A new update: I've connected my onboard soundcard's line-out (3.5mm jack), to the line-in of my X-Meridian, set my onboard soundcard as the default sound device in Windows, and enabled the line-in as the recording device, in my X-Meridian's control panel(disabled monitoring on this line of course). This way, any sound played by
Applications that don't support ASIO, is going through onboard card to X-Meridian, and made available in the ASIO software input channels of X-Meridian. From then on, i added a new track in Reaper, with stereo input assigned to X-Meridian's inputs 01/02 and send this signal to my Rearoute inputs 1/2. Everything seems to work as intended. I'm still able to play bit-perfect through foobar (or any Asio supporting player-Tried also JRiver Media), and i'm able to manipulated (eg process) any audio signal coming from non-ASIO applications(this is obviously not bit perfect, but it's not something i care, since it will be mainly for phone applications, rare use of movies and maybe navigation).
My initial intention was to use onboard SPDIF output and send to X-Meridian SPDIF input, but i didn't manage it. I'll keep trying, since the above method will definitely introduce hiss(noise?) to my output signal, unless of course i mute the ASIO input lines inside Reaper, every time i need to play some quality music using only ASIO (ie foobar).
That's it for now. I'll keep you posted on any more findings. Hope that i'll manage to connect onboard - X-Meridian through SPDIF the next time ti post in this topic