1.High-Resolution (Hi-Res) Audio

Hi-Res, short for "High-Resolution Audio," refers to audio sources and playback technologies that record sound at a higher resolution than CDs.
It is an audio format designed to reproduce music details and atmosphere more faithfully.
Since Hi-Res refers to the audio source itself, earphones labeled as "Hi-Res compatible" indicate that they support Hi-Res audio playback.

Features of Hi-Res Audio

A key feature of Hi-Res audio is its high sampling rate. The sampling rate refers to the number of data points recorded per second in an audio signal. In Hi-Res audio, the sampling rate is typically higher than the CD standard of 44.1kHz.

Examples: 96kHz, 192kHz, etc.

Another feature of Hi-Res audio is its high quantization bit depth. The quantization bit depth refers to the precision with which the amplitude (loudness) of the sound is converted into numerical values.
While CDs have a bit depth of 16-bit, Hi-Res audio generally uses 24-bit or higher, allowing for greater dynamic range and more detailed sound representation.

Hi-Res audio also supports a wider frequency range, extending beyond the typical human hearing range of 20Hz to 20kHz. For example, it can record frequencies above 40kHz.
This extended range allows for more faithful reproduction of overtones from instruments and the subtle nuances of the music's atmosphere, capturing details that would otherwise be missed in lower-quality audio formats.

2.Noise Cancelling

Noise Cancelling refers to a technology that reduces or eliminates external noise. It is primarily found in headphones and earphones, helping users enjoy music or audio in quiet environments and improve call quality.
There are different types of noise cancelling, as outlined below:

Active Noise Cancelling (ANC)

Mechanism: Noise cancelling works by using microphones to capture surrounding sounds (noise) and generating sound waves with the opposite phase (inverse phase) to cancel out the noise. These inverse-phase sound waves are played through the headphones or earphones to neutralize the unwanted noise.
Features:
Particularly effective at cancelling low-frequency sounds (e.g., airplane engine noise, the rumble of a train).
Since it uses electronic circuits, it requires power and therefore needs a battery.

Passive Noise Cancelling (PNC)

Mechanism: This type of noise cancelling works by physically blocking external sounds. The seal created by the ear pads or the fit of in-ear headphones (canal-type) plays a crucial role in isolating sound.
It operates solely through a mechanical system, without relying on electronics.
Features:
Particularly effective at blocking high-frequency sounds (e.g., conversation, door closing sounds).

3.Driver

The driver in earphones is the component that converts electrical signals into sound, and it is a core element of the earphones. It is similar to the speaker unit in speakers and has a significant impact on sound quality and characteristics. The driver inside the earphones vibrates, moving air to create sound waves that are perceived as sound.

Earphone product descriptions often list the driver size, which typically ranges from 5mm to 15mm. A larger driver size tends to enhance bass response and increases sound pressure, providing a more powerful sound. On the other hand, a smaller driver size tends to produce more detailed sound and is more effective at reproducing high frequencies.

Dynamic Driver

The most common type is the dynamic driver, which has a simple structure. It features a large diaphragm that moves significantly, making it strong in bass performance. Dynamic drivers are cost-effective to manufacture, so they are often found in more affordable models.

Balanced Armature Driver

Balanced armature drivers are small and highly precise, excelling at mid and high frequencies. They offer high resolution and can reproduce fine details, making them common in high-end earphones.
However, they are less effective at producing deep bass, so they are often combined with dynamic drivers to balance the sound across the frequency spectrum.

Hybrid Driver

This type combines dynamic drivers and balanced armature drivers, complementing each other by handling their respective strengths—bass (dynamic) and treble (balanced armature).
The combination results in a more balanced and detailed sound across the frequency spectrum. However, the manufacturing process is complex, and as a result, this configuration is typically found in higher-priced models.

Single-Driver

A single-driver setup reproduces all frequency ranges with one driver, ensuring high consistency in sound.
This design avoids potential phase issues between different drivers, resulting in a more unified and coherent audio experience.
However, achieving balance across the full spectrum of bass, mids, and treble can be more challenging with just one driver.

Multi-Driver

In multi-driver setups, different drivers are used to handle specific frequency ranges (e.g., one for bass, another for treble). This allows each frequency range to be reproduced more clearly and with better balance. Multi-driver earphones are typically found in higher-end models due to their complex design and higher manufacturing costs.

4.Codec

A codec (short for COmpression/DECompression) refers to the technology or standard used to compress and convert audio or video data, enabling efficient transmission and storage. When the term "codec" is used in the context of Bluetooth earphones or music playback, it specifically refers to the system that handles audio data.

SBC（Subband Codec）

A codec (short for COmpression/DECompression) refers to the technology or standard used to compress and convert audio or video data, enabling efficient transmission and storage. When the term "codec" is used in the context of Bluetooth earphones or music playback, it typically refers to the system that handles the audio data, determining how sound is compressed and transmitted wirelessly.

AAC（Advanced Audio Codec）

The AAC (Advanced Audio Codec) is a high-quality codec primarily used by Apple products. It is standardly supported on devices like iPhones, iPads, and the AirPods series. While AAC offers excellent audio quality, it is less suitable for gaming due to its higher latency, which ranges from approximately 150 to 200ms.

LDAC

The LDAC codec, developed by Sony, is a high-bitrate codec optimized for enjoying Hi-Res audio wirelessly. It supports a maximum bitrate of 990kbps, ensuring high-quality sound (Hi-Res compatible). However, depending on the network conditions, its stability may decrease.
LDAC also has higher latency than SBC and AAC, with a delay of approximately 200ms, making it less ideal for applications requiring minimal delay, such as gaming.

aptX

The aptX codec, developed by Qualcomm, is a high-quality codec widely adopted by Android devices. It offers better sound quality than SBC and improved latency (around 120ms), making it a good choice for music and video playback. It is supported on devices equipped with aptX technology, allowing for a better wireless audio experience.

aptX Low Latency

aptX Low Latency is one of the codecs in the aptX series developed by Qualcomm, specifically designed to minimize delay. With a latency of around 40–60ms, it is ideal for applications where low latency is crucial, such as gaming or watching videos.
It is commonly found in earphones with a dedicated game mode, ensuring a more synchronized audio-visual experience.

aptX Adaptive

aptX Adaptive is a new codec that optimizes both sound quality and latency according to the situation. It automatically switches between high sound quality and low latency, ensuring the best possible experience for each scenario.
The latency is typically around 80ms or lower, making it ideal for both high-quality audio and activities that require minimal delay, such as gaming or video streaming.