Isandisi sesandi sisixhobo esakha ngokutsha isiginali yesandi kwinto ekhupha isandi. Umthamo womqondiso owakhiwe ngokutsha kunye nenqanaba lamandla kufuneka zibe zezinyanisekileyo, ezisebenzayo kunye nokugqwetha okuphantsi. Uluhlu lweaudiyo lumalunga ne-20Hz ukuya kwi-20000Hz, ke loo nto isandisi-lizwi kufuneka sibe nempendulo entle kuloluhlu (kuncinci xa uqhuba isithethi esilinganiselweyo, esifana ne-woofer okanye i-tweeter). Kuxhomekeke kwisicelo, inqanaba lamandla liyahluka kakhulu, ukusuka kwinqanaba le-milliwatt lee-headphone ukuya kwii-watts ezininzi zeTV okanye i-PC audio, ukuya kumashumi eewts ze "mini" zestereo sasekhaya kunye nesandi semoto, ukuya kwikhaya elinamandla ngakumbi Inkqubo’Amakhulu ee-watts zikhulu ngokwaneleyo ukuhlangabezana neemfuno zesandi sayo yonke i-cinema okanye iholo

Isikhulisi somsindo lelinye lamacandelo abalulekileyo kwiimveliso zemultimedia kwaye sisetyenziswa ngokubanzi kwicandelo lezinto zombane zabathengi. Amanqwanqwa ombane wokukhulisa amandla ombane ahlala elawula intengiso yemveli yesikhulisi ngenxa yokugqwetha kwabo okuphantsi kunye nomgangatho olungileyo wesandi. Kwiminyaka yakutshanje, ngokwandiswa kwezixhobo zemultimedia ezinokuthwalwa ezinje ngeMP3, iPDA, iifowuni eziphathwayo, kunye neekhompyuter zencwadana, ukusebenza ngokukuko kunye nomthamo wezikhulisi zamandla alinganayo azikhange zikwazi ukuhlangabezana neemfuno zentengiso, ngelixa amandla ombane eCandelo D aye esiba ngaphezulu nangakumbi ithandwa ngokusebenza kwazo okuphezulu kunye nobukhulu obuncinci. Ukuthanda. Ke ngoko, izikhulisi zamandla ezikwizinga eliphezulu zodidi D zinexabiso lesicelo elibaluleke kakhulu kunye nethemba lokuthengisa.

Ukuphuhliswa kwesandisi-lizwi kuye kwavela ii-eras ezintathu: ityhubhu ye-elektroni (ityhubhu yokucoca), i-bipolar transistor, kunye ne-tube yesiphumo sentsimi. Isandisi sesandi sombhobho sinesandi esisolileyo, kodwa sinamandla amakhulu, ukusetyenziswa kwamandla okuphezulu, ukungazinzi okungagungqiyo, kunye nempendulo yamaxesha aphezulu; I-bipolar transistor audio amplifier ine-frequency band, uluhlu olukhulu lwamandla, ukuthembeka okuphezulu, ubomi obude, kunye nokuphendula okuhamba rhoqo okuhle, kodwa ukusetyenziswa kwayo kwamandla okumileyo kunye nokumelana kukhulu kakhulu, kwaye ukusebenza kunzima ukuphucula; i-amplifier ye-FET yesandi inethoni efanayo yokuthambisa njengetyhubhu ye-elektroniki, kwaye uluhlu lwayo olunamandla lubanzi, kwaye okona kubaluleke kakhulu, ukumelana kwayo kuncinci, Kunokufezekisa ukusebenza okuphezulu.