Vakawanda vanopinza mavara vanopa mafoni / earphone mafirimu nemagetsi ekurasira (ANC) teknolojia. Izvi zvakakosha kune vanhu vanoteerera mimhanzi kana kuona mavhidhiyo mumamiriro ezvinhu anotinhira uye / kana pavanenge vachifamba. Zvisinei, haasi yose yeANC yakaumbwa zvakaenzana. Tinotarisa kuti Bose QuietComfort 20 (QC-20) acoustic sound annulation earphones perform.
Bose QuietComfort 20 Nhamba
Takayera kushanda kweC QC-20 tichishandisa GRAS 43AG nzeve / cheek simulator, Clio FW audio analyzer, TrueRTA software ye laptop inotakura laptop neIm-Audio MobilePre USB mutinhiyo wekuteerera, uye Musical Fidelity V-Can headphone amplifier. (Hatiwanzoshandisi nzeve yakazara / cheek simulator kuverenga mumakutu -headphones , asi nekuda kwechimiro chisina kujairika cheC QC-20's silicon tips, haina kukodzera mumakambani a GRAS RA0045 anowanzoshandiswa pamiganhu ye in-nzeve.)
Zvimwe zviyero zvakanyatsotaridzirwa kune nhepfenyuro inopinda (EEP), inenge ichinyanya kuitika munzvimbo yekufa yepakati pavhudziro remunzwa wenyu. Takashandisa simbi yekugadzirisa ye 43AG kuti tive nechokwadi chechisimbiso chefonifoni pamusikirwo uye chiitiko chisingachinji zvachose. Cherechedza kuti kunze kwekugadzirisa EEP, hatishandisi-munda kana mamwe mavheti ekubhadhara. (Dzimwe tsvakurudzo dzakabvunzurudza kubhadharwa kwezvakadaro, uye kusvikira iyo inyanzvi ichibvumirana pane zvakanaka, tsvakurudzo-inotsigirwa, tinosarudza kuratidza dhizha yakasvibirira.)
Kutsigira kweC QC-20, yakayerwa ne 1 mW signal pa 32 ohms (standard impedance kuverengwa kwemukati-yakagadziriswa headphones seyo QC-20) iine 104.8 dB, yakakwanira zvokuti inogona kuve yakakosha kubva kune imwe nzvimbo inoshandiswa.
QC-20 Frequency Response
Frequency response yeC QC-20 kuruboshwe (bhuu) uye kurudyi (tsvuku) mitsara, test level inotsanangurwa kusvika 94 dB @ 500 Hz. Izvo hazvina mutemo we "zvakanaka" nguva zhinji mhinduro mu headphones, uye nokuti psychoacoustics yakaoma uye maumbirwo akasiyana-siyana, kuwirirana pakati pezvakarurama zvinotarisana nemhinduro uye zvido zvekuteerera zvinoteerera dzimwe nguva hazvisi pachena.
Zvisinei, chati ichi chinokubvumira kuti uenzanise mitero yakanyatsoenderana. IQ-20 inoratidzira zvishoma zvishoma pane zvakanyanya-munzeve, izvo zvinowanzova ne bump muzvinyorwa zvinenge zvakapoteredza 100 Hz. Inoratidzirawo chimwe chinhu chinonyanya kutaridzika mhinduro, ine simba rakawanda pakati pe2 ne10 kHz.
QC-20 Frequency Response, ruzha ruregerero uye ruchibva
Frequency response yeC QC-20, chiteshi chakarurama, neruzha rwekutsvaga (tsvuku tsvuku) uye kurega (yellow trace). Sezvaunogona kuona, mhinduro yacho inonyanya kufanana mumadziro maviri. Ichi ndicho chikonzero chakanakisisa chatakamboona pachimuedzo uyu. Mamwe manzwiro emhere-kubvisa musoro wepamusoro yakaedzwa kuchinja kupindura kwaro kunyanya zvishomanana apo ruzha rwekuregererwa rwunoshandurwa; dzimwe nguva kuchinja kwezwi kunoshamisa (uye kunogumbura).
QC-20 Kuparara Kwemavara
Kuora kwemawere (waterfall) chirongwa che QC-20, chiteshi chakanaka. Masero mashoma emabhuruu anoratidza zvinononoka, izvo zvinowanzosingadi. Kwete zvakawanda zvokufunganya pamusoro apa. Izvo chaizvo, zvakanyanya kwazvo (uye zvichida inaudible) resonance zvakapoteredza 2.3 kHz.
QC-20 Frequency Response, 5 vs. 75 ohms source impedance
Frequency respond of the QC-20, channel right, when fed by an amp (Musical Fidelity V-Can) with 5 ohms output impedance (red trace), uye 75 ohms output impedance (green trace). Zvakanaka, mitsara inofanira kuwirirana zvakakwana, uye pano ivo vanoita; iyo inowanzotarisirwa nekati internally amplified headphones seC QC-20. Nokudaro, yeC-20's frequency response uye tonal balance haingashanduki kana ukashandisa pasi-headphone amp, semamwe akavakwa mumapuraneti akawanda uye emafoni asina mari.
QC-20 Distortion
Kushandiswa kweHarmic (THD) yeC QC-20, nzira yakarurama, yakayerwa pachiyero chekuyera kwe 100 dBA. Pasi apa mutsara uri pa chati, zviri nani. Zvichida zvaizoputira muganhu wezasi we chati. Kunze kweiyo zvisinganzwisisiki zvishoma 4% kukanganisa kwepamusoro pa 600 Hz, yeC-20-kukanganisa kwakanyanya kwazvo, kunyanya mumabhasi.
QC-20 Isolation
Isolation yeC QC-20, chiteshi chakanaka, nekudururwa kwemheremhere (green trace) uye kuregererwa kworuzha ((trace yepepuru). Nhamba dziri pasi pe75 dB dzinoratidza kucheneswa kwekunze kweruzha (kureva, 65 dB pane chati zvinoreva -10 dB kuderedza mumanzwi emunharaunda panguva iyoyo inzwi rukuru). Icho chasi pasi mutsetse chiri pa chati, zviri nani.
Pamisasa yakakwirira, ruzha rwekudzima ruzivo rwakanaka, anenge -20 kusvika -25 dB. Muchikamu chezasi, apo ruzha rwejet injini runogara, chigumisiro ndicho chakanakisisa chatinogona kuyeuka kuenzanisa, zvakanaka se -45 dB pa 160 Hz. Izvo zvakaenzana ne 96 kubva muzana kuderedzwa kwehuwandu hwezwi. Cherechedza kuti trace yepepuru inorova pasi pechati.
QC-20 Impedance
Kusagadzikana kweC QC-20, nzira yakarurama. Kazhinji, imhedheni inogara isingagumi (kureva, yakadzika) pamativi ose ari nani, asi neyakakwirira zvikuru yeC QC-20 inopinza mukati mawo, izvi hazvisi izvo zvine hanya.