Pete,
No scientific (or "real") test was performed to determine the inductor saturation, but you could hear it saturating. Bass got flabby and distorted much too early before power handling was an issue.
In another life, I previously worked at Recoton and Audiovox (1997 to 2015), who owned the Advent and AR brand names. I worked closely with the engineers who designed and developed the later Advent and AR speakers. I designed and developed car audio. The Advent brand was price sensitive (from a production standpoint) and it showed in some products. Simple crossovers with small inductors that would just allow the woofers to handle the rated power, cheap (no brand name) capacitors, etc.
Although the Advent Heritage was made prior to my employment at the company, if the bean counters would have spared an extra dollar or so, the Heritage crossover would have been respectable.