The couple have had the studio built near their home in Helmsdale in Sutherland.
It is the latest project Edinburgh-born Collins has involved himself with after he almost died from a double brain haemorrhage 11 years ago.
His other projects include a film, The Possibilities are Endless.
Collins and Maxwell told BBC Radio 6 Music's Radcliffe and Maconie show of having the studio constructed close to their house and overlooking the Moray Firth.
Collins said: "My grandpa was born there, in the house.
"Local people were very positive about the studio."
Maxwell said the studio was treated like a retreat by the musicians who use it.
She said: "It has a beautiful atmosphere. The people who have been have loved it. When they get there they get their heads down in a relatively short space of time."
Collins is widely known for his work with the band Orange Juice and his 1995 solo hit A Girl Like You.
In 2005, he went into a coma after suffering a stroke and two haemorrhages.
After waking from his coma, the first two phrases Collins was able to say were his wife's name - and "the possibilities are endless".
The film, The Possibilities are Endless, explores his journey from the brink of death to rediscovering memories lost because of his medical condition.
Singer-songwriter Edwyn Collins and his wife Grace Maxwell have created a music studio that they describe as a musician's "Highland retreat".