OVERVIEW

How we use audio content is evolving by the day as our ability to share media becomes more accesible on dynamic audio/visual platforms. Whether it's music, audiobooks, narration, speeches, lectures, or the ambient chatter of family dinner, audio content has passively intertwined itself with our daily life thanks to the societal adoption of smart devices, and audio streaming.

As Audio Recording Technology has improved over time so has the capacity to manipulate and enhance the recordings. Through digital editing, we have the means to garner even greater clarity from the source material - which, in some formats, may have undergone a substantial degredation of quality, as a result of natural oxidization, or wear and tear.

Audio Formats

Both home and professional recording systems have gone through a number of iterative changes before we landed on versatile digital standards that we use today.

From vinyl discs, magnetic tape, or optical disc formats, to the early digital formats used in studio recording, each format has their own idiosyncracies, and unique degredational qualities.

post-processing

EQ (Equalization)

In terms of Audio Processing, EQ refers to Equalization, which is a process of manipulating specific audio frequencies, used to balance overall sound.

In this space, for example, we're able to identify vibration frenquencies as low as 20Hz, and as high as 20,000Hz. The higher the Hz, the higher the tone. In this case, 20,000Hz would house sounds that are faint and high pitched. Most audio sits best between these two extremes.

For our purpose, EQing is a tool that can be used to help reduce abrasive frequencies that tarnish the source audio, or to help add presence to a particular range of sounds embeded within the audio track.

Audio Compression

As a waveform, audio is comprised of a series of peaks and valleys which indicate quiet and loud parts of the recording. Sometimes, our home recordings, due to less than ideal settings or equipment, can result in inconsistent drops and peaks in loudness. Audio compression is a tool that can be leveraged to normalize a consistent volume by boosting quiet parts and reducing the loud parts.

The result is a much tighter sonic delivery, better suited for a wider ranger of speakers.

Noise Reduction

Audio can arise from less than ideal equipment, or if the microphone gain is too loud for the environment, causing it to pick up ambience as white noise, or it can be from a subject in the recording, such as a fan or heater.

Whatever the reason, a noise reduction process can help minimize it's prevalence, though in some cases, where the noise is particularly severe, reducing too much of it will also reduce the body of the intended content (ie. dialogue), and may not necessarily yield a preferred result. As with all media we process, it is assessed on an individual basis, with the primary intention to deliver a transfer as close to true to the original source as possible.

REEL TO REEL

Multi-Track
Variable Speeds
Analog

Reel to Reel is a format of analog audio, recorded directly onto spools of magnetic tape. Unlike many of the later audio formats which come housed in some sort of cartridge or plastic casing, the Open Reel format resembles the old Film Formats, wrapped around an unshielded reel.

The runtime of the Open Reel is dependent on a combination of the amount of linear footage and the speeds used to record the audio. A reduction in recording speed could provide much longer recording time, but it was at the cost of overall quality. Recordings at a lower speed were vulnerable to inaccurate audio pitch and noise (hiss).

REEL-TO-REEL approximate runtime information

Tape Length in Feet 1 7/8 IPS 3 3/4 IPS 7 1/2 IPS 15 IPS
150 16 mins 8 mins 4 mins 2 mins
200 22 mins 11 mins 5.4 mins 2.7 mins
225 24 mins 12 mins 6 mins 3 mins
300 32 mins 16 mins 8 mins 4 mins
450 48 mins 24 mins 12 mins 6 mins
600 1 hr, 4 mins 32 mins 16 mins 8 mins
900 1 hr, 36 mins 48 mins 24 mins 12 mins
1200 2 hr, 8 mins 1 hr, 4 mins 32 mins 16 mins
1800 3 hr, 12 mins 1 hr, 36 mins 48 mins 24 mins
2400 4 hr, 16 mins 2 hr, 8 mins 1 hr, 4 mins 32 mins
3600 6 hr, 24 mins 3 hr, 12 mins 1 hr, 36 mins 48 mins
approximate runtime information
C60 30 mins per side
C90 45 mins per side
C120 60mins per side

Compact Cassette

Double Sided
Analog

One of the most popular formats for commercially produced pre-recorded audio was Philips’ Compact Cassette. From its inception in 1968, the Compact Cassette, which was comprised of a magnetic tape, passed between two spools inside of a plastic casing, would be a viable option for consumers well into the 2000s, retaining its relevance from the age of the Vinyl record through the advent, and eventual takeover of the Compact Disc.

A unique feature of the tape cassette format is its ability to record 2 sets of stereo tracks, with 1 set exclusive to each direction the tape is ran. Which is why you might remember having to flip over the compact cassette to hear the remainder of the content as it ran the tape back in the opposite direction.

approximate runtime information
C60 30 mins per side
C90 45 mins per side
C120 60mins per side

Microcassette Cassette

Double Sided
Analog

Olympus developed the analog magnetic tape, Microcassette, in 1969. About the quarter of the size of a Compact Cassette, the miniature alternative could offer comparable runtimes by running a slower tape speed. Early version of the cassette would yield 30 minutes per side, and later an increased capacity of 45 minutes per side.

A unique trait of the format is that the tape, which is housed in a plastic casing around dual spools, is that unlike the compact cassette, the tape runs from right to left.

The format is widely recognized as the tapes most commonly found in Answering Machines, but was also a favourite among journalists and reporters for its size and compatibility with portable audio recorders, which often included tie-clip microphones.

approximate runtime information
C60 30 mins per side
C90 45 mins per side
C120 60mins per side

Minicassette Cassette

Double Sided
Analog

The Mini-Cassette is an audio recording cassette, released by Philips in the late 60s. Early on the format would find use as an anachronistic data storage medium for home computer systems. The engineering of the cassette design is in such a way that benefits the portability and allowed it to be much smaller than its contemporaries. However, the design which made it appealing in some markets, came with the cost of audio fidelity, as the format would suffer from speed related inconsistencies in the recording process.

