not "too much" back bow Shred ...its too little or none at all !!
have a look at your guitar (not u shred) from tail end towards the the neck line ....what do you see ?? or press down string at 1st fret and 9th fret at the same time ....now is there a minute clearance or is it touchin any in between frets ?? if it is then there isn't any bow thus causing buzz !!