公开(公告)号：US09685917B1

公开(公告)日：2017-06-20

申请号：US15272264

申请日：2016-09-21

申请人： Tack Ching Wun

发明人： Tack Ching Wun

IPC分类号： H04R27/04 ,  H03F3/181 ,  H03F3/45 ,  H03F3/22 ,  H04R1/10

CPC分类号： H03F3/181 ,  H03F3/22 ,  H03F3/45475 ,  H03F3/68 ,  H03F5/00 ,  H03F2200/03 ,  H03F2203/45112 ,  H04R1/1008 ,  H04R1/1025 ,  H04R1/1041 ,  H04R1/1058 ,  H04R5/033 ,  H04R5/04 ,  H04R2420/07

摘要： A hi-fi headphone device with two speakers, an integrated pentode vacuum tube, and a battery. The battery is electrically connected to direct and bias circuits, to provide proper voltage to the vacuum tube amplifiers, wherein input signal is amplified and output to buffer circuits and impedance is matched between the tube and output speaker terminals.

公开(公告)号：US09872121B1

公开(公告)日：2018-01-16

申请号：US15591283

申请日：2017-05-10

申请人： Ren Xu ,  Litang Gu

发明人： Ren Xu ,  Litang Gu

IPC分类号： H04S7/00 ,  H04R3/14 ,  H04S3/00

CPC分类号： H04S7/303 ,  H04R3/14 ,  H04S3/008 ,  H04S2400/01 ,  H04S2400/03 ,  H04S2420/01

摘要： A down-mixing method of 5.1 audio input channels for two channel replay by DRC processing of the LFE and the LS and RS channel signal before mixing, and by filtering LS and RS channels with BRTFs measured from placing a loud speaker at a corner of a room and measuring head at the diagonal corner of the room.