ĐIỆN tử VIỄN THÔNG DTVT2 nhom1 bai7 khotailieu

NHÓM – LỚP Đ8-ĐTVT - LƯƠNG NGỌC LONG HỒNG NGỌC TRUNG HỒNG THỊ LINH NGƠ ANH TUẤN PHÙNG THỊ QUỲNH PHẠM TRỌNG HOAN MSV: 1381510142 MSV: 1381510176 MSV: 1381510140 MSV: 1381510179 MSV: 1381510165 MSV: 1381510127 Lesson 7: Drum machine Coppy right belong to Nhom Task 1: A drum machine imitate the sound of drums and percussion instruments Closed hat and open hat, snare, kick are percussion instruments and Drum machine imitate the sound of them Task 2: abcde- c e b a d Task 3: Reading a b c d e f analogue recording – paragraph: what quantize means – paragraph: the advantage of digital sound – paragraph: what happens when one the drum buttuns is pressed – paragraph: how sound samples samples are stored in a drum machine – paragraph: in brief what the machine does – paragraph: Reading a Changes in pressure of the air around us are what we hear as sound Task 4: By pressing the pads which corresspond to particular sounds, you can create your own songs and rhythms withoout ever touching a drum kit 2 The machine’s read- only memory (ROM) stores sounds which have been prerecorded from the original instruments When we hear sound, our ears are detecting changes in air pressure These changes in pressure , which might be caused by vibrating a guitar string or banging a drum , are sound waves To the record these, the wave patterns in the air are converted by a microphone into electrical signals The voltage and frequency of these signals correspond exactly to the fluctuations in pressure of the original wave Measurements are taken at frequent regular intervals and then recorded as binary code Sounds recorded in this way remain accurate When you press one of the drum pads, how hard you press and for how long, tells the microprocessor how loud ang at which tempo the sound should be If you hit a note a little ahead or behind the beat, the machine will automatically place the drum hit right on the beat Taks 5: With a drum machine, pressing the right button, you can play any drum sound Without playing a drum, you can create drum music Changing the air perssure, what we hear as sound arc Using a microphone, these are converted to electrical signals Sampling the electtrical signals, the information contained in the drum machine memory consists A drum machine contains recording of sound taken at measured intervals This process is called sampling The functions of a drum machine include panning and tuning Panning means the positioning of the drum sound in stereo Coppy right belong to Nhom Task 6: A burglar alarm = an alarm which warns of burglar A clock timer = a clock which countdown time A mercury swich = a swich which contains mercury A car phone = a phone for use in a car A germanium diode = a diode which contains germanium A ground wave = a wave which travels along the ground, following the curvature of the earth’s surface A block diagram = a diagram which contains block An assembly line = a line which assemblies complex item A fuseholder = a device for protecting fuse 10 A wavemeter = an instrument for measuring wavelength 11 A cellphone = a device which receives and transfer signal 12 Headphone = a pair of small loudspeakers that are designed to be held in place close to a user's ears 13 An ammeter = an instrument for measuring ampere 14 A handset = a device that a user holds to the hands Task 7: A sine wave an example of an analogue wave The magnitude of a digital signal has only two levels, high and low, which can be represented by the binary digits and respectively ADC is analogue-to-digital converter, the analogue signal can be changed into digital signals The higher the frequency of the analoguesignal, the more often it must be sampled A four-bit ADC has sixteen different binary values , the smallest value is 0000 and the largest is 1111 An Eight-bit ADC has 256 different digital values It will cause the analogue signal to suffer some distortion Coppy right belong to Nhom