Considerations in Choosing
Digital Audio File Type

This window provides a summary of differences between the two groups of popular digital audio file sharing formats of Lossy (MP3, AAC) and Lossless (FLAC, ALAC).

Note. In addition to the above 4 digital audio file formats, TortoiseClimbing™ Audio is researching options for providing a limited, simple CD format "at cost." Uncompressed high resolution digital audio file formats of WAV and AIFF also exist that are commonly used by recording studios. (However, their file size is much larger, so TortoisClimbing™ Audio will not be offering them as digital download file formats for the mastered version of the AHS choir's 1959 The Crucifixion.)

Lossy

MP3 is the oldest and poorest quality digital audio file format discussed here. It was released the end of 1991 as a registered product requiring vendors who wanted to include MP3 codecs in their software to pay copyright royalties. (As of 2017 all copyrights associated with MP3 expired, and subsequently all attempts to enforce royalties on vendors have been dropped.) Customer use of the MP3 encoding file format was handled much like pdf is handled for print files, i.e., both pdf for print and MP3 for audio files was always made available for free use by end users.

The MP3 compressed file format meets 2 goals:

1. The need for much smaller music files for storing on then limited, expensive memory devices; and
2. The ability to transmit much smaller files, initially using limited availability of ISDN (Integrated Services Digital Network), but more commonly using modems to transmit files over telephone lines.

MP3 creatively uses lossy data-compression. The process begins by partially discarding data, and then compressing what remains. A major portion of its reduced file size is achieved by the first stage of discarding/eliminating certain components of sound, considered (by psychoacoustic analysis at that time) to be beyond most human hearing capabilities. That first stage is commonly referred to as perceptual coding or as psychoacoustic modeling. The remaining audio information is then recorded in a space-efficient manner, using MDCT (modified discrete cosine transform) and FFT (Fast Fourier transform) algorithms.

The appeal of MP3 was its much smaller digital file size compared to CD-quality digital audio. MP3 compression can commonly achieve an impressive 75 to 95% reduction in file size from a CD. The combination of small file size and "acceptable" audio fidelity to many, eventually led to a boom in distribution of music over the Internet. That began in the mid-1990's and blossomed in the late-1990s. MP3 served as the major enabling technology for music file sharing at a time when bandwidth and storage were at a premium. The MP3 format initially gained near-universal hardware and software support. That was primarily because it was the first functional compressed audio file format during the crucial first few years of widespread music file-sharing/distribution over the internet.

While saying MP3 generally eliminates pieces of the recording unheard by the human ear is a bit of an oversimplification. The fact is any compression that discards part of the original information does have an impact on the final recording. Thus, a CD-quality song compressed into an MP3 format will sound different.

Typically, cymbals, reverb and guitars are the sounds most affected by MP3 compression and can sound really distorted or "crunchy" when too much compression is applied.

Like a CD, the original MP3 file format was limited to a 16 bit depth, and a sampling rate of 44.1 kHz. (Video used a 48 Mhz sampling rate.) In the newer technology of streaming, the amount of information available from the original MP3 files is referred to as a 320 kbps streaming rate. Although MP3 has the worst audio quality of the digital audio files discussed here, it is supported by virtually all devices.

Note. More recently the MP3 format is now being used in even lower resolution formats in streaming, and with lower audio quality.

AAC (Advanced Audio Coding) is a better digital audio quality lossy file compression format. It was created as a better successor to MP3, with better audio quality at even lower file sizes. Like MP3, it too is a lossy compressed file format. It was designed to be the successor to the original MP3 format and was first declared a standard in 1997. Blind tests in the late 1990s showed AAC demonstrated greater sound quality and transparency than MP3 for files coded at the same bit rate.

AAC is still under copyright, meaning vendors who want to include an AAC codec in their software products to enable encoding into AAC format have to pay a royalty. However, like MP3 was, this digital audio file format is free for end users to play and make copies to share. Due to some unwavering industry support, this lossy digital audio file format is now a strong contender to MP3. An example is that in 2003, Apple switched from MP3 and adopted AAC as the standard it uses for compressed audio file format in Apple’s iTunes and iPods. It produces better audio fidelity at the same very small audio file sizes associated with MP3.

Much like MP3 did before it, industry supporters of this format do not require royalties for consumers to play and create copies of files in AAC format to share. Thus, there are no restrictions on TortoiseClimbing™ Audio using this as one of the audio formats in which to distribute copies of The Crucifixion for you to play.

Possibly because ACC is still under this copyright requirement for software vendors, the international community for HTML did not include AAC as one of the supported digital audio file formats for streaming by HTML5 using its audio control. However, as noted above, most smartphones and music-themed phones, digital audio players, and digital media players on computers support playback of both AAC and MP3.

If you are restricted to a small file storage area, such as as a mobile phone, and thus need a more significantly compressed file format than is provided by either of the lossless formats of FLAC or ALAC, you should consider AAC as your first choice. That is because of its superior sonic performance over MP3.

