Sorry for replying lately
with the PC are you going into the mic input? Does the PC have the options of Line or Mic input?
my pc has mic input
If you don't know much about electronics you're better off buying a commercial device.
Something like
http://www.amazon.com/Sonic-Super-P...H8G4/ref=sr_1_1?ie=UTF8&qid=1318892982&sr=8-1
Would work for you, 30 dollars is not expensive and even if that isn't sufficient simply adding a parabolic reflector will increase range and directionality dramatically.
Years ago I built a pretty simple amplifier with a home brew parabolic dish. It was directional but you could hear and record the birds in the trees.
i need an omnidirectional mic
It is simple to make a high gain preamp for a microphone. But what about loud motorcycles and jet airplanes?
I want to record footsteps or more accurately people on the stairs of my apartment.An audio detection software (like
http://www.zonetrigger.com/sound-detection/) will email me recordings whenever it detects someone so that i will know if someone is waiting for me inside the building.It may sound paranoid but there were some incidents around here lately.
I bought a cheap microphone and made some recording with audacity software
audacity software (to open the recording):
http://audacity.sourceforge.net/
recording:
http://www.2shared.com/file/uvcP35JD/1_online.html
Recording is amplified with 35db gain.I cant use audacity for my purpose because it doesnt amplify sound realtime.
My flat is on the second floor.In the recording i descended to the ground floor (at about 38th second) and then began climbing.
I want to be able to hear footsteps two floors up and down.Cheapest solution seems to be making a pre amp circuit.For a much more louder and clearer recording which simple preamp circuit do you advice?
specifications of the microphone i used for recording:
omni-direction
output impedance:1.4k+-30%
frequency response:50~16khz
sensitivity:-58db+-2db
operating voltage:1v~10v
current consuption:0.8ma max
s/n ratio 40db or more