Themis;517780 Wrote: > What was "worse" in the recording equipment 30 years ago ?
Basic history of audio recording quality: (this post doesnt even touch on studies showing that the vast majority of listeners over age 30 cant even hear better quality above 24 bit/48 kHz) Storage medium: On March 2, 1983 CD players and discs (16 titles from CBS Records) were released in the United States and other markets. This event is often seen as the beginning of the digital audio revolution. It wasnt till the end of that decade that CDs became ubiquitous. And that is 16 bit/ 44.1 kHz. Recording process: You have to take into consideration every component of every machine in the chain of analog recording (todays hard disk recording simplifies the process): "Mics", "Recording console", "Multi-track", "Mixing console", "Mix machine", "Mastering console". These components steadily evolved in quality every year. (Were not talking about recording electric instruments (guitar, synth) which wont benefit from very high bit or sample rates. The only type of music where higher quality might matter is of acoustic instruments and voice.) What the little "DDD" label on the CD booklet is supposed to mean: originally the first "D" was to designate whether the original multi-track machine was digital "D" or analog "A". The middle "D" was for mix-down to a digital machine, while an "A" in the middle was for mix-down to an analog machine. The final letter was for the process used to master the CD itself. If you play back your digital tape through an analog mastering console on its way to the Sony 1630 CD mastering machine then the last letter should be "A". If you play back your digital tape in the digital domain through a digital console and then to the 1630, having never gone through an analog conversion, then the last letter should be "D". Also, if you mixed to analog tape but mastered through a digital console, (converting to digital before the console instead of after) the last letter should be "D". The transition from analog tape to digital tape to hard disk recording occurred during the early 90s. The first version of Pro Tools was launched in 1991, offering 4 tracks with the recording at 16bit 44.1 kHz. In 1997 Pro Tools reached 24bit, 48 track versions. It was at this point that the migration from more conventional studio technology to the Pro Tools platform took place within the industry. Analog tape: Even though a recording on tape may have been made with studio quality, tape speed was the limiting factor, much like sample rate is today. Decreasing the speed of analog audio tape causes a uniform decrease in high-frequency presence, increased background noise (hiss), more noticeable dropouts where there are flaws in the magnetic tape, and shifting of the (Gaussian) background noise spectrum toward lower frequencies (where it sounds more "granular",) regardless of the audio content. In general, the faster the speed the better the sound quality. In addition to faithfully recording higher frequencies and increasing the magnetic signal strength and therefore the signal-to-noise ratio (S/N), higher tape speeds spread the signal longitudinally over more tape area. 7½ in/s highest domestic speed, also slowest professional. 30 in/ used where the best possible treble response is demanded, e.g., many classical music recordings. 3¾ in/s and 7½ in/s are the speeds that were used for (the vast majority of) consumer market releases of commercial recordings on reel-to-reel tape. Tape speed is not the only factor affecting the quality of the recording. Other factors affecting quality include track width, tape formulation, and backing material and thickness. The design and quality of the recorder are also important factors, in many ways that are not applicable to digital recording systems (of any kind.) The machine's speed stability (wow-and-flutter), head gap size, head quality, and general head design and technology, and the machine's alignment (mostly a maintenance issue, but also a matter of design--how well and precisely it can be aligned) electro-mechanically affect the quality of the recording. The regulation of tape tension affects contact between the tape and the heads and has a very significant impact on the recording and reproduction of high frequencies. The track width of the machine, which is a question of format rather than individual machine design, is one of two major machine factors controlling signal-to-noise ratio (assuming the electronics have high enough S/N not to be a factor), the other being tape speed. S/N ratio varies directly with track width, due to the Gaussian nature of tape noise; doubling the track width doubles the S/N ratio (hence, with good electronics and comparable heads, 8-track cartridges should have half the signal-to-noise of quarter-track 1/4" tape at the same speed, 3-3/4 IPS.) Tape formulation affects the retention of the magnetic signal, especially high frequencies, the frequency linearity of the tape, the S/N ratio, print-through, optimum AC bias level (which must be set by a technician aligning the machine to match the tape type used, or more crudely set with a switch to approximate the optimum setting.) Tape formulation varies between different tape types (ferric oxide [FeO], chromium dioxide [CrO2], etc.) and also in the precise composition of a specific brand and batch of tape. Backing material type and thickness affect the tensile strength and elasticity of the tape, which affect wow-and-flutter and tape stretch; stretched tape will have a pitch error, possibly fluctuating. Backing thickness also effects print-through, the phenomenon of adjacent layers of tape wound on a reel picking up weak copies of the magnetic signal from each other. Print-through causes unintended pre- and post-echoes on playback, and is generally not fully reversible once it has occurred. The print through effect is another, not well-known limitation of analog tape recording, whether in open-reel or cassette/cartridge formats. Before large hard disks became economical enough to make hard disk recorders viable, and before recordable CD technology was introduced, studio digital recording meant recording on digital tape. While the quality of digital tape did not progressively degrade with use of the tape, the physical sliding of the tape over the heads and guides meant that the tape still did wear, and eventually that wear would lead to digital errors and permanent loss of quality if the tape was not copied before reaching that point. The Digital Audio Stationary Head or DASH standard is a reel-to-reel, digital audio tape format introduced by Sony in early 1982. With the exception of the Sony PCM-3348HR and Studer D827, all of the DASH recorders have 16-bit resolution with a 44.1 kHz or 48 kHz sampling rate. The PCM-3348HR and D827 are capable of 20-bit (not 24-bit) 96 kHz operation, and are the only machines that still find significant use today, often in only the highest-end studios for music and film production. I haven't even touched on the quality of the components in the boards, desks, consoles, mixers. These also have evolved every year. -- mortslim ------------------------------------------------------------------------ mortslim's Profile: http://forums.slimdevices.com/member.php?userid=11039 View this thread: http://forums.slimdevices.com/showthread.php?t=74688
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