “24-bit” (or more) and they say “192k” (or more).  And the reviewers simply echo the numbers.

In the here and now, if it is a minority that can achieve the performance potential of 24/192, I take claims of higher numbers as a joke at best and cynical marketing at worst.  Just my opinion of course but with so few showing they can design for 4x rates, why would anyone think those same few could deliver 8x rates (or more)?  I find it interesting that those claims are not coming from the designers of gear that can achieve the potential of 4x rates.  (We have the equivalent of makers of 2-cylinder subcompacts claiming to make cars that an outrun a Lotus!)

The numbers game isn’t limited to hardware.  I’ve seen one company release CDs they claim were made with “32-bit mastering” and another claim “100 kHz resolution”.  (Do they have 100k gear or are they rounding up from 96k?)  Does anyone think those CDs are anything other than 16-bit, 44.1k?  If there are such folks, I have a fine bridge in New York City to sell.  The tools I use to create a CD master have 80-bit data paths and I’m working at 192k.  The higher quality tools do result in a higher quality CD but should I then say they are made with “80-bit mastering”?  Or that they exhibit “192 kHz [or 200 kHz] resolution”?  I’d rather make records than sell bridges.

The finest 24/192 I’ve heard to date has given me back recordings I have not yet been able to discern from the direct input from my microphones.  (To be clear, I am referring to gear that actually seems to achieve the potential of these numbers and not merely gear that sports them on a spec sheet.)  Would 32/384 sound better?  I suppose I’d have to hear the flaw(s) in properly done 24/192 first.  And second, if the first condition was met (and in my experience, it has not even been challenged yet), that 32/384 gear would have to actually achieve the potential of that resolution and not merely claim it on a spec sheet.  For me, right now, it is just marketing.  Someday perhaps, we’ll have the audible evidence.  Perhaps.  Right now, I’m trying to imagine how it might be better than what is (so far) indistinguishable from the input signal.

24/192?  32/384?  64/768?  Or should I wait for the 128/1536 version?
Is the best of today’s 24/192 too much?  Is it not enough?  I think it is just right.