Jargon and lingo glossary - S to 9.
SECAM = Sequential Couleur Avec Memoire
That would translate into Sequential Colour with Memory or something suchlike, variant of the PAL system used in France, parts of French Africa and parts of Eastern Europe, in the last case slightly modified.
Serial
Lit. in series or in sequence. Serial Interface : A digital interface that sends out data one bit at each cycle so it's throughput is determined by it's clock speed, see RS232 and also parallel interface. Serial Number : A number or other unique mark used differentiate an individual unit from otherwise identical ones. Serial Production : Mass produced, as opposed to hand made, individually made or prototype.
S/H = Second Hand (UK) or Shipping & Handling (USA)
1) = Second Hand I.e. used, previously owned or "cherished". 2) = Shipping and Handling I. e. the costs charged by seller for shipping or mailing the unit to you and packaging and/or handling costs associated with this.
Shellac
Wood sap that has been digested by flies and is left on the bark of trees in a tiny shell like form, harvested by hand in India and other Asian countries and was popular as a binding agent for records prior to the introduction of synthetic alternatives but was expensive and usually used with other binders and fillers, a typical shellac record having no more that 15% of it's mass made out of the material. Origin of the word is in Sanskrit and the current English spelling is the approximation of the modern Indian word, the currency restrictions placed on Indian businesses in the 20th century meant that the locally harvested shellac was used in the production of records much longer than it was in the rest of the world, 78 Rpm. shellac records were issued there until the late 70's at the least.
Sodium Potassium Tartrate See --> Rochelle Salts
Sound Reinforcement
Traditionally this term was used for exactly what it states, i.e. the amplification of audio signals in a "live" situation, be that a sound system for a live concert or a theatre of any sort, or a Public Announcement type system etc. In the last few decades the usage of the term has expanded to include most sound installations both permanent and portable, and in practice covers almost any type of sound system installation except those used in homes and recording studios.
SPDIF = Sony/Philips Digital Interface
A serial digital audio interface cooked up by Sony and Philips when they were designing the Compact Disc, it only offers basic transfers of an audio signal with no provision for synchronisation or error correction (will need an external Wordclock for sync capability) and thus is prone to problem such as Jitter. The standard provides for transfers using an coaxial cable terminating in a common RCA connector or via an optical cable, while theoretically the optical option should be the better choice, the coaxial variant gives better results in real life situations for a variety of reasons. Not to be confused with SDIF, another digital audio interconnection standard.
Special
On input selectors : This is a synonym for AUX. On cassette recorders : This denotes eq and/or bias settings for chromium tape formulations on early Japanese cassette recorders.
Spread-Spectrum
A radio broadcasting technique whereby the signal energy is spread over a range of carrier frequencies rather than a single carrier, this technique uses much less energy pr. information unit than if a traditional carrier method is used.
Stereo = Stereophony
Any audio system that attempts to give directional information or appear to do so, or in other words the opposite to Mono and not a term that is to be specifically applied to 2 channel systems only. While this term covers 2 dimensional system like the common Binaural systems and the various multichannel and Matrix systems commonly referred to as Surround Sound systems it is debatable if the term covers 3D systems such as 4 channel Ambisonics or the "Tomita Quad" systems and it was not the intention of the people that coined the term. Common usage/slang : As a synonym for a music system and in the 60's as a synonym for hi-fi.
Supertweeters
Basically a tweeter that not only will operate with frequencies well above the audible range but will do so with a reasonable linearity. Research into psychoacoustics in the resent years has shown that despite being unable to hear frequencies in the 25 to 40KHz range directly, most humans find loudspeaker systems with tweeters capable of operating in that range to be audibly better that those with normal tweeters that only go up to 25k or so, a fact that has not bypassed high end loudspeaker manufacturers in search of new gimmicks, dogs love this development of course. Not to be confused with piezoelectric tweeters that were sometimes called supertweeters when they were introduced in the 60's, such types can operate in this part of the spectrum but they were not designed with that application in mind and thus aren't usually very good at it.
Surround Sound
A synonym for stereo eg. any 2 dimensional audio system that gives the effect of "surrounding" you with an audio signal rather than come from a single source, it is often used for marketing purposes to differentiate multichannel or Matrix stereo systems from traditional Binaural ones.
