ADAPTIVE OUTPUT IMPEDANCE – AOI
It is very easy to get a loudspeaker membrane to move, but this movement needs to be perfectly controlled. It needs to accelerate and stop as fast as possible without creating any unwanted vibrations.
A loudspeaker membrane is pushed and pulled by the coil in the magnet gap depending on the current that goes through it. The mechanical construction of a transducer represents a mass on a spring that naturally doesn’t behave the same way at all frequencies. It typically has a resonance frequency where it moves easier.
Not only the transducer has resonance frequencies but also the material itself, the suspension, the spider, etc. It is important to know all these physical characteristics to be able to correct them with the electronics.
So whatever the material of the transducer (paper, fabric, polypropylene or any other) it has to be accounted for in order to avoid any coloration of the sound. The material of the membrane should not colour the sound, all materials should reproduce accurately and not “sound” different. We have chosen material for their weight, rigidity, durability as well as homogeneity in production.
In order to correct all of these physical characteristics we have implemented a feedback loop from the speed of the transducer and acting on the output impedance of the amplifier. Needless to say that this circuitry is impossible to function in real-time with any digital technology and only analogue technology will achieve a perfectly seamless result.
Our AOI technology ensures that there is no colouration of the sound from the transducers and that the transients are maximised.