Total bass suck out at 40hz

I have just went through the entire range of phase adjustment, moving the nob three clicks at a time and playing test tones up to 60hz. Above 60 nothing really changes no matter what I do.I have made the mode better but it is still there, down 8/9db from 30hs and 5/6db from 50hz. (i have some loss of volume at 50hz as well, although not nearly as much) I do notice a definite gain if I move my head and/or meter forward and down towards the floor. Maybe I should just get a much shorter chair. Or consider building a platform for one or both subs. 

Sub crawl. Put one sub exactly at your listening position. Play the 40 hz tone on continuous repeat. Get down on your hands and knees, and carefully cover the whole of the listening area--some kind of grid pattern is good so you know where you’ve been. Mark any spots where you can actually hear the tone. Hopefully there will at least two. Move the two subs to the marked positions, and return to your listening position to check result.

I wonder how many have actually done any of the stuff they recommend. I did the sub crawl. Subs wound up right back where they were, along the walls, asymmetrically different distances from the corners. Tim did the crawl, his are in the corners, same thing. Its no big mystery. Bass is ALWAYS strongest in these locations! 

Want good bass? Put a sub near each corner. 

We now return you to your regularly scheduled missing the point comments. 

I do not have enough cable to place subs at my listening chair. My room is very long at 38' only 14' wide. I bought a pair DL Labs sub cables here on the Gon at 12' each, also hampered by outlet locations. 

Mizike, leave everything as it is for now. Have you measured at different points in the room? It sounds like you are measuring in a null. Putting subs next to your sofa might be great for Movies but really bad for Hi Fi.
Subs in corners is alway a good idea as long as you can match them in time and phase with the satellites which without digital bass management you can not. So, with a point source system the best way to set up two subs is against the wall between the satellites on a radius from your listening position. This means that all speaker are the exact same distance from the listening position. Assuming none of your equipment inverts phase you should be pretty close. You will still have node issues in the room. The easiest way to deal with this is by moving your listening position forwards or backwards to a position were the bass sounds best.
without room control that will be the best you can do unless you are ready to add two more subs. I would keep them on the same radius but against the side walls. Hope this helps  🥴