Bass trapping - corners or walls?

I have experience with the ASC Tube Traps as I've been using them now for over 10 yrs. in my room. I love them & despite the fact that they do not have a high WAF I would not replace them w/ any other trap device.

I agree with Drummermitchell that bass loves the room corners where the floor-wall, wall-ceiling interfaces are. So, tube traps must be placed in the corners & yes, the diameter of the tube trap does make a diff with a 16" trap doing the best job. Pay attention to how much you absorb the mids using this round 16" tube trap. The articles give you a very good education on how-to.
Full room coverage is required so you would also need traps at the 1st reflection points & traps between the 1st reflection pt & your chair + traps behind your chair.
Panels are used to absorb mid freq & compliment a tube trap but do not replace them.
Absorbing bass is about controlling low-freq standing waves while absorbing mids is about absorbing/reflecting higher freq waves in motion. That's why you find panels a few inches off the wall & never flush with the wall. When the mid freq hits the wall, the orig wave motion stops (& uncontrolled reflections commence) & then a panel cannot do anything to that stopped wave. when the panel is off the wall you treat the wave in motion before it hits the wall to degree you desire & also control its reflection(s).
hope this makes sense.,.,,,, thanks.

I have followed the method outlined in the article above and it worked well for controlling bass resonance issues.  Bass traps place in the corners behind my speakers actually resulted in less ambience eventhough the reflectors were aimed into the room. With the bass traps directly behind me, against the rear wall, brought life back to the room and solved resonant issues.  ASC are expensive but they work.   

I have made four "ASC" type of traps, going by their diagram.  They have helped with general slap back immensely, however, IMO, if you have a bass problem, you will need to go with either a parametric eq, or something besides ASC type devices.  It all depends on your room. Some say any tone controls detract from the sound.  I'm running all analog and even though I have many absorption panels, believe I either need to get a very expensive parametric eq, or make some diaphragmatic absorbers.  I have a problem with  30-150hz.  I've put so many panels of 1" 2x4 703 compressed insulation, I have begun to suck the life out of the music.  I'm going to put some wood facing over about half of my panels and make a couple of diaphragmatic absorbers.  IMO, if you have a heavy bass problem, anything else will be a waste of time and money.  I'm very open to any suggestions.  I have a good quality graphic eq in the mix( Samson S-curve 231), it just doesn't get the job done. My room is 19x21x10 and has 'knee" walls.  I realize tone problem is my room dimensions-too square.  I keep saying I need to post some pics, but don't have a wide angled lens.  Equipment used:  VPI Scoutmaster w/ DRT XV-1s cart, Theta Miles CD transport, Aesthetix Rhea Signature, Aesthetix Calypso Signature, Krell EV-600 monoblocks and a couple of Wilson Maxx II's.  All suggestions welcomed!!  As Milla Jovovich once said "please help."

Has anyone tried one of the major companies I’ve seen advertised that claims their latest traps Are more efficient? I can’t seem to find the ad but it was tas or stereophile.

Also what are the best tri corner traps? I have some old room tune ones that are small but did work when I used them.

GIK Acoustics for the win. Extremely effective, pretty, cost sensitive. Look as well for their soffit traps.