Pehle jab home recording mainstream bani…
Yeh ek saral karan ke liye hua:
Dashkon pehle ka analog gear dheere, par zaroor hi badla ja raha tha…
Audio interfaces aur dusre digital gear ki ek nayi pidhi dwara jo pehle se jyada saste, aur asaani se prayog kiye ja sakte the.
Aur yeh trend tab se chal raha hai.
Aaj…digital audio ek standard hai lagbhag sabhi studios mein, dono pro aur amateur.
Phir bhi aashcharya janak bahut kam log samajhte hain ki yeh kis baare mein hai.
Toh aaj ki post mein, maine aapke liye ek comprehensive parichay taiyaar kiya hai Music Recording ke liye Digital Audio ka.
Yahan dekhiye 9 vishay jinhe hum cover karenge:
- Digital Yug ka Uday
- Digital Converters ka Vivaran
- Sample Rate
- Bit Depth
- Quantization Error
- Dither
- Latency
- Master Clocks
- Mp3 Encoding
Shuru karte hai…
1. Digital Yug ka Uday
Jabki digital audio sangeet mein ek standard hai aajkal…
Aisa hamesha se nahi tha.
Shuruaat mein, sangeet sambandhi jaankaari sirf sound waves (yaani, dhvani ki tarang) ki tarah rehti thi hava mein.
Par jaise jaise takhneek aage badhti gayi log inhe dusre formats mein convert karne ki khoj karte rahe, jinmein shaamil:
- notes ek page par
- electrical signals ek cable mein
- radio waves vatavaran mein
- bumps ek vinyl record par
Par aakhirkar, computers ke vikaas ke saath, digital audio sangeet recording ke liye ek pramukh saadhan ban gaya kyunki isne ijaazat di gaano ko asaani se copy aur transport karne ki, muft mein.
Aur jo yantra iss takhneek ko mumkin banata hai woh hai…digital converter.
Yeh kaise kaam karta hai, yeh samajhne ke liye, aage hai…
2. Digital Converters ka Vivaran
Recording studios mein, digital converters do roopon mein maujood hote hai:
- Ek stand-alone device ki tarah high-end studios mein, ya phir…
- Audio interface ke hisse ki tarah home studios mein.
Audio ko binary code mein convert karne ke liye, woh hazaaron-lakhon snapshots (samples) lete hai har second, analog waveform ki ek “anumaanit” tasveer banane ke liye.
Tasveer sateek nahi hoti, kyunki samples ke palon ke beech mein, converter ko andaaza lagana padta hai ki kya chal raha hai.
Jaisa ki aap iss upar ke diagram mein dekh sakte hai, jahan:
- laal line analog signal hai, aur…
- kaali line conversion ki hai…
Parinaam perfect nahi, par yeh kaafi hai shaandaar sound quality dene ke liye.
Yeh kitne shaandaar hai, yeh jyadatar nirbhar karta hai….
3. Sample Rate
Iss tasveer par nazar daliye:
Jaisa ki aap dekh sakte hai…
Har second jyada snapshots lene se, higher sample rates se:
- Jyada asli jaankaari milti hai,
- Kam anumaan lagana padta hai,
- Ek kaafi sateek tasveer bana sakta hai analog signal ki
Antim parinaam, bina koi shaq…behter sound quality hai.
Ab kuch khaas aankdo ki baat karte hai:
Pro audio ke aam sample rates mein shaamil:
- 44.1 kHz (CD Audio)
- 48 kHz
- 88.2 kHz
- 96 kHz
- 192 kHz
44.1 kHz kam se kam hai ek mathematical siddhant ki wajah se, jiska naam hai…
Nyquist-Shannon Sampling Theorum
Digital audio ko sahi record karne ke liye, converters ko manushya ke sunne ki kshamta ke poore spectrum ko pakadna hoga, jo 20Hz se – 20kHz ke beech mein hai.
Nyquist-Shannon Sampling Theorum ke hisaab se…
Ek khaas frequency pakadne ke liye, kam se kam 2 samples chahiye har cycle ke liye…taaki waveform par dono upar aur neeche ke points maape ja sake.
Jiska matlab hai ki, 20kHz tak ki frequencies ko record karne ke liye 40kHz ya jyada ka sample rate lagega. Aur isiliye CD audio isske bas thoda upar 44.1 kHz par hote hai.
High Sample Rates ki Keemat
Kyunki high sample rate behter sound quality dete hai…munafe muft nahi.
Iss daam mein shaamil:
- Jyada processing load
- Kam track counts
- Bade audio files
Par ek trade-off hamesha hota hai. Pro studios asaani se higher sample rates support kar sakte hai kyunki woh behter gear istemaal karte hai.
Home studios ke liye, jyadatar log payenge ki 48 kHz ki default setting achha kaam kar leti hai.
