Can two subwoofers reduce a bass problem?

@OP, 
Yes, using 2 or more subs help with room nodes.
I would PM Duke (audiokinesis), he manufactures the Swarm system.
Though I know you probably don't want to invest in that, I think Duke will be able to steer you in the right direction with regards to sub placement.
Bob

4 is better than 2, and 2 is better than 1, yet in my system one REL S/5 SHO works great...friend with almost identical system sounds best with 2 REL S/3 SHO...so, it depends...

It's interesting that your able to narrow down the problem frequencies.

You should be able to get a decent low frequency presentation at the listening position with one subwoofer by locating your rooms greatest mode using the Crawl method.
https://www.youtube.com/watch?v=AV3oLLMgS-M

During this test you might want to map out all your rooms modes in the event you add multiple subs. 
For reasonably priced long interconnects check out Blue Jeans Cable or Monoprice. Good luck with it.

BTW, OP you never mention if your problem is a peak or a null.

If it's a peak, EQ is your friend.

@erik_squires 
48 and 127 are peaks and a actually have a dip at 70.
EQ; from where do I get an analog (I'm listening much on LP:s too) mastering EQ cheap? I can't ruin the sound with some cheap budget EQ.


A strange thing happend when I replaced my old Supra Annorum speaker cable to Kimber 8TC. Besides giving a more open, wider sounstage with a tighter bass the problem with the bass peaks also was reduced. Now it's more like the peaks has become more narrow.

I'm looking at REL T5i and REL T Zero and wonder if I get a better result with two T Zero than one T5i. With two T Zero I might counteract my bass problems a bit, but on the other hand I will not get a real low bass.
With a T5i I will get low bass but maybe it will increase the bass problem again.

My smallish room is not just a listening room so I can't just put four subwoofers anywhere and build bass traps or a Helmholtz.

Now I remember why I bought a new headphone amp and new headphones:)