Ntau lub suab paj nruag manufacturers muab lub mloog pob ntseg / earphone ua qauv nrog lub suab nrov nrov tshem tawm (ANC) technology. Cov no yog cov zoo rau cov neeg uas mloog suab paj nruag lossis saib yeeb yaj kiab hauv cov cheeb tsam tsis muaj suab nrov thiab / lossis thaum mus ncig teb chaws. Txawm li cas los xij, tsis tag nrho ANC tsim tsim nyog. Peb saib qhov Bose QuietComfort 20 (QC-20) tshem tawm cov pob ntseg ua suab nrov li cas.
Bose QuietComfort 20 Kev Ntsuas
Peb ntsuas qhov kev ua ntawm QC-20 siv lub GRAS 43AG pob ntseg / cheek simulator, lub Clio FW suab analyzer, lub laptop computer khiav TrueRTA software nrog M-Audio MobilePre USB audio interface, thiab Musical Fidelity V-Tau lub mloog xov tooj cua amplifier. (Peb tsis yog siv lub pob ntseg / pob tw hauv siab los ntsuas hauv pob ntseg pob ntseg , tab sis vim qhov txawv ntawm QC-20's lub tswv yim silicon, nws tsis haum zoo rau hauv GRAS RA0045 coupler feem ntau siv rau kev ntsuam xyuas ntawm hauv-pob ntseg.)
Kev ntsuas tau raug tsa rau pob ntseg nkag (EEP), ntxig rau qhov chaw ntawm qhov chaw tuag thaum qhib ntawm koj lub pob ntseg. Peb siv cov clamp mechanism ntawm lub 43AG kom paub tseeb zoo ntawm lub lub pob ntseg ntawm lub simulator thiab ua kom pom txhua yam. Nco ntsoov tias dhau qhov kev txheeb ze rau EEP, peb tsis tso npe los yog lwm qhov kev nplua nyiaj. (Qee qhov kev tshawb fawb tau nug txog qhov raug mob ntawm cov nyiaj raug mob, thiab txog thaum lub lag luam pom zoo rau qhov zoo, kev tshawb nrhiav-txaus siab, peb xav qhia cov ntaub ntawv raw.)
Kev ntsuas ntawm QC-20, ntsuas nrog ib lub teeb meem ntawm 1 mW ntawm 32 ohms (tus lej ntsuas ntawm kev ua haujlwm sab nraud ntxiv rau QC-20) yog 104.8 dB, siab txaus kom nce siab los ntawm tej zaum qhov chaw twg los tau.
QC-20 Kev Tawm Sij Hawm
Kev teb ntawm QC-20 nyob rau sab laug (xiav) thiab txoj cai (xim liab), ntsuas theem hais txog 94 dB @ 500 Hz. Tsis muaj ib qho qauv rau qhov ua rau lub suab "zoo" rau hauv lub mloog pob ntseg, thiab vim hais tias muaj kev nyuaj siab thiab lub pob ntseg sib txawv, qhov kev sib txheeb ntawm cov teeb meem ntawm cov lus teb thiab kev mloog cov kev xav tau qee zaum kuj tsis meej.
Txawm li cas los xij, daim duab qhia no cia koj sib piv cov qauv. Lub QC-20 qhia me ntsis ntses bass feem ntau tshaj li hauv pob ntseg, uas yuav muaj ib qho thawv rau bass thaj tsam ntawm 100 Hz. Nws kuj qhia tau hais tias me ntsis ntxiv mas muaj tswv yim heev dua treble, nrog ntau zog ntawm 2 thiab 10 kHz.
