The transfer of energy from one system to another. Often used to describe the interface between a loudspeaker and the surrounding air.
"I was so excited to find your restoration and transfer service. I am going through my LP collection now to make up my first order. I already have a definite 12 selected with that many more on the "wish" list. Your service is a godsend because I have many wonderful LPs that have never been released on CD --I have spent countless hours trying to ..."