Ƙirƙirar Kiɗa. Jagora - Part 2

Na rubuta game da gaskiyar cewa ƙwarewa a cikin tsarin samar da kiɗa shine mataki na ƙarshe akan hanya daga ra'ayin kiɗa zuwa bayarwa ga mai karɓa a cikin fitowar da ta gabata. Mun kuma yi nazari sosai kan rikodin sauti na dijital, amma har yanzu ban tattauna yadda wannan sautin, wanda aka canza zuwa masu sauya wutar lantarki ta AC, ke jujjuya su zuwa nau'in binary ba.

1. Kowane hadadden sauti, ko da maɗaukakin maɗaukaki, haƙiƙa ya ƙunshi sautunan sinusoidal masu sauƙi.

Na ƙare labarin da ya gabata tare da tambaya, ta yaya zai yiwu cewa a cikin irin wannan igiyar da ba ta da tushe (1) duk abubuwan da ke cikin kiɗa suna ɓoye, koda kuwa muna magana ne game da kayan kida da yawa suna kunna sassan polyphonic? Ga amsar: wannan ya faru ne saboda gaskiyar cewa duk wani sauti mai rikitarwa, har ma da rikitarwa, yana da gaske ya ƙunshi yawancin sautunan sinusoidal masu sauƙi.

Halin sinusoidal na waɗannan nau'ikan raƙuman ruwa masu sauƙi ya bambanta da lokaci da girma, waɗannan nau'ikan igiyoyin suna haɗuwa, ƙarawa, ragi, daidaitawa juna, don haka da farko an ƙirƙiri sauti na kayan kida guda ɗaya, sa'an nan kuma cikakkiyar haɗuwa da rikodin.

Abin da muke gani a cikin adadi na 2 wasu nau'ikan zarra ne, kwayoyin halitta waɗanda suka haɗa da sautin sautinmu, amma a cikin siginar analog ɗin babu irin waɗannan ƙwayoyin cuta - akwai madaidaicin layi ɗaya, ba tare da ɗigo ba suna yin alamar karatun na gaba (bambancin ana iya gani a ciki). adadi a matsayin matakai, waɗanda aka ƙididdige su ta hanyar hoto don samun tasirin gani daidai).

Koyaya, tunda sake kunna kiɗan da aka yi rikodi daga majiyoyin analog ko dijital dole ne a yi ta amfani da injin lantarki na lantarki kamar lasifika ko transducer lasifikan kai, mafi yawan bambanci tsakanin tsantsar sauti na analog da na'urar sarrafa sauti ta lambobi. A mataki na ƙarshe, i.e. lokacin saurare, kiɗan yana isa gare mu kamar yadda girgizar barbashi na iska ke haifar da motsin diaphragm a cikin transducer.

2. Molecules da ke haɗa sautin mu

analog digit

Shin akwai wani bambance-bambancen da ake iya ji tsakanin sautin analog mai tsafta (watau analog rikodin akan na'urar rikodin analog, gauraye akan na'urar wasan bidiyo na analog, an matsa akan fayafai na analog, kunna baya akan na'urar analog da haɓakar amplifier analog) da sautin dijital - tuba daga Analog zuwa dijital, sarrafawa da gauraye ta hanyar dijital sannan a mayar da shi zuwa nau'in analog, shin a gaban amp ne ko a zahiri a cikin lasifikar da kanta?

A mafi yawancin lokuta, maimakon haka, ko da yake idan muka yi rikodin kayan kiɗa iri ɗaya ta hanyoyi biyu sannan muka sake kunna su, bambance-bambancen za su kasance a ji. Koyaya, wannan zai kasance saboda yanayin kayan aikin da ake amfani da su a cikin waɗannan hanyoyin, halayensu, kaddarorinsu, da iyakancewa sau da yawa, fiye da ainihin gaskiyar amfani da fasahar analog ko dijital.

