I'm not sure what you mean by "control." The smaller diameter driver will have superior dispersion, and that will help the extreme highs hold up better off axis. But unless the crossover to the super tweeter is very carefully designed, the extra driver could actually degrade the smoothness of the off-axis response. Given the price, I doubt that there's much of a crossover up there. The function of the 3rd driver is part marketing, and part an attempt to provide more open sound. Overall, I found the Sony to be the best of the entry-level monitors I've tried above 80 Hz (with one exception I won't mention). Sony probably could have accomplished that by throwing a little more money at the main tweeter and losing the super tweeter, but I'm not going to argue with success.