California-based premium audio brand Audeze helped design a pair of headphones to facilitate communication between doctors and patients during MRI scans without affecting the images produced. This led to the development of CRBN electrostatic headphones for audiophiles.

Audeze engineers worked with Dr. Mark S. Cohen from the University of California, Los Angeles School of Medicine, Semel Institute of Neuroscience and Human Behavior, SMRT Image's team and BoomBang's industrial designers to develop headsets to help doctors and patients during MRI scans.

The idea is not only to relieve the stress and anxiety experienced by the patient during the scan, but also to reduce noise (the sound pressure level can exceed 120 decibels). Due to the need for magnetic and electric fields to produce medical images, traditional headphones using moving coils, planes, and electrostatic drivers are not easy to use, and metal parts are almost unusable because the eddy currents caused by these things can cause image quality problems.

Therefore, Audeze's design team set out to develop a new type of electrostatic transducer.

"The principle of operation of electrostatic headphones is very simple," Audeze explained. "The electrostatic transducer consists of a diaphragm with a constant charge, sandwiched between two acoustically transparent stators separated by spacers. The music signal is applied to the stator in the form of equal but opposite high-voltage pulses.

"In other words, when a positive voltage is applied to one stator, an equal but opposite negative voltage is applied to the other stator. As a result, the diaphragm is pulled toward the stator with negative voltage and pushed away from the belt. A stator with positive voltage. "Voltage. Therefore, the diaphragm moves with the music signal, and this movement produces sound. A transducer designed in this way is called a push-pull configuration. "

The traditional electrostatic design uses a film with a resistive coating for the diaphragm, but due to the variation of the coating thickness, deformation may cause problems. For the new transducer, Audeze uses a patent-pending thin-film polymer membrane in which carbon nanotubes are embedded. Because the charge is evenly distributed throughout the film, it has ultra-low distortion.

Electrostatic headphones are also “famous for sub-class bass response”, and Audeze naturally aims to solve this problem, combining the use of large and efficient diaphragms, larger spacing between the large rigid stator and the diaphragm, acoustically transparent damping materials, and customization The ear cushions help provide "extremely good bass response down to 20 Hz" without affecting the treble.

For medical applications, CRBN headsets are combined with an image/cine system called Lumica AV from SMRT Image to provide a comfortable and distracting audiovisual experience designed to make MRI patients comfortable and distracting.

"What we intend to do at SMRT is to create a calm patient experience in a very harsh environment," said Tylor Garland, CEO of SMRT Image. "We are able to produce high-fidelity AV products that are compatible with MR, and patients can comfortably wear the product when scanning for long periods of time in a confined environment, which is very tricky. We are fortunate to find Audeze to help us with our work .solution."

Lightweight design, "extremely neutral" and accurate bass response are certainly the attractions of consumer headphones, so Audeze also created a pair of open headphones for audiophiles around CBRN transducer technology.

CRBN electrostatic headphones weigh only 300 grams (10.5 ounces) and are made of special materials such as carbon fiber and magnesium alloy. They provide a frequency response of 20 Hz to 40 kHz, a sound pressure level greater than 120 dB, and a total harmonic distortion of less than 01%.

They come with a specially designed 5-pin DIN audio cable and aluminum suitcase, and are compatible with all Stax-type 580-volt Pro Bias amplifiers. They can be ordered specially, with a suggested retail price of US$4,500.

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