I rarely if ever do reviews; but this little device made such a difference to my setup!
I have a pair of campfire andros and use these with a portable Dac/amp that has a reported output impedance of around 0.9ohms. Prior to using the IEMatch i could barely turn up the volume on my DAC (with my phone at 100% to ensure no resolution loss). The sound was very boxed in with a boomy low end and a very exaggerated forward mid and recessed treble. I was in fact about to sell my andros at this point in all honestly as I only ever use them portably when I’m working away.
I thought I’d trial this as this as any attenuation could perhaps help.