Jargon and lingo glossary - H to M.
HCC = Homogenised Crystal Copper
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Head Amplifier
An Amplifier that brings the I/O of a transducer to a common standard. While it may be confusing why a tape head amp always includes corrective EQ while a moving coil pickup head amp never has any such this has a really simple explanation, it's the standard they are amplifying to that dictates it, a pickup head amp is amplifying a signal to that of an common MM input of a amplifier that is already specified to have a corrective EQ onboard, while the tape head amp is bringing a signal to a line, pro or microphone level standards and all of them expect a straight signal and thus the preamp needs to perform any necessary alterations to the transducer signal before going any further. The term "head amp" comes from electric record cutters, but you had to buy an amplifier to suit the transducer which was called a cutter head and since the transducers of tape recorders were called heads as well the name stuck for all transducer amplifiers that amplify to or from a level signal.
High Blend
A circuit used in stereo FM tuners that blends the high frequencies into a mono signal, this is useful with low signals strength and with bad receiving conditions were you can get rid of the stereo noise in the higher frequencies since a lot of the noise is out of phase between the channels and hence disappears when you revert it to mono. The result is to greatly reduce overall noise but still give you a stereo signal in the lower frequencies. In personal and car radios this circuit is usually permanently on without the manufacturers ever telling you so, but this is a very useful function that should be on every tuner as an option (preferably as a variable option) and an inclusion of it is a pointer towards a careful design. Some manufacturers also have an automatic blending circuit which detects the presence of stereo noise and adjust accordingly, this is usually called AutoBlend.
HDCD = High Definition Compatible Digital
A simple but ingenious technique whereby a digital signal of 20 bit's or higher is slightly compressed and dithered into a 16bit 44KHz signal (the standard used in common CD's), then "hints" gained from original signal are buried in the least significant bit of the audio stream and on playback extracted by a digital filter that uses them to expand the data. All this resulting in a slight improvement of bandwidth and a not inconsiderable improvement in dynamics, the technique is not limited to CD standard bit rates but is most useful there since it allows it use with equipment that plays back standard CD's or comparable media, the HDCD technology does however not offer any improvements when the processed signals has a resolution higher than 24 bits. Note that the introduction to the HDCD technology on the company's homepage is a bit misleading and also that the original name was High Definition Compact Disk and you may have seen it defined and used as such but Philips lawyers where not happy about the usage of their CD trademark it was soon changed to the current one. Official homepage.
HDTV = High Definition TeleVision
A television system with higher resolution than the common terrestrial standard. This is not a new term, it has actually been used since the 1950's (UK) : where it was used to describe the 625 and 525 systems that where proposed to replace the 405 line standard that had been used in the UK since 1936, initially the UK was meant to use the 525 system but in the end and adapted the PAL system in 1964. 1980's (Japan) : Used to describe the HiVision system introduced in Japan in the latter half of the 80's. 1990's : A standard initially formulated in the USA and commonly referred to as just HD, intended as an answer to the Japanese HiVision format but ran into technical and political difficulties before finally being standardised in 1997 and then with the participation of European companies, has gained a foothold in the USA since quality of even the lower HD resolutions offer considerable improvement over NTSC, however in has seen almost no take-up in Europe since the difference between HD and PAL is less than was anticipated so most broadcasters have concentrated on introducing DVB.
HiVision
A widescreen high definition television with 1125 lines and 30 frames a second compressed using the MUSE standard, designed in Japan in the late 70's and early 80's and intended to replace the archaic NTSC standard but the American government resisted the usage of something not "home made" so it was never deployed outside Japan.
Humbucker
Used for transducers that have some sort of shielding or other design features that minimise the injection of hum from internal or external sources, this word sees little use these day's in audio circles but is used in musical instrument pickups and suchlike.
i-Link See --> 1394
Impedance
The combined effect of resistance and reactance in a device, the reactance can be inductive or capacitive. While inductance is measured in ohms like resistance on it's own the impedance characteristics of a device have a tendency to vary somewaht depending on the frequency that the device is opeerating with unlike resistance.
I/O = Input/Output
A units interfaces to other devices.
IP = Intellectual Property
Basically any idea that you can legally claim ownership of, either by registering it as in case of Trademarks and Patents, by automatic grant of rights as in Copyright or by taking matters into your own hands by making it a "trade secret" (i.e. hiding it under your bed).
