YU9 Audio U-554 U-556 In Ear Balanced Armature In-ear HiFi Monitor Earphone PK ER4B/S/P/XR/554 Detachable 2Pin 0.78mm
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Specifications
- Brand Name
- FENGRU
- Style
- Wired in-ear headphones
- Vocalism Principle
- Balanced Armature
- Origin
- Mainland China
- Material
- ABS
- High-concerned chemical
- None
- Communication
- Wired
- Volume Control
- No
- Category
- Earphones & Headphones
- Certification
- None
- Plug Type
- L Bending
- Impedance Range
- over 100 Ω
- Headphone Pads Material
- Other
- Active Noise-Cancellation
- No
- Sound Isolating
- No
- Waterproof
- No
- Frequency Response Range
- 16 - 20000
- Magnet Type
- Other
- Voice assistant built-in
- No
- Wireless Type
- None
- Resistance
- 116
- Line Length
- 1.2
- Control Button
- No
- Sensitivity
- 96
- Is wireless
- No
- NFC Technology
- No
- Connectors
- 3.5 MM
- Bluetooth Version
- Other
- Support Memory Card
- No
- Support APP
- No
- With Microphone
- No
- Features
- Detachable Cable
- Seller SKU
- S542
Product Description
Comfortable In-Ear Design
The in-ear design ensures comfort during long listening sessions, making these earphones ideal for everyday use.
Balanced Armature Technology
Experience superior sound quality with the balanced armature technology, offering a clear and detailed HiFi audio experience.
Detachable 2Pin 0.78mm Cable
The earphones feature a detachable 2Pin 0.78mm cable, providing flexibility and ease of use for different devices.
Versatile Compatibility
These earphones are compatible with a wide range of devices, including PK ER4B/S/P/XR/554, offering versatility and convenience.
High-Fidelity Sound
Enjoy high-fidelity sound with the YU9 Audio U-554 U-556 earphones, perfect for music enthusiasts seeking crisp and accurate audio.
YU9 Audio U-554 U-556 In Ear Balanced Armature In-ear HiFi Monitor Earphone PK ER4B/S/P/XR/554 Detachable 2Pin 0.78mm
Features：
Brand: Yu9 audio
Model: U556
Color Option:
U556 Black
U556 + One Pair ETY Gray Three Triple Eartips(S Size）
U554 Sapphire Blue
U554+ One Pair ETY Three Triple Eartips(S Size）
Plug diameter: 3.5
Cable length: 1.2
Is there a microphone: No
Wearing method: in-ear
Headphone plug type: L Bending
Whether wire control: No
Impedance: 110ohm
Item Pictures:
Pros & Cons
Pros
- Balanced Armature delivers clear, detailed HiFi audio comparable to ER4 series.
- Detachable 2Pin 0.78mm cable allows easy replacement and customization.
- Comfortable in-ear fit for extended listening without fatigue.
- High impedance (116Ω) and wide frequency range for audiophiles.
Cons
- No microphone, volume control, or wireless features.
- Not waterproof or noise-cancelling, sensitive to sweat.
- Over 100Ω impedance may require amp for mobile use.
- No certification or APP support.
Common Questions
What driver technology is in these YU9 in-ear monitors?
Balanced Armature vocalism principle for HiFi sound, frequency 16-20000Hz, sensitivity 96dB.
Are these earphones compatible with standard devices?
Yes, 3.5mm L-bending plug, detachable 2Pin 0.78mm cable, impedance over 100Ω for most phones and players.
What is the cable length and material of these wired IEMs?
1.2m line length, ABS material housing, no microphone or controls.
Are these PK ER4SR earphones suitable for long sessions?
Comfortable in-ear design with sound isolating features, no ANC but good for HiFi monitoring.
Shipping details for FENGRU YU9 U-554 earphones?
Ships from Mainland China, standard delivery for wired in-ear headphones.
Product information last updated on February 24, 2026