Why is an Acoustic Guitar so much LOUDER than an Electric Guitar?

[MileHigh]

The Observer:

By the "energy drain" I mean the following:  As you listen to the sound of the plucked string you know that the energy has to be going somewhere.  Some is obviously going into the air, some is making the body of the guitar vibrate, etc.  The final destination for all of the vibratory energy is heat energy, a.k.a. "heat."  So if you pluck a string and put 10 units of energy into it, you ultimately end up with 10 units of heat.  It might take two seconds, five seconds, or ten seconds, but you always end up with 10 units of heat energy.

So that's what I mean by the "energy drain to heat."  The vibrational energy becomes heat energy, and the longer it takes to get there, the slower you are "burning off" your vibrational energy and turning it into heat energy.  The rate of the burn-off is measured in units of power, Watts.  The vibrational energy is measured in Joules and the heat is measured in Joules.

    Well yes and no.
            Yes....Sound waves crossed the other strings and started them vibrating.
            No... No more energy left the Low E String to accomplish this !

Incorrect.  Energy does leave the Low E string (first one plucked) to get other strings vibrating.  This is fact.  The only way a second string can get vibrating in your example is to have energy get transferred into it from the first string.  The amplitude of the first string's vibrations decrease as a result of the energy transfer.

And reinforce the system of aforementioned Resonators including the High E. 

There is no "reinforcement" going on anywhere.  The initial energy from the string pluck is simply physically moving through space into the guitar body and air, etc, and at the same time this fixed original amount of energy is being converted into heat energy in various places.

My point is... our ears are not sensitive, they need to be UNsensitive to cover the range of volume that they do.

If you do some more reading you will find that human hearing is both sensitive and insensitive, it's dynamically adaptable and you are not normally conscious of it.

My next post will include a College Text Book Proof that the waves emitted from an Acoustic Guitar
                            are indeed 1000 times more Powerful than those from an Electric Guitar.

I am sure that you can find something but you have to understand the subtle point behind all of this.  Assume both the electric and the acoustic guitar strings are plucked and store the same initial energy.  Let's split the final form of the energy in this case into sound energy and heat.  The acoustic guitar will certainly convert more of it's initial energy into sound energy as compared to the electric guitar.  You assume that most of the heat energy in the case of the electric guitar is converted into heat in the body of the guitar.  That's your answer, as simple as that.

MileHigh

[The Observer]

Question...

How many times more powerful is an Acoustic Guitar than an Electric Guitar?
(Assume Acoustic is 60db and Electric is 30db at a nearby distance.)

                           30 db = 10^-9 W/m²            60 db = 10^-6 W/m²

                                      Intensity = Power/ Area

     Because we know The Intensity of the Wave in both situations         
                                                                            (Acoustic vs. Electric),

                 We rearrange using simple algebra .....    Power=Area * Intensity

     Acoustic Power is..... Area*10^-6 W/m²
     Electric Power is .... Area*10^-9 W/m²

              Divide answers for Ratio....(note -  Area cancels out if you were wondering where it went)

                    Acoustic Power /  Electric Power = 10^-6 W/m²  / 10^-9 W/m²

Ratio is 1000.
                            Or
                                 An Acoustic Guitar is 1000 times more powerful than an Electric Guitar !

Is it any wonder that Tesla was Obsessed with Resonance?
             And that nearly every bit of Stanly Meyer's inventions exploited Resonance?

Best Regards,
                     The Observer

[MileHigh]

The Observer:

You are correct, let's assume that an acoustic guitar can produce sound that's 30 dB, or 1000 times, higher in intensity than an unplugged electric guitar.

Then when you look at this situation at a deeper level, and since we are on a forum that is all about energy research, you want to be more precise with your choice of words to explain the phenomenon that you are observing in terms of energy.

In that sense, the acoustic guitar is not "1000 times more powerful" than the electric guitar because neither of these devices is a source of power or a source of free energy.  Saying that the acoustic guitar is more "powerful" than the electric guitar implies that there are inherent sources of energy in both guitars and that's not the case.

