Nighthawk AC1900 compatibility with Comcast voice on separate adapter

[chizwiz]

I see that the description for the Nighthawk AC1900 says it's not compatible with bundled internet and voice serice.  However, in my case I have Comcast Business internet and voice, but the voice coax is connected to a standalone Arris "adapter".  Basically, the coax coming from my wall goes through a splitter, one of which feeds to my Comcast-provided modem/router/wifi, and the other goes to this VoIP device.  If I replace the modem/router/wifi with this product, will everything work OK since the voice is already on a separate device?

Thanks!

[doraemon]

Your voip is not connected in anyway to your existing modem right?

As you can see the modem router doesn't have a voip port. 

Therefore, you should be able to replace it without a problem.