Sub best at high crossover?

The ideal situation has one setting the subwoofer to be coming in at the lowest possible frequency that works to provide the needed support. At higher frequencies, the subwoofer is working closer to the point where it is out of its element and your ear might be confused by the conflicting localization cues (the lower the frequency, the lesser your ability to localize the source of the sound). But, if, for example, you have a suck out at some frequency between say 150 and 200 hz because of floor-bounce cancellation of your woofers on the main speakers (a very common issue), the subwoofer might be filling in for that problem. To the extent the subwoofer can cure problems higher up in frequency than it is normally intended to help, I say stick with the higher crossover. It is MUCH more important to cure problems in the lower midrange than to have ideal subwoofer support at lower frequencies--the midrange takes priority.

I'm suppressing an "according to your sister" retort, and that's not easy.

I just encountered a similar experience. Crossing over my sub at 80Hz (used to be 35Hz) with sub built-in room correction. Very amazed it smoothly integrates with my floorstanders. Also in a relatively large room.

Thanks a lot, all of you! This is getting informative, more soon.

Here are my considerations so far.

First of all, it would be nice if more users of well-placed DD-18 subs (or similar) in fairly large rooms would chime in with their actual listening experiences in this debate.

What I hear in a situation with a good system and room, is a detrimental effect due to engaging the crossover in the sub. In many other situations, this may instead be a big plus, overcoming the minuses.

In my situation, I am not so much using the sub for what it does to the bass, since I have full-range speakers anyway, but more for what it does to the overall musical impression. The DD-18 helps my main speakers to "throw" the music at me and establish a depth perspective. It is the first of many subs I've used that I really liked. I had a Sunfire sub that was amazing although it danced along the floor and distorted a lot, and then, a Bowers and Wilkins that could never be woken from the big sleep. I next changed to a pair of REL Strata 3 that were quite good, but one DD-18 was even better.

This discussion concerns sub setup for augmenting speakers in fairly large rooms. My impression is, that if the positional and analog setup is good enough, it is best to "defeat" the crossover and the associated electronics. However, there is some give and take at this point, my best electronic presets with the DD18 sound very good also.