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These circuits prevent cross modulation of low frequencies with high frequencies, suppress tape saturation when large signal transients are present, and increase the effective headroom of the cassette tape system. As a result, recordings are cleaner and crisper with a much improved high-frequency response that the cassette medium heretofore lacked. With a good quality tape, the Dolby C response could be flat to 20 kHz at the 0 dB recording level, a previously unattainable result. An A-weighted signal-to-noise ratio of 72 dB (re 3% THD at 400 Hz) with no unwanted "breathing" effects, even on difficult-to-record passages, was possible.
701:
431:. It was much simpler than Dolby A and therefore much less expensive to implement in consumer products. Dolby B recordings are acceptable when played back on equipment that does not possess a Dolby B decoder, such as many inexpensive portable and car cassette players. Without the de-emphasis effect of the decoder, the sound will be perceived as brighter as high frequencies are emphasized, which can be used to offset "dull" high-frequency response in inexpensive equipment. However, Dolby B provides less effective noise reduction than Dolby A, generally by an amount of more than 3 dB.
451:
662:
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585:) in the 2 kHz to 8 kHz region where the ear is highly sensitive and most tape hiss is concentrated. Its noise reduction effect results from the dual-level (consisting of a high-level stage and a low-level stage) staggered action arrangement of series-connected compressors and expanders, with an extension to lower frequencies than with Dolby B. As in Dolby B, a "sliding band" technique (operating frequency varies with signal level) helps to suppress undesirable
566:
308:, receive no signal modification at all. Between the two limits, a varying level of pre-emphasis is applied. On playback, the opposite process is applied (de-emphasis), based on the relative signal component above 1 kHz. Thus, as this portion of the signal decreases in amplitude, the higher frequencies are progressively increasingly attenuated, which also reduces in level the constant background noise on the tape when and where it would be most noticeable.
531:
398:
390:
284:. The signal-to-noise ratio is simply how large the music signal is compared to the low level of tape noise with no signal. When the music is loud, the low background hiss level is not noticeable, but when the music is soft or in silence, most or all of what can be heard is the noise. If the recording level is adjusted so that the music is always loud, then the low-level noise would not be audible.
40:
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the same amount on playback so that the signal returns to the original volume levels. When the volume is reduced on playback, the noise level is reduced by the same amount. This basic concept, increasing the volume to overwhelm inherent noise, is known as pre-emphasis, and is found in a number of products.
592:
As a result of the extra signal processing, Dolby C-type recordings will sound distorted when played back on equipment that does not have the required Dolby C decoding circuitry. Some of this harshness can be mitigated by using Dolby B on playback, which serves to reduce the strength of the
479:
system, used in place of Dolby B on earlier JVC cassette decks, is considered compatible with Dolby B. JVC eventually abandoned the ANRS standard in favor of official Dolby B support; some JVC decks exist whose noise-reduction toggles have a combined "ANRS / Dolby B" setting.
287:
One cannot simply increase the volume of the recording to achieve this end; tapes have a maximum volume they can record, so already-loud sounds will become distorted. The idea is to increase the volume of the recording only when the original material is not already loud, and then reduce the volume by
685:
Dolby S is much more resistant to playback problems caused by noise from the tape transport mechanism than Dolby C. Likewise, Dolby S was also claimed to have playback compatibility with Dolby B in that a Dolby S recording could be played back on older Dolby B equipment
596:
With Dolby C-type processing, noise reduction begins two octaves lower in frequency in an attempt to maintain a psychoacoustically-uniform noise floor. In the region above 8 kHz, where the ear is less sensitive to noise, special spectral-skewing and anti-saturation networks come into play.
