Mutane da yawa masu yin amfani da labaran suna bada samfurin wayar da kai / kunne tare da fasahar fasaha (ANC). Wadannan su ne manufa ga mutanen da suka saurari kiɗa ko kallon bidiyon bidiyon da kuma / ko lokacin tafiya. Duk da haka, ba dukkan ANC an halitta daidai ba. Muna duban yadda Bose QuietComfort 20 (QC-20) masu sauraron karar murya suka yi.
Bose QuietComfort 20 Matakan
Mun auna aikin da aka yi na QC-20 ta yin amfani da na'urar GRAS 43 / kunne, mai jarrabawa na Clio FW, kwamfutar tafi-da-gidanka da ke gudana na software na TrueRTA tare da Intanit na M-Audio MobilePre. (Ba mu saba amfani da kunnen kunne / kullin na'urar kwaikwayo don auna kunne a kunne ba , amma saboda siffar sabon abu na Turantin Silicon na QC-20, bai dace ba a cikin mahadar GRAS RA0045 da aka saba amfani dashi don ma'auni na in-kunnuwa.)
An auna ma'auni don ƙofar kunne (EEP), kusa da batun a cikin cibiyar mutuwar sararin samaniya a buɗe kofar kunnen ku. Mun yi amfani da makirci na 43AG don tabbatar da kyakkyawan hatimi na wayar kai a kan na'urar kwaikwayo da kuma cikakkiyar sakamako. Lura cewa baya bayan gyarawa zuwa EEP, ba zamu yi amfani da filin yadawa ba ko sauran tsarar kudi. (Wasu bincike sun yi la'akari da inganci na wannan fansa, kuma har sai masana'antu sun yarda da kyakkyawan tsari, bincike-goyon bayan bincike, mun fi so mu nuna bayanan da suka dace.)
Sensitivity of the QC-20, wanda aka auna tare da siginar 1 mW a 32 ohms (lissafin rashin daidaituwa na ƙwararru kamar yadda QC-20) ke da 104.8 dB, wanda ya isa ya sami matakan ƙarfi daga wata ila duk wani na'ura mai tushe.
QC-20 Amsar Sauyawa
Sakamakon lokaci na QC-20 a hagu (blue) da dama (tashoshi), matakin gwajin da aka rubuta zuwa 94 dB @ 500 Hz. Babu daidaituwa ga abin da ya haifar da amsa mai kyau "kunne" a cikin kunne, kuma saboda rashin lafiyar jiki yana da rikitarwa kuma siffofin kunne sun bambanta, daidaitawar tsakanin matakan haɓaka da kuma sauraron sauraron ra'ayi wani lokaci ba a bayyana ba.
Duk da haka, wannan ginshiƙi bai bari ku kwatanta samfurin gaskiya ba. Aikin na QC-20 yana nuna alamar ƙarar bass fiye da yawancin kunnuwan, wanda ke da alaƙa da ƙuƙƙasa a cikin ƙarancin bass a kusa da 100 Hz. Har ila yau yana nuna wani amsa mai sauki, da yawancin makamashi tsakanin 2 da 10 kHz.
QC-20 Amsaccen Yanayin, sokewa da kashewa
Sakamakon karɓan lokaci na QC-20, dama hanya, tare da soke murya (kashewa) da kuma kashe (rawaya alama). Kamar yadda kake gani, amsawa tana da mahimmanci a cikin hanyoyi guda biyu. Wannan shine mafi kyawun sakamakon da muka taba auna akan gwajin. Kowace muryar kararrawa da aka yi amfani da ita yana canzawa da amsawa a kalla kaɗan lokacin da aka soke maɓallin motsi; wani lokacin canjin sauti yana da ban mamaki (kuma m).
QC-20 Spectral Decay
Spectral lalata (waterfall) mãkirci na QC-20, dama tashar. Tsawon zane-zane na tsawon lokaci yana nuna alamu, wanda ba a so. Ba da yawa ba damuwa game da nan. Kawai kawai sosai, sosai kunkuntar (kuma haka mai yiwuwa inaudible) resonance a kusa da 2.3 kHz.
QC-20 Yanayin Yanayin, 5 vs. 75 watsar matsala ta watham
Yanayin karɓa na zamani na QC-20, daidai lokacin da aka ciyar dashi (Fedelity V-Can) tare da nauyin haɓaka na 5 ohms (red trace), tare da 75 watst impedance output (kore alama). Tabbas, Lines ya kamata su shuɗe daidai, kuma a nan suna yin; wanda shine yawancin lamarin tare da ƙwararrun kunne kamar yadda kamfanin QC-20 yake. Saboda haka, amsawar mita na QC-20 da ma'auni na tonal ba zai canza ba idan ka yi amfani da amfanar murya mara kyau, kamar waɗanda aka gina cikin mafi yawan kwamfyutocin kwamfyutoci da masu amfani da wayoyin salula.
QC-20 Zubar da ciki
Jimlar jita-jita (THD) na QC-20, dama, wanda aka auna a matakin gwaji na 100 dBA. Ƙananan wannan layin yana kan chart, mafi kyau. Hakanan zai kaddamar da iyakar ƙasa na ginshiƙi. Fãce wannan ɗan gajeren abu kaɗan 4% murkushe tsayin daka a 600 Hz, ƙaddamarwar QC-20 ta ragu ƙwarai, musamman ma a cikin bass.
QC-20 Rawa
Tsarkarwa daga cikin kamfanin QC-20, dama, tare da soke sokewar (kore alama) da kuma sokewa a kan (m alama). Matakan da ke ƙasa 75 dB suna nuna alamar muryar waje (watau 65 dB a kan ginshiƙi yana nufin rage -10 dB a waje da sautuna a wannan sautin mota). Ƙananan layin yana kan chart, mafi kyau.
A ƙananan ƙananan ƙwayoyin, sakamako na sokewa nagari yana da kyau, game da -20 zuwa -25 dB. A cikin ƙananan ƙananan hanyoyi, inda hayaniya daga motar jet ta zauna, sakamakon shine mafi kyawun zamu iya tuna ma'aunin, kamar yadda -45 dB a 160 Hz. Wannan daidai yake da raguwar kashi 96 a matakin sauti. Ka lura cewa launi mai laushi ya fadi ƙasa na ginshiƙi.
QC-20 Baƙi
Madaba na QC-20, dama tashar. Yawanci, rashin daidaituwa wanda yake daidai (watau, ɗakin) a kowane fanni yana da mafi alhẽri, amma tare da ƙananan ƙazantar aikin shigarwa na intanet na QC-20, wannan ba damuwa bane.