well straight away we can see a difference in what the graphs tell us!! However, you seem to have lessened the db scale and now it looks a bit worse than it would if in the format I'm used too! The LH scale is usually set at 45-105 bd, ie swings of 30 db each way. The actual figures don't change of course, but after a while the standard scale gets used to if you follow me.
It looks like it would sound bright to my ears, (the 3-10 k region) but hey we are all different.
I could have missed what you are using to measure with, if it is the RS meter then it is totally unreliable above say 5 k so in that case I would ignore it for now.
Indeed if you are only interested in the bass frequencies, and are using the RS meter then it really only makes sense to graph up to 200 hz.
Truly, the forum to be posting your graphs in and getting answers to your question is the shack, though posting them here could very well introduce people to this area who may not come across it otherwise, which can only be a good thing.
The other advantage of posting there is that you will have real experts helping you, rather than me. Bear that in mind when I talk, I most certainly do not consider myself an expert.
As you can see, there are quite large swings in the bass region, and I don't feel I'm going out on a limb if I say you would notice an improvement if they were cleaned up!!
I have no idea what the system is that you are running, and the type and quality of any bass eq would be dependant on your system. You might not put a behringer bfd in a system worth $200,000 for example, but for most systems it would be a safe bet.
A very good but still reasonably priced option is the behringer DEQ 2496, a step up on the bfd's IMO.
Top of the line solution are something like the deqx, but with a price tag to match. (Does WAAY more than just bass eq mind).
You can muck about on paper (ie use the find filters function in REW, or do it manually) and dial in the eq and see graphically what the results would be.
I'm not sure what help you are now looking for, so ask if you have a question, but back to the starting point of this thread. Is it worthwhile investigating graphic eq to help?? No.
Can para eq help a response like this?? Most assuredly.
If I can, is it worth having room eq AND room treatment? Yes, the best way to go if you can. No room treatment? Well, significant results can still be gotten with eq.
Hope that helps, and if I can help further then let me know.
Just on a more general point, too often in audio (as in other areas of life I spose) people are bound by pre-existing or fixed ideas. The 'purist' would usually poo-poo or deride the entire concept of room eq for example, on some lofty theoretical plane no doubt, somewhere up there in the clouds, whilst the rest of us actually listen to music down here.
They could very well disdain the concept of measuring their system..." Hummph, measurements. I use my ears (often with things like 'the most exquisitely sensitive measurement system the universe has yet seen' or some such twaddle) and I laugh at the 'objective measurement crowd' ".
However, a graph of the bass response of a typical system in a typical room looks very much like yours, in other words your's is what I would have expected to see. Nothing unusual.
So, the purists can maintain whatever they want in the Ivory Tower, I'll listen to smooth natural bass myself.