Ua ʻike nā kānaka a pau e pono ana nā magnet i nā lako electroacoustic e like me nā mea haʻiʻōlelo, nā mea ʻōlelo, a me nā headphone, a laila he aha nā kuleana e pāʻani ai nā magnet i nā mea electroacoustic? He aha ka hopena o ka hana magnet i ka maikaʻi o ke kani? ʻO wai ka magnet e hoʻohana ʻia i nā mea haʻiʻōlelo o nā ʻano ʻano like ʻole?
E hele mai e ʻimi i nā mea haʻiʻōlelo a me nā mea hoʻokalakupua me ʻoe i kēia lā.
ʻO ka mea koʻikoʻi ke kuleana no ka hana ʻana i ke kani i loko o kahi mea leo leo he mea haʻiʻōlelo, i ʻike mau ʻia he leo. Inā he stereo a i ʻole ke poʻo, pono kēia ʻāpana koʻikoʻi. ʻO ka mea haʻiʻōlelo he ʻano mea hoʻololi e hoʻololi i nā hōʻailona uila i nā hōʻailona leo. ʻO ka hana a ka mea haʻiʻōlelo he mana nui i ka maikaʻi o ke kani. Inā makemake ʻoe e hoʻomaopopo i ka magnetism leo ʻōlelo, pono ʻoe e hoʻomaka me ke kumu kani o ka mea haʻiʻōlelo.
Hoʻokumu ʻia ka mea haʻiʻōlelo i kekahi mau mea nui e like me T iron, magnet, voice coil and diaphragm. Ua ʻike mākou a pau e hana ʻia kahi māla magnetic i ka uea hoʻokele, a ʻo ka ikaika o ke au e pili ana i ka ikaika o ka māla magnetic (ʻo ke kuhikuhi o ka māla magnetic e hahai i ka lula lima ʻākau). Hoʻokumu ʻia kahi māla magnetic kūpono. Hoʻopili ʻia kēia kahua hoʻopaneʻe me ke kahua magnetic i hana ʻia e ka magnet ma ka mea haʻiʻōlelo. ʻO kēia ikaika ka mea e haʻalulu ai ka puʻupuʻu leo me ka ikaika o ke au leo i loko o ke kahua mākēneki o ka mea haʻiʻōlelo. Hoʻopili pū ʻia ka diaphragm o ka mea haʻiʻōlelo a me ka puʻupuʻu leo. I ka wā e wiliwili pū ai ka puʻupuʻu leo a me ka diaphragm o ka mea haʻi'ōlelo no ka hoʻokuke ʻana i ka ea a puni e haʻalulu, hoʻopuka ka leo i ke kani.
Ma ka hihia o ka leo magnet like a me ka leo leo like, he hopena pololei ka hana magnet i ka maikaʻi o ka leo o ka mea haʻiʻōlelo:
-ʻO ka ʻoi aku ka nui o ka mākēneki flux density (magnetic induction) B o ka magnet, ʻoi aku ka ikaika o ka hana ʻana ma ka membrane kani.
-ʻO kaʻoi aku o ka nui o ka puʻupuʻu magnetic (magnetic induction) B, ka nui o ka mana, a me ke kiʻekiʻe o ke kiʻekiʻe o ke kani kani SPL (sensitivity).
ʻO ka naʻau o ke poʻo poʻo e pili ana i ke kiʻekiʻe o ke kani kani e hiki ai i ka pepeiao ke hoʻopuka i ke kuhikuhi ʻana i ka nalu sine o 1mw a me 1khz. ʻO ka ʻāpana o ke kaomi kani ʻo dB (decibel), ʻoi aku ka nui o ke kaomi kani, ʻoi aku ka nui o ka leo, no laila ʻoi aku ka kiʻekiʻe o ka naʻau, ʻoi aku ka haʻahaʻa o ka impedance, ʻoi aku ka maʻalahi o nā headphone e hana i ke kani.
-ʻO ka ʻoi aku ka nui o ka puʻupuʻu magnetic (ka ikaika induction magnetic) B, ka waiwai Q haʻahaʻa haʻahaʻa o ka huina o ka maikaʻi o ka mea haʻiʻōlelo.
ʻO ka waiwai Q (qualityfactor) e pili ana i kahi pūʻulu o nā ʻāpana o ka mea hoʻoheheʻe hoʻoheheʻe leo, kahi ʻo Qms ka hoʻoheheʻe ʻana o ka ʻōnaehana mechanical, e hōʻike ana i ka absorption a me ka hoʻohana ʻana i ka ikehu i ka neʻe ʻana o nā ʻāpana leo. ʻO Qes ka damping o ka ʻōnaehana mana, ka mea i ʻike nui ʻia i ka hoʻohana ʻana i ka mana o ka leo coil DC kū'ē; ʻO Qts ka huina hoʻoheheʻe, a ʻo ka pilina ma waena o nā mea ʻelua ma luna nei ʻo Qts = Qms * Qes / (Qms + Qes).
