Subwoofer location/facing question

you will get every answer possible...it's all system and room and preference dependent...I have my REL
 about one foot inside my right speaker, the face a few inches behind front of mains...my friend with a similar system, very different room, has his on outside of speaker, both of us use facing forward.

I’m sure Duke will give you some definitive info, but as an introduction, subs need to be located in a room so as to counteract that room’s high and low pressure zones (modes and anti-modes) created by the room’s wall boundaries (the room’s dimensions determine the frequencies of those modes). Except in the instance of OB/Dipole subs (which create a figure-of-8 output), which direction the sub cabinet faces is immaterial---frequencies below 100Hz are omnidirectional.

I have mine like jl35

Try a pair of subs on either side of your listening position. Not beside your speakers. 

Your subs location seems unusual.

Have you checked out REL's videos?
https://rel.net/tune-rel-video-series/

If your ears like that position, stick with it.

REL recommends corner placement, REL dealers often recommend next to main speaker placement...

I’ve been working this issue for a couple of days now on my system. Just got a pair of Rel .s812 which replaced a single MK.

Rel customer support gave me specifics based on photos and floorplans. I tried their recommendations then did what all the videos and crawl docs etc said to do. I wasn’t really liking what I was hear across varieties of music and it was fatiguing compared to my old setup

Finally got a calibrated mic and software to figure out what was going on. Huge spike like 30+db around 35Hz at all the suggested locations. I'm guessing that the old sub wasn't adding enough energy into the room to really excite my problem modes. 

After stripping my treatments out, pulled out the subs and started again. After resetting speaker position, toe in and take I was still seeing these room modes but much less. Finally starting to understand what those are. Gezz long enough.

Now I went around the room with a sub and found the peaks were less pronounced and suprisingly the bass smoothed out. Found the best spot on one side of the room the went to the other side a repeated.

What I came up with was unlike anything I’ve read. Subs are outside the speakers by at least 6 feet. 1 in a corner other side of a doorway, other mid wall. They face seemly random directions but direction seemed to really impact that peak.

Decay times came out low, average maybe 100ms.

My corner traps did nothing to help these modes. All are back in place and the system is less fatiguing them it was, still tuning. I also sent my data to GIK to get some ideas toward tweaking some other areas of interest

A sub loads the room. It doesn't or is not intended to be firing at you. Corner placement is the more efficient place to do this. 

Acquiring 4 subs solved my problems. I bought Gingko Audios version of the swarm system and it doesn’t just pressurize the room but it expands the soundstage incredibly well. Placement is still important.

Assuming you did the sub crawl and actually like the sound you are getting....conventional wisdom is to try moving either the sub or the listening position a few inches at a time until you either find and improvement... or not and if not it is likely you will benefit from a second sub.