Room Treatment Question, lost the lowest bass notes.

Your #6, when my room was brand new and empty, literally just one chair and the stereo on the floor, no room treatment at all, the bare walls created obvious modes at every frequency. There was a test CD with tones and some frequencies you could hear the dips and peaks dramatically come and go as you move around, sometimes in a foot or less. We don't notice this because most rooms are nowhere near so empty, and everything in a room either absorbs or reflects and scatters. So usually we only notice the modes with bass. But they're everywhere.

Hello millercarbon,

     Yes, exactly!  The negative sound quality effects of the combination, of highly directional midrange and treble sound waves constantly being  reflected off of hard and untreated room boundaries (floor, ceiling and walls) in an empty room,  are definitely numerous and obvious but it's also an excellent teaching tool.  
    As I think you're aware, until about 6 months ago I had zero room treatments in my room.  The odd part was I didn't notice any obvious negative sq effects in any part of the audible sound frequency spectrum without them.  The bass was near state of the art in my room with my 4-sub Audio Kinesis Debra DBA system without any bass traps or panels of any type.  The only semblance of bass room treatments in my room were fairly thick wall to wall carpeting and some well cushioned leather chairs and a sofa. 
      I even considered the midrange, treble and stereo imaging sq to be very good at my listening seat using a pair of large, 6'x2', 3-way  Magnepan 2.7QR dipole speakers with no absorbing or diffusing acoustic panels in the room at all.  I believe having my panels positioned over 4' away from the front wall, 2' away from the side walls, along with their being dipole speakers with a figure-8 radiation pattern, were probably responsible for them performing so well in my room sans room treatments.
     But I knew from online reading/research and audio forums, as well as having my room analyzed by GIK Acoustics, that adding the $3,500 worth of various room treatments that GIK recommended would likely be a very good investment.  I was most concerned that the suggested stacked bass traps in all 4 room corners, and the numerous other bass trap panels in the room, might negatively effecting the extremely good bass performance in my room.  But GIK and Duke convinced me that these bass room treatments would do no harm and probably only serve to improve bass performance. 
     So about 6 months ago, I bought the full $3,500 complement of GIK recommended room treatments and had them installed in my room. 
     What were my overall impressions of the sq effects of having all of these fairly extensive room treatments installed in my room?
     Well, the bass still sounds spectacularly good in my room but I don't think it's actually been improved with the added bass room panels and traps.  Sometimes I perceive the bass as sounding especially detailed, 3 dimensional, effortless or just plain amazingly natural and realistic on music or even tv programs and commercials.  But then I recall numerous times, prior to having any bass room treatments installed, that I noticed very similar bass perceptions.  I can definitely state with certainty, however, that Duke and GIK were correct and I don't believe the additional bass room treatments caused any negative effects to the bass sq in my room.
     On the other hand, the approximately 20 added absorption and diffusion panels in my room have had a profound positive effect on the midrange, treble and stereo imaging performance performance in my room at my designated listening position/seat. 
      I believe for the first time that my entire system has been optimized over the entire audible spectrum, from top to bottom while prior I perceived the bass performance only as being optimized and superior to the performance of the rest of the audio spectrum.  Overall, everything sounds very well balanced and a few degrees higher in sound quality.

Later,
Tim

That's why I'm looking forward to checking out Mike Lavigne's place this weekend. Some audiophiles are coming up from Portland. First stop my place, then on to Mike's. Kind of like a pub crawl. Heh.  

My room for sure has problems. Had a friend over a very long time ago, Holly Cole hits this one note and its just crazy overload loud. Told my friend sorry its the room I'm working on it. He says no way she just overloaded the mic. But I knew better. The corner tunes you can see in my system pics virtually eliminated this resonance. Cleaned up some other stuff as well.  

That like I said was a very long time ago. Like at least 20 years. My system is a whole lot better now. Room problems that back then blended in with other problems now stand out as room problems. To me anyway. Everyone so far thinks the room sounds great. Better than average sure. But not great. Mike Lavigne though, now THAT'S a ROOM!  

Bet your bottom dollar my eyes will be peeled every bit as much as my ears will be taking it all in especially looking for ideas to improve the sound in my room.

Problem is your room dimensions are conducive to suck out at a lot of low frequencies. Best short term benefit is listening position location. Which needs to be between two nodes one about 25Hz and another just over 40hz. I estimate you will want to be 16 feet from the front wall for best response.

Look up AMROC on the web and work it out exactly.

Lots of good suggestions for optimization in the thread.

Thanks for the reply's. 
I am not adding any subs. I got enough money spent on equipment, $45K.
I could spend money on having the Wilson Tech come set speaker placement. 
I have my seating position at 16 ft away from the front now. I could move it back a few more feet if needed.
I did shift the center of my speaker center to the right about 3 ft. That helped. I have a brain fart with the initial speaker placement.

I also added (2) 2 x 4ft sound absorption panels on the back wall and (2) 2 x 2 ft panels behind the speakers.  

Time to let my ears do the judging.  At this level of HiFi.... It is all in the room now.