Author Topic: Glossary of HT terms  (Read 33138 times)

Online Jag

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Glossary of HT terms
« on: November 27, 2002, 18:36 »
20Hz - 20kHz: Light extends beyond human perception - infra red below, ultra violet above our range of sight. Sound also extends further than our ability to process. The spectrum of sound that humans can hear is traditionally described as the frequency range of 20Hz to 20,000Hz. Below 20Hz is the infrasonic range, above 20,000Hz the ultra-sonic domain. With age and abuse, high-frequency hearing diminishes. In many adults, especially males, it actually extends only to 15-16kHz.

2-way / 3-way speakers: The word "way" in 2-, 3- or 4-way speakers signifies into how many parts the audible frequency spectrum of 20Hz-20kHz has been divided, to be covered by different transducers. While the preceding number often coincides with the amount of drivers used [i.e. a 2-way features two drivers, a 3-way three] this isn't always true. A 3-way for example might use paralleled woofers for a total of four or five drivers. Occasionally you will also see a 2.5-way designation. This refers to a 2-way speaker with dual or more woofers where only one woofer meets the tweeter. The other woofers work only in augmentation mode to add low frequency extension to where the full-range woofer begins its roll off. Adding a second crossover point creates a third frequency band that partially overlaps with that of the "full-range" woofer, hence the .5 designation.

-3dB point: This type of spec is the standard to describe a loudspeaker's bass extension. Let's say you were to play a chromatic scale on a synthesizer, from the very lowest audible note to the very highest. When you reproduce it via a loudspeaker, you'd expect every note to be played back equally loud, just as you played it on the synthesizer. That's rarely ever the case. Very few loudspeakers exist than can reproduce 20Hz at the same volume level as higher frequencies in a real-world environment. At equal input voltage, the point at which a loudspeaker's bass response is 3dB lower than the higher frequencies is specified as the "3dB down or minus 3dB point". 3dB represents a 50% difference in sound level, hence the spec for our imaginary speaker means that at 25Hz, it will play only half as loud as it would at higher frequencies when fed with the same signal strength. In a typical listening room, reflections [also called room boundary reinforcement] typically add what is called "room gain" and may extend a speaker's actual bass response to go a bit lower than specified.


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Reproduced from goodsound.com
« Last Edit: November 28, 2002, 17:49 by Jag »
Electronics : Denon 7200, MiniDSP Dirac 88A, Emotiva XPA-5 Gen2, MiniDSP 2x4HD for BEQ
ATMOS Audio : Martin Logan Ethos (L&R), ML Motif X(C), ML Motion 4 (14pcs surround spkrs)
LFE : Dual Rythmik FV25HP & Crowson Motion Actuator
Video : Sony VPL-HW55ES, Stewart Screen Studiotek 1.3
Source : HTPC
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Online Jag

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Re:Glossary of HT terms
« Reply #1 on: November 27, 2002, 18:37 »
Acoustic suspension speaker: A sealed-box loudspeaker with specially designed drive units that use the trapped air volume inside the cabinet as a quasi spring. Not all non-vented loudspeakers are acoustic suspension designs. To meet the criteria, the drivers in an acoustic suspension design must be literally gas-tight to prevent air leaks.

Active crossover: An external crossover that is inserted between preamplifier and multiple power amps, thereby replacing the passive filter networks inside the loudspeaker. Usually, active crossovers allow adjustments to the filter frequencies and slopes for in-room performance tuning. Certain manufacturers like Naim Audio offer an upgrade path that proceeds from internal passive to external active crossovers.

Air: An audio reviewer's description of a system's ability to convey the "aura" or "space" around individual performers. This is most commonly perceived in the treble range but also occurs in lower frequencies.

Air dielectric: In cable manufacture it's empirically understood that all dielectric materials, except actual air, influence the signal to some extent. Certain high-end cable designs minimize physical contact between conductor and dielectric with air gaps or pockets and call such cables air-dielectric designs.

Ambient or rear-firing tweeter: To add spaciousness and offset the loss of sound power in the treble, some manufacturers add rear-firing tweeters. This enhances the sense of ambiance and occurs naturally with bi-polar designs.

Amplifier: A device that increases signal strength. In audio, two different kinds of amplifiers exist -preamplifiers and power amplifiers. A preamplifier provides voltage gain for the small output voltage of a source component [tuner, CD player, DVD player, tape deck or turntable], while a power amplifier amplifies the preamp signal and adds the necessary current to drive and control a loudspeaker. Solid state power amplifiers are current devices while tube amps are voltage devices. Depending on how much input voltage an amplifier requires to be driven to full output [a function of its input sensitivity], a preamp may never actually amplify the source signal but merely reduce it [attenuate] and add volume control and source switching. A typical music amplifier sports two channels, while a single-channel amplifier is called a monoblock. Home theater amplifiers feature multiple channels anywhere from 1 to 7.

Amplitude/frequency: Amplitude is a measure of loudness expressed in decibels while frequency is a measure of pitch expressed in Hertz. In an amplitude/frequency graph, the amplitude of a waveform is depicted as the size of the wave's peaks and troughs above and below the central line and measured along the vertical axis. The horizontal line is the time axis. The distance between the wave's zero crossings on this axis shows the pitch - the higher the tone corresponding to the wave form, the more often the wave crosses this line per second. A 300Hz tone completes 300 complete cycles in one second and thus crosses the line 600 times. The peaks above the line depict positive phase, the troughs below it the negative phase.

AWG: A measure of wire diameters also called wire gauge. The lower the number preceding the wire gauge spec, the thicker the wire (i.e. 12AWG wire is thinner than 8AWG wire).

