microphone input -> speaker input

[davejs]

Hi

I am new here and dont have lots of knowledge of what i am trying to do but here is my question.....

I have a small device that can record sound when you press a button via an inbuilt mini microphone. This is then played back when another buttin is pressed. Very simple.... but i want to record sound direct into the device via my pc. (not through air into microphone)

I have removed the microphone from the device and soldered the wires from PC speaker direct onto the two remaining microphone connections!

This does actually work when i playback music from pc and then press record button on device BUT the resulting recorded sound is distorted when it is played back.

If i adjust volume on pc speakers as i record into the device it does not seem to change the level of distortion although the recording does reflect the volume change... but distortion remains.

I am guesing i can not simply expect the microphone input connections to accept what ever is coming down my speaker wire!!

Anyone have any advice as to how i would go about working out how to make this work without distoted sound being recorded?

Maybe a simple explanation of speaker and microphone electronics would also be a good idea, i have looked this up and think i am correct in thinking speaker wire is outputting variable AC levels depending on volume but thats about as much as i understand!

Cheers
Dave

 

[audioguru]

The output level from a microphone is only about 0.01V so the preamp has a lot of gain.
But the output level from a speaker is a few volts which is 500 times too high to feed into a mic input even if the speaker volume control is turned down.

You need to make an attenuator with two resistors.

 

[davejs]

Thanks for this, been looking up attenuators and resitors... still learning lots...

Is this the sort of thing i should be doing:

Line signal to microphone input

Thanks
Dave