Originally Posted by: bilinmeyen.13

I think tuning keeps getting better, but ive noticed that there is a minimal intonation problem on g string ...[/quote][p]Good observation.

Yes, you are right. The guitar is difficult to keep intonation consistent with both open string notes & fretted notes. This is especially noticable on acoustic guitars with non-compensated bridges. Sometimes you can lower the bridge a bit. Or lower the nut slot on the G string. Those can help you close the gap. But the are pretty drastic options & best left to a pro guitar tech.

This is why electric guitars have individual sliding therefore adjustable bridge saddles. To close the gap between the open string notes & the fretted notes.

Another possible solution is to install a compensated bridge for acoustics.

http://www.musiciansfriend.com/accessories/graph-tech-tusq-fully-compensated-saddle-1-8

https://www.youtube.com/watch?v=Xm1pXryt0Nk

The idea is to have a bridge topology with the necessary micro adjustments to get better intonation. Again, this is definitely a job for a pro guitar tech.

Originally Posted by: bilinmeyen.13ive researched a bit and people on internet say that this is normal no guitar is perfectly intonated, no fret is perfectly intonate according to a=440 there is always a minimal difference, is this true?

It depends on what you mean by perfect. :)

There are some musicians that claim since real world fretted instruments can't play in just intonation in multiple keys, they are imperfect. So, if you want to play in multiple keys across an instrument (guitar, piano, etc.) you have to use a different tuning called equal temperament, which, unlike just intonation, has "beats" so it's a compromise & imperfect.

Personally, I think it's poor reasoning to claim that something that is impossible to do is the standard of perfection & that something that solves a problem is imperfect & a compromise. In my estimation, equal temperament solves the problem perfectly & is therefore perfect, as well as practical.

Every time I have a discussion or debate about this topic with someone that claims equal temperament is somehow imperfect, I ask the question, "Why is having no beats on any interval a desirable solution?" That's the crux of the issue. Another good question is, "Why is having no beats on any interval preferable to being able to play chromatically in multiple keys?"

Anyway, it's a complex topic. :) Here's a wiki article about it.

https://en.wikipedia.org/wiki/Equal_temperament

Meanwhile, back in the real world. :p Regarding the guitar, it is difficult to tune completely across the guitar. But most of this is due to the difference in angle between 2 different things:

1. An open string note which rings from nut to bridge with no angle.

2. A fretted note which immediately has an angle from the nut to the fret you are fingering, then back up toward the bridge.

That's why sanding down the nut slots & getting a better bridge can help narrow the gap between open & fretted notes. But most of this is due to the nature of trying to make a machine precise enough that it will work no matter where a human finger is placed, high or low on the fretboard.

[quote=bilinmeyen.13]

...is g string a little thicker (maybe) then the first two nylon strings? can you tell me are these frequencies normal (a fret on g= 220.6 g 12th= 394.4 g open= 196.0)

If you are tuning to A 440Hz, then the open G string is 392Hz.

https://www.seventhstring.com/resources/notefrequencies.html

But, yes you will probably notice small differences all the time between the fretted notes & the open string notes.

Hope this helps!