Martin-Logan Descent or Rel Stadium Subwoofer

Sugarbrie, in filter design the term "high-pass" refers to a filter which "passes" the "high" frequencies, i.e., blocks out the low frequencies. Similarly, "low-pass" is a filter which blocks out high frequencies. Thus the RELs have no "high-pass" filters whatsoever; they allow the amp signal to run full-range to the mains without any interruption or filtering at all. They do, of course, have the best low-pass filters on the planet.

I don't have any experience with the Descents so can't comment on the comparison. I own a Stadium III and it is a phenomenal sub, but it does not have any adjustment for the high-pass side. Like all RELs, it makes the satellites run full-range with no signal interruption at all (can be set up several different ways, but the recommended and best one is to take the signal to the sub from the power amp's output terminals in parallel with the speaker cable connection). I don't know how the Descent is designed to be set up, but I will say that the REL is the only sub I've heard that doesn't get in the way of the music from the sats, because it can't! I also don't run electrostats, but have heard a lot of good things about RELs from those who do.

I have to respectfully disagree with Gtejr; the stadium III is a major step up from the storm III (which I have owned also) in both extension and authority, giving an overall impression of much greater you-are-thereness. A lot will depend on the size of the listening room; if you are only loading a small room and don't need to reach into the 20-Hz range then the strata/storm will work fine. If you have a larger room and/or value what 15-Hz extension does for the soundstage, impact, and presence of the system (not to be underestimated, IMO), the stadium is a minimum starting point, and the stentor is definitely worth a listen as well.