« Last Edit: November 28, 2002, 17:50 by Jag »
Electronics : Denon 7200, MiniDSP Dirac 88A, Emotiva XPA-5 Gen2, MiniDSP 2x4HD for BEQ
ATMOS Audio : Martin Logan Ethos (L&R), ML Motif X(C), ML Motion 4 (14pcs surround spkrs)
LFE : Dual Rythmik FV25HP & Crowson Motion Actuator
Video : Sony VPL-HW55ES, Stewart Screen Studiotek 1.3
Source : HTPC
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Online Jag

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Re:Glossary of HT terms
« Reply #2 on: November 27, 2002, 18:37 »
Balanced components: Components that amplify or process positive and negative signal phase entirely separately and, unlike push/pull, aren't summed at the output. Such components will feature XLR-type balanced connectors. However, the presence of XLR-type connectors alone doesn't necessarily signify that the preceding circuitry is truly balanced - some XLRs are merely converted single-ended connections by shunting one of the hot pins to ground. A fully balanced stereo component features essentially four complete channels of signal processing or amplification - one each for the left and right channel positive and negative phase. In recording studios or other professional applications where very long runs of cables act like sensitive antennas and pick-up of noise, the superior noise rejection of balanced operation is often a requirement. However, most reviewers agree that the short cable lengths commonly employed in home-based listening systems don't warrant the additional cost of balanced componentry.

Banana: In audio, one possible termination for speaker cables. A banana connector is a leaf spring-loaded plug that fits tightly into the central hole of a binding post column. Dual bananas for hot/ground connection are spaced to fit standardized binding posts, and locking bananas feature an internal expansion mechanism that provides optimal contact pressure.

Bandwidth: In audio, the bandwidth of human hearing is 20Hz to 20,000Hz. However, the bandwidth of electronic audio components often far exceeds the audible limits. For example, an amplifier may be rated as being flat from 6Hz - 100kHz, or a tweeter may be rated at extending to 35kHz. The covered range between the lowest and highest frequency that a component can reproduce is considered its bandwidth. In a loudspeaker, different drivers cover different bandwidths -- in a 3-way design, a woofer may go from 28Hz to 160Hz, a midrange from 160Hz to 1800Hz, and a tweeter from 1800Hz to 22kHz.

Barrier strip: A screw-type terminal block for speaker cable connections, often used in car audio but sometimes also in consumer audio, like Vandersteen and Quicksilver.

Bass/mid/treble: The range of human hearing extends from 20Hz to 20,000Hz, essentially divided by three groups of three octaves each. These octaves are: Low bass [20-40Hz], mid bass [40-80Hz], upper bass [80-160Hz], lower midrange [160-320Hz], midrange [320-640Hz], upper midrange [640-1280Hz], lower treble [1280-2560Hz], treble [2560-5120Hz], upper treble [5120-10240Hz] and the highest harmonics [>10kHz].

Bi-amping: Two schemes exist to use multiple amplifiers in a traditional two-channel audio system. You can dedicate one amp per channel [horizontal bi-amping] or dedicate one amp for the tweeter/midrange band, the other for the bass register [vertical bi-amping]. Horizontal bi-amping requires identical amplifiers. Vertical bi-amping relegates the more powerful amp to drive the left/right channel woofers while the smaller amp drives the mid/tweeter drivers. Vertical bi-amping requires a means to adjust the output levels between both amps to avoid that the more powerful amplifier will cause a tonal imbalance of bloated and excessive bass. Means for adjustments are either input level controls on one of the amps or trim pots on an external crossover. Non-identical amplifiers in vertical bi-amp schemes will add their unique sonic signature to the respective frequency range they cover. This may or may not be audible and beneficial.

Bypass or direct option: In components with tone controls, a switch that defeats them to remove them from the signal pass.

Bi-wiring: Speakers with dual binding post pairs can be bi-wired. This means running two pairs of speaker cables between amp and speaker. This can be done in shotgun or internal bi-wire mode. In shot-gun mode, both cable pairs remain physically separate up to the amplifier where the two plus and minus legs are tied together into a common spade or banana terminal. Internally bi-wired cables require a minimum of four conductors that are then terminated as two leads on the amp, and four leads on the speaker end. Bi-wiring electrically separates the woofer from the tweeter or mid/tweeter circuit and isolates potential back-EMF [electromotive force] from the woofer at the amp instead of bleeding back into the tweeter or mid/tweeter circuit. Bi-wirable speakers connected in standard single-wire mode must have their jumpers installed so that both the hi- and low frequency drive units receive amplifier signal. In many cases, jumpers made with the same raw wire as the chosen speaker cable will sonically outperform manufacturer-provided jumpers. The subject of bi-wiring is a disputed topic even among loudspeaker manufacturer and the presence or absence of dual terminal pairs on a loudspeaker doesn't give any indication as to the design's sonic quality.

Bipolar/dipolar: A loudspeaker in which either the drivers' rear waves aren't absorbed by a cabinet but allowed to freely propagate into the room, or rear-firing drivers have been added instead. All panel loudspeakers [electrostats and planar-magnetics] radiate front and back, with all backfiring radiation out-of-phase or dipolar. Dynamic designs with both front- and rear-firing drivers can be in-phase/bipolar or out-of-phase/dipolar. Sometimes, a switch can select between either mode. In designs using only front-firing conventional dynamic drivers that are mounted into an open-backed baffle or where the rear wave exits through a tunnel, the rear-wave is naturally out-of-phase [examples of this style are speakers by Alon and the new Futures by Proac].

Break-up modes: Conditions of cone resonance in all loudspeaker drivers, but commonly well outside the pass band in which the drivers are used and thus inaudible.

