A REL is a SYSTEM, hence the term Sub-Bass System. “What makes a REL a REL?”
Lord began referring to them as sub bass systems, because the performance he had been able to achieve was the result of system engineering. Where common subwoofers rely on amplifying a line level signal, Lord had intuitively realized that the signature of the entire system had to be built forward into a pre-conditioning signal that allowed the sub to disappear into the music. Thus, from almost the very beginning RELs used a special high-level circuit. Many of the basic elements present in modern day RELs began finding their way into production RELs in the later 1990’s
For pure fidelity to be realized, every part of every note in the music must be reproduced, along with the acoustic signature of the recording space.