Raul, from my earlier post, you know I agree with the benefits of subwoofer(s) to both extend low frequency response and reduce distortion on speakers and amps for the upper bass and midrange.
But I have a question for which I wonder if your experience may suggest an answer. At what frequency will these benefits diminish to the point where they may be of little value?
For example, I don't doubt adding subwoofer(s) while rolling off the bass on the main system will benefit a two-way speaker where the woofer is operating up to somewhere between 1,200 to 2,400 Hz before crossing over. Similarly it still benefits any three-way speaker where the woofer operates up to somewhere between 320 and 600 or so Hz. But what about a system where the woofer crossover is near the top of the accepted bass range, 160 Hz? If this is also a candidate for reduced distortion benefits to the upper bass and midrange, it would seem the subwoofer crossover would be quite low, say around 40 Hz. Is this correct?
Please share any experience that can answer these questions.