Bridging: Certain stereo power amplifiers allow the summing of their left and right channels in parallel to increase power output. In bridged single-channel mode, the increase in output power over regular stereo mode can be between 2 and 4 times. A bridged amplifier's low impedance stability diminishes compared to its stability in regular mode. Whether bridging is a sonic improvement or not depends on many factors and should be subject to personal experimentation.

BNC: A true 75ohm bayonet-type locking cable interface commonly used in pro audio/video application for digital and video signals. In consumer audio, BNC connectors appear as upscale digital and video in- and outputs to offer an upgrade over the lesser non-75ohm RCA connectors. The superiority of true 75ohm transmission of digital and video cables becomes more pronounced as cable lengths increase.

Break-in: An empirical phenomenon with little hard-science measurements, break-in refers to an audio component's conditioning period before stable and optimum results are achieved. Length of break-in time depends on components and your ability to perceive any real improvements.

« Last Edit: November 28, 2002, 17:55 by Jag »
Electronics : Denon 7200, MiniDSP Dirac 88A, Emotiva XPA-5 Gen2, MiniDSP 2x4HD for BEQ
ATMOS Audio : Martin Logan Ethos (L&R), ML Motif X(C), ML Motion 4 (14pcs surround spkrs)
LFE : Dual Rythmik FV25HP & Crowson Motion Actuator
Video : Sony VPL-HW55ES, Stewart Screen Studiotek 1.3
Source : HTPC
Fully automated HT via Alexa, Z-wave and Logitech Harmony Remote Control

Online Jag

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Re:Glossary of HT terms
« Reply #3 on: November 27, 2002, 18:38 »
Capacitive coupling: In audio a proximity effect between physically separate wires that, under signal, can exert a modifying effect on each other depending on signal strength and physical closeness.

CDR: Recordable CD medium, comes in either record-once [CD-R] or record-many versions [CD-RW]. Due to copyright restrictions, consumer CD recorders only accept the more expensive consumer blanks, not computer CDRs, and don't allow multiple copies of your recordings.

Choke-filtered power supply: To prevent power supply ripple from contaminating the audio signal, an inductor follower acts as noise filter. This is common in tube amplifiers but more rare in solid state components [Musical Fidelity is an example of a solid-state company using chokes in certain of their solid-state components].

Circuit board: In electronics a non-conductive base material onto which conductive traces are applied into which resistors, capacitors, inductors, transformers, ICs and other parts are inserted to create electrical circuits.

Clipping: An undesirable over-drive condition that occurs when an amplifier runs out of power and creates a potentially dangerous wave-form distortion that can destroy loudspeaker voice coils, especially in tweeters. Clipping is a very audible and unpleasant distortion and always the result of output levels that are in excess of what the particular amplifier/speaker combination is capable of. Quickly turning down the volume remedies this condition. Incidentally, clipping occurs not because an amplifier is too powerful but because it is underpowered. Loudspeaker units damaged by clipping are usually not covered under manufacturer's warranties and are considered abusive failures.

Coaxial cable: A single or multiple twisted conductor cable with a surrounding active ground return shield.

Coaxial driver: Common in car audio where space is at a premium, a tweeter is mounted over the center of a mid/woofer, which itself is occasionally mounted atop a larger woofer for a tri-axial design. Coaxial drivers have become more common in consumer loudspeakers, and British speaker manufacturers KEF and Tannoy have built their careers on dual-concentric drivers that locate the tweeter inside the mid/woofer's voice coil rather than suspending it via a bridge over the larger driver.

Coil/Inductor: Multiple windings of wire, often around an iron-core but, to prevent saturation, without a core in upscale designs [aircore inductor], a coil blocks high frequencies. Inductors are a staple ingredients in crossovers where they appear in woofer and midrange circuits. The number of windings determines the effective frequency at which signal passing through the coil is blocked.

Compatibility: In audio the recognition that certain components work better together than others. The most critical system juncture is the amplifier/speaker interface. Reactive loudspeaker loads with erratic impedance curves require high-current amplifiers with capable power supplies that remain stable into low-impedance loads. Low-sensitivity loudspeakers mandate powerful amplifiers. Tube amplifiers prefer high-impedance speakers with narrow phase angles. Low-power tube amps can't drive low-efficiency speakers to reasonable levels. Large-woofered speakers require more current than small 2-ways. "Bright" speakers might sound better with "darker" electronics. Cables can be used as tone controls to balance a system's overall sonic signature. In short, if you're an audio novice, the advice of a good dealer or experienced friend is mandatory for best results.

Compound loading: In loudspeakers, a driver arrangement whereby one driver is situated behind another one.

Contact enhancer: A solution that removes oxidation from metal connectors such as RCA jacks, binding posts and cable terminations to improve conductivity.

Crossover: A frequency divider network that separates the audible frequency spectrum into different parts that are reproduced by dedicated drivers, i.e. a tweeter for the high frequencies, a midrange for the vocal range and a woofer for the bass.