A lokaci guda, muna ɗauka cewa kawo sauti zuwa nau'i na dijital, watau. a zahiri atomized, ba ya yin tasiri sosai akan tsarin rikodin da sarrafa kansa, musamman tunda waɗannan samfuran suna faruwa a mitar wanda - aƙalla a ƙayyadaddun ƙa'idar - ya wuce iyakar mitocin da muke ji, sabili da haka wannan ƙayyadaddun ƙwayar sautin ya canza. zuwa nau'i na dijital, ba a ganuwa a gare mu. Duk da haka, daga ra'ayi na sarrafa kayan sauti, yana da mahimmanci, kuma za mu yi magana game da shi daga baya.

Yanzu bari mu gano yadda ake juyar da siginar analog zuwa nau'in dijital, wato sifili-daya, watau. daya inda wutar lantarki ke iya samun matakai biyu kacal: na dijital matakin daya, wanda ke nufin karfin wuta, da matakin sifiri na dijital, watau. wannan tashin hankali a zahiri babu shi. Duk abin da ke cikin duniyar dijital ko dai ɗaya ne ko sifili, babu matsakaicin ƙima. Tabbas, akwai kuma abin da ake kira ma'ana mai ban mamaki, inda har yanzu akwai tsaka-tsaki tsakanin jihohin "kunna" ko "kashe", amma bai dace da tsarin sauti na dijital ba.

3. Jijjiga barbashi na iska wanda tushen sauti ya haifar da wani tsari mai haske na membrane.

Canje-canje Kashi Na Daya

Duk wani siginar sauti, ya kasance na murya, gita mai sauti ko ganguna, ana aika shi zuwa kwamfuta ta hanyar dijital, dole ne a fara canza shi zuwa siginar wutar lantarki. Yawancin lokaci ana yin hakan ne da makirufo inda girgizar barbashin iska da tushen sauti ke haifar da tsarin diaphragm mai haske (3). Wannan na iya zama diaphragm da aka haɗa a cikin kwandon kwandon shara, bandeji na ƙarfe a cikin makirufo kintinkiri, ko diaphragm mai nada da ke haɗe da shi a cikin makirufo mai ƙarfi.

A cikin kowane daga cikin wadannan lokuta siginar lantarki mai rauni mai rauni yana bayyana a fitowar makirufowanda zuwa babba ko žasa yana kiyaye ma'auni na mitar da matakin daidai da sigogi iri ɗaya na barbashi na iska. Don haka, wannan wani nau'i ne na kwatankwacinsa na lantarki, wanda za'a iya ƙara sarrafa shi a cikin na'urori masu sarrafa siginar wutar lantarki.

Da farko Dole ne a ƙara siginar makirufosaboda yana da rauni da yawa ba za a iya amfani da shi ta kowace hanya ba. Matsakaicin ƙarfin fitarwa na makirufo yana cikin tsari na dubunnan volt, wanda aka bayyana a cikin millivolts, kuma sau da yawa a cikin microvolts ko miliyoyi na volt. Don kwatanta, bari mu ƙara da cewa baturi mai nau'in yatsa na al'ada yana samar da ƙarfin lantarki na 1,5 V, kuma wannan shi ne akai-akai wanda ba zai iya daidaitawa ba, wanda ke nufin ba ya watsa duk wani bayanin sauti.

Koyaya, ana buƙatar wutar lantarki ta DC a cikin kowane tsarin lantarki don zama tushen makamashi, wanda zai canza siginar AC. Mafi tsabta kuma mafi inganci wannan makamashi shine, ƙasa da nauyin nauyi na yau da kullun da damuwa, tsabtace siginar AC da kayan aikin lantarki zai kasance. Shi ya sa wutar lantarki, wato wutar lantarki, ke da muhimmanci a kowane tsarin sauti na analog.

4. Makirifo amplifier, kuma aka sani da preamplifier ko preamplifier

Makirifo amplifiers, kuma aka sani da preamplifiers ko preamplifiers, an ƙera su don ƙara siginar daga microphones (4). Ayyukan su shine ƙara siginar, sau da yawa har ma da yawa na decibels, wanda ke nufin ƙara darajar su da ɗaruruwa ko fiye. Don haka, a wurin fitar da na'urar tantancewa, muna samun canjin wutar lantarki wanda ya yi daidai da ƙarfin shigarwar kai tsaye, amma ya wuce shi da ɗaruruwan lokuta, watau. a matakin daga juzu'i zuwa raka'a na volts. An ƙaddara wannan matakin siginar matakin layi kuma wannan shine daidaitaccen matakin aiki a cikin na'urorin sauti.

