Bahlahisi ba bangata ba li-audio ba fana ka mehlala ea li-headphone / earphone ka theknoloji e matla ea ho hlasela (ANC). Tsena ke tse loketseng bakeng sa batho ba mamelang 'mino kapa ba shebellang livideo libakeng tse lerata le / kapa ha ba ntse ba tsamaea. Leha ho le joalo, hase bohle ba ANC ba bōpiloeng ka tsela e tšoanang. Re sheba kamoo Bose QuietComfort 20 (QC-20) e hlahisang li-earphone tsa khanya ea lerata li etsa kateng.
Bose QuietComfort 20 Mehato
Re lekantse tshebetso ea QC-20 re sebelisa GRAS 43AG tsebe / cheek simulator, mohlahlobi oa molumo oa Clio FW, software ea TrueRTA ea k'homphieutha ea laptop e nang le sebopeho sa audio sa M-Audio MobilePre USB, le Musical Fidelity V-Can e hlalosang li-headphone amplifier. (Ka tloaelo ha re sebelise li-earphone tse ngata tsa tsebe / litlhapi ho lekanya li -headphones , empa ka lebaka la litebelisoa tsa silicon tsa QC-20, ha lia ka tsa kena hantle mofuteng oa GRAS RA0045 o tloaelehileng bakeng sa litekanyo tsa ka litsebeng.)
Litekanyo li ne li lekanngoa bakeng sa monyako oa monyako oa monyako (EEP), hoo e ka bang ntlha ea setsi se shoeleng sepakapakeng ha ho buloa kotopo ea tsebe. Re sebelisitse mechine ea clamp ea 43AG ho netefatsa tiiso e ntle ea selefouno ka simulator le phello e tsitsitseng ka kakaretso. Hlokomela hore ka ntle ho ho lekanyetsa ho EEP, ha re sebelise tšimo e fapaneng kapa e meng ea matšeliso. (Lipatlisiso tse ling li 'nile tsa belaella botšepehi ba joalo,' me ho fihlela indasteri e lumellana le litekanyetso tse ntle tse fanoang ke lipatlisiso, re khetha ho bontša data e tala.)
Sensitivity ea QC-20, e lekantsoe ka letšoao la 1 mW ho 32 ohms (e leng mekhahlelo e tloaelehileng ea impedance bakeng sa headphones-amplified amplified joaloka QC-20) ke 104.8 dB, phahameng ho lekaneng ho fumana maemo a holimo mohlomong mohloli leha e le ofe mohloli.
QC-20 Frequency Response
Makhetlo a mangata a araba QC-20 ka letsohong le letšehali (le leputsoa) le le letona (le khubelu), tekanyo ea teko e boletsoeng ho 94 dB @ 500 Hz. Ha ho na tekanyetso ea se boleloang ke "hantle" khafetsa karolong ea li-headphone, 'me kahobane li-psychoacoustics li rarahane ebile libopeho tsa litsebe li fapana, ho lumellana pakeng tsa litekanyo tsa ho arabela ka sepheo le maikutlo a ho mamela ka nako e itseng ha ho hlakehe.
Leha ho le joalo, chate ena e etsa hore u bapise mehlala e nepahetseng. QC-20 e fana ka karabo e fokolang haholo ho feta e mengata-ea litsebe, eo hangata e nang le bump e hlahisoang ke bass ka holimo ho 100 Hz. E boetse e bontša karabo e tsotehang haholoanyane, e nang le matla a mangata pakeng tsa 2 le 10 kHz.
QC-20 Frequency Response, lerata le hlakola le ho tima
Makhetlo a mabeli a arabelloang ke QC-20, mocha o nepahetseng, ka ho hlakola lerata ho (khubelu e khutšoanyane) le ho tima (yellow trace). Joalokaha u ka bona, karabelo e ts'oana hantle ka litsela tse peli. Ena ke sephetho se setle ka ho fetisisa seo re kileng ra se lekanya tlhahlobo ena. Mofuta o mong le o mong oa lerata-ho hlakola li-headphone o lekoa liphetoho tsa oona bonyane hanyenyane ha lerata le hlakola; ka linako tse ling phetoho ea molumo ke e hlollang (le e halefisang).
QC-20 Pheliso ea Lintho
Sebaka sa ho senngoa ha limela (waterfall) sepheo sa QC-20, mocha o nepahetseng. Melao e meholo e mebala e meholo e bontša li-resonances, tseo ka kakaretso li sa lakatseheng. Ha ho letho leo u ka tšoenyehang ka lona mona. Hona feela, moqotetsane haholo (mme ka hona mohlomong o sa fumaneha) ho pota 2.3 kHz.
QC-20 Frequency Response, 5 khahlanong le impedance ea mohloli oa 75 ohms
Makhetlo a mabeli a karabo ea QC-20, e nepahetseng, ha a feptjoa ke amp amp (Musical Fidelity V-Can) le 5 ohms output impedance (red trace), mme o na le 75 ohms output impedance (green trace). Ka tsela e loketseng, mela e lokela ho kopana hantle, 'me bona ba e etsa; eo ka tloaelo ho leng joalo ka hare-hōle li-headphones tse kang QC-20. Ka hona, karabo ea QC-20 le phallo ea tonal e ke ke ea fetoha ha u sebelisa helmoro ea boleng bo tlaase, joalo ka tse hahiloeng ka li-laptops tse ngata le li-smartphones tse theko e tlaase.
QC-20 Distortion
Kakaretso e fapaneng ea harmonic (THD) ea QC-20, mocha o nepahetseng, o lekantsoe ka tekanyo ea tekano ea 100 dBA. Karolo e ka tlaase mona ke sethaleng, se molemo. Ha e le hantle e ne e tla feta moeli o ka tlase oa chate. Ntle le tlhōrō e nyenyane ea 4% ea ho fapanyetsana ho 600 Hz, ho sotha ha QC-20 ho tlase haholo, haholo-holo maboteng.
QC-20 Isolation
Ho aroloa ha seteishene sa QC-20, se nepahetseng, ho hlakola lerata (tseleng e tala) le ho hlakola lerata ho (pherese e pherese). Litekanyo tse ka tlase ho 75 dB li bonts'a ho hlokomoloha lerata le ka ntle (ke hore, 65 dB ka chate e bolela ho fokotsa -10 dB ka melumo e ka ntle ho nako ea molumo). Tsela e ka tlase ea mohala e chate, e molemo.
Maemong a phahameng, lerata la ho hlakola lerata le molemo, hoo e ka bang -20 ho -25 dB. Libakeng tse tlaase, moo lerata la li-jet li lulang teng, phello ke eona e molemo ka ho fetisisa eo re ka e hopolang ho e lekanya, e ntle ho -45 dB ka 160 Hz. E lekana le ho fokotsa karolo ea 96 lekholong ea litekanyetso tsa molumo. Hlokomela hore trace e pherese e otla ka tlaase ho chate.
QC-20 Impedance
Ho felloa ke tšebeletso ea QC-20, mocha o nepahetseng. Ka kakaretso, khatello ea phekolo e sa tsitsitseng (e bolelang, e teteaneng) maemong 'ohle e molemo, empa ka phekolo e phahameng haholo ea tlhahiso ea matla-hare ea QC-20, sena ha se na taba.