Legato playing on higher frets

[waxlyrical]

For some reason, the notes don't ring out as clearly when i access the higher frets (12th fret above) when playing legato. The low frets are commonly known to be harder to play but i don't have a problem with that. I'm using the same technique when playing different parts of the neck.

any advice on how to counter this problem?

 

[csds92]

IMO, im thinking maybe ur guitar's neck is a little convex? if not, the only thing left to do is to practice till ur fingers have enough strength to hammer and pull off the higher frets~

 

[subversion]

we often neglect playing our routine practices at the upper frets. the finger posture/ pressure are just different when we play there. part of the psychology is to overcome the bulky neck heel which affects our fingering...

 

[Watchtower]

Bring your thumb lower to compensate for the change in position. It's not comfortable up there.

 

[garbagetruckdriver]

Watchtower is right, your left hand position is crucial. You may have to raise the height of the guitar strap, or pull a van-halen-esque guitar hero pose to get your hand in the right position. Ideally you want your thumb behind the neck, not hanging over it.
Of course, you may want to take a look at the set up of your guitar. Most legato players only need a light touch because they will have their neck truss rod set for something like 0.006" relief at the 12th fret (if you don't know how to set this up, get a luthier to teach you) and have a generally low action with light strings. I like jumbo fretwire - Malmsteen likes to scallop his fretboard... Whatever -it all helps you get a lighter touch, which really helps when you want to sound fluid.