how the phone conversation went

We decided to separate the background noise after a preliminary practice of the phone conversation. We found that as there was similar background noise in both voice selections, it could make the audience think the characters are meeting, not in a phone conversation.
Character X - based in the refectory to make it appear as if he was in a cafe.
Character Y - based in the library where it is much quieter.
We did this in these settings because: character Y is much higher up in the group so he sounds in authority, however, character X is less in authority therefore, showing that Y is the boss over X.
To make the conversation sound like its a phone call we added a 3-band equalizer, making the frequency high and the Gain low, this made it appear more muffled, sounding like a phone. The other thing we are adding to make it sound more like a phone conversation is a dial tone or drone, which will aid the viewer to know thy are in separate places.

Update.
We found that having separate background noise can make it have little continuity.
The 3-band equalizer muffles the background noise a lot, however, we may have to refilm the section to improve the audio.