Tape Speed
The speed at which a tape travels across the recording or playback head measured in centimetres per second. Most open reel recorders offer a choice of recording speeds so that the user can choose between recording quality and length, this is also possible with some cassette decks and other analogue recording formats, but by no means common. In the English speaking world tape speeds are often expressed in the archaic IPS or inches per second, note that while ips is indeed an abbreviation and should be spelled all caps there is a long running tradition of using and spelling it as a word esp. in England. The most common speeds are : 2,38cm (15/16ips), 4,75cm (1.7/8ips), 9,5cm (3.3/4ips), 19,05cm (7.1/2ips), 38,1cm (15ips) and 76,2cm (30ips), those numbers are often rounded nb. The origins of the tape speed standard are simple, the first tape recorder from Telefunken ran at 77 cm and later portable models from the company featured speeds that were divides of that number, and since stolen Telefunkens were heavily used by the US broadcasting industry after WWII the first US based manufacturers of recorders needed to make their equipment compatible with pre-recorded tapes and averaged the speed to the nearest inch, this is also the reason the early Ampex units used DIN spools.
Terabyte
1024 Gigabytes of data or 1024 * 1024 * 1024 * 1024 * 8 bits (sigh) or 1012 if you are a hard disk manufacturer.
Terrestrial
A term used in the broadcasting industry to descibe radio broadcast that originate in the earths athmosphere as in traditional TV and radio broadcasting, opposed to signals beamed in from space or brought to you via cable.
Transducer
Any device that converts mechanical or acoustical energy into electrical energy or vise versa. Phonographic pickups, loudspeakers and microphones are all examples of a transducer. There term is also used for mechanisms that convert mechanical energy into acoustic energy and so on, but those have not been used in the audio industry since the days of wind up gramophones so the simplified explanation given here above is more pertinent.
Transient
Term literally means something of a short duration but it's usually meant to mean a sudden and sharp increase in energy or information volume (i.e. a "spike" in a waveform), this can cause all sorts of problems in that either the device has not expected this amount of energy and thus reacts by ignoring everything beyond it's expectations causing distortion (in extreme cases can damage the equipment) or the equipment can react and adapt to the transient but by doing so creates abnormal conditions for the normal signal. For instance in loudspeakers a transient can cause the woofer to travel to it's extremes, this can not only mask or distort the sounds immediately around the transient since the woofer cannot react to them but the counter force will cause sounds that come after the transient to be masked or lose their timing coherence (their attack and decay characteristics are partially lost resulting in a muddled sound).
Ternary
The representation of number in powers of 3, this is occasionally used as the basis for a digital system mostly as a "last resource" when you need to build a system that has to be compatible with an older binary based standard but also to offer a higher resolution as with Supermidi, in such "upgrade" cases the system used is typically Balanced Ternary using the digits 0, 1 and -1 rather than the usual 0, 1 and 2 as is used in logical applications (i.e. a normal ternary system), the legacy systems ignore the negative and see the data as binary while the ternary based systems take advantage of it.
Uncle Technology
A derogatory term taken from the computer industry, either technical advise with not even a tenacious link to reality or a hardware/software modification by someone that has no idea what the is doing. This sort of technical expertise is usually dispersed by your 13 year old nephew, some unidentified uncle (hence term), or this website.
Unit Audio
Archaic English term for hi-fi separates occasionally used in the UK, note that the term meaning has changed a bit over the years, in the 50's and up to the late 70's any audio equipment that had the speakers separate from the rest of the system was considered unit audio, traditional consoles having the speaker or speakers built into the base unit. In fact to qualify as unit audio, a console by definition only had to have one speaker adjunct from the base, this usage of the term stopped when consoles were replaced in the marketplace by Music Systems and if you see it used today it is as a synonym for separates.