Canji kashi na biyu

Ana iya riga an wuce siginar analog na wannan matakin tsarin digitization. Ana yin wannan ta amfani da kayan aikin da ake kira analolo-to-dijital converters ko transducers (5). Tsarin juyawa a cikin yanayin PCM na al'ada, i.e. Modulation na Pulse Width Modulation, a halin yanzu mafi shaharar yanayin sarrafawa, an ayyana shi ta sigogi biyu: ƙimar samfurin da zurfin bit. Kamar yadda kuke zargin daidai, mafi girman waɗannan sigogi, mafi kyawun jujjuyawa kuma mafi daidaiton siginar za a ciyar da ita zuwa kwamfuta ta hanyar dijital.

5. Mai jujjuyawa ko mai jujjuyawa-zuwa-dijital.

Gabaɗaya doka don irin wannan juyi samfuri, wato, ɗaukar samfurori na kayan analog da ƙirƙirar wakilcin dijital. Anan, ana fassara ƙimar ƙarfin lantarki nan take a cikin siginar analog kuma ana wakilta matakinsa a lambobi a tsarin binary (6).

Anan, duk da haka, ya zama dole a ɗan tuno mahimman abubuwan ilimin lissafi, gwargwadon abin da kowane ƙimar ƙima za a iya wakilta a ciki. kowane tsarin lamba. A cikin tarihin ɗan adam, ana amfani da tsarin lambobi daban-daban kuma har yanzu ana amfani da su. Misali, ra'ayoyi irin su dozin ( guda 12) ko dinari (dozin 12, guda 144) sun dogara ne akan tsarin duodecimal.

6. Ƙimar wutar lantarki a cikin siginar analog da wakilcin matakinsa a cikin nau'i na dijital a cikin tsarin binary

Don lokaci, muna amfani da tsarin gauraye - sexagesimal na daƙiƙa, mintuna da sa'o'i, ƙayyadaddun duodecimal na kwanaki da kwanaki, tsarin bakwai don kwanakin mako, tsarin quad (wanda ke da alaƙa da tsarin duodecimal da tsarin sexagesimal) na makonni a cikin wata guda, tsarin duodecimal. don nuna watanni na shekara, sa'an nan kuma mu matsa zuwa tsarin decimal, inda shekarun da suka gabata, ƙarni da millennia suka bayyana. Ina tsammanin misalin yin amfani da tsarin daban-daban don bayyana tafiyar lokaci da kyau yana nuna yanayin tsarin lambobi kuma zai ba ku damar bincika abubuwan da suka shafi juyawa yadda ya kamata.

A cikin yanayin analog zuwa jujjuyawar dijital, za mu zama mafi yawan jama'a canza ƙimar decimal zuwa ƙimar binary. Decimal saboda ma'aunin kowane samfurin yawanci ana bayyana shi a cikin microvolts, millivolts da volts. Sa'an nan wannan darajar za a bayyana a cikin tsarin binary, watau. ta yin amfani da rago biyu aiki a cikinsa - 0 da 1, wanda ke nuna jihohi biyu: babu wutar lantarki ko kasancewarsa, kashe ko kunnawa, halin yanzu ko a'a, da dai sauransu. Don haka, muna guje wa murdiya, kuma duk ayyuka sun zama mafi sauƙi a aiwatarwa ta hanyar aikace-aikacen. abin da ake kira canjin algorithms wanda muke hulɗa da su, alal misali, dangane da masu haɗawa ko wasu na'urori masu sarrafawa na dijital.

Kai sifili ne; ko daya

Da waɗannan lambobi biyu, sifili da ɗaya, zaku iya bayyanawa kowane ƙima na lambakomai girmansa. A matsayin misali, la'akari da lamba 10. Maɓalli don fahimtar juzu'in ƙididdiga-zuwa-binary shine cewa lamba 1 a cikin binary, kamar a cikin decimal, ya dogara da matsayinsa a cikin kirtan lamba.