Crossover slope: A typical crossover specification indicates the network's "order" [i.e. 1st order, 2nd order, 3rd order, 4th order] and crossover frequency [i.e. 2300Hz in a typical two-way acts as the dividing line between mid/woofer and tweeter]. Each "order" adds 6dB of roll-off, so that a 1st order network rolls off its various drivers at 6dB/octave above and below their respective bandwidth, while a 2nd order crossover equals a 12dB/octave slope and a 3rd order 18dB/octave. Think of different handshakes. In Roman times, men used to greet each other by clasping each other's forearms. The area of contact was from hand to elbow crease. This would equate a 1st order network -- adjacent drivers separated from each other by the crossover have a lot of overlap [physical contact], i.e. reproduce many of the same notes. A contemporary handshake in our example would refer to a 2nd order crossover -- the point of physical contact is reduced to the hands, i.e. less of the same notes are reproduced by two adjacent drivers. An inner city greeting of fist-against-fist reduces physical contact even more. Now only the knuckles are touching. This would be a 3rd order or 18dB/octave network -- adjacent drivers roll off very fast so that the frequency range of overlap between them is much diminished. The most common crossover choices are 1st through 4th, with the 4th order slope of 24dB/octave being the steepest and the 6dB/octave 1stt order the most shallow or gradual. Joseph Audio's "Infinite Slope" and Speaker Art's 7th or 8th order networks are exceptions.
« Last Edit: November 28, 2002, 17:55 by Jag »
Electronics : Denon 7200, MiniDSP Dirac 88A, Emotiva XPA-5 Gen2, MiniDSP 2x4HD for BEQ
ATMOS Audio : Martin Logan Ethos (L&R), ML Motif X(C), ML Motion 4 (14pcs surround spkrs)
LFE : Dual Rythmik FV25HP & Crowson Motion Actuator
Video : Sony VPL-HW55ES, Stewart Screen Studiotek 1.3
Source : HTPC
Fully automated HT via Alexa, Z-wave and Logitech Harmony Remote Control

Online Jag

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Re:Glossary of HT terms
« Reply #4 on: November 27, 2002, 18:38 »
DAC: Acronym for digital-to-analog converter, an intrinsic part of any CD or DVD player and available also as a separate component that then requires a preceding transport to make a complete digital front-end. Separating the transport from the converter introduces jitter and might require additional componentry to eliminate.

Damping factor: An amplifier spec, the damping factor is the relationship between source and load impedance, i.e. the amp's output impedance and speakers' input impedance. The lower the amp's output impedance and the higher the speakers' input impedance, the higher the damping factor. Tube amps with output impedances of 2-4ohms into 4-8ohm speakers naturally have poor damping factors of 1 or 2. Solid state amps with output impedances of 0.05ohms or lower into the same speakers have high damping factors of 100 - 1000. A higher damping factor provides both greater control over a loudspeaker's drivers and greater immunity to these drivers' back EMF [electromotive force]. The larger a transducer's diameter and associated motor structure, the higher the levels of potential back EMF it can produce. Back EMF is thus most significant in bass drivers. Because horn-loaded loudspeakers reach high output levels with significantly reduced driver excursion, such designs generate comparatively low levels of back EMF which makes them more compatible with low damping factor amplifiers such as SETs.

D'Appolito design: Named in reference to its inventor, d'Appolito-type loudspeakers feature a mid/woofer -- tweeter -- mid/woofer array and are most commonly used for Home Theater center channel applications due to their controlled dispersion pattern.

Deltron plug: A version of the banana plug that's a solid barrel instead and features a single side-mounted spring.

Dielectric: Usually Teflon, polyethylene or other plastics that acts as insulators and encapsulate signal-carrying conductors.

Diffraction control: In a loudspeaker, the physical contouring of the speaker baffle away from the drivers or the application of damping materials to prevent early reflections of driver output.

Diffuser: In audio, any multi-faceted irregular surface such as partially-opened blinds or plants and trees that disperse sound waves into multiple directions and thus break up powerful direct reflections.

DIN connectors: A European connector format with multiple miniature pins. In audio, pin connectors are primarily used for S/Video and the I-squared-S digital interface. Certain European companies like Naim Audio champion DIN connectors, which necessitates the use of DIN-to-RCA conversion plugs to interface with standard US/Canadian components.

Directivity: Also referred to as dispersion characteristic, this relates to a loudspeaker's propagation pattern of sound. Smooth and even dispersion is generally considered an important attribute since room boundaries cause most of the sound to be reflected rather than direct. In the low bass, sound propagation is essentially omni-directional like a circular wave emanating from the impact of a rock. With rising frequencies, sound becomes directional and behaves like a more and more tightly focused spotlight.

Doubling: In audio the observation that subwoofers without sufficient bass extension reproduce the very lowest notes so reduced in output that their first upper harmonics dominate them. This doubles the frequency of the fundamental to be reproduced. Instead of hearing a 25Hz signal, you're actually hearing its 50Hz first upper harmonic an octave higher.

Down-firing woofer: A common practice with subwoofers when the main woofer faces the floor. This creates a different room-loading effect from front-firing woofers.

Dual concentric drivers: Made popular by British speaker manufacturers KEF and Tannoy as well as French speaker maker Cabasse, a dual-concentric or coaxial driver places a tweeter inside a mid/woofer's voice coil.

DSP: Digital signal processing, used in audio for digital-to-analog conversion, surround sound decoding, speaker correction and certain digital amplifier circuits.

DVD-A: A new high-resolution 24bit/192kHz audio format that's based on the existing video DVD standard and allows for up to 6 channels of music. Software support is still scarce, but DVD-A discs are backward compatible with all video DVD players and promise audio quality superior to CD once the first DVD-A players mature. DVD-A's competitor in the market place is Sony's SACD format. To date, a true universal player [compatible with CD, CD-R, CD-RW, DVD-V, DVD-A and SACD] is still to be introduced.

Dynamic compression: In loudspeakers the phenomenon of voice coil heating which changes its impedance and mis-terminates the crossover network. During massive crescendos or extended high-level listening, this can cause non-linearities when the drive units in a loudspeaker lose the ability to track high signal amplitudes properly. Because not all drivers in a loudspeaker will exhibit the same recovery times when their voice coils cool back to normal, different parts of the frequency spectrum will be affected to different degrees and at different times. Dynamic compression is most obvious in the bass but can occur at all frequencies.

Dynamic loudspeaker: The most common of all loudspeaker categories in which conventional round [or occasionally elliptical] drive units surrounded by rubber or foam suspensions are used for pistonic transducers. Other categories include horn speakers, planar, electrostatic, ribbon and flat panel designs.

