TECHWEEK
The Audio-Technica ATH-DSR9BT is the top-of-the-line Bluetooth wireless headphones in the DSR series. The headband and ear cushions of the model are made of eco-leather and have a filling with memory effect, which ensures a high level of comfort. The earbuds have the right weight distribution, making them even more comfortable. The model’s cups can be rotated 90 degrees. horizontally and sport a stylish polished silver finish.
The Audio-Technica ATH-DSR9BT is equipped with 45mm True Motion drivers, the diaphragms of which have a DLC (Diamond-Like Carbon) coating, which increases their rigidity and improves frequency response linearity. The speakers are equipped with lightweight coils wound with four twisted strands of refined OFC copper. The result is precise control of head movement and exceptional sonic clarity.
The headphones use the innovative Pure Digital Drive system, which transfers the signal digitally from the source directly to the speaker. The system uses the Trigence Semiconductor Dnote chip, which works by analogy with PWM and transforms the signal into digital pulses that “push” the coil and, accordingly, the speaker membrane. As a result, there is no need to use a DAC, which introduces additional distortion.
Audio-Technica ATH-DSR9BT have a built-in microphone. Onboard Bluetooth supports aptX and aptX-HD codecs. With aptX-HD, Hi-Res audio playback up to 24-bit / 48 kHz is now available. Alternatively, you can use the micro-USB port integrated in the left cup, which not only charges the built-in battery, but also accepts PCM up to 24 bit / 96 kHz from a computer.
There is also a volume control (a slide switch, which, in addition to the main purpose, allows you to “jump” to the next or previous track) and a touchpad for controlling playback, working with phone calls and performing other operations. On the left cup there are three LED indicators of operating modes, signaling the charge level, the use of a certain codec, etc. The switch on the right earcup is used to activate the headphones. In addition to the standard method, NFC technology can be used to establish Bluetooth pairing. On the headband, next to the adjustment slider, there is a tag to which you need to attach an appropriate NFC-enabled device. The headphones are supplied with a hard case for storage / carrying and a case for a regular USB cable.
Audio-Technica ATH-DSR9BT is the current flagship model of the Japanese company’s wireless headphones. In such cases, we expect a lot of innovations from engineers, but with these headphones the Japanese have exceeded all our expectations! Usually, Bluetooth headphones have a separate receiver, then a DAC and a headphone amplifier. Since there is very little space in the headphones, they often get by with a ready-made highly integrated codec with compromises in everything related to sound. The Audio-Technica ATH-DSR9BT headphones redefine the usual wireless models, as they are completely digital headphones – they do not have a receiver, DAC and amplifier. Instead, there is a single digital chip with a direct connection to the speaker. And it was all designed from the ground up for a specific model.
The new technology is called Pure Digital Drive. Its essence is that the DAC and amplifier are replaced by a fully digital amplifier with a very high efficiency, more than 90%. The signal really remains digital throughout its entire path, from the Bluetooth source to the speaker, and is converted to analog only at the very end, by the proprietary Audio-Technica emitter of a special design.
Although a similar idea has been used many times, the specific implementation has its advantages. The electronics have been developed in close collaboration with Trigence Semiconductor, the inventor of the Dnote chipset. What is the point here? First, the PWM modulation frequency is a very high 12 MHz. Secondly, the signal is not 1-bit, but multi-bit! Multiple emitter coils operate in parallel as multi-bit modulators, which improves modulation accuracy and reduces signal power outside the audio range. This means that it is easier to filter and there will be less distortion in the sound. By the way, all processing inside the DSP is performed in 32 bits, with a quality margin. There are eight digital amplifiers here, four for each speaker. Judging by the passport parameters, the maximum power is hundreds of milliwatts with a power supply of only a few volts. At the same time, power consumption at medium and low volume is significantly reduced. As a result, the earbuds run continuously for 15 hours from the built-in small lithium polymer battery and are capable of delivering high volume when needed. Standby time is 1000 hours.