Note however, there are reports of variablity in the quality of reproduction on equipment using the Android operating system for AAC files, especially when transmitting it via Bluetooth to ear phones. So, there may be variability in the ability of particular android based devices being able to take advantage of the better fidelity of an ACC file vs an MP3 file.

Lossless

CD The previously established standard that dominately replaced LPs is the optical CD. (Note. A niche market for LPs has experienced substantial growth in the last several years. As of 2022, vinyl outsold CDs.) The CD has a higher audio resolution than the lossy MP3 and AAC digital audio files, but less than the lossless FLAC and ALAC audio files. CDs use a bit depth of 16 bits and a sampling rate of 44.1 kHz. The CD format does not remove data like the MP3 encoding file format, and it has a bit rate of 1411 kbps, which is far above the highest MP3 or AAC bit rate of 320 kbps.

TortoiseClimbing™ Audio is researching options for providing a limited number of simple CDs "at cost."" (There will be a minimal cost associated with this option.)

FLAC (Free Lossless Audio Codec) is an open music format for lossless digital audio file compression. It has always been provided under royalty-free licensing. It was first created in 2001, a decade later than MP3, WAV and AIFF. That was when:

• The price of file storage memory for storing audio files was decreasing;
• The bandwidth available over the internet was increasing for transmitting larger files; and
• There remained the desire for a higher fidelity digital audio file format, but at a smaller file size than CDs, and especially than the AIFF or WAV digital audio file formats.

In that environment, for purposes of storing and transmitting audio files, it was still important to make audio files smaller than CD size, but the desire to have a compression methodology that also preserves the original sonic quality had become important enough that a digital encoding format meeting that requirement was needed.

Thus, while FLAC is a compressed format, it doesn’t eliminate any detail from the original recording. In contrast to both MP3 and AAC, it is a lossless compression file format. That means no audio data is discarded during the compression process. While this results in larger files than MP3 or AAC lossy audio files, FLAC audio files are still 50 to 70% smaller than a CD audio file, dramatically smaller that WAV of AIFF, and it meets the requirement that no audio details are missing from the files you’re hearing.  (A FLAC file can be converted to an MP3, but not the reverse. The data discarded to make the MP3 cannot be recovered.)

Now days:

• Since the older systems like early mobile phones, older Digital Audio Players and even original iPods, the cost of file storage has plummeted even more than from when the FLAC audio file format was created in 2001. That means on a number of systems, the impact of the audio file size on cost of file storage has become pretty much no longer a serious limiting issue of concern.
• Additionally, the bandwidth of the internet has continued to expand, meaning the ability to download somewhat larger FLAC audio files is no longer a practical impediment.

Because FLAC is a lossless compression technology, it is also suitable as an archive format for owners of CDs and other media who wish to preserve their audio collections. If the original media are lost, damaged, or worn out, a FLAC copy of the record in this case, or any other audio tracks, ensures that an exact duplicate of the original data can be recovered at any time.

TortoiseClimbing™ Audio's recommendation is you consider using one of the Lossless formats, such as FLAC, to preserve all the sound quality from the original record pressed from the AHS combined choirs’ performances in 1959. (The same audio quality could be achieved with WAV or AIFF, but the file size would be significantly larger.)

Audio purists are drawn to FLAC because it is both a smaller file size than WAV, and it leaves the sonic qualities of the recording untouched. Additionally, FLAC supports a range of bit depths and sampling rates that go high enough to satisfy all high resolution desires.

NOTE. Audio files processed by TortoiseClimbing™ Audio's current recording studio, Slipped Disc in Ashland, VA, routinely uses WAV files as the working medium with a bit depth of 24 bits, and a sampling rate of 88.2 MHz.

NOTE. It is possible to play FLAC files on Apple products, but it requires a 3^rd party software player/app. Such software players/apps are readily available for download and installation, including from Apple's App store.

ALAC (Apple Lossless Audio Codec). While Apple does not natively support use of the FLAC lossless audio file format, it does provide 3^rd party software players that are downloadable from its App store. However, Apple does natively support their Apple Lossless Audio Codec (ALAC) format for lossless digital music encoding on their products. For the benefit of those who are Apple users, TortoiseClimbing™ Audio is including the ALAC format as a choice for Apple devices.

Note. However, while Apple's current native support for the ALAC audio file format supports up to 24 bit depth, the digital to analogue converter (DAC) output capabilities in their devices are limited to only a 48 Mhz sampling rate. (That is also true of various Windows based products as well.) Thus, even if you have 3^rd party software installed to play FLAC files, Apple devices will still only output 24 bit/48 mHz equivalent when playing the music. (You likely will not perceive much, if any, difference between a 48 mHz output analogue signal and 88.2 mHz sampling rate.)

TortoiseClimbing™ Audio is providing an ALAC formated audio file that is based on a 32 bit 88.2 mHz.

Notes on Uncompressed Studio Files

AIFF (Audio Interchange File Format). Apple developed its own uncompressed digital audio file format called AIFF for the Macintosh computer in 1988, allowing full studio-quality audio recording and playback on Apple computers. Thus, it is available for use on Apple Macintosh systems by recording studios and others.

