Abakhiqizi abaningi bomsindo banikeza izinkomba zekhanda / imisindo ngekhono lobuchwepheshe bokukhansela (ANC). Lezi zinhle kubantu abalalela umculo noma babukele amavidiyo ezindaweni ezimnandi kanye / noma ngenkathi behamba. Kodwa-ke, akuwona wonke ama-ANC adalwe ngokulinganayo. Sibheka indlela ama-earphone akhansela ngayo umsindo we-Bose QuietComfort 20 (QC-20).
Bose QuietComfort 20 Izinyathelo
Silinganise ukusebenza kwe-QC-20 usebenzisa i-GRAS 43AG indlebe / isekisi simulator, i-analyzer ye-Clio FW, isofthiwe yekhompyutha ephathekayo eqhuba i-TrueRTA software ne-interface yomsindo ye-M-Audio MobilePre ye-USB, ne-Musical Fidelity V-Can. (Asivamile ukusebenzisa i-earphone / ihlathi yesimulator egcwele ukukala imisindo ye-headphones , kodwa ngenxa yesimo esingavamile se-QC-20 sika-silicon amathiphu, ayihambisani kahle nekhamera ye-GRAS RA0045 evame ukusetshenziswa ukulinganisa ezindlebeni.)
Ukulinganisa kwakulinganiselwe iphuzu lokungena kwendlebe (EEP), cishe iphuzu esikhungweni sokufa esikhala ngesikhathi sokuvula umthamo wakho wezindlebe. Sasebenzisa indlela yokugubha ye-43AG ukuze siqinisekise uphawu oluhle lwekhanda le-simulator kanye nomphumela ohambisanayo jikelele. Qaphela ukuthi ngaphesheya kokulinganisela kuya ku-EEP, asisebenzisi inkambu yokusabalalisa noma enye ikhefu lesinxephezelo. (Olunye ucwaningo luye lwafakazela ukuthi leso sinxephezelo siyasebenza, futhi kuze kube yilapho imboni ivumelana ngesilinganiso esihle, esekelwe ucwaningo, sikhetha ukubonisa idatha eluhlaza.)
Ukuzwela kwe-QC-20, kulinganiswe nesignali esingu-1 mW ku-32 ohms (ukulinganisa okujwayelekile kwe-impedance ye-headphones-amplified ngaphakathi njenge-QC-20) engu-104.8 dB, ephakeme ngokwanele ukuze uthole amazinga aphezulu kusuka mhlawumbe noma iyiphi idivayisi yomthombo.
I-QC-20 Impendulo Yezimvamisa
Ukuphendula kwamavamisa we-QC-20 ngakwesokunxele (okuhlaza okwesibhakabhaka) nakwesokudla (izitshalo ezibomvu), izinga lokuhlola elibhekiswe kuma-94 dB @ 500 Hz. Ayikho indinganiso yalokho okushiwo impendulo "emihle" yama-headphones, futhi ngenxa yokuthi ama-psychoacoustics ayanzima futhi ama-ear shape ahlukahluka, ukulungiswa phakathi kwezinyathelo zokuphendula izimpendulo kanye nokubuka okulalelayo okulalelayo ngezinye izikhathi akucaci.
Noma kunjalo, leli shidi likuvumela ukuba uqhathanise amamodeli ngokuhlulekayo. I-QC-20 ibonisa ukusabela okuncane okungaphansi kwezindlebe eziningi, okuvame ukuba ne-bump ekuphumeni okungezansi kwe-100 Hz. Liphinde ibonise impendulo ebonakalayo evelele kakhulu, enamandla amaningi phakathi kuka 2 no-10 kHz.
