Ah, okay, thanks. I was supposed to measure the amplitude on an oscilloscope in terms of a peak to peak voltage. How can I convert avg. 75 dB to units voltage gain? I looked up dB = 20 log(V2/V1), so would it be:This is impossible to answer because we don't know the efficiency of the speaker.
However, you might try for 70db to 80db as, "comfortable".
P = V^2 /RYou are completely out of the ball park. The missing part is how much sound the speaker makes for a certain voltage of input. Without that, you have nothing. I have seen speakers rated for 78 db for one watt at one meter of distance and 103 db at one watt of input and one meter of distance. Suppose you have a really awful Radio Shack speaker at 78 db per watt. What voltage puts one watt into an 8 ohm speaker?
VRMS = Vpeak/2^0.5 = 2^1.52.82 volts is the RMS value. You have to convert that to peak-to-peak.
You forgot the square root of 2 to get from RMS to peak.
NOW you use db = 20 log (V2/V1)
dB SPL? That's not exactly a 'comfortable' listening level in a room:This is impossible to answer because we don't know the efficiency of the speaker.
However, you might try for 70db to 80db as, "comfortable".
nice link!dB SPL? That's not exactly a 'comfortable' listening level in a room:
http://www.sengpielaudio.com/TableOfSoundPressureLevels.htm
Says a vacuum cleaner at 1m is 70dB and a busy street is 80dB SPL.
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