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Direct Servo Demo
Direct Servo is a patented technology that dramatically reduces many different problems which prevent conventional subwoofers from reproducing accurately.

Fig 1.0 - Direct Servo demo
The animation above shows how Direct Servo works to reproduce the most accurate bass possible. A sensing coil (blue) adjacent to the driver voice coil (red) is used to generate a feedback signal which is then used to correct any difference between the original and the reproduction. The sensing coil acts as a microphone, and the feedback is sent to the servo board where the necessary corrections are made instantly.

The animation above shows how our Direct Servo Technology works. The following steps have been numbered and described for illustration purposes, however, in reality 2 and 3 occur at the same time and the feedback signal is transmitted instantaneously. The following steps are illustrated:

1. Amplified signal

The plate amplifier receives a signal which is filtered on the pre-amp board to achieve correct integration. The signal from the preamp passes to the power amplifier which then sends the amplified signal to the voice coil of the driver. The amplified signal is shown above in red.

2. Cone excursion

As the amplified signal passes through the voice coil, the cone moves and begins to reproduce the signal.

3. Correction signal

At the same time as the cone is moving in response to the amplified signal, the sensing coil is generating a feedback signal. There is no time delay between step 2 and 3 because they occur simultaneously. While the cone is moving, the sensing coil is sending feedback. The sensing coil is a specialized microphone which measures the precise output of the driver. The correction signal is shown above in blue.

4. Feedback

The correction signal is fed back into the summing points of the amplifier. It is compared to the original signal and corrections are made without the use of any active circuits.

5. Corrected signal is accurately reproduced

The driver reproduces a signal that has been corrected by instantaneous feedback. Detrimental memory effects have been eliminated and the sound is true to the original.


Direct Servo and speed

Sometimes we are asked whether our servo makes the sound slower. Our servo is a big part of being able to create what many audiophiles call "fast bass." But if this reference to speed is an objective one, actually referring to the speed at which the servo can act, this concern is unfounded. Other servo systems based on an accelerometer have a response time but with Direct Servo the response time is zero. The sensing coil and voice coil operate simultaneously. View extended answer >


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