461:
Prior to the introduction of later consumer variants (Dolby C being the first), cassette hardware supporting Dolby B and cassettes encoded with it would be labeled simply "Dolby System," "Dolby NR", or wordlessly with the Dolby symbol. This continued in some record labels and hardware
434:
The Dolby B system is effective from approximately 1 kHz upwards; the noise reduction that is provided is 3 dB at 600 Hz, 6 dB at 1.2 kHz, 8 dB at 2.4 kHz, and 10 dB at 5 kHz. The width of the noise reduction band is variable, as it is designed to be
373:
As with the Dolby B-type system, correct matching of the compression and expansion processes is important. The calibration of the expansion (decoding) unit for magnetic tape uses a flux level of 185 nWb/m, which is the level used on industry calibration tapes such as those from Ampex; this
369:
circuit has a threshold of −40 dB, with a ratio of 2:1 for a compression/expansion of 10 dB. This provides about 10 dB of noise reduction increasing to a possible 15 dB at 15 kHz, according to articles written by Ray Dolby and published by the Audio
Engineering Society
311:
The two processes (pre- and de-emphasis) are intended to cancel each other out as far as the actual recorded program material is concerned. During playback, only de-emphasis is applied to the incoming off-tape signal and noise. After playback de-emphasis is complete, the apparent noise in the output
744:
HX-Pro only applies during the recording process. The improved signal-to-noise ratio is available no matter which tape deck the tape is played back on, and therefore HX-Pro is not a noise-reduction system in the same way as Dolby A, B, C, and S, although it does help to improve noise reduction
327:
On some high-end consumer equipment, a Dolby calibration control is included. For recording, a reference tone at Dolby Level may be recorded for accurate playback level calibration on another transport. At playback, the same recorded tone should produce the identical output, as indicated by a Dolby
740:
continued work in the same direction, which resulted in a 1981 patent (EP 0046410) by Jørgen Selmer Jensen. Bang & Olufsen immediately licensed HX-Pro to Dolby
Laboratories, stipulating a priority period of several years for use in consumer products, to protect their own Beocord 9000 cassette
630:
The Dolby SR (Spectral
Recording) system, introduced in 1986, was the company's second professional noise reduction system. It is a much more aggressive noise reduction approach than Dolby A. It attempts to maximize the recorded signal at all times using a complex series of filters that
374:
is set to 0 VU on the tape recorder playback and to Dolby Level on the noise reduction unit. In the record (compression or encoding) mode, a characteristic tone (Dolby Tone) generated inside the noise reduction unit is set to 0 VU on the tape recorder and to 185 nWb/m on the tape.
213:
When recording a signal on magnetic tape, there is a low level of noise in the background which sounds like hissing. One solution to this issue is to use low-noise tape, which records more signal, and less noise. Other solutions are to run the tape at a higher speed or use a wider tape. Cassette
296:
to certain frequencies, the total amount of distortion of the original signal can be reduced and focused only on the problematic frequencies. The differences in the various Dolby products are largely evident in the precise set of frequencies that they use and the amount of modification of the
332:, and calibration tapes were available to assist with the task of correct level setting. For accurate off-the-tape monitoring during recording on 3-head tape decks, both processes must be employed at once, and circuitry provided to accomplish this is marketed under the "Double Dolby" label.
291:
On top of this basic concept, Dolby noise reduction systems add another improvement. This takes into account the fact that tape noise is largely heard at frequencies above 1,000 Hz. It is the lower-frequency sounds that are often loud, like drum beats, so by only applying the
631:
change according to the input signal. As a result, Dolby SR is much more expensive to implement than Dolby B or C, but Dolby SR is capable of providing up to 25 dB of noise reduction in the high-frequency range. It is only found on professional recording equipment.
686:
with some benefit being realized. It is basically a cut-down version of Dolby SR and uses many of the same noise reduction techniques. Dolby S is capable of 10 dB of noise reduction at low frequencies and up to 24 dB of noise reduction at high frequencies.
315:
The correct calibration of the recording and playback circuitry is critical in order to ensure faithful reproduction of the original program content. The calibration can easily be upset by poor-quality tape, dirty or misaligned recording/playback heads, or using inappropriate
496:
started to transmit programs with Dolby NR, and soon some 17 stations broadcast with noise reduction, but by 1974 it was already on the decline. Dolby FM was based on Dolby B, but used a modified 25 μs pre-emphasis time constant and a frequency-selective
721:. To overcome this, a high-frequency signal, known as bias, is mixed in with the recorded signal, which "pushes" the envelope of the signal into the linear region. If the audio signal contains strong high-frequency content (in particular from percussion instruments such as
681:
as the dominant mass market music format. Dolby Labs claimed that most members of the general public could not differentiate between the sound of a CD and a Dolby S encoded cassette. Dolby S mostly appeared on high-end audio equipment and was never widely used.