You can restate it like this:  If you put the same energy into acoustic and electric guitars by plucking their strings, the acoustic guitar can produce 1000 times the sound intensity of the electric guitar.

Again, both types of guitars are passive devices that only respond to energy being put into them and they react by resonating.  Some of the energy stored in the resonator becomes audible sound, and within a fraction of a second the audible sound energy becomes heat energy.  The rest of the energy stored in the resonator becomes heat also.  For the electric guitar, it is safe to assume that a substantial amount of the energy stored in the plucked string resonator makes the whole body of the guitar vibrate.  The vibrating guitar body quickly turns this vibrational energy into heat energy.

Here is a thought experiment:  You have an electric guitar and you suspend it in air with two wires.  Next to the guitar there is a rotating wheel with a pick on it.  The wheel rotates at two revolutions per second so the guitar string is being plucked twice per second.  You have a thermocouple attached to the middle of the guitar on the back of the guitar.  You note the temperature of the guitar body, then switch on the rotating wheel and start the experiment.  The temp of the guitar body at the start of the experiment is 20.2 C.  After one hour the temp is 20.8 C.  After two hours the temp is 21.3 C, etc.

The conclusion:  When you pluck the guitar strings of an electric guitar some of the string-pluck energy becomes heat energy, and this heat energy slowly starts to heat up the body of guitar itself.  With further measurements we could calculate how many milli-joules of heat are produced with each string pluck.

MileHigh

[The Observer]

Mile High,

I appreciate your time on this.

If there's one thing I know about you... you like to talk about heat.

OK... let's talk heat.

Your thought experiment is to find out how much of an electric guitar's string energy is transfered
              to the hard body of the electric guitar using a thermometer.

I like it !

I just want to add one more thing to it if I may.

Let's substitute the acoustic guitar for the electric in your automatic string plucker thing-a-majig.
    Then place the hard body of the electric guitar next to the acoustic.

Now the hard body is absorbing waves 1000 times larger than before !

         Because Waves of Higher Amplitude carry More Energy...
            This means the hard body will heat up far faster than when absorbing only the waves from the string.

                 The extra heat is the extra energy I am talking about.

                                            The Observer

[MileHigh]

The Observer:

I give you credit for putting up a spirited argument.

Now the hard body is absorbing waves 1000 times larger than before !

         Because Waves of Higher Amplitude carry More Energy...

The problem here is you are not putting a number on the waves that are "1000 times larger."  Larger than what?  How large are they?

Let's try to answer those questions.  First of all, there is no "what" to compare to.  Let's answer how large they are, which is the real question.

For starters, lets talk in terms of average power, because it is easier.  The string plucking has an average power associated with it, the resonating strings, the sound energy, etc.  Every measurable energy process in the system is running at some average power.

To make life simple, let's just say that we start with 100 units of average power at the input, the string plucking.  Now let's follow the energy trail:

String plucking - 100 units
Less 2 units lost to heat (a.k.a inefficiencies)
Strings resonating - 98 units

Now let's beak down the string resonating power, it gets split into three things
audio power - 5 units
heating body of guitar - 33 units
heating air in vicinity of string - 50 units

Now let's see what happens to the audio power
audio power heating up electric guitar body - 1 unit
audio power reflecting off electric guitar body - 4 units

So, you started off with 100 units of string pluck power going into the acoustic guitar, and only 1% of that energy ended up heating the body of the electric guitar.

Here is something to ponder:  When you feel heat with your fingertip, you might be sensitive starting at about 1/4 watt of power.  However, when you hear sound with your ears, you probably start to hear sound when the audio power is around a few microwatts or even much less than that.  A loud acoustic guitar might be putting out 1/10th of a watt of acoustic power.  I am just taking ballpark guesses.  But when you barely pick one string, that's microwatts of audio power and you can still easily hear it.

For your ideas, you can try to follow the "energy audit trail" as a thought or real experiment.

MileHigh