Microphone external vs built-in


Hi folks! I wonder about this small thing. Have newer liked movie shooting too much. But I am quite fond of going on concerts and occasionally record a part here and there just for memories. And I shoot some documentary things sometimes also. Rarely, I must say, but anyway.

However. These last weeks of good prices made me buy an external microphone! It have got quite ok reviews, it has frequency response of 35-20k Hz (spec). So I thought it should be a big step up regarding quality.

After some shooting and comparison with built-in mic, cellphone with built-in and this, and also, computer with a table mic. I concluded that this microphone has the flattest sound of ALL tests I did. Clearity however is probably best. But the sound is somewhat flat in comparison. I noticed that you need to adjust the gain manually to get better sound overall. But even when I have tweaked gain (and has the camera set to "wide range") the outcome is the opposite of what I thought it would be.

However. Since the clarity is good, and probably the sound file is of high quality (and resolution), so after some post-processing it might sound better. But aside from that, I think the original file could sound a little more vivid.

Anyone has some ideas of this? Is this normal for external microphones? I have no idea, never used external before.

Here is a photo of camera with mic:
(no idea what spec the internal mic has, but it seems quite "ok")

Here is a photo of my table mic for the computer which I also compared with:
(20-20k Hz spec)