435:
responsive to both the amplitude and the frequency distribution of the signal. It is thus possible to obtain significant amounts of noise reduction down to quite low frequencies without causing audible modulation of the noise by the signal ("breathing").
167:, which used a relatively noisy tape size and speed. It is common on high-fidelity stereo tape players and recorders to the present day, although Dolby has as of 2016 ceased licensing the technology for new cassette decks. Of the noise reduction systems,
725:), this adds to the constant bias causing magnetic saturation on the tape. Dynamic, or adaptive, biasing automatically reduces the bias signal in the presence of strong high-frequency signals, making it possible to record at a higher signal level.
340:
Dolby A-type noise reduction was the Dolby company's first noise reduction system, presented in 1965. It was intended for use in professional recording studios, where it became commonplace, gaining widespread acceptance at the same time that
1371:
1326:
267:
Encoding characteristics for Dolby B-type and C-type noise reduction systems for a −60 dB input signal level. The decoding curves used in playback are the exact inverse and thus the overall record/replay frequency response is
438:
From the mid-1970s, Dolby B became standard on commercially pre-recorded music cassettes even though some low-end equipment lacked decoding circuitry, although it allows for acceptable playback on such equipment. Most pre-recorded
672:
Dolby S was introduced in 1989. It was intended that Dolby S would become standard on commercial pre-recorded music cassettes in much the same way that Dolby B had in the 1970s, but it came to market when the
312:
signal is reduced, and this process should not produce any other effect noticeable to the listener other than reduced background noise. However, playback without noise reduction produces a noticeably brighter sound.
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The Dolby HX circuitry driven by the industry-standard NEC uPC1297 integrated circuit. It modulates the incoming bias current and injects it into the two channels of the stereo recording head via two ferrite
1378:
1333:
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Dolby B-type noise reduction was developed after Dolby A, and it was introduced in 1968. It consisted of a single sliding band system providing about 9 dB of noise reduction (
492:
broadcasts and some tuners and amplifiers were manufactured with decoding circuitry; there were also some tape recorders with a Dolby B "pass-through" mode. In 1971
577:
Comparison of noise and frequency response characteristics of Dolby B-type and Dolby C-type noise reduction systems, from a
Nakamichi ZX-7 high-performance cassette deck
300:
Within each band, the amount of pre-emphasis applied depends on the original signal volume. For instance, in Dolby B, a low-level signal will be boosted by 10
745:
encode/decode tracking accuracy by reducing tape non-linearity. Some record companies issued HX-Pro pre-recorded cassette tapes during the late 1980s and early 1990s.
741:
tape deck. By the middle of the 1980s the Bang & Olufsen system, marketed through Dolby
Laboratories, became an industry standard under the name of Dolby HX Pro.
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1010:
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1149:
534:
A typical consumer cassette deck from the late 1980s, featuring automatic reverse, electronic transport controls, and Dolby B and C, among other features
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levels/frequency for the tape formulation, as well as tape speed when recording or duplicating. This can manifest itself as muffled-sounding playback, or "
1728:
214:
tapes were originally designed to trade off fidelity for the convenience of recording voice by using a very narrow tape running at a very slow speed of
815:
1395:
1211:
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Dolby C first appeared on higher-end cassette decks in the 1980s. The first commercially available cassette deck with Dolby C was the
616:. Cassette decks with Dolby C also included Dolby B for backward compatibility, and were usually labeled as having "Dolby B-C NR".
403:
845:
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at 9 kHz. (The stacking of contributions from the two high-pass bands allows greater noise reduction in the upper frequencies.) The
700:
401:
Three different music cassettes encoded with Dolby B, showing the various ways in which the use of the system could be indicated.
604:
6150C, which came onto the market around 1981. Dolby C was also used on professional video equipment for the audio tracks of the
1502:
964:"Audio Noise Reduction: Some Practical Aspects – Part 1: Operating principles and details of a professional noise-reduction system"
450:
1713:
1522:
415:
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Noise and frequency response analysis of a
Nakamichi 580M high-performance cassette deck with Dolby B-type noise reduction system
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manufacturers even after Dolby C had been introduced, during the period when the new standard was relatively little-known.
