explaining decibel understand nature signal audio by sarbini, s.pd (smk muhammadiyah 3 yogyakarta)

EXPLAINING DECIBEL

UNDERSTAND NATURE SIGNAL AUDIOBy Sarbini, S.Pd (SMK Muhammadiyah 3 Yogyakarta)

Teknologi dan Rekayasa

DECIBEL

DECIBEL PURPOSE :

In technology for audio signals expression levels and sound pressure difference, power, voltage and current.

To measure the difference in the coverage figures for small and large states often also a large number of unwieldy.

Decibel can also be considered from the view point of psychoacoustical connect directly to the purpose of stimuli associated with the feelings of most


1. COHERENCY WITH POWER

Bell = log (P1/Po)

(dB) = 10 log (P1/Po).

P1 (Watt) Stage in Db

P1 (Watt) Stage in Db

1 0 1000 30

10 10 10 000 40

100 20 20 000 43

Illustrated the concept of useful


P1 (Watt) Stage in Db P1 (Watt) Stage in Db

1,0 0,00 3,15 5,00

1,25 1,00 4,00 6,00

1,60 2,00 5,00 7,00

2,00 3,00 8,00 9,00

2,50 4,00 10,00 10,00

Power relations and levels decibell


2. CONNECTING VOLTAGE, ELECTRIC CURRENT AND PRESSURE

P = I2 ZP = E2/Z

Rate 10 log (E1/Eo)2 = 20 log (E1/Eo)

Level dB = 10 log (E1/Eo)2 = 20 log (E1/Eo)

Rate dB = 10 log (I1/Io)2 = 20 log (I1/Io). Level dB = 10 log (I1/Io)2 = 20 log (I1/Io).

Rate dB = 20 log (P1/Po). Level dB = 20 log (P1/Po).


Determine the level of db to comparison voltage, flow and pressure

Comparating Voltage, Current and pressure

Level (dB)

1,00 0,00

1,25 2,00

1,60 4,00

2,00 6,00

2,50 8,00

3,15 10,00

4,00 12,00

5,00 14,00

6,30 16,00

8,00 18,00

10,00 20,00


3. Tier Pressure contours Relations Voice (SPL) and the Violence Voice (Loudness)

Sensitifity hear ear


Frequency response characteristics slm


Typical level of sound in general


4. Strong inverse proportionate Voters With Wide

Conection revers kuadrat


Nomograph to determine loss proportionate inverse square


5. The addition of Power Level in dB 6. Level Preferences

Monograph ekspression add power in dB


7.Value Signal Peak, average and RMS

Most of the measurement of voltage, current, or sound pressure in the acoustic work is given in RMS (root mean square).

RMS value of the wave form of the same repetitive with its equivalent value in the DC power transmission.

Puncak ke puncak 2 volt

1,0 puncak

0,707 rms

Rata-rata 0,637

1

0

-1

Volt


Based on the image to sine waves with the maximum value of 1 volt, the value rms the same as the maximum value divided by 2 (Vm/2) =0,707 volt (0.707 Vm) , equivalent to 3 dB difference.

The average value of sine wave equal to 2 times the maximum value divided or 0.637 volt

waktu

Nilai puncak

Nilai rata-rata

Gambar 1-45. Harga puncak, rata-rata dan rms gelombang

sinus (A) dan bentuk gelombang komplek (B)

explaining decibel understand nature signal audio by sarbini, s.pd (smk muhammadiyah 3 yogyakarta)

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