The thing is, that there is no ideal configuration for it. The basic plugins that come with the emulator are usually the most compatible though. First and foremost, disable Sync to Audio as it creates more trouble than it's worth in most games (I know only two games that actually benefit from this option). As for why the sound is so bad, I haven't got the slightest clue. Your set up should be able to handle N64 emulation at least fairly well, and sometimes the sound issue might not be your SPU plugin's fault, rather the problem lies somewhere else. Since I guess you have an intergrated graphics card, what's the make of it? This might be where the problem is, but I'm just throwing ideas around.