1193:
1115:
634:
In the motion picture industry, as far as it concerns distribution prints of movies, the Dolby A and SR markings refer to
509:
891:
1192:
Prüfung eines modifizierten HIGH COM-Kompanders für den
Einsatz bei der RF-Übertragung im UKW-Hörfunk (Report) (in German).
645:
SR prints are fairly well backward compatible with old Dolby A equipment. The Dolby SR-D marking refers to both analog
1448:(in German). Vol. 36, no. 8. Heidelberg, Germany: Dr. Alfred Hüthig Verlag GmbH. August 1981. pp. 269–271.
638:
which is not just a method of noise reduction, but more importantly encodes two additional audio channels on the standard
736:, was invented in 1979 by Kenneth Gundry of Dolby Laboratories, and was rejected by the industry for its inherent flaws.
1723:
345:
became standard. The input signal is split into frequency bands by four filters with 12 dB per octave slopes, with
328:
logo marking at approximately +3 VU on the VU meter(s). In consumer equipment, Dolby Level is defined as 200
1708:
1515:
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321:
1413:
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256: in/s (9.5 cm/s) was of lower fidelity. As a result of their narrow tracks and slow speed, cassettes make
548:
413:
uses a Dolby logo with "B NR" (also with "HX PRO" to indicate the complementary use of that technology);
581:
The Dolby C-type noise reduction system was developed in 1980. It provides about 15 dB noise reduction (
163:(introduced in 1968), a sliding band system for the consumer market, which helped make high fidelity practical on
1733:
1718:
519:
broadband compander system, but never introduced commercially in FM broadcasting. Another competing system was
870:
1399:
1106:
Mielke, E.-Jürgen (1977). "Einfluß des Dolby-B-Verfahrens auf die Übertragungsqualität im UKW-Hörrundfunk".
769:, but Dolby's analog noise reduction systems are still widely used in niche analog production environments.
823:
765:, music streaming) has made analog audio production less prevalent and therefore changed Dolby's focus on
440:
1094:
1050:
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281:
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noise reduction system for recording studios that was first demonstrated in 1965, but the best-known is
140:
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were recorded directly onto magnetic tape, its reproduction would be extremely distorted due to this
342:
778:
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144:
61:
27:
A line of noise reduction systems for reel-to-reel, compact cassette, and videocassette recorders
228: in/s (4.8 cm/s) housed in a simple plastic shell when 15 in/s (38 cm/s) or
612:
videocassette formats. In Japan, the first cassette deck with Dolby C was the AD-FF5 from
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885:
737:
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346:
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Encoding characteristics of Dolby C-type noise reduction for a range of input signal levels
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1140:(in German). Vol. 38, no. 12. Dr. Alfred Hüthig Verlag GmbH. pp. 494–497 .
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The Dolby A-type system also saw some use as the method of noise reduction in
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89:
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Funk-Technik - Fachzeitschrift für Funk-Elektroniker und Radio-Fernseh-Techniker
906:
505:
273:
1131:"Rundfunk für Europa - Pressekolloqium Rundfunktechnik während der IFA 83"
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198:
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1439:"Hi-Fi-Cassettenrekorder: Bessere Höhenaufzeichnung mit dem Dolby-HX-System"
609:
362:
358:
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317:
257:
154:
113:
17:
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1417:
1372:"Dolby B, C, and S Noise Reduction Systems: Making Cassettes Sound Better"
944:. 33rd Audio Engineering Society Convention, Paper Number 543. Los Angeles
1602:
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1557:
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625:
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A fully Dolby B-compatible compander was developed and used on many
516:
489:
350:
305:
1241:. 70th Audio Engineering Society Convention, Paper Number 1850. New York
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Dolby S tape deck, released 1991 and also incorporating HX Pro
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781:(DNR), a playback-only noise reduction system often confused with Dolby
605:
301:
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original signal volume that is applied to each of the frequency bands.
1446:
1507:
1261:"A 20 dB Audio Noise Reduction System for Consumer Applications"
488:
In the early 1970s, some expected Dolby NR to become normal in
39:
1235:
A 20 dB Audio Noise
Reduction System for Consumer Applications
1538:
699:
589:, which is often a problem with other noise reduction techniques.