Ultimately, the Mini-Cassette made for a fine choice for situations that didn’t require perfect audio clarity, such as Answering Machines and transcription.

approximate runtime information
C60 30 mins per side
C90 45 mins per side
C120 60mins per side

MiniDisc

Double Sided
Analog

The MiniDisc format is an optical format digital disc that was used to store audio or data from early 90s until mid 2000s. In North America MiniDisc failed to capture the market share away from the Compact Disc and Compact Cassette, despite its advantages including an anti-skip feature, and flexibility to simultaneously operate as an erasable data storage device and a playable audio format.

You can identify the MiniDisc by its outer shell. Looking more like a floppy disc than a CD, the optical disc is permanently encased in a plastic housing.

approximate runtime information
C60 30 mins per side
C90 45 mins per side
C120 60mins per side

Compact Disc

Digital

First release in 1982, the compact disc improved upon Philip's laserdisc technology which provided for media information to be laser read of a polycarbonate disc lined with aluminum, by migrating to digital information streams, and reducing the size down from 12-inches to 4.75-inches.

The digital information is commited to the CD as a series of "pits" and "lands", which refers to physical indentations etched into the topside of the plastic disc. The combination patterns of these indentations, via non-return-to-zero, inverted encoding, translates digitally, to a string of 1s and 0s that manifest in a digital environment as a complete file(s).

CDs, while extremely vulnerable to damage and deterioration, maintained a cultural relevance across nearly 3 decades since their release, before consumer audio platforms shifted to a purely digital realm of mp3 players, iPods, and streaming.

MiniDVDs were manufactured in both single and dual layer. Each of which offered different storage capacity for video and computer data. Single layer discs would allow for up to 1 hours of recorded video, while the dual layer option would double that to a capacity to 2 hours.

Like standard DVDs, the MiniDVD would become largely obsolete in the eventual shift to a digital first society.

approximate runtime information
C60 30 mins per side
C90 45 mins per side
C120 60mins per side

DTRS

Digital

Invented in 1993 by California based Tascam, the Digital Tape Recording System, much like the Digital8 Video, made use of Sony’s magnetic Hi8 tape to hold the digitally recorded audio. The format garnered great success in the music industry for its affordability, reliability, and range in recording in excess of 24 audio tracks simultaneously (with the right equipment).

DTRS content, stored on a Hi8 cassette would provide for up to 108 minutes of continual recording.

approximate runtime information
C60 30 mins per side
C90 45 mins per side
C120 60mins per side

DAT

Digital

DAT (Digital Audio Tape) is a 4mm magnetic tape format introduced in the late 80s by Sony. Only a fraction of the size of Philips’ Compact Cassette, the design was similar in that it passed the tape along two spools housed in a plastic casing. Unlike Philip’s Compact Cassette that could be flipped over for additional recording, the DAT could only record and playback in a single direction.

The benefit of the new Digital format, that Sony was hoping would replace the Compact Cassette as market leader for commercial standard, was the ability to record audio at a sampling rate that would rival, and potential to exceed, the Compact Disc. The technology was also in place to allow listeners to skip tracks, due to the player’s ability to ID individual titles and time codes encoded into the content.

Unfortunately Sony had failed to capture the marketplace with this product due to its high price point and a new awareness from the RIAA (Recording Industry Association of America) of the consumer’s ability to recreate unauthorized, lossless, duplicates of the tapes (what would later come to be known as Pirating), since digital information can be perfectly cloned with available technology.

approximate runtime information
C60 30 mins per side
C90 45 mins per side
C120 60mins per side

ADAT

Digital

The Alesis Digital Audio Tape made its debut in the early 90s as a cost effective alternative to the limited, and expensive DAT (Digital Audio Tape) option from Sony.

Geared for a pro-level studio environment, the ADAT could record up to 8 tracks of digital audio. However, Alesis made it possible to synchronize multiple ADAT machines to achieve a simultaneous recording of up to 128 tracks of digital audio. This was a startling advantage over Sony’s DAT, which only allowed for 2 Track recording.

The machine would utilize Sony’s S-VHS tapes to capture the data, and while ADAT specific tapes were produced, virtually any S-VHS cassette could be used for recording, and would yield up to 40 mins digital audio.

ADAT was able to establish a strong foothold due to its affordability and widespread adoption by the industry, and would continue to have a presence until 2003, before it was superseded by the ADAT HD - a computer based recording format.

Vinyl Record

Analog
Double Sided

A popular collectible, Columbia’s Vinyl LP provided an analog audio format that used a groove-based transmission of signal to deliver significantly longer high quality run times at a lower cost than the open reel. A full sized LP, stored on both sides, typically holds around 45 minutes, and in some rare cases as much as 52 minutes.

Some downsides to the LP is it’s vulnerability to the elements of dust and heat. Dust would affect the overall sound during playback, while heat could promote warping and physical deformation.

The record industry was quick to embrace the LP as the new format of choice due to its easy handling and marketability, taking off in the 60s through the late 70s, eventually being phased out by the Compact Cassette. However, recently, the LP has made a comeback generating nearly 15 million units in sales in 2015.

VINYL RECORDS approximate runtime information
Album Size Speed Runtime Per Side
12-INCH 33 RPM 22 Mins
12-INCH 45 RPM 15 Mins
12-INCH 78 RPM 5 Mins
7-INCH 33 RPM 7 Mins
7-INCH 45 RPM 5 Mins
10-INCH 33 RPM 15 Mins
10-INCH 45 RPM 15 Mins
10-INCH 78 RPM 3 Mins