« Last Edit: November 28, 2002, 17:57 by Jag »
Electronics : Denon 7200, MiniDSP Dirac 88A, Emotiva XPA-5 Gen2, MiniDSP 2x4HD for BEQ
ATMOS Audio : Martin Logan Ethos (L&R), ML Motif X(C), ML Motion 4 (14pcs surround spkrs)
LFE : Dual Rythmik FV25HP & Crowson Motion Actuator
Video : Sony VPL-HW55ES, Stewart Screen Studiotek 1.3
Source : HTPC
Fully automated HT via Alexa, Z-wave and Logitech Harmony Remote Control

Online Jag

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Re:Glossary of HT terms
« Reply #5 on: November 27, 2002, 18:39 »
Early reflections: Of particular concern in loudspeaker placement, early reflections of driver output against the side walls or floor will mix with the actual signal such that the ear/brain mechanism can't distinguish the reflections as a separate echo event. With enough distance from the sidewalls, first reflections are delayed enough that the ear/brain mechanism can differentiate. Toe-in of loudspeakers as well as room treatments can minimize or eliminate these reflections.

Electrostatic loudspeaker: A loudspeaker in which the conventional dynamic drive elements have been replaced by Mylar foils suspended between electrically charged metal stators. The most well known manufacturer of this type of loudspeaker is Martin-Logan.

Equalizer: An equalizer separates the audio spectrum into specific bands to allow cut and boost tailoring of the overall frequency response. Non-intrusive high-quality equalizers are rare but can be useful to tailor in-room bass response or sprighten up old and compressed recordings. Certain high-end subwoofers add user-adjustable EQ.

« Last Edit: November 28, 2002, 17:58 by Jag »
Electronics : Denon 7200, MiniDSP Dirac 88A, Emotiva XPA-5 Gen2, MiniDSP 2x4HD for BEQ
ATMOS Audio : Martin Logan Ethos (L&R), ML Motif X(C), ML Motion 4 (14pcs surround spkrs)
LFE : Dual Rythmik FV25HP & Crowson Motion Actuator
Video : Sony VPL-HW55ES, Stewart Screen Studiotek 1.3
Source : HTPC
Fully automated HT via Alexa, Z-wave and Logitech Harmony Remote Control

Online Jag

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Re:Glossary of HT terms
« Reply #6 on: November 27, 2002, 18:39 »
Far-field listening: In speaker/listener positioning, an arrangement whereby the listener-speaker distance is significantly larger than the speaker-to-speaker distance. Far-field listening often occurs when speakers are placed on the short wall of a rectangular room. The opposite is near-field listening which often is the only workable solution when a system is placed on the long wall of a rectangular room. Certain multi-driver full-range speakers work better in far-field positions where the increased distance allows the physically widespread drivers on the speaker baffle to converge at the listener's ears for proper integration
« Last Edit: November 28, 2002, 17:58 by Jag »
Electronics : Denon 7200, MiniDSP Dirac 88A, Emotiva XPA-5 Gen2, MiniDSP 2x4HD for BEQ
ATMOS Audio : Martin Logan Ethos (L&R), ML Motif X(C), ML Motion 4 (14pcs surround spkrs)
LFE : Dual Rythmik FV25HP & Crowson Motion Actuator
Video : Sony VPL-HW55ES, Stewart Screen Studiotek 1.3
Source : HTPC
Fully automated HT via Alexa, Z-wave and Logitech Harmony Remote Control

Online Jag

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Re:Glossary of HT terms
« Reply #7 on: November 27, 2002, 18:40 »
Hardwired: A direct electrical connection without intermediate junctions.

Harmonics: Harmonics or overtones provide the characteristic timbre of instruments and voices and occur above and below the so-called fundamental or base note. The popular soft plastic pipe can be used to explore harmonics -- as you swirl it around faster and faster, you "climb up" from one harmonic to the next. You can also over-blow a glass bottle with higher and higher air velocity for the same experiment. The first harmonic is one octave higher than the fundamental. The second harmonic an octave + a fifth. The third harmonic is two octaves higher than the fundamental. The forth adds another third. Odd-order harmonics are more pleasing to the human ear because they act as octave-doublers. Most tube amps have high odd-order distortion, which causes a euphonic coloration. Even-order distortion introduces fifth, thirds and diminished thirds and isn't harmonically benign. THD specs report on the Total Harmonic Distortion behavior of amplifiers.

Heatsink: In audio, a usually finned metal body that conducts heat away from resistors and solid state output devices. Amplifier heatsinks can be internal or external. Due to its inherent inefficiency, Class A solid state amplifier operation requires massive heatsinks while Class A tube amps use the free-air glass envelope of the vacuum tube for heat convection. High-power pro-audio amplifiers that need to remain small and light often use fans instead of heatsinks.

Hi-Fi: Abbreviation for High Fidelity, used to denote the industry's goal to remain true to the music signal without subtracting data or adding colorations.

High amplifier output impedance: Not an issue with solid state amps, high tube amplifier output impedance, when coupled to speakers with a broad impedance window [like 2 - 26 Ohms], can modulate the speaker's frequency response and cause severe deviations from flat. If your amplifier's output impedance is 2 Ohms or higher, you need partnering speakers with suitably narrow and stable impedances.

High-End: In audio, components that aspire to the state-of-the-art and are thus usually rather expensive.

Highpass filter: In loudspeakers, the part/s of the crossover that block/s lower frequencies to let higher ones pass.

Horn-loaded loudspeaker: Refers to loudspeakers that feature a bell-like embouchure or compression chamber in front of their drivers that increase loudspeaker sensitivity to attain significantly higher output levels when compared to the same design without horn-loading. Very popular in pro-audio applications such as nightclubs and arenas, horns are less common in home audio [Klipsch excepted] due to certain colorations that are difficult to expunge from the breed.