564:
529:
449:
388:
242: in/s (19 cm/s) tape speeds were for high fidelity, and
1503:
Overview of Dolby and other noise reduction systems, Richard Hess
474:
447:
video recorders used Dolby B on linear stereo audio tracks.
205:
of the sound during recording, and expanding it during playback.
871:"Dolby Laboratories Awarded International Honour for Excellence"
613:
508:
was evaluated in
Germany between July 1979 and December 1981 by
493:
469:
1511:
324:" of the noise level as the volume level of the signal varies.
465:
444:
457:
tape recorder with Dolby noise-reduction system (ca. 1972)
280:
used during playback, which work in tandem to improve the
1038:. Audio Engineering Society Convention. Cologne, Germany.
123:
1485:
709:
Magnetic tape is inherently non-linear in nature due to
846:"A Chronology of Dolby Laboratories: May 1965–May 1998"
147:
for use in analog audio tape recording. The first was
1036:
A noise reduction system for consumer tape recording
512:, and field-trialed up to 1984. It was based on the
1680:
1664:
1636:
1545:
119:
109:
101:
85:
77:
67:
57:
49:
276:employed during recording, plus a form of dynamic
193:were designed for the consumer market. Aside from
761:and consumer applications (e.g., compact discs,
304:, while signals at the "Dolby Level", +3
1523:
8:
1000:"Audio Noise Reduction: Part 2 (Conclusion)"
642:, giving left, center, right, and surround.
552:
32:
1398:(in Danish). jollyjokers.dk. Archived from
809:
807:
370:(October 1967) and Audio (June/July 1968).
272:Dolby noise reduction is a form of dynamic
1530:
1516:
1508:
1492:Some Not Well Known Aspects of Analog Tape
1416:(in Danish). Datamuseum.dk. Archived from
1196:(IRT). 1981-12-30. Technical Report 55/81.
38:
31:
1265:Journal of the Audio Engineering Society
911:Journal of the Audio Engineering Society
660:
572:
396:
262:
803:
44:Dolby 361 A-type noise reduction module
883:
557:, English: "Noise reduction system").
551:in the 1980s. It was called RMS (from
419:uses a Dolby logo with "Dolby System."
1598:Dolby Surround/Pro Logic/Pro Logic II
1095:Popular Science, February 1974, p. 50
177:were developed for professional use.
7:
1498:, AES 1990 March, Arndt Klingelnberg
1327:"Dolby SR: Dolby Spectral Recording"
349:(3 dB down points) as follows:
194:
25:
1729:Audiovisual introductions in 1965
1414:"B&O/Beocord 9000 - DDHFwiki"
1070:Gilmore, C. P. (September 1971).
907:"An Audio Noise Reduction System"
357:from 80 Hz to 3 kHz; a
197:, all the Dolby variants work by
753:The widespread proliferation of
713:of the magnetic material. If an
1463:from the original on 2021-07-10
1307:from the original on 2022-10-09
1214:from the original on 2021-05-09
1155:from the original on 2021-04-25
1129:Reuber, Claus (December 1983).
1108:Rundfunktechnische Mitteilungen
1034:Dolby, Ray (16–18 March 1971).
1016:from the original on 2022-10-09
980:from the original on 2022-10-09
938:An Audio Noise Reduction System
1291:"Dolby C-Type Noise Reduction"
1:
728:The original Dolby HX, where
501:arrangement to reduce noise.
361:from 3 kHz; and another
173:
1593:Dolby noise-reduction system
1194:Institut für Rundfunktechnik
1116:Institut für Rundfunktechnik
869:Foster, Alana (2017-09-06).
814:White, Paul (January 1996).
189:
183:
159:
149:
133:Dolby noise-reduction system
33:Dolby noise-reduction system
1370:Dolby Laboratories (2004).
1325:Dolby Laboratories (1987).
998:Dolby, Ray M. (July 1968).
962:Dolby, Ray M. (June 1968).
935:Dolby, Ray (October 1967).
905:Dolby, Ray (October 1967).
1750:
1049:Woram, John (1976-12-04).
890:: CS1 maint: url-status (
693:
677:was being replaced by the
653:soundtracks on one print.
623:
549:German Democratic Republic
427:), primarily for use with
407:uses a simple Dolby logo;
404:You Don't Bring Me Flowers
1546:Technologies and products
1444:. Produkt-Informationen.
