MSGEQ7 + microphone

I'm going to try to build the classic LED spectrum analyzer. Surfing the Net I found lots of tutorial but I do not understand if it is possibile to use a microphone instead of a 3.5mm jack as audio souce. What about the sound sensor modules? Do they give just the intensity of the sound or the can be used in my project?
Thanks

You do need a preamp because the signal from a mic is about 1/100th the voltage of a line-level or headphone signal. Of course, the actual voltage depends on the loudness and the microphone sensitivity. (Electret microphones also need power.)

What about the sound sensor modules? Do they give just the intensity of the sound or the can be used in my project?

I've seen two kinds. There are sound sensor boards that put-out a digital signal when the sound is louder than a preset level (not what you want). [u]This one[/u] has an actual analog audio signal output. The SparkFun board has a 2.5V biased output (so you can run it into the Arduino without loosing the negative half of the audio signal). You'll need a capacitor between the microphone board and the MSGEQ7 to block the DC. (The MSGEQ7 may need a capacitor anyway, as shown on the datasheet.) It also has fixed gain, so there is no adjustment.