I have this solo and when i start double tounging for the fast part...i hear throat sounds and it`s not clear. i try to get weird of that sound...but i DON`T KNOW HOW!!

oops. i mean, i tried to get RID of the throat sound.

It could be that your using your throat to control the sound rather than your tongue. I have the same problem. When I first started playing I didn`t learn how to tongue, I just learned how to use my throat. It works fine for some parts, but if I try to go too fast, I`ll start getting that sound. I`m now in the process of teaching myself all over again (which is a pain.) Just try to keep yourself from stopping the air with your throat and instead use your tongue to simply interrupt it.

I think I know what you`re talking about.

Try forward tonguing.

You have to keep your throat relaxed, or this will happen, also keep your chin and jaw relaxed and use as little tongue movement as possible when you double tongue

Or if i don`t double tounge, i get this throat sound. hmm...it`s quite annoying. my teacher told me to relax..but how? i tried to force the throat sound, so i could figure out how i do it, but i could do it.

try singing and playing at the same time, but don`t toungue the notes, slur them to practice. It might take a few tries to be able to do it, but it REALLY helps relax your throat.