Ab aage…
4. Bit Depth
Bit depth samajhne ke liye, pehle bits ke baare baat karte hai.
Binary digit ke liye chhota, bit ek single unit hai binary code ka, jiski value 1 ya 0 hoti hai.
Jitne jyada bits istemaal kiye jaate hai, utne jyada combinations mumkin hai. Udhaaran ke liye…
Jaisa ki aap neeche ke diagram se dekh sakte hai, 4 bits kulmilkar 16 combinatons dete hai.
Jab information ko encode karne ke liye istemaal hote hai, inmein se har number ek khaas value par saumpa jaata hai.
Bits ko badhaane se, jitne mumkin values hai woh tezi se badh jaate hai.
- 4 Bits = 16 mumkin values
- 8 Bits = 256 mumkin values
- 16 Bits = 16,536 mumkin values
- 24 Bits = 16,777,215 mumkin values
Digital audio mein bit depth ke saath, audio waveform par har ek value ko ek khaas amplitude saumpa jaata hai.
Jitna jyada bit depth, utne jyada volume increments honge loud aur soft mein…aur utni jyada recording ki dynamic range.
Yaad rakhne ke liye ek achha niyam hai ki: Har ek extra “bit” ke saath, dynamic range 6dB se badhti hai.
Udhaaran ke liye:
- 4 Bits = 24 dB
- 8 Bits = 48 dB
- 16 Bits = 96 dB
- 24 Bits = 144 dB
Aakhirkar iska matlab hai…jitna jyada bit depth utna kam shor…
Kyunki adhik headroom daalne se, useful signal (spectrum ke loud-end par) record kiya ja sakta hai noise floor (spectrum ke soft end par) ke upar.
Ab aage…
5. Quantization Error
Yeh prabhaavshaali sunayi de raha hoga ki ek 24 bit recording lagbhag 17 million values deti hai, hai na?
Yeh phir bhi kam hai anant mumkin values se jo analog signal mein hoti hai.
Toh lagbhag har ek sample ke saath, asli value hoti hai do possible values ke beech mein. Converter ka samadhaan hai ki unhe saraltah round-off ya “quantize” kiya jaye sabse nazdeeki value par.
Parinaamswaroop distortion, jisse quantization error ke naam se jaane jaata hai, recording process ke 2 phases mein hota hai:
- shuruaat mein, A/D conversion ke dauraan
- antt mein, mastering ke dauraan
Mastering ke saath, final track ka sample rate/bit depth conversion par aksar reduce kiya jaata hai uske final digital format (CD mp3 ityaadi mein) ke hisaab se.
Jab aisa hota hai, kuch jaankaari delete aur “re-quantized” ho jaati hai jiske nateeje se awaaz ki aur distortion hoti hai.
Iss samasya ko sambhaalne ke liye, ek asaan samadhaan, jiska naam hai…
6. Dither
Jab 24 bit file ko 16 bit file par reduce kiya jaata hai, dither istemaal hota hai parinaamik distortion ke ek bade hisse ko dhakne ke liye…
“Random noise” ke low-level ko audio signal mein daalkar.
Kyunki audio ke saath iss concept ki kalpana karna mushkil hai, tasveeron ke saath dithering ek mushhoor analogy hai jo istemaal ki jaati hai isse samjhaane ke liye.
Yahan dekhiye yeh kaise kaam karta hai:
Jab ek colour photo ko black and white mein convert kiya jaata hai, ganit anumaan (yaani, mathematical guesswork) lagaya jaata hai yeh tay karne ke liye ki pixel ko kaali pixel ya safed pixel mein “quantized” kiya jaaye…
…Waise hi digital audio samples ko quantize kiya jaata hai.
Jaisa ki aap neeche ki di gayi “before” tasveer se dekh sakte hai, kaafi kharaab dikh rahi hai, hai na?
Par dither ke saath…
- kuch safed pixels kaali kshetron mein badle jaate hain…
- kuch kaale pixels safed kshetron mein badle jaate hain…
Aur isko “random noise” mein daal kar, “after” ki tasveer kaafi achhi dikhti hai. Audio dithering ke saath yeh concept ek samaan hai.
Ab aage…
7. Latency
Digital studios ki EK BADI KAMI hai aajkal ki, time-delay (latency) jo signal chain mein jama hoti hai, khaaskar DAW’s ke saath.
Woh saari calculations jo hoti hai, woh kuch milliseconds se kuch DARJAN milliseconds ke beech ho sakti hai audio signal ke system se bahar jaane tak.
- 0-11 ms of delay ke saath – kaafi chhota hai jisse aam aadmi iss par dhyaan bhi nahi dega.
- 11-22 ms ke saath – aap ek slapback effect sunte hai jiski aadat daalne ke liye aapko thoda samay lagega.