IPS See --> Tape Speeds
I2S = Inter-IC Sound
A high speed serial bus standard for use with digital audio and/or video communications developed by Philips in 1986 and based around their I2C chip-to-chip communication standard (aka 12S), were it differs from most such serial systems is that high resolution clocking signal is sent alongside the data itself to ensure synchronisation and reduce or eliminate problems such as Jitter. It was originally designed for on board communications between electronic parts as can be seen from the name and is used as such on everything from high end digital televisions to mobile phones, but has more recently been seen used on high end audio as an external interconnect standard in the form of I2S Enhanced. Basically an IS2 bus consists of 3 signal paths, one has 2 channels of audio or video data multiplexed onto it using TDM, the second channel has clock info and the third is a word select line. Get more info from Philips here (PDF file) or information on the I2s Enhanced here.
K7 = kah + sept = Cassette
Common French shortening for a Compact Cassette.
Kilobyte
1024 bytes of data or 1024 * 8 bits.
Kunstharz See --> Bakelite
Kunstkopf
An interesting and technically sophisticated recording system for making Binaural recordings. Recordings are created using a microphone called Kunstkopf (or dummy head) that is actually modelled on reasonably anatomically correct in shape and external density, has microphones located in the ear cavities were the eardrum would be and sits on a resonating chamber that simulates the chest cavity of a human. This produces a recording that has an uncannily lifelike quality when listened to on headphones but has a somewhat limited compatibility with normal loudspeaker systems, the recordings are normally slightly equalised to enhance that compatibility. This technique has got something of a bad rap due to a number of recordings made and distributed in the early 80's that were done with home made kunstkopf systems that were so amateurishly done that the binaural effect was severely limited, this gave rise to the myth that recordings made with the system are "head dependent", i.e. that the binaural effect was dependant on the shape of the listeners head. There are loads of such imitations of the original system that usually simplify the head structure too much to be fully functional, skipping the resonating chamber is fine for scientific and technical purposes such as noise monitoring an analysing but almost absolutely necessary for audio related recordings, the head needs to have a nose and a reasonable emulation of an outer ear and an ear canal, without those last 2 it's simply useless. This is the correct name for both the technique and the microphone, the technique is sometimes referred to as "dummy head recording".
Magazines
A sort of a homepage but done on paper, outdated format but still mildly popular with geriatric audiophiles.
Magpie
An obsessive collector or hoarder of old junk, as opposed to someone who collects vintage pieces systematically, although the end result has a tendency to look and smell similar. This is an English term but local variants of the language have other naturalistic idioms, in the USA the term Packrat is the most used one etc.
Masking See --> Psychoacoustic Masking
Megabyte
1024 kilobytes of data or 1024 * 1024 * 8 bits, see also Disk Megabyte.
MIDI = Musical Instrument Digital Interface
A serial digital control interface for musical instruments.
MLan See --> 1394
Mod-tro = Modern retro
Japanese slang for modern equipment with retro looks and asthetics.
Mono = Monophonic
In Hi-Fi : Any audio system that gives out a single audio signal, this is regardless of the number of loudspeakers or amplifier channels used. In music : An instrument that is only capable of producing one note at a time. Dual Mono : A design feature in 2 channel stereo audio systems were the 2 signal paths are kept completely separate from each other both electronically and mechanically, high end variants of this type of design also have a separate power supply and transformer for each channel.
MPX = Multiplex
Usually seen used for the Multiplex filter on analogue recorders, FM radio uses a 19KHz multiplex pilot tone to control the demodulation of the radio signal, this is not properly filtered out by most tuners and is thus still present in the audio signal that you get from the tuner, this is mostly inaudible but creates problems when you use some noise reduction system that use de emphasis as the tone interferes with the tracking of the system and in older recorders in particular it also created problems with the bias circuit for similar reasons.
Muntzing
The practice of removing all parts and features not needed for a basic operation from an electronic design for cost saving purposes. Named after Earl Muntz who ran a a small consumer electronics empire in the southern USA in the 50's and 60', he sold good such as TV's and car radios that were designed down to a price, he was in particular fond of clipping out any capcitors used for somoothing purposes, all this resulting in TV's that where cheaper than the competicion but had a tendency to work only under ideal conditions.
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