I recently purchased the KZ Axas IEMs. I originally opted for the 3.5mm cable, but I ran into some mic issues during Microsoft Teams calls for work. I ended up ordering the USB-C DAC/DSP version, and the difference is noticeable.
The USB-C cable features a built-in DAC with four EQ modes, indicated by an LED-backlit KZ logo on the plug. Switching modes is easy via a small gray button:
Green: Slight bass roll-off, but fuller than the Red mode.
Blue: The “Bass Head” setting—maximum bass boost with a slight treble reduction.
Red: Leanest bass response with a slight boost to the treble frequencies.
Violet: Subjectively feels like an “overall” boost, though measurements indicate it primarily increases sub-bass.
Compatibility: I tested this on a Windows 11 PC and a MacBook Pro; both recognized the cable immediately. (Note: I couldn’t test on my iPhone as it uses Lightning, but the cable should work with USB-C iPhones and Androids).
Tuning & Value: I’ve included a graph (sourced from Squig.link, credit to TLD) comparing these modes against the PEQdb Ultra and Harman 2025 MoA targets. I really appreciate that KZ is moving toward DSP tuning in the cable rather than adding more physical dip switches, which often makes the IEM shells too bulky for a comfortable fit.
Overall, the Axas is a great set, but I highly recommend the USB-C version for the added versatility. If any durability issues pop up with the cable, I’ll update this review.
Axas Technical Details (Linsoul)
Cable Technical Specifications (via Gemini 3)
Cable Material: High-purity Oxygen-Free Copper (OFC) with a Silver-Plated braided structure (typically 0.05x25x2).
DAC Chip: Features a high-performance KTmicro KT0231H (or similar) integrated digital-to-analog converter.
Resolution Support: Supports up to 32-bit / 384kHz Hi-Res audio output.
SNR/DNR: 103dB.
Crosstalk: Very low, due to the balanced output design of the DSP chip.
Connectors: 0.75mm 2-pin (QDC Type-C) gold-plated pins.
Microphone: Dual-Mic system with front and rear omnidirectional capacitive microphones (~-26dB sensitivity) designed for 360° voice pickup and noise reduction.
Cable Length: 1.2m ± 3cm.
EQ Mode Profiles (USB-C Only)
The cable uses an integrated button to cycle through four distinct digital tuning profiles, indicated by the backlit LED logo:
Violet (Balanced/Standard): The default profile. It offers a balanced, neutral signature across the bass, mids, and treble.
Blue (Bass Boost): Significantly increases low-end energy starting around 200Hz for a “bass-head” experience.
Green (High-Resolution): Attenuates some bass to emphasize treble detail and clarity, often preferred for critical listening.
Red (Game/Immersive): Similar to Green but with a more pronounced roll-off in the low-end and a sharper boost in the upper-mid/treble frequencies to help with sound positioning.