Sonion:33aj Series Dual BA*2(Ultra-Low Frequency)
Sonion:37ap Series Dual BA*1(Mid-Low Frequency)
Knowles:TWFK Series Dual BA*2(Mid-High Frequency) Knowles:PSWFK Series Dual BA*1(Ultra-High Frequency)
For being a BA only IEM and for its price, it’s a very good set.
Nevertheless it sound very good, and aesthetically I love them.
Unfortunately it’s out of production, but they remains one of my favorite CCA.
Running through a Hidizs DAC I would rate them as good with a clean sound. Bass separation is good but the high end sounds a little weak to me. No issues with comfort.
They are magnificent, both in sonority and in build quality.
Very comfortable to wear, even for prolonged sessions.
The cable is very good, well built, does not twist and is not too heavy.
They are certainly IEMs to buy.