- 22 ms+ ke saath – yeh in-time delay namumkin banata hai track sesaath gaane ya bajaane ke liye.
Ek sadhaaran digital signal chain mein, 4 stages hai jo total delay time mein judti hai:
- A/D Conversion
- DAW Buffering
- Plugin Delay
- D/A Conversion
A/D aur D/A conversion sabse chhote apraadhi hai, jo 5 ms se kam total delay dete hai.
Jabki…
Aapka DAW buffer, aur kuch plugins (jinmein shaamil “look-ahead” compressors aur virtual instruments) 20, 30 40 ms ya jyada tak jod sakte hai.
Inko ek kam se kam level par rakhne ke liye:
- Saare unaavshyak plugins ko deactivate kare, jab aap record kar rahe ho.
- Apne DAW buffer settings ko theek kare, jo aapka computer sambhaal sake freeze hoye bina.
Jaisa ki aap dekhenge, buffer times samples mein measure ki jaate hain, miliseconds mein NAHI. Aur isse convert karne ke liye:
- Number of samples ko sessions ke sample rate (in kHz) mein divide kare latency time miliseconds mein paane ke liye.
Udhaaran ke liye: 1024 samples ÷ 44.1 kHz = 23 ms
Agar aapko maths karna pasand nahi, toh yeh ek asaan tareeka hai isse yaad rakhne ka, 44.1kHz par:
- 256 samples = 6 ms
- 512 samples = 12 ms
- 1024 samples = 24 ms
JYADATAR kisson mein, yeh kadam latency ko ek sanchaalniya sthar par laate hai…
Par kabhi kabaar, agar aapka gear bahut puraana ya phir bahut sasta hai, yeh aisa NAHI kar sakta.
Uss kisse mein…
Antim Upaay
Kai budget interfaces mein ek “mix” ya “blend” knob hota hai, jo aapko session playback ko jodne ki anumati deta “live signal” ke saath jo record ho raha hai.
Apne live mic/guitar signal ko split kar, uske aadhe ko computer par bhejna record hone ke liye aur aadha seedhe aapke studio headphones par, aap latency se bachte hai signal chain ko poori tarah se taal kar.
Iss takhneek ki kami hai ki…aap live signal ko sunte hai poori tarah se sukha, bina koi effects.
Umeed hai ki, kyunki computers aur tez hote ja rahe hai, isse bhavishya mein koi pareshaani nahi hogi.
Ab aage…
8. Master Clocks
Jab bhi do ya jyada devices digital information ki adla-badli karte hai real-time mein…
Unki internal clocks sync ki jaani chahiye taaki samples aligned rahe…
Unn annoying clicks aur pops se bachane ke liye jo aksar audio mein hote hai.
Inko sync karne ke liye, ek device function karta hai “master” ki tarah, aur dusre “gulaam” ki tarah.
Saral home studios mein, audio interface clock jyadatar default se hoti hai.
Pro studios mein, jinhe premium digital conversion aur complex signal routings ki zaroorat hoti hai…
Ek khaas stand alone-device istemaal hota hai, jisse digital master clock (urf world clock) ke naam se jaana jaata hai. Jaisa ki kai maalik kehte hai, inn high-end clocks ke sound-benefits aapki kalpana se kahin jyada komal hain.
Ab aage…
9. Mp3/AAC Encoding
Aaj ki duniya mein, compressed audio files aam ban gaye hain digital audio mein.
iPods, smartphones aur internet streaming ki seemit storage space ke kaaran, sabhi files chhoti se chhoti honi chahiye.
“Lossy data compression” ka istemaal karke, mp3, AAC, aur dusre aise hi formats audio files ko shrink kar sakte hai unke original size ke 1/10 bhaag par.
Encoding process kaam karta hai manushya ki sunne ki kshamta ke siddhant ka istemaal kar, jisse “auditory masking” kehte hai…
Jisse kai saari musical information delete karna mumkin hota hai, jyadatar sunnewalon ke liye sveekarya quality banaye rakhne ke liye.
Anubhavi audio engineers matbhed sun sakte hai, par aam upbhokta nahi.
Theek-theek kitni information delete hoti hai, woh depend karta hai file ke bitrate par.
High bitrates ke saath, kam information remove ki jaati hai aur jyada detail sanrakshit hoti hai.
Udharaan ke liye, mp3 ke saath:
- 320 kbit/s adhiktam sambhav bit rate hai
- 128 kbit/s kam se kam ki sifarish hai
- 256 kbit/s woh meethi jagah hai jo jyadatar log pasand karte hai
APNE music ke liye ideal format aur bitrate jaane ke liye, hamesha dobara jaanch kare uske antim manzil (iTunes, YouTube, SoundCloud, ityaadi) ki sifarishon par.