This week we tested the Aëdle ODS-1 in-ear headphones, a 2-way model which features dynamic drivers coupled with balanced armature drivers. Designed and assembled in France by Aëdle, like the Aëdle VK-1 headphones, the Aëdle ODS-1 offers a frequency response ranging from 20 Hz to 20 kHz, for a sensitivity of 109 dB (@ 1 mW) and an impedance rating of 32 ohms. Looking at these specs, the ODS-1 was clearly designed to be used with smartphones paired up with a low-power headphone amplifier, DAP, and portable USB DACs.
Aëdle ODS-1: what is a balanced armature driver?
Most in-ear headphones are equipped with small drivers called dynamic transducers. The working principle of a transducer is similar to that of a speaker driver. It is composed of a cone paired up with a copper coil which is set in motion (front to back) by the electrical current transmitted by the amplifier and the magnetic field created by a magnet. A balanced armature transducer works differently.
A balanced armature transducer differs from a dynamic transducer in that the voice coil is wound around an armature suspended between two magnets. The magnets generate a magnetic field which centers the armature, and the latter is not subject to the mechanical constraints inherent to dynamic drivers. It freely swings back and forth, set in motion by the electrical current-thus offering a better transient response. The coil’s armature is connected to a very thin diaphragm which creates sound waves when it moves.
Due to their structure, balanced armature drivers focus on certain registers-namely the mids and highs. Since the restitution of low frequencies requires additional mass, balanced armature technology is very seldomly used for the lower end of the sound spectrum. The only brands to manufacture high-end headphones exclusively featuring balanced armature drivers are Earsonics, Shure and Westone.
Aëdle chose to use a classic 0.4? dynamic driver for low frequencies, and a balanced armature driver for mids, high-mids and highs. Due to the fact that they employ two different types of driver technologies, the Aëdle ODS-1 headphones are classified as a hybrid model.
Aëdle ODS-1: design and accessories
The Aëdle ODS-1 headphones stand out for the unique form of their detachable cable, which is shaped to sit perfectly around the ear. The arched part is covered with leather and the cable features a remote control and a microphone for phone calls and playback control when using the Aëdle ODS-1 with a smartphone.
Aëdle ODS-1: test conditions and listening impressions
We listened to the Aëdle ODS-1 headphones using the Encore mDSD headphone amplifier and a Xiaomi Redmi Pro smartphone. We listened to FLAC files (studio quality and CD quality). We also used the ODS-1 while watching movies and TV series. We conducted our tests using the silicone earbuds as the foam tips greatly reduce high frequencies.
The bass range is brought to the fore, with an emphasis on upper-bass frequencies which brings extra energy and a stronger foundation to the listening experience. The enthusiasm of the sound restitution is directly linked to the type of earbuds used, as some are more airtight than others. The transient response in the lower end of the spectrum could be improved, but the overall delivery is pleasant and benefits from sufficient extension in the infra-bass.
The mids are slightly rolled-off under 1 kHz, probably due to the low-pass filtering applied to the 0.4? driver in order to leave room for the balanced armature transducer. During our listening session, we noticed a bump in the response around 2 kHz and another one around 8 kHz. Nevertheless, the velocity of the balanced armature driver favors the restitution of a generous amount of micro-details.
The bump in the response around 2 kHz inevitably has a negative impact on the restitution of high frequencies with certain types of music. This part of the sound spectrum is slightly set back, a peculiarity which adds to the overall depth.
Aëdle ODS-1: conclusions
What we liked: the wide sound stage, the overall space, the high sensitivity.
What we would have liked: more neutral mids, brighter highs, and more detailed lows.
The main qualities of the Aëdle ODS-1 in-ear headphones are their wide sound stage and the spacious listening experience they offer. Paradoxically, the Aëdle ODS-1 headphones particularly shine with films and series, probably due to the balance of Dolby and DTS audio tracks. With the appropriate earbuds, the sound placement is enjoyable. The generous lows and the swiftness of the high-mids and highs captivated us, but we would have liked less coloration in the mids, as sound clarity with some types of music (classical music and rock, for example) is at times compromised. Note that the cable can cause some interference (nothing major) when it comes into contact with certain fabrics. The wired remote control features a high-quality microphone and phone calls are crystal clear. A beautiful set of in-ear headphones.