Idan 1 ya kasance a ƙarshen kirtani na binary, to, 1, idan a cikin na biyu daga ƙarshen - to 2, a matsayi na uku - 4, kuma a matsayi na hudu - 8 - duk a cikin decimal. A cikin tsarin decimal, 1 guda ɗaya a ƙarshen shine 10, 100 penultimate, 1000 na uku, XNUMX na huɗu shine misali don fahimtar kwatankwacin.

Don haka, idan muna so mu wakilci 10 a binary form, muna buƙatar wakiltar 1 da 1, don haka kamar yadda na ce, zai zama 1010 a matsayi na huɗu da XNUMX a na biyu, wato XNUMX.

Idan muna buƙatar musanya ƙarfin lantarki daga 1 zuwa 10 volts ba tare da ƙimar juzu'i ba, watau. ta amfani da lamba kawai, mai canzawa wanda zai iya wakiltar jeri 4-bit a cikin binary ya wadatar. 4-bit saboda wannan canjin lambar binary zai buƙaci har zuwa lambobi huɗu. A aikace zai yi kama da haka:

0 0000

1 0001

2 0010

3 0011

4 0100

5 0101

6 0110

7 0111

8 1000

9 1001

10 1010

Waɗanda ke jagorantar sifili don lambobi 1 zuwa 7 kawai suna kunna kirtani zuwa cikakkun ragi huɗu don kowace lambar binary tana da ma'ana iri ɗaya kuma ta ɗauki adadin sarari iri ɗaya. A cikin hoto mai hoto, ana nuna irin wannan fassarar lamba daga tsarin decimal zuwa binary a cikin hoto na 7.

7. Maida Integers a Tsarin Decimal zuwa Tsarin Binary

Dukansu na sama da na ƙasa suna wakiltar dabi'u iri ɗaya, sai dai wanda ake iya fahimta na farko, alal misali, na na'urorin analog, kamar mitoci masu ƙarfin lantarki na layi, da na biyu na na'urorin dijital, gami da kwamfutoci masu sarrafa bayanai akan irin wannan harshe. Wannan nau'in igiyar igiyar ruwa tana kama da madaidaicin-cike murabba'i, watau. daban-daban rabo na matsakaicin dabi'u zuwa mafi ƙarancin ƙima akan lokaci. Wannan abun ciki mai canzawa yana ɓoye ƙimar siginar binary da za a canza, don haka sunan "mosulation code modulation" - PCM.

Yanzu komawa zuwa canza siginar analog na gaske. Mun riga mun san cewa ana iya siffanta shi ta hanyar layin da ke nuna matakan canza salo, kuma babu wani abu kamar wakilcin tsalle na waɗannan matakan. Koyaya, don buƙatun analog zuwa juzu'i na dijital, dole ne mu gabatar da irin wannan tsari don samun damar auna matakin siginar analog daga lokaci zuwa lokaci kuma wakiltar kowane irin ma'aunin da aka auna a cikin sigar dijital.

An ɗauka cewa mitar da za a yi waɗannan ma'aunin ya kamata ya zama akalla sau biyu mafi girman mitar da mutum zai iya ji, kuma tun yana da kusan 20 kHz, saboda haka, mafi girma. 44,1kHz ya kasance sanannen ƙimar samfurin. Ƙididdigar ƙididdiga ta ƙididdigewa yana da alaƙa da ayyuka masu rikitarwa na lissafi, wanda, a wannan mataki na ilimin mu na hanyoyin tuba, ba ya da ma'ana.

Ya fi kyau?

Duk abin da na ambata a sama na iya nuna cewa mafi girman mitar samfur, watau. auna matakin siginar analog a tsaka-tsaki na yau da kullun, mafi girman ingancin juzu'i, saboda shine - aƙalla a cikin ma'anar fahimta - mafi daidai. Shin gaskiya ne? Za mu san game da wannan a cikin wata daya.