From the EQ800 manual:
Smart Phone Call Functions
The ML 80 headphones can be paired with 2 devices at once, so
you can also pair them with your smart phone. However, when a
call is received it will interrupt the detecting audio.
I have tried to pair my iPhone and the EQ800 with the ML80s. I have tried every combination of connecting sequences . I can pair one or the other but have not been successful pairing both simultaneously. I have a cheap pair of Bluetooth earbuds that supports dual pairing and I can pair my phone and my Equinox to them without issue.