Next thing I noticed is that M's SQ sounded very thick, heavy and aggressive. The bass is much stronger and heavier than both my AK120 and AK240 and the mids are also much more forward. Even my X3 which I did not bring along does not sound so forward and warm. The highs are clear but the overall clarity lacks behind the AK240. I would say the clarity is roughly about the same level as AK120, but because of the thick SQ it makes M sound less expansive/clear, some would say it is more natural depending on individual's preference. However, the 3D soundstage seems much smaller than the AK120 and definitely does not come close to the expansive soundstage of the AK240. The Calyx M's SQ is definitely far from neutral at all. It is even less flat than FiiO X3 which most people would already consider X3 as having a warm signature. I would reckon it has a pretty big boost around the 200-400 Hz, making the M's SQ sounds thick. For a quick analogy, I would say M to AK120/240 is like Roxanne to JH13 pro. I tried swapping my 1plus2 IEM to my Sony EX-1000 on Calyx M. I get the same thick sound but less detailed because of the Sony IEM. In fact M > EX-1000 = AK240 > ASG-2. Calyx M's SQ kind of "EQ" the normally bright treble of EX-1000 down to the level of ASG-2 and the neutral mid/low of EX-1000 to the more forward/bassy mid/low of ASG-2.
How does the Femto sound like? More like the house sound of AK series or like X3/X5 or DX90/100?