Hybrid loudspeaker: A loudspeaker in which drivers from different categories are used. The most common hybrids use conventional dynamic woofers with horn-loaded, electrostatic or ribbon midranges and tweeters. Other examples of hybrid tweeter/midrange types are bending wave drivers [German Physik], Radialstrahler [mbl], the Heil air-motion transformer, the Anthony Gallo tweeter and the Linaeum tweeter and midrange.

Hybrid amplifier: An amplifier that features both tube and transistor elements.

« Last Edit: November 28, 2002, 17:59 by Jag »
Electronics : Denon 7200, MiniDSP Dirac 88A, Emotiva XPA-5 Gen2, MiniDSP 2x4HD for BEQ
ATMOS Audio : Martin Logan Ethos (L&R), ML Motif X(C), ML Motion 4 (14pcs surround spkrs)
LFE : Dual Rythmik FV25HP & Crowson Motion Actuator
Video : Sony VPL-HW55ES, Stewart Screen Studiotek 1.3
Source : HTPC
Fully automated HT via Alexa, Z-wave and Logitech Harmony Remote Control

Online Jag

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Re:Glossary of HT terms
« Reply #8 on: November 27, 2002, 18:40 »
IC: An integrated circuit in chip form.

IEC: A receptacle for a removable power cord.

Image specificity: An audio reviewer's description of how precisely a system assigns each instrument and performer its own specific location within the soundstage.

Imaging: An audio reviewer's description of the phenomenon whereby an audio system localizes individual instruments and performers within the soundstage between and behind the speakers.

Inductor/coil: Multiple windings of wire, often around an iron-core but, to prevent saturation, without a core in upscale designs [aircore inductor], a coil blocks high frequencies. Inductors are thus staple ingredients of crossovers where they appear in woofer and midrange circuits. The number of windings determines the effective frequency at which signal passing through the coil is blocked.

Infrared/RF remote control: Infrared remote controls require line of sight whereas radio-frequency remotes, like hand-held or cell phones, send their signals through walls. Infrared remotes can be operated from a different room via infrared repeaters that are hard-wired to the control unit and installed in-wall like a light switch or taped to the outside of an audio cabinet.

Integrated amplifier: An amplifier with integral preamp stage that can be either passive or active.

Isobaric: In loudspeakers, a driver loading arrangement in which two identical drivers are placed inside a vented chamber but face opposite directions.

I-squared-S: A digital cable interface pioneered by Audio Alchemy and since embraced by other manufacturers. I-squared-S separates the left/right channel signal, the master clock and de-emphasis on individual pins.

« Last Edit: November 28, 2002, 18:00 by Jag »
Electronics : Denon 7200, MiniDSP Dirac 88A, Emotiva XPA-5 Gen2, MiniDSP 2x4HD for BEQ
ATMOS Audio : Martin Logan Ethos (L&R), ML Motif X(C), ML Motion 4 (14pcs surround spkrs)
LFE : Dual Rythmik FV25HP & Crowson Motion Actuator
Video : Sony VPL-HW55ES, Stewart Screen Studiotek 1.3
Source : HTPC
Fully automated HT via Alexa, Z-wave and Logitech Harmony Remote Control

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Re:Glossary of HT terms
« Reply #9 on: November 27, 2002, 18:41 »
Jitter: An artifact of the digital-to-analog conversion process, jitter is a timing error that occurs during reconstruction of the digital "ones and zeros" into an analog signal. Jitter becomes a real liability with separate DACs. Certain companies offer anti-jitter boxes that insert between a transport and DAC to lower or reduce jitter. While going to an outboard DAC can improve performance, especially with an outdated CD player now only used as transport, it also increases system complexity and adds a digital interconnect cable.

Electronics : Denon 7200, MiniDSP Dirac 88A, Emotiva XPA-5 Gen2, MiniDSP 2x4HD for BEQ
ATMOS Audio : Martin Logan Ethos (L&R), ML Motif X(C), ML Motion 4 (14pcs surround spkrs)
LFE : Dual Rythmik FV25HP & Crowson Motion Actuator
Video : Sony VPL-HW55ES, Stewart Screen Studiotek 1.3
Source : HTPC
Fully automated HT via Alexa, Z-wave and Logitech Harmony Remote Control

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Re:Glossary of HT terms
« Reply #10 on: November 27, 2002, 18:41 »
Law of diminishing returns: True also for industries other than audio, this phrase refers to the observation that beyond a certain point of expenditure, increased financial outlay purchases smaller and smaller increments of additional performance. In audio, this point for loudspeakers and electronics is often considered to be around $2000 while 16bit/44kHz CD technology has matured such the $1000 mark may now be considered the dividing line.

Live/dead room: A "live" room features a lot of hard reflective surfaces such as stone, concrete, glass, wood paneling and tiles. A "dead" room features a lot of soft, absorptive surfaces such as curtains, carpets, drapes, overstuffed couches and pillows. The ultimate "dead" room is an anechoic chamber. Real-world living rooms usually feature a combination of reflective and absorptive attributes and much basic room tuning can be accomplished with judicious decorating.

Line source: In loudspeakers the paralleling of multiple drivers that cover identical frequencies. This is the opposite of a point source. An extreme line source example is the Nearfield Acoustics PipeDream speaker.

Loudspeaker impedance: A loudspeaker specification usually given as "nominal [or average] impedance". 8ohm or higher signifies an easier load on a partnering amplifier while 4ohm or lower requires an amplifier that is stable into low-impedance loads. Certain affordable receivers are not stable into 4ohm speakers. A stereo amplifier stable into 4ohm will only be stable into 8ohm when bridged to mono.