1289:Hull, Joseph (May 1981).
1259:Dolby, Ray (March 1983).
1051:"Update: Noise Reduction"
37:
1486:Dolby Laboratories, Inc.
1173:Schröder, Ernst F.
1136:. Systeme und Konzepte.
139:, is one of a series of
1714:Noise reduction systems
1175:"The Story of HIGH COM"
779:Dynamic Noise Reduction
504:A similar system named
260:a very severe problem.
1396:"Jørgen Selmer Jensen"
1351:"Harman Kardon TD4800"
816:"Tape Noise Reduction"
706:
669:
578:
570:
554:Rauschminderungssystem
553:
535:
458:
420:
394:
269:
124:Dolby official website
1090:Free, John R. (1974)
785:dbx (noise reduction)
703:
694:Further information:
664:
576:
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533:
523:, which was based on
453:
400:
392:
381:for motion pictures.
282:signal-to-noise ratio
266:
143:systems developed by
844:Dolby Laboratories.
793:, a competing system
787:, a competing system
343:multitrack recording
1724:American inventions
1232:Dolby, Ray (1981).
201:: compressing the
34:
1709:Dolby Laboratories
1613:Dolby Surround 7.1
1578:Dolby Digital Plus
1539:Dolby Laboratories
738:Bang & Olufsen
734:Headroom eXtension
707:
670:
640:optical soundtrack
593:high frequencies.
579:
571:
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459:
455:Advent Corporation
443:use this variant.
421:
395:
347:cutoff frequencies
270:
145:Dolby Laboratories
62:Dolby Laboratories
1696:
1695:
1072:"Look and Listen"
153:, a professional
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16:(Redirected from
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851:. Archived from
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696:Adaptive biasing
675:Compact Cassette
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1118:(IRT): 222–228.
1105:
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1100:
1092:Look and Listen
1089:
1085:
1077:Popular Science
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698:
692:
690:Dolby HX/HX-Pro
659:
628:
622:
563:
541:
486:
472:
387:
353:at 80 Hz;
338:
252:
248:
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141:noise reduction
110:Previous owners
93:
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1494:-- concerning
1488:
1481:
1480:External links
1478:
1475:
1474:
1430:
1405:
1402:on 2013-09-14.
1387:
1384:on 2012-10-21.
1362:
1342:
1339:on 2012-10-02.
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1181:on 2016-04-16.
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858:on 2024-04-23.
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820:Sound On Sound
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782:
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763:music download
750:
747:
723:hi-hat cymbals
691:
688:
658:
655:
636:Dolby Surround
624:Main article:
621:
618:
562:
559:
547:in the former
545:tape recorders
540:
537:
485:
482:
429:cassette tapes
386:
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337:
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210:
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165:cassette tapes
127:
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97:(1986-present)
92:(1976-present)
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71:United Kingdom
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1688:Dolby Theatre
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1573:Dolby Digital
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1420:on 2021-08-04
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1210:(in German).
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1059:. p. 30.
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973:: 19–22, 55.
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826:on 2016-06-04
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755:digital audio
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719:non-linearity
716:
715:analog signal
712:
705:transformers.
