School project wm-61a question

I am building a mic preamp out of transistors and modifying a wm-61a capsule for a school project. On Linkwitz-Riley's website it says the capsule has a 5V peak to peak output voltage swing at about 140 db. This seems really high. Is this correct or is it a lower value. If its wrong what is about the output voltage from the capsule. Thanks


Paid Member
2007-09-15 8:14 am
Use a 'scope and measure it. 140dB, what are you trying to measure, a rifle shot ? :) In all fairness it's a valid question but one that is not easy to answer. Do as you say 9volt, 10k resistor and measure across capsule, clap your hand next to it and try and get a peak voltage reading. Not sure if this would work but why not use a speaker of known sensitivity e.g. 90dB for 1 watt @ 1 meter and try and calculate and interpolate readings yourself. Each doubling of power will give 3dB increase. 1W 90dB 2W 93dB 4W 96dB and so on. Measure the output and project results out to 140 dB.Would be interesting school project I would have thought.
Regards Karl