Concerned with guitar

[kpinks]

I noticed on my guitar, when I play a perfect 4th or 5th on the high E and B strings above the 15th fret, they sound slightly dissonant. I restrung with new strings, checked intonation and everything seems fine, until I play these 4th's and 5th's on the high frets? They are in tune on the lower fret register. What does this mean and how do I fix it? Is it possible I have an uneven fret or something?
Thx
Kev

[Rich]

It is intonation, and even if you match the strings to each other 30% of the notes will still be out.

[Kasper Kowalski]

Originally Posted by kpinks

I noticed on my guitar, when I play a perfect 4th or 5th on the high E and B strings above the 15th fret, they sound slightly dissonant.

welcome to the joys of equal temperament tuning. in short, nothing you can do... the guitar is a compromised instrument and will never sound perfect everywhere on the neck.

[Petie]

Easy fix: Vibrato the hell out of absolutely everything you play