-ʻO ka ʻoi aku ka nui o ka mākēneki flux density (magnetic induction) B, ʻoi aku ka maikaʻi o ka transient.
Hiki ke hoʻomaopopo ʻia ʻo Transient ma ke ʻano he "pane wikiwiki" i ka hōʻailona, ʻoi aku ka kiʻekiʻe o Qms. Pono e pane koke nā pepeiao me ka pane transient maikaʻi i ka wā e hiki mai ai ka hōʻailona, a e pau ka hōʻailona ke kū. ʻO kahi laʻana, ʻo ka hoʻololi ʻana mai ke alakaʻi i ka hui e ʻike nui ʻia i nā pahu a me nā symphonies o nā hiʻohiʻona nui aʻe.
ʻEkolu ʻano o nā mea hoʻokani leo ma ka mākeke: aluminika nickel cobalt, ferrite a me neodymium iron boron, ʻO nā mea hoʻohana i hoʻohana ʻia i nā electroacoustics ka nui o nā neodymium magnets a me nā ferrites. Aia lākou ma nā ʻano nui o nā apo a i ʻole nā ʻano disc. Hoʻohana pinepine ʻia ʻo NdFeB i nā huahana kiʻekiʻe. ʻO ka leo i hoʻopuka ʻia e nā neodymium magnets he maikaʻi ke kani maikaʻi, elasticity kani maikaʻi, hana leo maikaʻi, a me ka hoʻonohonoho ʻana i ke kahua kani kūpono. Ke hilinaʻi nei i ka hana maikaʻi o Honsen Magnetics, ua hoʻomaka ka liʻiliʻi a me ka māmā neodymium iron boron e hoʻololi mālie i nā ferrites nui a kaumaha.
ʻO Alnico ka magnet mua loa i hoʻohana ʻia i nā mea haʻiʻōlelo, e like me ka mea haʻiʻōlelo i nā makahiki 1950 a me 1960 (i ʻike ʻia ʻo tweeters). Hana ʻia i loko o ka leo ʻōlelo magnetic kūloko (loaʻa pū kekahi ʻano magnetic waho). ʻO ka hemahema ʻo ia ka liʻiliʻi o ka mana, he haiki, paʻakikī a palupalu ke ʻano alapine, a paʻakikī loa ka hana ʻana. Eia kekahi, he waiwai liʻiliʻi ka cobalt, a he kiʻekiʻe ke kumu kūʻai o ka nickel cobalt aluminika. Mai ka hiʻohiʻona o ka hana kumukūʻai, ʻoi aku ka liʻiliʻi o ka hoʻohana ʻana i ka nickel cobalt alumini no nā magnet leo.
Hana ʻia nā ferrites i loko o nā mea ʻōlelo magnetic waho. He haʻahaʻa haʻahaʻa ka hana magnetic ferrite, a pono kekahi leo e hoʻokō i ka ikaika hoʻokele o ka mea haʻi'ōlelo. No laila, hoʻohana maʻamau ia no nā leo leo leo nui. ʻO ka maikaʻi o ka ferrite ʻo ia ka maʻalahi a me ke kumu kūʻai; ʻO ka hemahema ʻo ia ka nui o ka leo, liʻiliʻi ka mana, a haiki ka laulā alapine.
ʻOi aku ka maikaʻi o nā waiwai magnetic o NdFeB ma mua o AlNiCo a me ferrite a ʻo ia ka mea i hoʻohana nui ʻia i nā mea hoʻohana ma nā mea haʻiʻōlelo, ʻoi aku ka nui o nā mea haʻiʻōlelo kiʻekiʻe. ʻO ka pōmaikaʻi ʻo ia ma lalo o ka flux magnetic like, liʻiliʻi kona leo, nui ka mana, a ākea ka laulā. I kēia manawa, hoʻohana nā headphone HiFi i kēlā mau magnet. ʻO ka hemahema, ʻo ia ka mea ma muli o nā mea o ka honua laha, ʻoi aku ka kiʻekiʻe o ke kumu kūʻai.
ʻO ka mea mua, pono e wehewehe i ka mahana ambient kahi e hana ai ka mea haʻiʻōlelo, a hoʻoholo i ka mea magnet e koho ʻia e like me ka mahana. He ʻokoʻa nā hiʻohiʻona kūpaʻa wela o nā magnet like ʻole, a ʻokoʻa hoʻi ka wela hana kiʻekiʻe e hiki ai iā lākou ke kākoʻo. Ke ʻoi aku ka mahana o ke kaiapuni hana o ka magnet ma mua o ka wela o ka hana, hiki ke hana ʻia nā hanana e like me ka hana magnetic attenuation a me ka demagnetization, e hoʻopili pololei i ka hopena leo o ka mea haʻiʻōlelo.
