This is haaard to synthesize well. I "finished" it, started typing up this post, and then went back and spent another 20 minutes on it. The final thing is two layers of noise, filtered in different ways, both of them using the "fast sawtooth LFO" trick that makes it sound more like multiple impulses. A third layer might make it sound richer, but I stopped there. For a really good example of this style of synth clap see "Being Boiled" on Human League's Travelogue.