> Assuming you aren't playing on typical plastic computer speakers and wondering where
> the bass went, the answer is probably "the cabinet". Wooden arcade cabinets are a
> pretty decent approximation of an echo chamber for bass, so they tend to sound
> bassier than the crappy car-door speakers installed in them would normally merit.
You're right, and there's a world of difference between typical computer speakers and even the same-quality ones installed in a cabinet. Most games sound better in my MAME cabinet than on the Macbook, etc.
That said, I know the variant the OP is referring to, and have to agree with him that it's not in MAME. The best way I can describe the difference is in the sound Donkey Kong makes during the opening sequence when jumping along the top girder: the landing sounds are more... Authoritative. It's not so much that they're bassier (which would be down to the cabinet) as they are more pronounced (which would be down to whatever code generates the sound).
The version shown in the video was fairly common in Ireland in the '80s, at least in the greater Dublin area. There was one that I used to play that had the same sounds as the one shown in the video - it's a very distinctive difference to the ones I'd play in the US at the same time, even including the Crazy Kong variants that were common there.