That alcove is going to do unpleasant things to the bass. You should move the Sub out into the room where it can breathe more freely.

Rooms and speakers interact, this is the way that the physics work.

Here’s an experiment: Play something with an active, thumping bass, then walk around the room close to the walls with a handful of Post-It’s. As you discover a spot with accentuated bass, leave a Post-It. You’ll discover spots where the bass seems doubly accentuated, mark this Post-It with “!!”. When you step back, you’ll notice that the Post-It’s are somewhat regularly distributed around the room. These are “peaks”. Midway between these peaks are “nulls” where the bass is much quieter. If you place SUB at a peak, it will be more efficient. At a null SUB will be less efficient. The size and shape of the room determines the location and significance of the peaks and nulls. After you are accustomed to locating peaks and nulls, you’ll be able to discover smaller peaks and nulls throughout the 3D space.

In my college apartment I discovered a monster peak (along a wall) and placed a chair at that spot. Bass seemed to explode from inside the body. This was the favorite chair for males. If I moved the chair a few inches, the peak was gone. Smarter, more observant males would move the chair back to the peak.

Wow man, thank for the insight!

I hoped it was me and not the sub.. 

now that you mentioned it the sub does have accentuated spots, like the one I was referring to .. ill put a chair there too 

You can also do it in reverse. Put the sub in the main listening position, then scan the room for accentuated spots. Once you found them, place subwoofer at one of those spots. Then you should experience bass best possible from the main listening position. 
This is also described as the “subwoofer crawl”.

For me it was quite a proces to find the best possible spot, once found, it’s worth it. 
Also it’s worth to mention that at this moment there is a Trueplay bug for Arc+Sub users. I expect this will be solved with the next upcoming patch, but we’ll need to wait and see if that’s true. 
This bug is causing the sub to be very under-powered when using Trueplay, especially in the very low-end. What I did to compensate the lack of power is put the sub physically in another room and power it up (for example hallway and close the door), then tune Trueplay. Because the microphone will hardly detect the Sub, it will bump that part up. After you’re done, put the sub back into its original spot and you will find out, it’s way more powerful. 
 

Now put the Sub in the main listening position, scan the room and find the best spot. Put it there, and you’re all set

Thanks for the tips @JeroenVR ! Will try.

Do you have specific recommendations for songs to test? Would love to try this out. Also, does the whole in the sub mini point towards or to the side like the logo on top suggests?

I don’t have a favorite track, I’ll just thumb through the rock stations until I notice something that is constantly ‘thumping’. This will minimize the time required to scan the room because you won’t need to wait for the next bass hit.

Did you notice anything special about those “!!” spots?

After the answers I got here I did a little searching on the interwebs and found the “sub crawl” , where you put the sub on the couch where you usually sit, than crawl around the house (point being you are on the same height as the sub) and find some good spots where you hear it best, than choose one and put the sub there .