Can Room Correction Be Added to an Existing DAC?

@ OP
Take a look at 
https://www.stereophile.com/content/music-round-57
The Dualcore can be used prior to or post DAC.
I‘d strongly recommend a linear power supply. The switching unit that comes with it is a source of noise.
I have used this unit for years post DAC (OPPO 205) using its XLR Input and Output (amps: LSA Statement and Bladelius ASK). 
The Stereophile  review is entirely consistent with my experience.
Good luck!

Paradigm PW Link is an inexpensive way to ARC. Optical in and corrected optical out.

Since I began using Innous server with Roon and convolution filters through Acourate running my ATC 150 asl/D&D 8c  there is no way back.

Mahler123, the answer is yes sort of. If you just use two speakers you can use a DAC after a room control unit by taking a digital output. The problem comes when using sub woofers. Now you need two 2 channel DACs. The good room control units allow tailoring the entire frequency band including and probably most importantly the bass. They include bass management software which gives you the best subwoofer integration possible. Units Such as the Anthem STR, DEQX and the Trinnov Amethyst include 4 DAC channels. IMHO a complete unit is the best way to go. If you do not use subwoofers and have a DAC there are certainly less expensive ways to go but, warning, bass can deviate +- 10 dB. Correcting this requires a speaker of massive power handling and a very powerful amp. You can deal with this by going into the program and reversing some of the correction to keep yourself from clipping amps and blown speakers.

gosta, I certainly agree. I have been using a TACT unit for 25 years. I have ESLs and subwoofers. Once you hear a system with full digital correction there is no turning back.

mijostyn, I would like to run stacked Quads with subs. Heard this in the late 70’s playing Little Feat Waiting for Columbus. Still a reference in my memory :-) Actually got a pair of Quads 63 in my wardrobe so maybe, but don't know how to get a stacked pair...