#MusicMonday: Expert Advice on ‘Microphone Levels & Pressure Zone Mics’ | #audiophile
Good, quick read from EDN on PZMs – possibly how impulse responses are designed, although I’m still piecing together the theory behind it all let alone the real-world applications.
Many engineers and audio people don’t realize just how much signal can come out of a microphone. A hot mic with large signal can output many volts. That a dynamic microphone does this with a 120 ohm impedance is all the more remarkable (Figure 1). My pal, audio guru Steve Williams, recalled an entry in the Ampex Audio Digest bulletin board system (BBS):
“The circa 1968 demo for those who didn’t understand how much level could come out of a microphone (like those who were still trying to do rock-n-roll with Altec 1567 mixers with no input attenuators): Take your Simpson 260. Set it on the 2.5 VAC range, and connect it to the output pins of a Shure vocal mic. Hand the mic to someone with a good set of lungs, and have them do a good rock-n-roll scream. I never saw anyone pin the meter at 2.5 volts, but 1.5 volts was easily achieved.” anon
Figure 1 This plot shows microphone levels of a speaking voice can easily reach 0.1 volts. Shouts, screams, or loud music can be 20 times greater. (Source: Clifton Laboratories)
Make a robot friend with Adafruit’s CRICKIT – A Creative Robotics & Interactive Construction Kit. It’s an add-on to our popular Circuit Playground Express, FEATHER and other platforms to make and program robots with CircuitPython, MakeCode, and Arduino. Start controlling motors, servos, solenoids. You also get signal pins, capacitive touch sensors, a NeoPixel driver and amplified speaker output. It complements & extends your boards so you can still use all the goodies on the microcontroller, now you have a robotics playground as well.