Screaming high frequency loudspeaker?

Question

What actually happens if I take a piezo or magnetic hf loudspeaker and raise the voltage past the recommended limit please?

Thanks Marcus R.
What will happen if i drop the current so the total power does not exceed the maximum for the driver. However the voltage is increased. I know that increasing voltage will not increase heat so the driver is unlikely to burn out. I know the spl db output increases, but what will happen to sound quality please?

A couple of extra quick questions. Firstly, I understand that the loudspeaker will lose sound quality, and increase noise, however I was wondering how much of an increase in output would be gained? 5db, 10db, more..?

I have also heard that the increased voltage will cause the speaker to start broadcasting some electrical noise or emf, is this correct?

Hi LeAnne, thanks for this. I agree that Ohm's Law must hold (Where v = ir) however if a resistor is added to the circuit after the driver then the total resistance of the circuit has increased. As you know resistors are added in series (r = r1 + r2 + ...). Therefore v = ir will hold as the resistance has increased.

Now the power equation states p = iv. Where p = power, i = current and v = voltage. So i can increase voltage over the recommended voltage, and keep the current below the recommended amount, in such a way that the total power does not exceed the recommended power.

For those interested, see http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html click on "Electricity and Magnetism" then click on "Ohm's Law" and have a read. You may also go from here and click on the keyword "resistance" to see the information on "Resistor Combinations".

Answer 1

higher voltage lower amperage respecting the wattage ratio, according to ohm s law and simple formulas would lead you to believe that the voice coil in a speaker driver would heat less, in a sense its true seen as a simple resistance, but converting electrical energy to mechanical energy, isn t simple resistance, the action of the piston encounters resistance by the air opposing it and the voice coil experiences an electric counter faze reaction that also creates heat in the coil, and that happens exponentially as the speaker driver exceeds its manufactured specs., and the increase in voltage would also increase magnetic memory in the voice coil creating more resistance, and as for gain and increased sound, you would have to increase the voltage substantially to notice a difference or benefit in sound pressure and to that point the greatest problem would be voltage arcing. I answered your question excluding sound quality and longevity affecting the driver as per your request.

Answer 2

What exactly are you trying to do?

Raising the voltage will raise the current - that's simply a function that you can't get around.

Remember Ohm's Law? E=IR where E equals the voltage, I equals the current and R equals the resistance. As you can see, if the resistance (impedance) is constant, raising the voltage must necessarily raise the current - and that will toast the driver if it exceeds the maximum current handling of the devise.

Answer 3

You overload the curcuit.