On Mon,1/23/2017 12:54 PM, Jim Brown wrote:
The impedance of mics is defined as 5X their minimum load impedance.
Correction -- one-fifth of their minimum load impedance. For example, a 250 ohm mic should drive an input impedance no lower than 1.25K. Most pro mics are in the range of 150-250 ohms.
Another point I forgot to mention. ALL electro-acoustic transducers (mics, loudspeakers, headphones) are very complex, and their equivalent circuits are also very complex, containing multiple reactive components and a few resonances. The impedance curve of a typical loudspeaker or headphone has a low frequency peak of hundreds of ohms, a broad minimum at the lower middle of its operating range, and rises rapidly with frequency as it approaches the top of its operating range. The impedance of a loudspeaker or headphones is defined as that minimum value of the impedance. Multi-way loudspeakers have two such drivers, each with its own equivalent circuit, fed respectively by low pass and high pass filters.
73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
