If you otherwise love your existing speakers, I agree, a stereo pair of powered subs might be the first thing to try.
Bass is stereo despite all the yap about bass being mono. Important for main music system, my speakers have 15" woofers.
You could try 1 sub if budget or positioning limits. I do successfully use a single sub in my small home theater (velodyne, 1,000 watt servo control of 10"), . I also use a single sub in my office added to bookshelf speakers, a velodyne 12", servo, less power, I forget how much. Great for adding lows, but not imaging of lows which is not critical, but, wonderful for a main music system.
In any case, I suggest you get this CD, listen to Stereo Bass in your existing system, then have it for future evaluation. (I had it in LP, loaned to one of my son's friends, never got it back).
https://www.barnesandnoble.com/w/double-bass-niels-henning-rsted-pedersen/190661?ean=0716043105526&st=PLA&sid=BNB_ADL+Core+Generic+Media+-+Desktop+Medium&sourceId=PLAGoNA&dpid=tdtve346c&2sid=Google_c&gclid=Cj0KCQiAw4jvBRCJARIsAHYewPOSDx8OUNnOlnVUn4IqbMsZcS8p1gKF9-GKPS0czZtQRQ1Ge7BPJhUaArJoEALw_wcB
Make sure you can return the sub(s), get them, live with them for a few weeks, keep or return.
Self powered subs take a big load off of your amp, and a big load off the speakers. When not trying to do low bass, you have more positioning options with your mains, that can be quite advantageous.
I would keep source/tt upgrades for later, after you get the punch you are looking for.