Guitar rattle noise when playing two strings at specific distances (with video)

Question

Video link:

This has been bugging me for a while and I am one just one step away from taking to a repair shop.

My guitar is perfectly tuned and I have also adjusted the intonation (hopefully). The problem is that at particular positions, I get this annoying like buzz/rattling noise. Also, let's say I get this bad noise at position call it 'B', now, I can fine tune the guitar to solve this, but now position 'A' starts sounding bad.

Things I have tried:
1. Lower the pick ups
2. Raise the string action (remove fret buzz)
3. Lower the gain on the amp

Answer 1

I don't hear anything unusual.

With distorted guitar tones, anything but the perfect intervals (perfect fourths, fifths, and octaves) will sound muddy. For major thirds, it's tolerable; for others, it can sound jarring.

This is caused by intermodulation distortion. Basically, distortion adds sum and difference overtones. That is, when you play two notes with frequencies A and B, extra frequencies of A+B and A-B will also be heard. And this will happen for all overtones that are already present in the notes you're playing . With perfect intervals, these extra frequencies happen to fall on harmonically pleasing places, but for other intervals, they sound muddy.

This is the reason of the rattling quality of your major sixth, minor third, and major third (to a lesser extent). There aren't many ways around it. It's just how a distorted guitar sounds. And that's why musicians prefer power chords (bare fifths) instead of full chords on distorted guitars.

You may try lowering the gain until it's less jarring or recording separate parts to avoid it.

Answer 2

Dude, when your guitar is distorted, if you hit two notes that aren't harmonically aligned (I'm not much of a reader, but I think it has to do with fourths and fifths and octaves) then if the crossing sound waves hit each other and the peaks hit peaks (as with harmonically unrelated intervals) the result, at least when you're using distortion, will be a jarring "buzzing/dirty/grating" sound.

Try just playing 4ths or 5ths and you'll probably find that that effect goes away. Or turn down the distortion. It's not a physical fault of your guitar.