Digital Speakers

Digital speakers, also known as Digital Sound Reconstruction (DCR) systems involve loudspeaker technology. These types of speakers are different from modern digital formats and processing because engineers have not yet developed them as a mature technology. 

Digital Sound Reconstruction systems bring the digital signal closer to the transducing process and are capable of transforming electrical signals into air-pressure variations or sound energy. Digital speakers include a sound generating area with small digital on/off elements that are energized by a variety of electromagnetic solenoids or piezo actuators. 

Modelling shows that the piezo exciter can be generated by spiral forms. By arranging the digitally processed signal to a full resolution (16-bit 44/48 kHz PCM), the matrix of elements is able to reconstruct the original acoustic wavefronts in time, frequency and amplitude. If this happens, the problems of ultrasonic and beat-frequency noise generation would increase, so the system may never be commercially released.

Micro-machine pumps are capable of converting digital signals to sound pressure and they can achieve this by subdividing the voice-coil of a direct radiator driver. When this happens, each element drives digitally and data integration occurs over the complete coil. The upper half is handled by a split-coil winding the lower half, so the remaining 8 bits operate in the analog domain with the simple DAC. 

An intermediate digital speaker starts with an analog or conventional speaker with an active design, where the user can choose to place a D/A converter inside the loudspeaker. A digital audio processor can be present and digitally coded signals can be fed directly to the system. This process prevents loses in intermediate analog control electronics, as well as in inline-level linking cables. A different digital line achieves the control of the signal replay level, so a managing microcomputer is in the speaker. When used in home systems, it would be ideal to have an interface via a hand-held infrared remote control. Remote D/A and A/D converters are frequently used, and the more the audio signals are handled in a digitally coded form, the danger of degradation in the transmission chain decreases. This is very common in digital studio practice. 

It’s worth mentioning that digital speakers are quite large for the number of bits required for high-quality sound reproduction.