The graphs I use are generated using the Vibro Veritas coupler and ARTA software. Ken Ball (ALO/Campfire) graciously provided me with measurement data which I have used to recalibrate my Veritas so that it mimics an IEC 711 measurement standard (Ken uses two separate BK ear simulators, we measured the same set of IEMs, and I built my calibration curve from shared data). I do not claim that this data is 100% accurate, but it is very consistent, and is as close as I can get to the IEC 711 standard on my budget. I suspect it is slightly down at around 9-10 kHz, and tend to dip slightly at sub bas with foam tips), but seems reasonably accurate through the rest of the spectrum.

I do not claim that the measurements are in any way more accurate than anyone else’s, but they have been proven to be consistent and I think they should be enough to give a reasonable idea of response – especially if you’ve followed any of my other reviews. When measuring I usually always use crystal foam tips (medium bore opening) – and the reason I use them is for very consistent seal and placement depth in the coupler. I use the same amp (E11K) for all my measurements – and output is under 1 ohm.

The graphs are provided merely as a point of discussion, and later in the review I’ve included comparisons to other IEMs for similar reference.

Channel matching is extremely good (practically perfect) over the entire frequency range with just a small difference at 4-5 kHz (crossover on this pair?). It is rare to find an IEM with such perfect matching at this price point (in my experience).