During the early eighties a small group of Audio Professionals aligned themselves with respected mathematician and locally renowned Audio system designer engineer Mr. Marcel Put, to develop a loudspeaker system that would sound totally natural whenever loud music was desired or needed. From a modest laboratory and test facility, located in his native town of Lummen in Belgian Limburg, Mr. Put embarked on an extensive research project with the objective of finding a solution to the excessive levels of distortion typically experienced from listening to medium and medium/high frequency spectrums produced by loudspeaker systems used for live sound touring purposes at the time. As a result of burning lots of proverbial “midnight oil”, Mr. Put recognized that it was not possible to offer a solution to this problem within the confinements of the commonly practiced way of utilizing horn loaded compression drivers to reproduce medium and high frequencies. The core of the problem was found in that at high SPL levels these horn loaded electro-magnetic transducers deliver as much as 25 to 50% unwanted but very audible and annoying harmonic distortion. Another approach was called for: a totally hornless design became an option.
By the mid eighties, various driver technologies had been researched and mostly abandoned, until by accident, a French speaker component manufacturer made a compact 7” low frequency driver. It turned out, this particular driver performed excellently as a medium transducer. What first caught the attention of Mr. Put was not only the clarity of the mid frequencies produced by this driver, but also the unusual efficiency of this device. Contacts were made at engineering level with the manufacturer in France and an agreement was reached to start a collaborative research program to further develop this exciting speaker product. Several versions of cabinets were made and used by many Belgian rental companies. These cabinets comprised of two 15” low frequency drivers, a single 12” lomid driver, four of the above mentioned 7” drivers made by Audax and two high frequency devices of unknown specification. All these drivers were mounted in such a way that they formed a vertical line. This was about 6 to 7 years before another French speaker manufacturer introduced the first commercially available “line array” to the world’s audio community.
By continuing research in this direction, a new alliance was formed between ex-Audax engineers and Marcel Put. One of these engineers was Mr. Jacques Mahul, creator of the highly acclaimed JM Lab brand of speakers as well as Focal HI-FI and automotive speaker components. Mr. Mahul set up a manufacturing facility to produce small quantities of specialized drivers in his father's foundry in St. Etienne, France. He sought to continue the R&D collaboration with Mr. Put. This resulted in both a second generation 7” midrange driver that would reduce the number of units required from 4 to 2 and in the development of a high quality 12” and 15” driver. This was a technological breakthrough. It was decided to prepare for larger quantity production of these drivers under the Focal brand. Focal ended up supplying this second-generation 7” driver and 15” drivers to Christian Heil for the famed V-DOSC speaker system.
Marcel’s 20+ years of research, however, by now had started to pay-off in substantial knowledge of materials used in the manufacturing of these exciting 7”, 12” and 15” drivers. He embarked on the development of a 3rd and consequent 4th generation device that would replace a unit on a one-to-one ratio in terms of efficiency. The high precision manufacturing techniques of these drivers are mastered by a small, but dedicated group of engineers, currently located in France. Consequently, several versions of cabinets are designed and produced with this 3rd and 4th generation drivers under the brand MP Audio.
During his life, Mr. Marcel Put was captivated by the complicated theory of Small-Thiele parameters of loudspeakers. Intensive research led to an admirable result. With sophisticated measuring apparatus, software and mathematics, the free air parameters are measured with very high precision. With complicated mathematical formulas, he derived ST-parameters useful for developing a bass reflex cabinet, which was his next research project. Mr. Put embarked on the design of a bass reflex cabinet for an optimal bass reproduction. The ideal volume, tuning frequency and tube length for a bass reflex cabinet can be unambiguously determined. This was a second technological breakthrough. It made Mr. Put his bass reflex cabinet to the most famous and beloved.
"A Truly European Idea" - indeed - and, until recently, little known by Asian audio professionals. To change that situation, in 2001, Mr. Put gave his approval to start production of a limited number of his cabinet designs under license in South East Asia, all featuring original 3rd and 4th generation MP branded 7” drivers. The relentless endeavours of a small group of faithful-to-the-cause colleagues and customers promise a bright future to this small but top class audio enterprise, straighten out by the ever changing and often unreasonable marketing demands of the day.
Mr. Put is known as an intensive research designer who always strove to the absolute perfection and who made high demands on his competences which paid-off in remarkable results in audio acoustic. Regrettably and sadly missed, Marcel Put passed away toward the end of 2002. Fortunately, his work to offer unmatched standards of excellence to the audio industry is carried on by his engineering trained daughter, Heidi Put. The manufacturing base in Thailand is led by a number of very dedicated engineers. So far, this has resulted in an ever-growing client base in Asia and the Middle East, and a number of exiting new products. The emPad design engineers adhere to multi-application capabilities of the products as their primary design priority. This, in combination with reliability, ultra high efficiency and very low distortion characteristics, results in repeat business for our clients and emPad alike.