Upsampling
Usually when a DAC has a higher bitrate and/or sampling frequency than the material it's converting what you gain is basically improved headroom since the data that the converter is getting is still confined to the lower bitrate (i.e. the same granularity of a signal), upsampling is a technique whereby the original digital information is first converted into the maximum bitrate and frequency that the converter is capable of prior to converting the information into an analogue signal, this means a although the amount of original information is the same the converter is getting more detailed information and thus puts out a more granular signal. The net result of this is highly dependent on the design of both the upsampling software and the DAC but can be quite an improvement. Despite claims by certain UK based manufacturers of an upsampling capable CD players, a 16bit signal converted into 24bit/192KHz (or whatever) will never be as good as material originally recorded in that resolution.
USB = Universal Serial Bus
A high speed digital serial bus standard for computers and consumer electronics, developed by Intel in the early 1990's with the intention of getting rid of legacy I/O devices from the PC standard (i.e. Keyboard, mouse, parallel interface Printer and RS232 serial connectors which take 3 to 5 interrupts while each USB interface takes only one and can handle multiple devices while the legacy interfaces only handled one each). Intel had problems getting manufacturers to use the standard even though it was included on every motherboard chipset shipped by the company and it was ironically enough popularised by Apple Computer Corp. when they introduced the original iMac with the PC world following suit soon thereafter. Please note : It is often qouted in technical publications that USB v.2 has a better transfer rate that the competing 1394 (i.e. that it is faster), this is a common misunderstanding based on the better theoritical burst rate of the USB v2 specification, the throughput of the current 1394 versions both in theory and even more so in practice is considerably better than of USB.
VCA = Voltage Controlled Amplifier
Just that, usually a small signal amplifier that can be controlled by a voltage for automation or remote control purposes, this is useful in compressors, noise reduction units and mixers of any kind (but not in volume controls Nb.). A difficult device to manufacture, the quality of the VCA is often the deciding factor in the sound quality or accuracy of the unit that's built around it.
White Goods
As opposite to Brown Goods, historically it refers to the types of electric household products that were traditionally white in colour i.e.. fridges and washing machines etc., today it is used to cover all household products that are used for utilitarian purposes.
Wordclock
A master clock signal sent out by a digital audio playback device such as a DAT recorder or a CD transport to a receiver such as another recorder or a D/A converter side by side with a digital audio signal such as SPDIF, this means that the receiving device input converters/processors are being controlled by the clock of the device that is sending the audio signal, although in hifi it is often the other way around with the receiver controlling the sender and in professional audio circles a master clock is often used but that is a specially built high precision device that will in turn control multiple transmitting and receiving devices. The use of a wordclock minimises Jitter and other clock mismatch errors, this is especially important when further conversion has to take place on the receiving end such as sample rate conversion or dithering etc. Primarily seen in the pro audio industry although not unknown in high end audio products, the use of a wordclock obviously requires the correct I/O on both the transmitting and the receiving device and the connectors are usually BNC.
WORM = Write Once Read Many
Any recordable technology or format that does not allow deletion and/or re-recording of it's media. Examples include almost all mechanical recording technologies such as paper tapes, recordable disks and acetates, but some more modern technologies such as Compact Disk Recordable and so on are also WORM's due to technical or marketing reasons, some types of WORM disks such as MO disks are referred to as "postscript media" and are variants of normally re-recordable media especially designed for archival purposes (longer lifetime and durability in addition of no chance of you writing over any existing data).
XRCD = Extended Resolution CD
A set of standards put forward by JVC that specifies how a CD should be mastered to a great detail. It's important to note that this is a standard, not a technology like HDCD and that JVC's classification of it as a "high resolution format" is misleading at best, but as a sort of a quality assurance it's a "good thing™". Official homepage.
1394
A high speed serial digital communication interface invented by Apple Computer Corp. and often seen on digital consumer equipment such as video cameras and personal computers, usually goes by the name of "Firewire" (Apple term) or "iLink (Sony term). Has been adopted as a carrier for high resolution and or multitrack digital audio in the SACD interconnect standard and is also used by some manufacturers as a property digital interlink especially for home A/V applications were higher data rates are needed than established standards will allow. For more info visit the 1394 LA page or the 1394 Industry Association homepage. Yamaha also has an interesting 1394 based protocol called Mlan (Music Lan) that allows for the transport of multiple tracks of audio data along with other music data such as MIDI, sadly however it appears that this is confined to PCM audio only, no DSD, although high PCM bit rates are supported, more info here.