Lowpass filter: In loudspeakers, the part/s of the crossover that block/s higher frequencies to let lower ones pass.

Lowther: A woofer with a central whizzer cone and single voice coil that's used in high-efficiency SET-compatible loudspeakers and acts as a crossover-less point source. Because Lowther drivers have limited frequency extension in both treble and bass, they're often rear-horn loaded or augmented by a separate woofer enclosure and/or super tweeter.

LSIC: A large-scale integrated circuit in chip form that combines multiple functions.

« Last Edit: November 28, 2002, 18:01 by Jag »
Electronics : Denon 7200, MiniDSP Dirac 88A, Emotiva XPA-5 Gen2, MiniDSP 2x4HD for BEQ
ATMOS Audio : Martin Logan Ethos (L&R), ML Motif X(C), ML Motion 4 (14pcs surround spkrs)
LFE : Dual Rythmik FV25HP & Crowson Motion Actuator
Video : Sony VPL-HW55ES, Stewart Screen Studiotek 1.3
Source : HTPC
Fully automated HT via Alexa, Z-wave and Logitech Harmony Remote Control

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Re:Glossary of HT terms
« Reply #11 on: November 27, 2002, 18:42 »
Main-in: A complementary feature to a pre-out, a main-in on a receiver or integrated amplifier allows bypassing of the internal preamplifier by connecting to the integral amplifier stage via an outboard preamp or processor. A pre-out / main-in pair can also be used to insert another component such as an equalizer or crossover into the signal chain.

Mechanical roll-off: In loudspeakers drivers whose mechanical roll-off needs no further electrical attenuation and can be employed without further crossover parts.

Microphonic: In audio the observation that vacuum tubes can amplify extraneous noise, while loudspeaker crossover components, especially capacitors, can change their behavior in the presence of strong vibrations.

Midrange: In a three- or four-way loudspeaker, the driver that reproduces the vocal range.

Electronics : Denon 7200, MiniDSP Dirac 88A, Emotiva XPA-5 Gen2, MiniDSP 2x4HD for BEQ
ATMOS Audio : Martin Logan Ethos (L&R), ML Motif X(C), ML Motion 4 (14pcs surround spkrs)
LFE : Dual Rythmik FV25HP & Crowson Motion Actuator
Video : Sony VPL-HW55ES, Stewart Screen Studiotek 1.3
Source : HTPC
Fully automated HT via Alexa, Z-wave and Logitech Harmony Remote Control

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Re:Glossary of HT terms
« Reply #12 on: November 27, 2002, 18:42 »
Near-field listening: In speaker/listener positioning, an equilateral triangle arrangement that equals listener-to-speaker distance with speaker-to-speaker distance and optimally subtracts room interaction from the playback event. The near-field position is often the only workable solution if a long-wall arrangement in a rectangular room is mandatory due to practical considerations.

Negative feedback: A portion of an amplifier's output signal is fed back to its input to reduce distortion. Most solid state amplifiers use various amounts of local and global feedback while many single-ended triode amps eschew all negative feedback and many push/pull tube amps offer user-adjustable global feedback.

Noise floor: In audio, the audible noise a component generates without passing a signal but merely by being powered on. The specification that describes this phenomenon is called S/N or signal-to-noise ratio. Noise is also generated through the power delivery system and often referred to as "power line grunge". In addition, every listening environment is ridden with its own noise floor or background noise that's a combined function of interior machinery [refrigerators, fans, heaters, air conditioning, light dimmers] and outside noise [animals, voices, traffic, wind, rain].

« Last Edit: November 28, 2002, 18:01 by Jag »
Electronics : Denon 7200, MiniDSP Dirac 88A, Emotiva XPA-5 Gen2, MiniDSP 2x4HD for BEQ
ATMOS Audio : Martin Logan Ethos (L&R), ML Motif X(C), ML Motion 4 (14pcs surround spkrs)
LFE : Dual Rythmik FV25HP & Crowson Motion Actuator
Video : Sony VPL-HW55ES, Stewart Screen Studiotek 1.3
Source : HTPC
Fully automated HT via Alexa, Z-wave and Logitech Harmony Remote Control

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Re:Glossary of HT terms
« Reply #13 on: November 27, 2002, 18:43 »
Off-axis response: Related to loudspeaker dispersion, off-axis response refers to the sonic window on either side of a speaker's direct axis to the listener. Typical loudspeaker measurements show 0, 15, 30 and even 45, 60 and 75 degrees response curves. Ideally, the off-axis curves should remain closely grouped and duplicate the general on-axis curve in shape and roll-off because the final sound at the listener's ear is the sum total of direct, early and reverberant reflections. Significant suck-outs or peaks in the off-axis response will reflect in this final sum and be audible.

OTL: Output-transformer-less tube amp topology that creates acceptably low output impedance without an output transformer but requires many tubes and high impedance speakers. Of all tube amplifier topologies, OTLs tend to require the most care with proper speaker matching and prefer 12-16 Ohm loads.

Output taps: Many tube amplifiers feature output transformers with multiple windings optimized for different speaker loads and offer multiple taps, usually 4 and 8ohms, sometimes even 16. For best results, one matches the tap closest to the speaker's nominal impedance. Occasionally, an apparent impedance mismatch might give better results so the rule is to use the tap that sounds best.

Output transformer: A necessary feature of tube amplifiers to lower output impedance, output transformers are rarely used with solid state amplifiers but exceptions exist [McIntosh for example].

