Best place to put a single subwoofer?

Great feedback everybody. I agree about the corner placement being "overpowering". I have done that already and found that room boundries do boost the bass, but not in the best way, and the left side of my listening room where the sub was situated, was bass "heavy" despite the fact that bass below 100hz is supposed to be non-directional. I never set the crossover above 60hz and still it dominated the left side of the room. So I moved it inbetween my speakers. I have spent months pulling away from, and pushing it back toward the wall. Not sure if closer, or further away from wall matters. Doesn't seem to make too much difference. Currently x'd-over at 65hz. Spiked as well using 2 inch spikes.
Meiwan suggested 6 inches or so slightly BACK from the face of the main speakers. I have done that and can't be sure it made any difference.
A few more specifics: Sub is a JM LAB/Focal (Berrillium series) "UTOPIA". It has a 1000w. "bash" amp built in, a single, forward firing 16 inch driver, and is ported at the rear of the cabinet (transmission line I believe it's called). I am running it in balanced xlr mode. Not using the LFE input, but the L/R stereo inputs (summed bass??). My wall behind the speakers & S.W. are acoustically treated. 5 floor to ceiling absorption panels populate the ENTIRE wall. MBL radialstrahlers as you all know, have HUGE amounts of output in all directions, which made my wall VERY "live" and reflective. The sound was BRIGHT as hell. So I had panels built to "tame" it. Things are wonderful now. BUT. And that's a big BUT, it appears that my bass impact is suffering. Or does what I did to the wall not have as big a bearing than placement? This is why I struggle, and why I have turned to fellow Audiogoners for input and advice. So far alot of good advice given. Most of it I have already done before. So what do you folks think is REALLY going on? Is my JM LAB sub a piece of shit? Might I be better suited with 2 subs, instead of just 1? Run in stereo? Or do you think that my MBL's might just be overshadowing/outperforming my current sub?
I know I have posed a number of questions for your kind consideration, advice. But I am in sort of a quandry about this, and have (obviously) spent a fair amount of money on my system, and still I can't achieve the leval of "punch" and "slam" that I experience at C.E.S. in the MBL room. And they aren't even using a subwoofer. Ok, so that's what the meat of the matter is. More input please!

Shadorne, What? A singles bar? WTF?

You folks are all great! Thanks so much for all the input. Now my head is SPINNING! Oh where to start? Sounds like I have a few projects that lie ahead. In response to Mrdecibels input- I used to have stereo subs, (Von Schweikert Towers of power), And they DID mate very well with my Martin Logan Quest z's, but they didn't have that hard hitting "slam" factor I love. I suspect the MBL's would overshadow them alot. I have since sold the VS subs.
I HAVE given consideration to selling my JM Lab/Focal Utopia sub and perhaps replacing it with a couple of JL Audio subs. However, I want to optimize what I already have. I want to arrive at some type of solution to my current situation...and not just throw MORE MONEY at the problem, or buy more stuff. I have done that already. Gone through subs like Charmin toilet paper (15 different subs owned, and sold in the last 15 years). Don't get me wrong, my sound is KILLER right now. I just know it can be better. It's that never-ending Audiophile quest to improve what we hear. Kinda like a drug addiction if you will. I know there are many variables here, and I recognize the differences between MY system, and those that MBL sets up in hotel rooms at CES each year. The 101e's absolutely slam. The bass is powerful and punchy. I LOVE that stuff. My bass is....NOT SO MUCH. Kind of "lacking" in authority. A bit "soft" if you all know what I am getting at? So I have been disappointed. I am clearly looking for a much higher leval of quality in the bottom end.
I do not have any testing equipment, or room equilization software. Not yet. I do have one of those cheapo Radio Shack sound leval meters-works alright I guess? I have in fact moved my sub all around the friggin' room, and discovered where NOT to put it, (cause it integrates like shit). Maybe my listening room is too small? Maybe I have "over damped" it with sound absorbtion stuff? Maybe my expectations are too high? Nah! that's not it. Things can ALWAYS be better.
I will no doubt continue to try and improve upon what I already have. Anybody want to come hang out for the weekend? I'll buy the beer! I have some great Scotch and fine cigars too. I'll order pizzas and you can impart your Audiophile wisdom upon me, help tweak my set up, and then lounge around all weekend long and listen to tons of great music! No shit! I would do that. The learning experience continues. Thanks everybody for all your advice and input so far!

