OK, some good advice here. All rooms need treatment, it is paramount for good sound. EQ/DSP may help after getting the room sorted out. The problem with room correction electronics is they can't reduce the overly long decay of sound in an untreated room, how can they? They also can do nothing about the full nulls created when low frequencies recombine out of phase. It does not matter how much power you pump into the speakers the sound will just cancel with the same power. Partial nulls can be boosted but if you try and correct for example a 15dB dip you will not have enough power. It requires a doubling of power to achieve a 3dB boost. Try doubling your amp's power 5 times!
When sound is left to decay naturally in a small space (the average room) detail is obscured by the confused and smeared sound. So determine the required time it takes for your sound to decay by 60dB across the full spectrum, known as RT60 or T60. The average room needs T60 to be about 300 to 400ms.
The thing to do is download a great free program REW and measure your room. You will need to buy an inexpensive mic. for the job. This can provide a CSD plot of your room showing the peaks and nulls. Yes, you will need bass traps. REW can help you best position your speakers and show the effect subs have on the performance. Multi -subs can and should be used to smooth out the bass response. The optimum would be to treat the room in combination with 2 or 3 subs and you will get to hear, probably for the first time, the music info that has been 'black-holed' by the nulls. Some who have heard of multi-subs envisage thunderous bass but properly placed and dialed in they enhance the entire spectrum from top to bottom. Think of them as tuning units.
WARNING: place a cushion between your feet in case your Jaw hits the floor 😁