To Sub or not to Sub...?

I would like to nominate this for " best" 'most informative threads I've ever read.It really fleshes out the "sub/or not" theorys. For what it's worth;I enjoyed reading everybody! Different opinions"are" necessary. Congrats/y'all- and thanks.

Well,I took the plunge! My third sub / not the sandwich/ I previously had a Velodyne and an Infinity. I got the REl storm 3. I got mine from a dealer. Got all the advice I needed from them. The first one that works,and you can't tell it's there / where it is.This may or may not help. I got new speakers. Went from Aerial10ts to Montana ESPs. The Montana, is better, by a large margin in the treble/mid. But the bass is not near as clean or low. This is what promped me to look for either bi amping; or a sub. The sub is the way to go. Thanks again everybody.

I think the real low bass add nuances and detail. I also think that sub set up is as important as the sub itself.

I was always suspicious over addition of subwoofer into the two channel system. Now, after connecting the ACI Titan along with ACI Sapphire's monitors, i am wholheartedly
going along with the suggestions of the majority. Placement of the is probably hardest thing, but if you have a time and patience it will be worth experimenting with it. Well, i 'talked' to much and haven't said nothing new. As usual.

Is it the case that some sub owners tailor their setup to leave a hole or depression at a problematic room resonance frequency? Say you've got a monitor that goes down to about 45 -50 Hz, and you've got a room resonance at about 40 hz. Do you dial out the sub below 40 to avoid that frequency? Does that create any audible anomaly? Or, maybe that's a bad example; is this strategy frequency dependent... e.g., works if the hole is closer to 30 than 40? Thanks.