tennis is a game of physics. The sweetspot is simply an area of concentrated mass, so to speak... this is why head-heavy racquets have a ginormous sweetspot, and traditionally weighted head-light racquets maybe heavier, but still have a smaller, lower sweetspot. Because the majority of the racquet's mass is near the handle area
If you want to raise your sweetspot, i would recommend you put your lead tapes at 2 and 10o'clock. This way, theoretically you'll raise your sweetspot and give it some extra width across the stringbed. Read how Prince's Triple Threat technology works, it can be duplicated with lead tapes.
hope this helps!