It is true: one would not likely trip the breaker, even with 2x 2000 watt pro amps driving the subs during
normal use. However, it is also true, that one will not likely use 1/20th the output that this proposed set up ( 2x TC Sounds 2000 in large ported enclosures) can produce in normal use. The only time one would run into possible breaker tripping is when playing constant test signal(like a sine wave) and pushing to limits in order to 'show off' and/or measure the maximum SPL capability. The breaker is going to trip under those conditions, if one actually tries to reach the output capability of 2x 2000 watt amplifiers on a single standard 120VAC line. Even if one used two lines, it is not likely maximum power of the amlifiers would be reached, due to line voltage sag. To get around that, the amplifiers would need an internal regulated PS. I am only aware of very expensive amplifiers offering this feature.
Average actual power used in normal applications? Probably 40-80 watts.
-Chris