Decibel & voltage formula

  • Thread starter introuble
  • Start date
  • #1
introuble
3
0
Hey im 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:smile:
 

Answers and Replies

  • #2
Eidos
108
1
To convert voltage into decibels:
[tex]G_{\mathrm{dB}}=20\log V[/tex]

Where [tex]G_{\mathrm{dB}}[/tex] is the value in decibels and V is the voltage measured in volts.

Thats log base 10 by the way :tongue:
 
  • #3
introuble
3
0
To convert voltage into decibels:
[tex]G_{\mathrm{dB}}=20\log V[/tex]

Where [tex]G_{\mathrm{dB}}[/tex] 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 :confused:

does it depend on the speaker size or not.
 
  • #4
Eidos
108
1
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.
 
  • #5
sirzerp
33
0
A db to watt per speaker might be better.
 
  • #6
introuble
3
0
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.
 
  • #7
Eidos
108
1
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:
[tex]A=10^{\frac{G_{dB}}{20}}[/tex] 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.
 
Last edited:

Suggested for: Decibel & voltage formula

  • Last Post
Replies
1
Views
1K
Replies
9
Views
10K
  • Last Post
Replies
5
Views
9K
Replies
1
Views
5K
Replies
4
Views
889
  • Last Post
Replies
1
Views
2K
Replies
10
Views
5K
Replies
10
Views
2K
  • Last Post
Replies
14
Views
3K
  • Last Post
Replies
4
Views
1K
Top