Ingmar trained at Island Records under the guidance of Chris Blackwell and Stephen Street, and eventually succeeded Street as House Engineer at Island Studios. He then worked on everything from Bob Marley mixes and tracks with U2, to deal-winning demoes for Suede and Pulp. He also recorded Sly'n Robbie, Aswad, The Cranberries, Julian Cope, Jackson Browne and many others.
As a freelancer he then produced Bob Marley's Iron Lion Zion and other remixes for Island, along with projects for Sony, Virgin and EMI, plus three albums in Tokyo which included a Japan No 1 album by Lindberg. He has also worked with Power of Dreams, Liam O'Maonlai, Luan Parle, Damien Dempsey, Iarla O'Lionaird, Donovan, Sinead O'Connor and many others.