I don't have the HS6 stacking kit.
Most pictures feature the X5 stacked with E12/A but the kit should still work irregardless.
X5 features a more clear sound sig. But messes up a lot on the quality of its transparency by being too harsh and clear whereas the E17K sports basic level high-end features but with a nice fun sound.
I would heavilly prefer having the sound of the E17K on the x5 yes
So much less fatiguing. The dark background on E17K works well for passive listening as well.
You lose a bit of detail...but I can dig it now that my ears wont fall off from long term X5 listening.
I'm curently doing AUX input on the E17K. Meaning using DAC of X5 and amps on the E17K. I like this sound more for passive listening (X5 has a more clear and forward sig) but its really a waste of money.
You should NOT drop $500 ($350 X5 and $150 E17K) for this....... I'm only doing it because you and others requested it and because I have these devices.
Don't waste your money stacking the E17K and X5. There are much better stacks you can do for $500.
Instead, stack a dedicated amp with the X5. The E17Ks cost goes into it being multi function, and not on its abilities seperately as an amp or DAC. Drop that $150 into maybe an ALO, Leckerton, headroom amp etc. You get the point.