parallelizing 2 or more dac

I just was wondering whether its possible to combine the audio outputs of 2 dacs (be it of the same company or different ), the reason being i was thinking of designing one just for the lolz one where a pcm 1704 and a ess 9038pro (maybe something different havent thought too deep about it ) are used together.
 
With DACs that have built-in digital filters of different lengths, you will get comb filtering effects.
So if i set both to have brickwall filters or a fast roll off filter it should be fine then ? Or perhaps even there the filters could be different. So if i am not wrong there is a way to have an external digital filter or something on both the pcm1704 and ess chips maybe they could be a way to achieve the result.