How can i convert dB to Hz? is there any relation between them? | Yahoo Answers
dB.. Decibels Power-ratio.. P2/P1 (P2 is the power being measured, and P1 is the reference) Voltage-ratio.. V2/V1 (V2 is the voltage being measured, and V1. The decibel (symbol: dB) is a unit of measurement used to express the ratio of one value of a The extra factor of two is due to the logarithm of the quadratic relationship between power and amplitude. .. The suffix is often connected with a dash (dB-Hz), with a space (dB HL), with no intervening character (dBm). When the frequency is in the range of several thousands Hz, the sound can still be . The lowest sound audible with a normal (average) hearing is 0 dB (2 ∙ .
According to Hickling, "Decibels are a useless affectation, which is impeding the development of noise control as an engineering discipline". One advantage is that the total decibel gain of a series of components such as amplifiers and attenuators can be calculated simply by summing the decibel gains of the individual components.
Similarly, in telecommunications, decibels denote signal gain or loss from a transmitter to a receiver through some medium free spacewaveguidecoaxial cablefiber opticsetc.
The decibel unit can also be combined with a suffix to create an absolute unit of electric power. For example, it can be combined with "m" for "milliwatt" to produce the " dBm ". A power level of 0 dBm corresponds to one milliwatt, and 1 dBm is one decibel greater about 1. In professional audio specifications, a popular unit is the dBu. When used in a ohm circuit historically, the standard reference impedance in telephone circuitsdBu and dBm are identical.
Video and digital imaging[ edit ] In connection with video and digital image sensorsdecibels generally represent ratios of video voltages or digitized light intensities, using 20 log of the ratio, even when the represented optical power is directly proportional to the voltage, not to its square, as in a CCD imager where response voltage is linear in intensity.
Most commonly, quantities called "dynamic range" or "signal-to-noise" of the camera would be specified in 20 log dB, but in related contexts e. Photographers typically use an alternative base-2 log unit, the stopto describe light intensity ratios or dynamic range.
What is dB and frequency?
Suffixes and reference values[ edit ] Suffixes are commonly attached to the basic dB unit in order to indicate the reference value by which the ratio is calculated. In instruments such as the pipe organ it is augmented with a variable number of partial tones that enable the listener to detect the musical pitch of the tone. When the frequency is in the range of several thousands Hz, the sound can still be heard, but defining its exact pitch becomes problematic. Pitches beyond the six-lined C C6, Hz are usually not defined.
It is very difficult to determine the pitch of tones any higher than this. As mentioned earlier, frequencies can be detected up to approximately 20 kilohertz kHz.Decibel (dB): What is dB, dBm, dBW, and dBV in Electronics? Difference between dB and dBm
This limit is, however, more or less approximate and depends of a variety of factors, such as the intensity of the sound. Young individuals are able to detect even higher sounds as something more than mere pressure variations occurring inside the ear. The upper limit of the hearing range, however, unavoidably falls with age, and many elderly individuals may have trouble hearing even loud sounds below 10 kHz. Defining the hearing range as the range between 16 Hz and 20 kHz or any other range cannot therefore be considered more than a highly artificial average that only pertains to young population on the whole.
The following equations hold true between frequencywavelength and sound velocity: The successive compressions of the sound wave are 75 centimetres apart.
Sound velocity depends on medium such as metal, water or air and temperature. The velocity of sound propagating through air is In the following exercise, you will have an opportunity of seeing for yourself how sound velocity is affected when the air temperature changes. What is the speed of sound on a cold winter day oC?
Sounds higher than 20 kHz are called ultrasoundswhile sounds below 16 Hz are called infrasounds. C cent, from Lat. It stands for one hundredth of an equal-tempered semitone. In other words, one octave consists of cents. An equal-tempered whole tone can be expressed as C, while an equal-tempered fifth would be C, or seven semitones.
Decibels: dB Frequency Ohms Law
Cents are used to express the size of individual microintervalsbut also to illustrate the ratio of any given interval such as a second or a third. The differences between the intervals of different tuning systems can be compared easily when the intervals are expressed as cents. In an equal-tempered system the intervals are always multiples of one hundred.