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 Measurement Microphone 20 microseconds per division Pulse retouched |
AKG CK1-C451 cardioid condenser mic 100 microseconds per division. Note polarity |
Electro-Voice DO-54 Dynamic Omnidirectional 100 microseconds per division |
Dan Gibson Parabola - Dynamic Mic 200 microseconds per division. Note second pulse which is from dish |
Sennheiser ME-88 / K3U Shotgun 100 microseconds per division |
AKG CK9 / C451 Shotgun 200 microseconds per division |
Sennheiser MKH-104 Omni 100 microseconds per division |