MrD, no offense taken. At this point in time I am sponge and I am open to all input, suggestions, questions.
My system is as follows, (and is a mulligan stew of stuff):
Amps: B.A.T. Vk600se monoblocks (solid state) 600w/4ohm
Preamp: B.A.T. Vk51se (tubed)
Digital: Theta Digital Carmen 2 transport
Theta Digital DSpro Gen.5a dac
Analog: Linn Sondek LP12 w/Akito arm & Linn Adikt m.m.
PS Audio GCPH (solid state) Phono pre
F.M.: Magnum Dynalab MD102 tuner
Magnum Dynalab MD205 "signal sleuth" f.m. amp.
Speakers:MBL 101e Mk2's
Sub: JM Lab/Focal Utopia (Berrillium series)
Cables: All sorts of different shit. AudioQuest,Nordost,
Cardas,AcousticZen,Transparent. Some of it older
versions, but all of it either reference caliber
and/or top of the line in their respective brand.
(too many to list, too many to remember)

I have 5 dedicated 20amp circuits, 2 for the front end, 1 each for the B.A.T. amps., and 1 for the Subwoofer

The custom wall panels are 24"wide x 8feet tall x 3"thick (the frames that is). They are stuffed with "auralex-type" open cell foam that is 2" thick, then wrapped in in 1/2" thick batt insulation. The panels are then covered in a loose, open weave wool/polyester fabric. (Gotta look pretty for the wife. WAF is super important right?)

As for SPL's I am trying to "achieve"? Not particularly interested in any such maximum SPL's. Just want it CLEAN. And it is. Using my "hokey" little Radio Shack sound meter, it is entirely possible to reach a continuous 100db. NOT that I sit in the room and subject myself, or others to that for any length of time. But it will play loud as hell, as would be expected for MBL's. I have actually seen the spl meter hit 108 to 110db peaks. I know, friggin' crazy huh? (I don't know how entirely accurate a $35.00 Radio Shack meter is, but the sound pressure in the room is devastatingly "unbearable" at those extremes).
To reiterate my thoughts from earlier- it's really quite good. NO, actually it sounds KILLER. Just not KILLER enough, at least where bass is concerned.

Hello Everybody. Hello MrD, Thanks for the feedback. I am not rolling off the last octave and I am in fact running the MBL's full range. I am not a big fan of routing the audio signal through Hi-pass filters in the subs crossover. I have found that to degrade the sound to the main speakers, in my experience, so I run my sub straight from my preamp, X'd-over at between 50 and 65hz. My MBL's run full range. (I did the same thing with the Martin Logans and the plethora of subs that I mated with them. Allways full range).
I agree about the running of stereo subs as I have indeed done that. Dual Velodynes, Dual Bagend Infrasub 18's, Dual Von Schweikerts, and even Dual Sunfire "True" Subwoofers-God forbid! (which by the way were absolute pieces of shit for music. I refer to them as "nuclear bombs in a small box"- No pitch definition, 1 note bass pieces of poop that they were!). Yes it is difficult to make a pair of stereo subs integrate properly, and does not take much to overdrive the hell out of the listening room.
I have given some thought to the fact that maybe I "over-damped" the wall with all those big panels I had made, and have considered taking a few of them down, like maybe 2 of them. Leave 3 up? But I have not done that yet. The one thing I am mindful of is how much that wall behind my MBL's reinforces the sound, making the overall musical presentation rather "bright" and "strident" sounding. Not a good thing IMHO. Been there, done that, didn't really like the effect. Room definately sounds better with a "dead" wall behind the speakers. But I should try taking a FEW of them down and see what the effect is. Good suggestion MrD.
As for the tubes in my preamp going "microphonic"?? I haven't a clue. How would I know? What is "microphonic" anyway? (showing my tube ignorance now. This B.A.T. preamp is the first AND only piece of tube gear that I've ever owned. Always had solid state my whole life.) I have heard the term "microphonic" used, but wouldn't know if something like it is occuring with my toys. Please enlighten me if you would?

Hello Fellow Audiogoners, been out of town for a few days, just rolled in at 10:00pm (P.S.T.) from a concert at the ORACLE Arena in Oakland, California. Mrdecibel, no new developments or news to report as of yet. Probably do some experiments n' stuff this weekend. Despite the fact that I think I have done alot/exhausted all the options...there is SO much good stuff here! Much of it worthy of my efforts and full attention. Several of you have offered me help and input far beyond what I would ever have imagined! Thank you all. I have had several direct emails from folks (who haven't even participated in this discussion), and Mrdecibel I WILL be emailing you- for sure. I definately want to gleen more input from you. So far good stuff. Very informative indeed. Stay posted folks. Something WILL happen. I will get to the bottom of this bass "situation" with all yer help. Then I'll have a big party and invite everybody over for beer, cigars , and music listening! You think I'm bullshitting right? I'm not. Love to share the joy with everybody!