- Comfortable, fatigue-free clip-on cuff fit with IPX4 water resistance
- Noticeably improved bass response over earlier open-ear driver designs
- Enhanced microphone array delivers clearer voice call quality
- Extended battery endurance on a single charge
- Lacks Auracast broadcast audio streaming support
- Acoustic output can reach uncomfortably high volume levels
- Minimal passive noise attenuation in loud environments
Overview
Engineered around an ear-cuff clamping architecture, the physical chassis balances a 0.35 oz (10 g) enclosure across the outer helix to eliminate ear-canal occlusion while maintaining secure mechanical retention during movement. The flexible barrel-to-cuff junction distributes lateral clamping tension evenly along the outer cartilage, preventing the localized cartilage fatigue and pressure points common to rigid ear-hook designs. Sized at 1.85 x 1.02 x 2.60 in (47 x 26 x 66 mm), the compact acoustic housing carries an IPX4 water-resistance rating, protecting internal transducers and circuitry against sweat and directional moisture ingress without sacrificing acoustic porting.
Acoustic reproduction utilizes an optimized open-ear dipole transducer arrangement engineered to focus sound directly into the concha while attenuating external acoustic leakage, generating distinctly stronger low-frequency extension than earlier open-ear driver designs. Operating across the 2402 to 2480 MHz spectrum under Bluetooth 5.4 (FCC ID: A94638L, hardware model 638L), the wireless link maintains stable packet transmission alongside updated beamforming microphone processing that isolates speech from ambient wind and street noise for voice capture. Thermal dissipation operates purely passively across the polymer enclosure, eliminating localized heat buildup across extended listening sessions.
In daily use, the open acoustic architecture allows full ambient situational awareness, though it offers negligible passive noise isolation in high-decibel environments such as public transit. The acoustic drivers are capable of reaching uncomfortably loud output levels if gain is not moderated by the listener. While the platform omits Auracast broadcast sharing, extended single-charge battery endurance and dependable wireless stability deliver a reliable, non-occluding audio experience for everyday listening.
Technical Specifications
| Brand | Bose |
| Model | Ultra Open Earbuds (2nd Gen) |
| Form Factor | Clip-on open-ear cuff |
| Model Number | 897806-0030 |
| Hardware Model | 638L |
| Fcc Id | A94638L |
| Wireless Connectivity | Bluetooth 5.4 |
| Operating Frequency | 2402 - 2480 MHz |
| Water Resistance Rating | IPX4 |
| Dimensions | 1.85 x 1.02 x 2.60 in (47 x 26 x 66 mm) |
| Weight | 0.35 oz (10 g) |
Primary Sources & Audited Citations
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At a Glance
How reliable is the Bose Ultra Open Earbuds (2nd Gen) Review: Open-Ear Clarity Meets Cuff Ergonomics according to Mizex audits?
A premier choice for listeners who prioritize open-ear ambient awareness and fatigue-free cuff ergonomics over passive acoustic isolation and Auracast compatibility.
What are the known quirks or drawbacks of the Bose Ultra Open Earbuds (2nd Gen) Review: Open-Ear Clarity Meets Cuff Ergonomics?
Our reliability audit identified the following documented caveats:
- Lacks Auracast broadcast audio streaming support
- Acoustic output can reach uncomfortably high volume levels
- Minimal passive noise attenuation in loud environments
What are the key engineering highlights of the Bose Ultra Open Earbuds (2nd Gen) Review: Open-Ear Clarity Meets Cuff Ergonomics?
The top strengths recorded in our evaluation include:
- Comfortable, fatigue-free clip-on cuff fit with IPX4 water resistance
- Noticeably improved bass response over earlier open-ear driver designs
- Enhanced microphone array delivers clearer voice call quality
- Extended battery endurance on a single charge