What are the best microcontrollers, processors, and fpgas for real time processing of microphone arrays?

I have developed a microphone array with Microchip dsPic33E, however I feel that it is very limited due to the max 70MIPS, when using a FIR filter I noticed that it took it about 15ms to filter one signal for a N of 30 so I guess there should be better options. Any ideas?