Sounds about right. But my computer is not hooked up to any kind of sound system, so it's hard for me to tell. The noise, if I remember played maybe 3 or 4 times in the whole movie and it's very overpowering. IT was this random output noise the harvester terminator made sometimes. Really loud, and really low pitched. And you're right, it is like a warble sound, like a steel ship rubbing against another one or something.
I thought of a much better example of LFO, you can hear a ton of LFO in this similar to the sounds in Terminator:
It sounds overpowering because it constant and ddiiirrrttyy. YouTube's quality is too bad to really hear this, but, pickup the album Distance - My Demons .... great subwoofer workout.
I don't know the movie terms, but in dubstep and drum and bass (where this sort of sound comes from), soundsystems had to be setup specially for our music because of the sine 'weight' at the bottom with the LFO over the top. Speaker manufacturers use a 2x peak value, but with the these sorts of low end the speakers really have to be run around their rms, because the subwoofers will blow from THERMAL limitations rather than what most people are used to, excursion or peak limitations. Basically, with the sort of bass in this movie, you can cook your subwoofer(s). When they blow its a slow and non-violent process from the heat building up until the voice coil expands to the point that it locks up.
This movie kept these scenes pretty short, but if this becomes a trend in bass for movie making (which I think it will), expect to see a lot of posts along the lines of "My subwoofer is locked up." A lot of home theaters run their subwoofers far over their rms value, and doing that with this sort of bass will cook the voice coils very fast.
That said, I think it is the most effective sort of bass. It's the sort of bass that makes people ears get fuzzy and chest flutter. Also, when used effectively, it echos the way bass is with real machinery. Big engines, big electric motors, turbins, and so forth all have natural "LFO" because they are rotating with frequency.
Okay, I'm rambling.