# Decibel & voltage formula

• introuble
In summary, you are conducting an experiment with a speaker connected to a power supply playing a continuous note. You will be using a decibel reader to measure the volume from 0v to 12v. To compare these results, you can use the equation G_{\mathrm{dB}}=20\log V, where G_{\mathrm{dB}} is the decibel value and V is the voltage measured in volts. This equation uses log base 10. To find the amplitude of the sound, you can use the equation A=10^{\frac{G_{dB}}{20}}, where G_{\mathrm{dB}} is the decibel value. This will give you the amplitude of the sound as a function of

#### introuble

Hey I am writing an experiment which has a speaker connected to a power supply playing a continuous note. a decibel reader reads the volume from 0v to 12v. i know that as the voltage goes up so does the decibels but what theorem can i use to compare this with the results that will be recieved? thanks To convert voltage into decibels:
$$G_{\mathrm{dB}}=20\log V$$

Where $$G_{\mathrm{dB}}$$ is the value in decibels and V is the voltage measured in volts.

Thats log base 10 by the way :tongue:

Eidos said:
To convert voltage into decibels:
$$G_{\mathrm{dB}}=20\log V$$

Where $$G_{\mathrm{dB}}$$ is the value in decibels and V is the voltage measured in volts.

Thats log base 10 by the way :tongue:

How would i use this? i am really confused atm lol does it depend on the speaker size or not.

Ok, start slowly.

What are you trying to measure?

My understanding is that you are playing a pure tone from a signal generator into a speaker. Then what?

I thought that the 0v to 12v was a voltage out across the speaker terminals that you wanted to convert to decibels.

A db to watt per speaker might be better.

Eidos said:
Ok, start slowly.

What are you trying to measure?

My understanding is that you are playing a pure tone from a signal generator into a speaker. Then what?

then by a decibel reader i read the decibels from the speaker and and turn the voltage up and record the decibels again.

Ok, so the decibels are from the sound and you want to find out the amplitude of the sound as a function of the amplitude of the voltage put into the speaker.

Is that right?

If it is:
$$A=10^{\frac{G_{dB}}{20}}$$ will give you the amplitude of the sound. The amplitude of the voltage is a known quantity then since you are putting that into your speaker.

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## 1. What is the formula for converting decibels to voltage?

The formula for converting decibels to voltage is V = 10^(dB/20), where V is the voltage and dB is the decibel value.

## 2. How do I convert voltage to decibels?

To convert voltage to decibels, use the formula dB = 20 * log(V), where dB is the decibel value and V is the voltage.

## 3. What is the relationship between decibels and voltage?

Decibels and voltage have a logarithmic relationship, meaning that a small change in voltage can result in a large change in decibel value.

## 4. Can decibels and voltage be negative?

Yes, both decibels and voltage can be negative. Negative decibel values indicate a decrease in sound or signal intensity, while negative voltage values indicate a decrease in electric potential.

## 5. What are some common uses for the decibel and voltage formula?

The decibel and voltage formula are commonly used in audio engineering to measure and adjust sound levels, in electronics to measure and adjust electrical signals, and in telecommunications to measure and adjust signal strength.