I own a Proace Titanium 11 racuqet, with BG 66 string at 25 pounds.
However, I feel that I can't get the power from the racquet.When I smash, the sound is like glass breaking sound, although the BG66 on my Carlton produces good sound.....can anyone tell me what's wrong ?

If we neglect the skills, I would guess it's the string tension.
Perhaps the tension is too high?

If you have changed racket recently it could be that the timing is marginally out or it could be that the differences in the flex of the rackets is somehow hampering your smash or it could be a mixture of the two.

If you bring in the tension issue than a mixture of the three. :eek:

Might take a few hours of hitting to sort it out

That racket is a very, very powerful racket, but it is also (I find quite difficult to use, as it is both very stiff, immensley head heavy,heavy overall and long. This, combined with a string tension like that can lead to it being a very unforgiving racket. The stiffness of a racket cooperates with the tension of the string, so if you have a a stiff racket with tighter strings, then the change is multiplied.

Take for example, as you say you have a problem with the smashing sound, probably because you are not hitting correctly on the face. It is a problem i presume, as it didnt happen before. If for example before you had a racket before that was more flexible (highly likely, as it is very stiff) and you used lower tension, then when you use a stiff racket, with higher tension, it will feel like a plank of wood.

Neglecting string tension...probably the timing of your swing needs to be adjusted?. I had the same prob with the Ti-11. I was labouring with the smash...and was wondering why. After a few smashes I realise that since it has a long shaft, my timing could be off. So I became conscious of my swing and wrist snap and wallah!, the shuttle went "boom" across the court and went through an opponent's legs. So you might want to try adjusting your hand up and down the grip to see what is best for you.