Inside each earphone there are four 7N OFC Oxygen-Free Copper coils, where each wire is woven from four thinner ones. The coils are connected to a 45 mm diaphragm, coated with DLC (Diamond Like Carbon) for increased rigidity. There is also acoustic damping to control the low frequency behavior of the membrane and to avoid booming.
Although it is not clear from the name “Bluetooth-headphones” whether Audio-Technica ATH-DSR9BT has a microphone, everything is in order in this model, there is a microphone and it transmits the voice quite well during a conversation. It would seem that it would be worthwhile to call this model not wireless headphones, but a wireless headset. But, obviously, the word “headset” is more associated with devices not entirely for music, and the Audio-Technica ATH-DSR9BT model is primarily high-quality headphones. Therefore, we will call them exactly headphones. From the control buttons, in addition to power and volume, it is worth highlighting an unusual touch sensor. It has several different control methods: short press, double press, hold. A bit unusual, but after getting used to it, it is quite comfortable to operate by touch.
The set includes two covers: a large one for the headphones and a smaller one for the USB cable. The wire is quite high quality, has a length of 2 meters. It serves two important functions. Firstly, this is the only way to recharge the built-in battery, which will take about 4 hours. Secondly, if you connect the headphones to the computer with a wire, you will receive a bonus digital sound card with support for modes up to 24 bit 96 kHz. No drivers are required, headphones are seen as a standard USB audio device and allow you to listen to music immediately after connecting to any computer.
The Bluetooth wireless connection seems to support every conceivable kind of progressive protocol, including Qualcomm’s aptX HD optimized for high-definition music. It transmits music data up to 24 bit / 48 kHz with 4: 1 compression, the bit rate of the stream is 576 Kbps, which is one and a half times higher than that of conventional aptX.
By the way, the headphones have 3 indicators that also tell you which protocol is currently being used. For example, when pairing with a mobile phone, the highest quality aptX protocol was automatically selected. This is also a good protocol, it will do if you only want to listen to regular 16-bit recordings. In this case, 24-bit Hi-Res files will be converted to 16 bits. We took apart the headphones to see the insides. Indeed, there are 45mm radiators inside, each of which has 8 wires connected to connect 4 coils to separate amplifiers. The digital part is completely separate from the emitter chamber. You can see the acoustic damping of low frequencies by special materials.
We listened to the sound of the Audio-Technica ATH-DSR9BT headphones in the highest quality mode, with a USB connection, as well as with aptX and aptX HD. The sound can be safely called high quality. It is bright, bass, somewhat similar to other Audio-Technica headphones. One can feel a certain proprietary handwriting of the developers. I would also like to note that the most important frequency range – the middle – the headphones play flawlessly. At the same time, we had the feeling that the headphone membrane was made of metal – it is very fast, dynamic, with its own characteristics at HF. Perhaps this is due to the diamond coating and the new digital amplifier. In this sense, the sound is not like other models of the company. With a little EQ, you can make the sound more natural in terms of timbres. However, this applies to any headphones. The timbre balance of the headphones can always be slightly adjusted, but if the sound is distorted or the sound is sluggish, suffocated (poor dynamics), nothing can be done here. Therefore, we do not pay much attention to the frequency response, preferring to evaluate everything in a complex, for all quality parameters at once. Overall, the Audio-Technica ATH-DSR9BT has a very good sound, which matches their place as top-end wireless headphones.
Conclusion
Based on the results of testing, we found out that the Audio-Technica ATH-DSR9BT headphones are rightfully the flagship in the line of the Japanese manufacturer. They feature impressive groundbreaking digital emitter technology and the highest quality aptX HD wireless transmission.
With new speakers and a truly digital amplifier, both powerful sound quality and excellent battery life are achieved. It is interesting that the headphones work not only with mobile devices: for PC users there is the possibility of a wired connection to a computer via an existing 2-meter USB cable, with support for any format up to 24 bit 96 kHz.
