Yeah - but I am not sure how that is done with a full range speaker without filtering out some of the sub frequencies.
It seem like one would have too much energy somewhere.
- Either too much below 40Hz,
- or if the main speakers started at 60 Hz, then too much in the 60-8100Hz region.
Of course with a room, and modes, it may all just work out fortunately.
But luck is not a plan, so in a different room it could end up be a disaster,.
And working well with your speakers, may not be replicated with other speakers.
But at least the OP has a sense of what it should be like.
Luck is not a plan indeed. You need a strategy, great care in setup and proper adjustability of the subs.
My speakers are capable of producing more deep bass than in their current position. Yet as many others have found, optimizing for bass reproduction is not necessarily the best for other things. In my particular room, at the current position there is the least room distortion, distortion in mid and high frequencies due to room excitement by the speakers at loud SPL. Also, at the current position the speakers reproduce the most *controlled*, articulate bass. So I optimized for position of the main speakers, then filled on with the subs. Result: Most extended, yet also cleanest bass that I could achieve. Would not have been possible without subs.
Excessive room nodes are a problem and my room has bad ones, unfortunately. I tamed the ones in my room with ASC TubeTraps.
As I said in #25, in my mid-sized room I had to use the e.l.f. (extreme low frequency) attenuation of my JL Audio subs in order to prevent room overload (if you have a large room you may get more lucky). Adjustability rules.
For the floorstanders I used the sharper roll-off slope of the subs of -24 dB per octave. You don't want to intrude with the subwoofers into mid- and upper bass (for two-way monitors a more shallow slope may be warranted). If I remember correctly, my old REL Storm III did not provide the option of such a sharp slope. Again, adjustability rules. -- Of course, you also want to choose the roll-off frequency of the subs wisely.
I used to be more of a bass head than I am now, and boost the bass with subs too much. I suspect others still do too. Yet now I want to hear extra low bass where warranted, not more bass from the subs all the time (again, support of two-way monitors may be a different story).
The volume of the subs is therefore adjusted judiciously. Cheap effects are a no-no. I listen to a lot of classical, and in general I do not want to "feel" the bass there, it robs the illusion. In the concert hall you don't feel bass either -- except from the large bass drum. The bass in my room is adjusted so that mostly I avoid "feeling" the bass in classical music (as much as that is possible in my mid-sized room even from just the main speakers; large rooms are easier in that respect). At the same time, deep bass electronica still provides the intended chest-pumping deep bass.
I am confident that I could put my strategy, also allowed by the adjustability of my subs, to good use in another room as well, if I had to.