Optimization for iPhone/iPod/iPad

I want this [Phaser implementation][1] optimized. The orginal code sounds great but is not fast enough when played back on the iPhone. I need it optimized as it is in mono and i need to run two of them at once to get a stereo effect. I would like a generic solution that could be run on other platforms if possible, i.e. I would like to not end up in assembler if it is avoidable. However if this is the only solution, so be it.