« Last Edit: November 28, 2002, 18:02 by Jag »
Electronics : Denon 7200, MiniDSP Dirac 88A, Emotiva XPA-5 Gen2, MiniDSP 2x4HD for BEQ
ATMOS Audio : Martin Logan Ethos (L&R), ML Motif X(C), ML Motion 4 (14pcs surround spkrs)
LFE : Dual Rythmik FV25HP & Crowson Motion Actuator
Video : Sony VPL-HW55ES, Stewart Screen Studiotek 1.3
Source : HTPC
Fully automated HT via Alexa, Z-wave and Logitech Harmony Remote Control

Online Jag

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Re:Glossary of HT terms
« Reply #14 on: November 27, 2002, 18:43 »
Palpability: An audio reviewer's description of a system's ability to render the perfect illusion that the performers are present in one's living room. Sometimes nearly synonymous with "presence" or "immediacy."

Passive radiator: In a loudspeaker, a [usually flat] drive unit that doesn't transmit any signal but acts as a quasi port and lowers bass response.

Pass-thru: When a music system serves double-duty for movies, certain owners prefer to use a preamp for music and a separate surround sound processor for Home Theater. Some preamps feature a pass-thru [also called "loop-thru" or "direct"] feature that enables whatever source is connected to that specific input, to be passed straight through to the processor, bypassing all preamp circuitry and volume control.

Passive preamplifier: Because most modern source components provide enough output voltages to drive most power amps directly, a new type of preamp called "passive" was introduced. Rather than provide additional gain, a passive preamp merely attenuates or reduces the output voltage of whatever source component is connected to it. The frequency response of passive preamps can be modulated by the impedance of interconnects and input impedance of the associated amp. Before you decide on a passive preamp, consult with your dealer to assure optimal results with your amplifier.

Pentode: A vacuum tube featuring five elements, like a 5881, 6550, KT88 or EL34. Pentodes can be operated in triode mode by disconnecting two out of the five elements.

Phase- and time-coherent loudspeaker: A class of loudspeakers using 1st order networks and either a sloped or stepped baffle to time-align the driver's acoustical centers.

Phase plug: A bullet-shaped stationary insert that replaces a loudspeaker driver's dust cap.

Pitch definition: An audio reviewer's description of a system's ability to accurately convey precise pitch. Our human hearing ability with regard to pitch is naturally poor in the bass [think about very low piano notes - they may rumble but can you tell them apart, exactly?]. A system's ability to portray pitch as precisely as possible, especially in the lowest two octaves, can make an appreciable difference.

Placement sensitive: In audio the observation that certain components perform differently purely as a function of where and how they are situated. Components that generate heat or have many moving parts shouldn't be stacked atop each other. Vacuum tubes are microphonic and sensitive to foot falls and external vibration and should be appropriately isolated. Turntables especially must be isolated from extraneous vibration and impact. The tonal balance of loudspeakers is heavily influenced by their relative placements within room boundaries and their relationship to the listener's position. Monitor type loudspeaker must be sited on a stand for proper performance, the height usually determined by the tweeter axis adjusted to ear level. Loudspeaker cables running across carpet may be sensitive to static electricity, and interconnect cables in close proximity to power cables can pick up noise.

Point source: With loudspeakers, the ideal of the "pulsating sphere" that has all audible frequencies emanate from a single point. Except for single-driver speakers and headphones, this remains a theoretical ideal for full-range loudspeakers but prompts many designers to group transducers as closely as possible together, in many cases minimizing the driver basket rims at the point of contact. This is reflected in tight proximity tweeter/midrange groupings and has resulted in a resurgence of coaxial or dual-concentric units.

Point-to-point wiring: Very common in tube components, point-to-point wiring substitutes circuit board traces with wire connections. In marketing often used as a qualifier of superiority, point-to-point wiring, by virtue of hand labor involved, can't guarantee 100% accurate repeatability as a machine-made circuit board.

Port/vent: In loudspeakers, a usually round opening in the cabinet through which the back wave of the enclosed drivers exits into the room.

Pre-out: A preamplifier output via which the interconnect cable connects to an external power amplifier. If a receiver or integrated amplifier is equipped with a pre-out, you can bypass the internal power amp stage and go off-board to a stand-alone amplifier, or bi-amp.

Push/pull amplifier topology: To reduce distortion and increase output power and amplifier efficiency, a push/pull amplifier topology splits the input signal into its positive and negative phase and amplifies each with a dedicated bank of transistors/tubes before summing the signal at the output. The opposite approach is called single-ended and more typical of tube amps even though Pass Labs, for example, manufactured a line of solid-state single-ended amps with their Aleph series.

Preamplifier or linestage: In the days before CD, the output voltage of the available sources, turntables and then tape decks, wasn't large enough to drive a power amplifier to full output. To provide the additional gain necessary and a means to select inputs, a preamplifier was inserted between the source components and power amp. A turntable requires still additional gain before even a preamplifier can accept it. It's thus first connected to either a preamp's in-built phono stage or an external phono stage. A preamplifier with in-built phono stage is also called a full-function preamplifier. Most modern preamps are linestages that don't include a phono stage. Because today's source components possess high-enough output voltages to drive most power amplifiers directly, a preamp's primary function now is volume attenuation and source selection. Single-source systems don't require a preamp if an alternate way to control volume is provided. This could be a CD player with variable outputs or an amplifier with input level control. Going amplifier-direct requires a high-quality volume control in either the amp or the source component.

« Last Edit: November 28, 2002, 18:04 by Jag »
Electronics : Denon 7200, MiniDSP Dirac 88A, Emotiva XPA-5 Gen2, MiniDSP 2x4HD for BEQ
ATMOS Audio : Martin Logan Ethos (L&R), ML Motif X(C), ML Motion 4 (14pcs surround spkrs)
LFE : Dual Rythmik FV25HP & Crowson Motion Actuator
Video : Sony VPL-HW55ES, Stewart Screen Studiotek 1.3
Source : HTPC
Fully automated HT via Alexa, Z-wave and Logitech Harmony Remote Control

 

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