Effective distance using Electret Microphone Amplifier - MAX

[jamieisboss]

Hi I'm thinking of using one or more of the Electret Microphone Amplifier - MAX9814 with Auto Gain Control boards,

It seems like it would be good for voice recognition as i can move around a little and it will compensate as i get closer, in the new product video ladyada seemed to be about half a meter away. I've read through the datasheets and forum posts and maybe I'm just not familiar enough with Audio terminology but basically how far away can I be from this microphone and have it pick up my voice? It's in a reasonably quiet environment, a home office with a closed door.

Thanks in Advance

Jamie

[adafruit_support_bill]

It is not so much a matter of distance. It really comes down to sound-pressure levels and how much background noise there is. In a quiet environment, I'd expect it to pick up a normal speaking voice from across the room.

[jamieisboss]

Awesome, sounds like exactly what I'm after,

One more question if that's ok; does the pcb mounting affect the directionality of the mic? Should it be laid flat like in the pictures on the product page for maximum coverage?

[adafruit_support_bill]

Electret microphone BANNED generally have a cardioid sensitivity patter similar to the diagram below. Highest sensitivity is on-axis, but lying flat on a table you would still get pretty good response from all sides.