Integration of MiniDSP Flex

I am a current owner of a second system of Parasound Hint Halo 6, B&W 805D3s, REL T7x pair, Arcam ST60, Empire Turntable with Ortofon MC cartridge, Apple TV, Roon and a Parasound JC Junior +. My room is about 275 sq ft with a custom room diffuser added to a back wall. I have used an XTZ room analyzer to examine the sound. 

First, I am not displeased with the overall sound as it is very good and friends have complimented on the sound. I also have been learning to play the bass guitar and want to have a little cleaner bass response. I have been told that a MiniDSP flex would help and also see comments with the amps that have built in DSP is a bonus. 

Next, Does anybody have experience implementing a Flex MiniDSP? I am using the high level cables for the subs. I have been told that with the Flex that I would switch to RCA with the solution. I would also need to use SUB optimizer and then the room correction. I only use this system for listening to music and not a home theater.

Finally, I will add a couple of quick questions and thank you for any feedback.

1. Implement DSP? What process would I use to tune with DSP?

2. Change Integrated Amp? 

Regards