QC-20 Kev Tshaj Tawm Txog Kev Tshaj Tawm, kev tawm lub suab nrov thiab tawm
Cov lus teb ntawm QC-20, txoj cai channel, nrog lub suab nrov ntawm kev txiav (xim liab) thiab tawm (xim daj). Raws li koj tau pom, cov lus teb yeej tseem zoo tib yam hauv ob hom. Qhov no yog qhov zoo tshaj plaws tshwm sim peb tau ntsuas ntawm qhov kev xeem no. Txhua txhua lub suab nrov ntawm lub suab nrov tau hloov cov lus teb tsawg kawg me ntsis thaum lub suab hais lus kaw lawm; qee zaus qhov kev hloov hauv lub suab yog qhov ua rau (thiab tsis muaj teebmeem).
QC-20 Spectral Kev Txiav Txim
Spectral lwj (dej tsaws tsag) ntawm QC-20, txoj cai channel. Cov kab xiav ntev ntev qhia tias resonances, uas feem ntau yog tsis nyiam. Tsis ntau txhawj txog ntawm no. Tsuas yog ib tug heev, heev nqaim (thiab yog li tej zaum inaudible) resonance ib ncig ntawm 2.3 kHz.
QC-20 Kev Tawm Sij Hawm, 5 thiab 75 ohms qhov chaw impedance
Cov lus teb ntawm QC-20, txoj cai channel, thaum pub los ntawm ib qho amp (Musical Fidelity V-Tau) nrog 5 ohms tso tawm impedance (liab kab), thiab nrog 75 ohms tso tawm impedance (ntsuab kab). Qhov zoo tshaj, cov kab yuav tsum sib zog txig, thiab nyob ntawm no lawv ua; uas feem ntau yog cov ntaub ntawv nrog rau kev ua kom nrov ntxiv hauv lub headphones xws li QC-20. Yog li, QC-20 qhov kev teb thiab qhov nyiaj tonal yuav tsis hloov yog tias koj siv lub xov tooj cua tsis zoo, zoo li cov uas tau ua rau cov laptops thiab pheej yig smartphones.
QC-20 Distortion
Tag nrho harmonic distortion (THD) ntawm QC-20, txoj cai channel, ntsuas ntawm kev xeem ntawm 100 dBA. Qhov qis dua ntawm kab no yog nyob ntawm daim phiaj, qhov zoo dua. Qhov tseeb nws yuav sib tshooj hauv qab ciam teb ntawm daim duab. Tshwj tsis yog tias coj txawv txawv me ntsis 4% distortion peak ntawm 600 Hz, QC-20 tus distortion yog heev tsawg, tshwj xeeb tshaj yog nyob rau hauv cov ntses bass.
QC-20 Kev Rho Tawm
Kev rho tawm ntawm QC-20, txoj cai channel, nrog lub suab nrov tawm tshem tawm (ntsuab kev cim) thiab kev tshem tawm lub suab nrov (xim liab kab). Qib qis tshaj 75 dB qhia tias tsis hnov suab nrov sab nrauv (piv txwv li, 65 dB ntawm daim phiaj qhia tias txhais tau tias yog poob ntawm -10 dB nyob sab nraum lub suab ntawm lub suab nrov ntawd). Qhov qis ntawm kab yog nyob rau hauv daim qauv, qhov zoo dua.
Thaum muaj zog ntau dua, lub suab tshem tawm lub suab nrov zoo, zoo li -20 rau -25 dB. Nyob rau sab qis qis dua, qhov twg hauv lub suab nrov ntawm cov dav hlau cav nyob, qhov tshwm sim yog qhov zoo tshaj plaws uas peb tuaj yeem nco qhov ntsuas, zoo li -45 dB ntawm 160 Hz. Qhov no yog sib npaug ntawm 96 feem pua ntawm cov qib suab. Nco ntsoov tias cov xim liab his hits hauv qab ntawm daim phiaj.
QC-20 Empedance
Impedance ntawm QC-20, txoj cai channel. Feem ntau, impedance uas zoo ib yam (piv txwv li, sib tiaj) ntawm txhua lub sijhawm nrawm nrawm dua, tab sis nrog lub siab heev ntawm QC-20 tus txheej txheem sab hauv lub zog, qhov no tsis yog qhov kev txhawj xeeb.