Microphone impulse response

One is prone to wonder, from time to time, why do microphones sound so different. Or, the microphone as a filter. An uncommon but informative view is the impulse response of a mic. To get a fast enough pulse I made a high voltage spark discharge in a space reasonably free from echos at high frequencies.  The scope photos shown here are pretty much un-retouched. The Polaroid's are ten years old and fading. I thought it made sense to share these rather that wait until I got a paper put together. When I did these I was still doing a lot of bio-acoustics stuff where response to rapid pulses was very important. Shotgun mics and a parabola with a dynamic mic are included because most of that type of recording is done in the field at some distance from the critter. You can see that every mic wants to sing along. Some more than others.

Bruel and Kjaer 4133 15kb

Bruel and Kjaer 4133 Measurement Microphone 20 microseconds per division   Pulse retouched

AKG CK1 / C451 Cardioid Mic 15kb
AKG CK1-C451 cardioid condenser mic
100 microseconds per division. Note polarity
EV DO54 Omnidirectional mic 14kb
Electro-Voice DO-54 Dynamic Omnidirectional
100 microseconds per division

Dan Gibson Parabolic Mic  14kb
Dan Gibson Parabola - Dynamic Mic
200 microseconds per division.  Note second pulse which is from dish

Sennheiser ME88 / K3U Shotgun Mic 15kb
Sennheiser ME-88 / K3U Shotgun
100 microseconds per division
AKG CK9 / C451 Shotgun Mic 13kb
AKG CK9 / C451 Shotgun
200 microseconds per division
Sennheiser MKH-104 Omnidirectional Mic 17kb
Sennheiser MKH-104 Omni
100 microseconds per division