With the Apple airpods, Samsung galaxy buds and other Bluetooth earphones’ popularity on the market, one can definitely notice the shift from traditional wired headphones to these wireless earphones. But here comes in the question: Can these wireless earbuds really transmit high-quality sound as compared to the wired ones? Tommaso Melodia, associate professor in the Department of Electrical and Computer Engineering at Northeastern University, explains the science behind Bluetooth headphones and how their quality compares to wired devices.
First of all, Bluetooth is a family of standards for wireless transmission of digital data over short distances using short-wavelength radio waves at frequencies between 2.4 and 2.485 gigahertz. Basically, anyone can transmit these signals at low power over these frequency channels without a special permit from the government. But there is always the possibility of interference when the number of Bluetooth devices simultaneously transmitting signals at the same location increases, which might result in performance and quality degradation.
But to better understand transmission quality of sound, one must understand how audio signals are transmitted and played out. Audio signals are digitally stored in our phones. With wired headphones, they are first converted to analog signals and then transmitted to the headphone for the audio playout. With Bluetooth, the signals are not converted before sending it to the earphone but transmitted digitally over the wireless link. The signal is then converted into an analog signal. Therefore the quality of the output depends on the DAC (digital to analog converter) built inside the phone or the earbud. Because of limitation in size, it may not be easy to incorporate high-quality DACs inside an earbud. But, like all electronic devices, DACs get smaller and less expensive with time. High-quality earphones can have exactly the same audio quality as a wired earphone.
Many users agree the convenience of the wireless earphones wins over the wired mess that ends up in tangles. In crowded and loud places like the gym or the airport, users prefer convenience over a higher quality of sound. But there always is a chance of interference from other devices in a crowded place, delaying the output. Melodia says “Except for factors not strictly related to technology, like pricing, I don’t see any compelling reasons not to use Bluetooth-based headphones”.