A dominant Digital Audio Workstation (DAW) widely used by recording studios, Pro Tools, can work equally well with audio files in either WAV or AIFF format. Thus, Pro Tools is equally at home on Mac or Windows computers in recording studios.

.

WAV (Waveform Audio File). This file format for digitally encoding audio was created by a partnership between Microsoft (Windows) and IBM in 1992, so high resolution WAV audio files could play natively both on computers using the Windows and OS/2 operating systems. (At that time the Windows operating system was Windows 3.1, which was replaced by the very successful Windows 95 in 1995.) (IBM was involved because they were still working with Microsoft on their operating system for PCs known as OS/2, initially written by Microsoft for IBM.)

WAV is deliberately a high resolution digital encoding file format, and results in very large file sizes. It can encode much higher fidelity material than is possible on a CD. It is widely used internally within portions of the recording industry for sharing working files during the process of creating a recording. While it could be used for presenting final recordings, its very large file size has thus far discouraged that use.

Result

Today, because of the popularity of small portable devices such as mobile phone, tablets, iPods, etc., the use of digital audio files, especially MP3 and AAC, have substantially cut into the sales of CDs. Even though there are other digital audio encoding formats in addition to the 4 discussed here, it is interesting to note that almost every record label and independent is now onboard with including the FLAC digital audio file format as an option for audio files they sell.

As a result, consumers can buy FLAC encoded lossless audio files from both major and indie acts for the same price as tunes from the iTunes Store. (Although since iOS 11, iPhones have supported an indirect version of FLAC playback, Apple does not natively support FLAC or sell FLAC encoded files from the iTunes store. None of Apple's products, MAC included, natively support playing FLAC files without a 3^rd party software player.

However, such software players are readily available from 3^rd parties that enable all Apple products to play FLAC audio files, including on iPhones. Thus, the easiest way to play FLAC files on an Apple product is to download and install a 3^rd party software player. There are a number of suppliers. For more information see 10 Best Music Players for Mac users (January 2022).

Most Windows devices as well as Android operating systems will play FLAC audio encoded files natively without any additional 3^rd party software.

Options for Playing Digital Audio Files

Many think of the iPod, introduced in October 2001, as popularly introducing the concept of a Digital Audio Player (DAP). It initially used the MP3 digital audio file format. (However, in April 2003 Apple migrated to using AAC after they embraced that audio file format as a better alternative to MP3.) Although Apple announced (in 2022) it is discontinuing manufacture of iPods, there are a number of other DAPs available on the market for playing high resolution digital audio files.

A DAP can be added as an input to your stereo system, comparable to how you would add a CD player, tape player or turntable. The DAP essentially reads the digital audio file and provides a signal to your stereo system. Just like other stereo components they range in price from low to very high.

NOTE. It is even possible to use your smartphone/tablet as the device to provide your stereo system with the input signal from digital audio files stored on your phone. This is commonly done via an adapter cable with a plug that fits into the port on your phone and appropriately plugs into your stereo. This is essentially the same thing you would do to connect a DAP as input to your stereo.

Commonly newer iPhones come with a Lightening connector port on the bottom of the iPhone. (In the future it likely will become a USB C port.) Plug a cable with a Lightning connector on one end into your iPhone or iPad and appropriate stereo plug(s) on the other into your stereo. Alternatively, you can use a short adaptor which will connect to the Lightening port on an iPhone and perhaps a 3.5 mini-phone jack on the other to plug the cable into.

The end(s) needed on the cable that connect to your stereo depends on what ports are available on your equipment. Those could be a pair of RCA input jacks, or a stereo input jack such as 3.5 mini-phone or full size (6.35mm/1/4 in) phono jack.

So, 50 years ago you might have used a turntable to play LPs, or 40 years ago a CD player. (Note. The LP is undergoing a growing renaissance.) Now, you can get a DAP (Digital Audio Player) that will play multiple varieties of digital audio file formats. FLAC is one of the popular digital file formats for such high resolution players.

DAP's come in small portable versions, like the iPod did, to slightly larger. (They are all relatively small.) They can drive headphones directly, or you can plug them into your sound system. There are numerous articles evaluating available DAP players, such as 15 Best Hi Res Audio & HD Music Player's for Audiophile's (March 2022)

As a digital audio file format, FLAC may never be as popular a format as CD and DVDs were in their heydays, but it's quickly become a digital audio file format of choice for a number of people who care about sound quality.

File Formats Available for Download

TortiseClimbing™ Audio is offering the mastered and restored The Crucifixion, from the 1959 recording of the AHS choirs, in the following 4 digital audio file formats and resolutions:

• FLAC - 24 bits at 88.2 kHz;
• ALAC - 32 bits at 88.2 kHz;
• ?CD? - 16 bits at 44.1 kHz (researching options - This will be an at cost option - guesstimate is perhaps $3.50);
• AAC - 24 bits at 44.1 and
• MP3 - 16 bits at 44.1 kHz;

File sizes of the mastered and restored digital audio file for The Crucifixion album are:

• FLAC - 369 MB;
• ALAC - 365 MB;
• AAC - 59 MB
• MP3 - 95 MB