I-QC-20 Impendulo Yezimvamisa, umsindo ukhansela futhi uvaliwe
Ukuphendula ngokuphindaphindiwe kwe-QC-20, isiteshi esifanele, ngokukhansela umsindo (ukulandelela obomvu) nokuvala (ukulandelana okuphuzi). Njengoba ubona, impendulo ihambisana ngokufanayo kuzo zombili izindlela. Lena yikho imiphumela engcono kakhulu esake silinganisela kulolu vivinyo. Zonke ezinye zekhanda lokukhansela umsindo zihlolwe ukushintsha ukuphendula kwayo okungenani kancane uma ukukhansela komsindo kushintshiwe; ngezinye izikhathi ushintsho lomsindo luyinkimbinkimbi (futhi lusizi).
I-QC-20 I-Disay Spectral
Isakhiwo se-spectral (waterfall) se-QC-20, isiteshi esifanele. Izindebe ezindala eziluhlaza okwesibhakabhaka zikhombisa ukuhlaselwa, okuvamile okungathandeki. Akudingeki ukhathazeke ngalokhu lapha. I-resonance encane kakhulu (futhi ngokunjalo mhlawumbe inaudible) cishe i-2.3 kHz.
I-QC-20 Impendulo Yemivamisa, imelene ne-75 ohms impedance yomthombo
Ukuphendula okuphindaphindiwe kwe-QC-20, isiteshi esifanele, uma sidliwe yi-amp (Musical Fidelity V-Can) nge-5 ohms impedance yokukhipha (ukulandelela obomvu), nangemiphetho engu-75 ohms yokukhipha (ukulandelana okuluhlaza). Okuhle, imigqa kufanele ihambe ngokugcwele, futhi bheka yenza; okuyinto evame ukwenzeka ngaphakathi kwe-headphones ephakanyisiwe njenge-QC-20. Ngakho-ke, impendulo ye-QC-20 ye-frequency kanye ne-tonal balance ngeke ishintshe uma usebenzisa i-headphone yekhwalithi ephansi, njengalezo ezakhiwe kuma-laptops amaningi nama-smartphone angabizi.
Ukukhishwa kwe-QC-20
Ukuphazamiseka okuphelele kwe-harmonic (THD) ye-QC-20, isiteshi esifanele, esilinganisiwe ezingeni lokuhlola lika-100 dBA. Okuphansi kwalokhu umugqa kusebusheni, kungcono. Okungcono ukuthi kwakuyofaka umngcele ophansi we ishadi. Ngaphandle kwalokhu okungaqondakali kancane kwe-4% okuphambene nendawo ku-600 Hz, ukuphazamiseka kwe-QC-20 kuphansi kakhulu, ikakhulukazi ezansi.
I-QC-20 Isolation
Ukuhlukaniswa kwe-QC-20, isiteshi esifanele, ngokukhanselwa komsindo kuvaliwe (ukulandelela okuluhlaza) nokukhanselwa komsindo ku (umkhondo olandayo). Izinga ezingezansi kwe-75 dB zikhombisa ukunakekelwa komsindo wangaphandle (okungukuthi, 65 dB eshadini kusho ukunciphisa -10 dB emisindeni engaphandle kuleyo mvamisa yemisindo). I-line engezansi ishadi, kungcono.
Ezimeni eziphakeme, umphumela wokukhansela komsindo kuhle, cishe -20 kuya ku -25 dB. Ezingxenyeni eziphansi, lapho umsindo wezinjini ze-jet uhlala khona, umphumela uyona engcono kakhulu esingayikhumbula ukulinganisa, njengoba nje -45 dB ku-160 Hz. Lokhu kufana nokunciphisa amaphesenti angu-96 ezingeni lezwi. Qaphela ukuthi umlandeli obomvu uhlasela phansi kweshadi.
I-QC-20 Impedance
Ukuchithwa kwe-QC-20, isiteshi esifanele. Ngokuvamile, impedance engaguquki (ie, flat) kuzo zonke izikhathi ingcono, kodwa nge-impedance ephakeme kakhulu ye-QC-20 yangaphakathi yokufakelwa kwe-amplifier, lokhu akukona ukukhathazeka.