These roles are often confused and nearly always misunderstood even by those in the industry. On big-budget releases most of the time they will not be the same person. The simplest way of defining a producer is this: a producer is to music what a director is to film. They shape the creative direction of the project.
A producer will typically control the flow of a recording session – it is him/her who decides what is recorded next, by whom, with what, and how long they’re allowed to spend doing it. In some cases they are songwriters and arrangers, in others cases a producer only guides in realising what is in the artist’s head. If a take, part or arrangement isn’t good enough it is the producer’s job to tell you.
An engineer is the technical guy or gal. They press the buttons and twiddle the knobs. Often they will be responsible for getting a sound ready on a particular instrument, but will then look to the producer for approval. Sometimes there will be a separate Pro Tools engineer, assistant engineer, or tape-op, and when a single project is recorded at more than one studio there will often be more than one main engineer in the credits too. These people all fit into a hierarchy with the producer on top.
A mix engineer is responsible for creating the final mix. In some cases the producer is not even present for the final mix (although we would not recommend it!). Often people hear a great sounding mix and think an album is very well produced, but these are in fact separate entities. Although they do go hand in hand very often, as a well produced record is far easier to mix than a badly produced one.
It is certainly possible for an individual to be all of these, which we often do here at Mad Hat. An artist can be their own producer if they so desire. What’s important to the flow of a session is that everyone understands who is playing which role.