If your speaker is really blown, then nothing apart from replacing it will fix it. You could try giving the speaker a clean as sometimes you can get very small metal filings that stick to the magnet and hold the diaphragm down, thus bringing distortion when the voice coil has to move more (ie at higher volumes)
Using glue will not fix it and is likely to make it worse and inaudible, as the diaphragm will not move correctly. Especially for high frequencies.
Hope this may help!
K.