silent notes in middle and low register?!

yeah that's the problem i have to deal with...I tried to blow harder, but the sounds only got worse: the notes in the low register either get weaker or just silent, and the notes in the middle register end up being very high-pitched... can anyone please help?!

I don't have problems with middle regster, but in low register; DO NOT blow hard....Well it works for me...Worked today at the concert...

You're likely just overpowering the flute. Playing in the low range means not blowing harder, but blowing downward, slowing the air down, perhaps diffusing the airstream slightly, and trying to focus the sound. If you blow too hard anywhere in the flute's range, you'll notice that the note cracks. This is especially easy to do with the low range, so blowing hard is not the answer, nor is it a good way to play anywhere in the range. Blowing hard without the proper compensations will make you go very sharp. Focus your airstream down to bring yourself back to pitch, and realize that you can't blow the same way for every note if you want good results.

wow it scares me to just know how much there is to "blowing" ...
Ok thank you guys... ill try!

Watch your tuner as you correct your air flow and embouchure.

IMHO, problems like these are best solved one step at a time. First he should learn to produce these notes with a good sound whenever he needs to, and then he can worry about their intonation. I agree, however, that at some point, he must do some tuner work to get the pitch where it should be. I just think starting that from the very beginning will be too much to focus on, and something else will suffer.

ok... hehe first 'f all, if u were talking about me up there, im a girl... lol um... yeah, u see ..(new problems)... now the notes are in the right pitch, but they still seem very soft, lack some richfulness, kinda hollow. Or say, the notes dont vibrate like my other notes do in the middle and high registers. And o i tried to not over blow, but then the sounds would come in late

That's a matter of practice. The low register is generally the most difficult to get down, as the response often is slower, and even small problems with the flute can keep the pitches from speaking. You don't want to overblow, so you're headed in the right direction. Now it's a matter of learning to control these notes so they speak immediately and have the tone you want. All of this relies on the airstream, so start experimenting with changes there, and remember to keep everything open and blow downwards so you get the richest possible sound.

i dont know Micron, u see , i usually cover 1/3 of the hole, and it really does produce optimum sound i want, so i dont think there's any problem w/ that...

Well, that is just about the average amount you'd want to cover the hole, but Micron's right on his other point. A good teacher will work wonders for you. We can't observe your playing, or hear what you hear, so any suggestions we make a very general. A good teacher will be able to help with specific exercises designed to address whatever issues you may be having. I would really consider looking for a private instructor.

thank u so much every body! I think i found the right position to play on the embouchure hole,(actually it happened just 10 seconds ago) im thrilled...
Yeah, i do have a private teacher, but um... we've been working on double-tonguing and such recently, dont really have time for this, but i sure will ask my teacher more about it. ^^

Quite frankly, if you lose the ability to play notes in the middle and low registers simply because you're focusing on something else, it probably means you're not ready for that something else, or that you need to be doing extra exercises to maintain the other parts of your playing. Your teacher should have noticed your difficulties, assuming you've seen h/im/er since they began, and IMHO, should have pulled back on the double tonguing in favor of the basics. Being able to articulate faster doesn't really matter if you can't produce the necessary pitches. Definitely be sure to bring these troubles to h/is/er attention.