Measuring the Differences
As always we will start with them solo measurements to get a bit of a feel for what these earphones are capable of.
Great channel matching is shown and impressive because even though these are a universal fit model they are still hand made like a custom. There is obviously a tight quality control when it comes to driver and channel matching. From 1kHz there is an upwards slope, all the way to 100Hz where it hold its position strongly until 60Hz where it then starts to roll off. It is not the most robust of sub bass extensions while also not a horrible roll off. I am not too sure why there is a little dip between 2.5kHz and 6kHz but nothing is lacking in the music because of this. You then have a drop off at 7kHz which is obviously ideal for a lack of fatigue in the treble.
Now to add the 10.A plot. The IEM 10.0 is orange and the 10.A blue.
As you can see the bass actually shows a dramatic difference from 300Hz, with the 10.As staying flatter and rolling off much more dramatically. One of my 10.A channels shows quite an obvious variation as well but I think that may be an issue while measuring, still there is a 4dB difference by 100Hz and 7dB by 50Hz. From 300Hz upwards they are much more similar measuring earphones but there are still differences. The 10.A also has nowhere near as good driver matching. The 10.A has more at 10kHz, well at least it does on one channel and past there things seem different but that is a hard area to accurately measure even on much more expensive audio analysers than my Vibro Veritas. Based solely off measurements though I would say the IEM 10.0 looks much better with matched channels, better extension and less jolty treble. These can only show that they are either using different bass drivers or tuning them differently but then likely using the same set up from there on out.