702:
697:
689:
687:
683:
680:
676:
667:
666:Harman/Kardon
663:
656:
654:
652:
651:Dolby Digital
648:
647:Dolby SR
643:
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619:
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416:Tour De Force
412:
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208:
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204:
203:dynamic range
200:
196:
195:Dolby HX
192:
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174:Dolby SR
170:
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137:Dolby NR
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73:United States
70:
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36:
30:
19:
1623:Dolby Vision
1618:Dolby TrueHD
1608:Dolby Stereo
1592:
1568:Dolby Cinema
1495:
1491:
1465:. Retrieved
1445:
1433:
1422:. Retrieved
1418:the original
1408:
1400:the original
1390:
1379:the original
1365:
1354:. Retrieved
1345:
1334:the original
1320:
1309:. Retrieved
1297:
1284:
1273:. Retrieved
1268:
1264:
1254:
1243:. Retrieved
1234:
1227:
1216:. Retrieved
1202:
1187:
1179:the original
1168:
1157:. Retrieved
1137:
1124:
1111:
1107:
1101:
1091:
1086:
1075:
1065:
1054:
1044:
1035:
1029:
1018:. Retrieved
1006:
993:
982:. Retrieved
970:
957:
946:. Retrieved
937:
930:
919:. Retrieved
917:(4): 383–388
914:
910:
900:
875:. Retrieved
864:
853:the original
839:
828:. Retrieved
824:the original
819:
767:Dolby Vision
759:professional
752:
743:
733:
729:
727:
708:
684:
679:compact disc
671:
649:and digital
644:
633:
629:
599:
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433:
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376:
372:
339:
326:
314:
310:
299:
290:
286:
274:pre-emphasis
271:
212:
188:
182:
179:Dolby B
178:
172:
169:Dolby A
168:
160:Dolby B
158:
150:Dolby A
148:
136:
132:
130:
90:Dolby Stereo
50:Product type
29:
18:Dolby HX Pro
1638:Doremi Labs
1628:Dolby Voice
1553:Dolby Atmos
1271:(3): 98–113
732:stands for
506:High Com FM
473: [
278:de-emphasis
1703:Categories
1656:CinePlayer
1651:CineExport
1467:2021-07-10
1424:2020-11-09
1356:2023-09-02
1311:2020-11-11
1275:2023-08-27
1245:2023-08-27
1218:2021-05-09
1159:2021-04-25
1020:2020-11-09
984:2020-11-09
948:2020-11-09
921:2023-09-02
877:2024-09-09
830:2023-09-02
798:References
711:hysteresis
583:A-weighted
514:Telefunken
499:companding
425:A-weighted
294:companding
199:companding
78:Introduced
1672:Ray Dolby
1646:CineAsset
1472:(3 pages)
1454:0016-2825
1300:: 20–25.
1146:0016-2825
1056:Billboard
1009:: 26–30.
610:Umatic SP
587:breathing
441:cassettes
367:compander
363:high-pass
359:high-pass
355:band-pass
322:breathing
258:tape hiss
155:broadband
114:Ray Dolby
105:Worldwide
1603:Dolby SR
1563:Dolby 3D
1558:Dialnorm
1458:Archived
1302:Archived
1212:Archived
1208:"SK 900"
1150:Archived
1011:Archived
975:Archived
886:cite web
791:High Com
773:See also
626:Dolby SR
620:Dolby SR
517:High Com
490:FM radio
484:Dolby FM
410:Apurimac
351:low-pass
1583:Dolby E
657:Dolby S
606:Betacam
561:Dolby C
385:Dolby B
336:Dolby A
251:⁄
237:⁄
223:⁄
209:Process
120:Website
102:Markets
68:Country
1665:People
1452:
1144:
187:, and
1681:Other
1461:(PDF)
1442:(PDF)
1382:(PDF)
1375:(PDF)
1337:(PDF)
1330:(PDF)
1305:(PDF)
1298:Audio
1294:(PDF)
1239:(PDF)
1153:(PDF)
1134:(PDF)
1080:: 38.
1014:(PDF)
1007:Audio
1003:(PDF)
978:(PDF)
971:Audio
967:(PDF)
942:(PDF)
873:. IBC
856:(PDF)
849:(PDF)
749:Today
477:]
330:nWb/m
135:, or
58:Owner
1450:ISSN
1142:ISSN
892:link
614:Aiwa
608:and
494:WFMT
470:ANRS
318:bias
268:flat
171:and
81:1965
757:in
602:NAD
539:RMS
521:FMX
510:IRT
468:'s
466:JVC
445:VHS
1705::
1456:.
1296:.
1269:31
1267:.
1263:.
1148:.
1114:.
1112:21
1074:.
1053:.
1005:.
969:.
915:15
913:.
909:.
888:}}
884:{{
818:.
806:^
730:HX
527:.
525:CX
475:ja
306:VU
302:dB
181:,
131:A
1531:e
1524:t
1517:v
1470:.
1427:.
1359:.
1314:.
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1162:.
1023:.
987:.
951:.
924:.
894:)
880:.
833:.
253:4
249:3
246:+
244:3
239:2
235:1
232:+
230:7
225:8
221:7
218:+
216:1
190:S
184:C
20:)
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