Although a source told OK! magazine that Murphy gave Edmonds an enormous yellow diamond engagement ring last week, the source also said the couple's wedding will likely be "something very low key and very romantic."
Murphy married Nicole Mitchell in 1993 in a lavish ceremony that made a Forbes top 10 list of most expensive celebrity weddings.
They had five children together, but Mitchell filed for divorce in 2005.
An Oscar nominee for the movie musical, "Dreamgirls," Murphy has been making headlines in recent months for the court battle he is having with his former girlfriend, Melanie Brown, known to Spice Girls fans as Scary Spice. She gave birth to a daughter with Murphy in April, shortly after they split up.
Brown has said she didn't know her relationship with Murphy was over until he said so during an interview and questioned the child's paternity.
A DNA test revealed the child is his, but Brown has said she is still fighting to get Murphy to act like the baby's father.