Well it appears these are going to be quite the polarising IEM.
(redacted a bit)
Blue and Black are practically identical and upper mid-range is overdone - making things appear too vivid, thin and a little brash.
Red and Grey are again practically identical, and only issue I have with this combo is that the sub-bass is too dominant, and needs cutting so that it doesn't mask other frequencies. Mid-range is really nice on both the red and grey.
If you're prepared to EQ - these are a pretty good IEM. Without it, they probably aren't my cup of tea. The good news is that there should be the possibility of retuning to a certain extent through filter modifications.
I am starting to wonder if there is quite a bit of variability in the filters themselves. Based on Brooko's comments I put in the red filter. I had been living in gray. And the life was literally sucked right out of these IEMs. High was gone as was imaging. Put the gray back in and all was good. Hi end is a bit more brash than with my beloved FLC8S (where I hang out in in red - gray - gray/gunmetal). If you know the FLC8S, most users prefer the gold mid/treble filter over the gunmetal. The gold is more mid range forward and has a bit less high end the the gunmetal on the FLC8S.
And the low end on the A5 is definitely stronger than the tuning I am using for the FLC8S. So certainly more V shaped than my tuning on the FLC8S; but not radically so. Again, that is the A5 with the gray filter.
So the A5 that I have definitely does not sound the same with both red and gray filters.
If I am on to something, that might explain the wild swings in reviews of this unit. Variability in filters could explain quite a bit.
I very much respect Brooko's work; so variable filters (e.g. not much consistency between batches) is my best theory right now.
Oh.... I should mention that my source is the Cayin N5II with a balanced cable; not the stock cable.
Test material was Mahler's first symphony, later movements, and in a non sequitur kind of way, Led Zeppelin I (recent remastering, hi res version). No EQ applied. The FLC8S is also being tested (well really compared) with the factory balanced cable.
I am enjoying these so I must admit some confusion as to what is going on here. So many mixed opinions from people with good ears.