Move your sub

@contuzzi

true, the phase adjustment does add delay but it has always worked for me.  my typical method is to reverse polarity on the sub and take an RTA measurement using uncorrelated pink noise.  It is easy to spot the main speaker's roll-off frequency.  Adjust the crossover on the sub to match, measure again.  There will probably be peaks or valleys near the crossover frequency.  Adjust the phase angle to flatten the response and then adjust the level by ear. 
Another important consideration is to avoid pre-amp connection to the sub and always use speaker level connections.  Much better for the sub to see the amplified signal that is identical to the signal the main speakers see. 
I use this method and have a completely smooth response curve with one sub from 20Hz through the midbass region.  It is non directional and bass comes directly from center stage- no peaks in the sound and as you said absolutely no room correction or EQ.  It sounds perfect.      

Best bass sound is when you sit on the subwoofer in your listening position. You really "feel " the bass...

contuzzi, erj1953,

I am using (2) JL Audio F-113 subs slightly behind and the side of  the main speakers. 
First I set them with there own JL calibration mic. 
Then, I own a DEQX Premate along with its many features it has an electronic crossover. With its calibration process you can set levels including delay. All of this frees the sub for placement most anywhere in the room.
I also have ASC Bass Traps in the corners of the room. 

ozzy

@avanti1960  +1! about always connecting subs from the main speaker amplifier.  As you said, it integrates so much better with the main speakers.  I cannot tell where the mains leave off and the subs pick up with the bass!

I've had just the opposite experience connecting my JL subs to the speaker connection (high level inputs).  It changed the tonality of my system and seemed to soften dynamics. 

Using the outs from my pre-amp has been better.  I'm now going to try actually crossing over to my mains to check that out.