Hey. I recently took apart an old monitor that was broken and sourced out a set of speakers. As the monitor is broken, I can't test how much voltage it put out to the speakers. I'm afraid I will overvolt them, so I need to know how much voltage it can take. I know I could use Ohm's law if I had the resistance and amperage, but I can't get the amperage without applying voltage to it.. Is there any way to get what voltage is needed? I've looked all over the speakers trying to find a model number, but none of the numbers or sequenses of letters I found on and inside the speakers found a match on google.
so I need to know how much voltage it can take.
Basically you can't make any measurements simply that will give you that information.
The simplest way would be to set up a microphone into an oscilloscope. Then apply a signal from a sin wave generator and increase the voltage until the microphone's signal begins to clip. Then turn it down about 10% and use that.
However it is normally the wattage that defines how hard you can drive a speaker not the voltage.
Measure the speaker resistance (or read the impedance from the label!), and estimate the
power dissipation from the coil size - speakers are normally thermally limited. Look at some
details of speakers from websites to compare size / weight / power handling.