Yep, that’s it. I’m sorry if I sounded convoluted; it’s a bit tricky to explain anyhow. I basically did as you suggested and the .wav file was fine, and the versions (one mp4, one mpg) I made of the trailer with just that .wav as the soundtrack gave me the same result as the original–everything worked fine in VLC and WMP and when viewed through a browser. But again, MPC and KMPlayer showed the same strange muffling phenomenon I experienced earlier. Which is why I suspect Vegas fails to render it correctly and those last two players can’t compensate for that glitch. My only problem is that I’d just want the trailer to be working perfectly in most video players–especially since it’s not just a case of one random player not playing it right, but two fairly popular ones. It really is especially odd as the sound was fine in MPC when I was still testing out earlier versions of the trailer, but I’ve made so many changes that I can’t revert back to the version that worked.
It’s like I added something that Vegas just couldn’t handle right, but now I’ve tried removing various clips from the middle just in case they magically screwed up the rendering process somehow and haven’t had any luck. The only similar situation I can remember is when I tried to make a video with clips from an old Technicolor movie and the Technicolor parts constantly threw up glitches, like Vegas just didn’t understand how to render such rich colours. So I was wondering if there were any idiot-proof sound settings/codecs I could try to smooth this thing out?
Thanks again for your help and again, apologies if I’m explaining these things clumsily.