The EMT 240 Reverb Foil was a groundbreaking evolution in artificial reverb technology, building on the success of its predecessor, the EMT 140 Reverberation Plate. Developed through a collaboration between the Institut für Rundfunktechnik and Dr Walter Kuhl, the EMT 140 debuted in 1956 and became a studio mainstay, covered by global patents.
Its innovative design, based on a tensioned steel plate, offered a natural, lush reverb that transformed the recording industry. Building on this legacy, the EMT 240 introduced significant advancements that pushed the boundaries of reverb design and application.
Released in the mid-1970s, the EMT 240 introduced a revolutionary approach by replacing the steel plate of the EMT 140 with an electrolytically produced gold foil, a mere 12 inches square. This shift was not just a matter of materials but a complete rethinking of how artificial reverb could be achieved.
The use of gold foil resulted in a unit that was only one-fifth the size of the EMT 140, dramatically reducing its footprint and making it far more portable and practical for smaller studios and mobile recording setups. Despite its compact size, the EMT 240 delivered twice the resonant density of the EMT 140, eliminating perceptible colouration and ensuring a clear and consistent reverb character.
The EMT 240 offered a host of technical advantages that made it a preferred choice among engineers. Its foil-based design ensured a constant resonant density across the audible spectrum, avoiding issues like flutter echo and minimising dispersion. The unit’s reverb decay adhered to an ideal exponential curve, providing a smooth and natural tail. Furthermore, the EMT 240 excelled in isolation, significantly reducing susceptibility to shock, vibration, and ambient noise, which was a challenge with earlier plate designs.
This innovation in design also made the EMT 240 remarkably user-friendly. Unlike the EMT 140, the new unit required no recalibration or re-tensioning after transport, making it a practical choice for studios with demanding schedules or those requiring equipment mobility.
The EMT 240’s impact on music production was profound. It became a staple in professional studios worldwide, used on iconic recordings to deliver lush, detailed reverbs that were previously only achievable in large acoustic spaces. From classical recordings to pop hits of the late 20th century, the EMT 240’s unique sonic character left a lasting imprint on the sound of the era.
The EMT 240 Reverb Foil stands as a testament to EMT’s commitment to innovation and excellence. By combining cutting-edge materials science with the practical demands of recording studios, EMT delivered a reverb solution that remains revered in the annals of audio technology. Its contributions to the evolution of artificial reverb are undeniable, cementing its place in the history of recorded music.
Despite its innovative design and significant advancements, the EMT 240 Reverb Foil never fully replaced the larger EMT 140 Reverberation Plate in professional studios. While the compact size, portability, and improved technical features of the EMT 240 made it an attractive option, the EMT 140’s larger steel plate produced a richer, more expansive reverb that many engineers and producers continued to prefer for its distinctive character.
As a result, the EMT 240 was often used as a complementary tool rather than a direct substitute, providing a unique tonal flavour that suited specific applications but did not entirely supplant the enduring popularity of its predecessor.
