Something WEIRD about fret buzz...

Hi everyone!

I wanted to share something that might interest you. There is something weird about fret buzz Ive noticed and I want opinions.

So, I have three guitars. Before telling you, I will say I took all of them to my tech and the nut and bridge is set up for all of them. Also, they have more than 18 lbs of tension.

- 7 string: It has .72 as the lowest string. Has quite a nice neck relief and action is near 1.50 on the lowest string.

- First 6 string: It has a .58 as the lowest string. Very little neck relief and action is 1.25 on the lowest string.

- Second 6 string: It has a .52 as the lowest string. Almost NO relief, and action is something stupid between 1.0 and 1.25 on the lowest string. As low as it can get.

Now, the thing is... my second guitar is the one that has the less fret buzz, and somehow, my seven string is the one that has the most fret buzz. Of course, its not fret buzz across all the fretboard. Its just sometimes, not anoying at all. But logic tells me the second six string should be the one with the most buzz but is the one with less. Funny thing, it is a brandless chinese guitar.

Why do you think this happens? Tell me you knowledge!