DSP with an Integrated Amp?

My gear consist of a Parasound Hint6 integrated driving B&W 606 S2s and a pair of REL t7i's. I have been unsuccessful in integrating my subs using the method REL recommends. My listening room front wall opens on the right into the dining room and the bass is superb... when I'm in the dining room! 

I thought DSP might be the way to go and use Dirac room correction so I contacted miniDSP asking which product I should go with and told them specifically I had an integrated and was wanting to do room correction.. They recommended DDRC24.

I tried numerous configs and was unable to get the program to work so contacted them again. This is the reply I got- 

Unfortunately that won't work in that case as we only support line level. You can't apply DSP to an amplified connection. the DSP needs to be "before" amplification, not after. You'll have to figure out a way to put the processing before... With an all in one amplifier doing 2.1 processing, adding DSP won't be possible I'm afraid..

I reached out to forums and was told I could run source in (Toslink) to the DDRC and run analog out to the integrated analog in. How would/ does this work to do room correction? The only thing it can process is the source correct? I know I'm probably confused and I know Millercarbon will post another link to his system but I could use some help understanding and thus far miniDSP customer service is non existent after purchase.