One thing that baffled me with the K7 was the EQ feature built in the device. This got me thinking “what exactly does the EQ do to the IEM/headphone when measured?”
That led me to this. I measured the Softears Volume S through the Fosi K7 and cranked the EQ values all the way up (+12 bass, +6 treble) and all the way down (-12 bass, -6 treble).
It seems like Fosi used a high shelf and low shelf filter with a rather low Q factor, particularly on the low shelf and a further cut at the 150 – 300 hz region. This makes the K7 a fantastic way to cut mud or add midbass on your IEMs. The treble is a bit more subtle and really only works if you want to cut energy from the upper mids to treble.
I did further testing and mixed up the values and I will upload this on my database at obodio.squig.link for convenient comparisons. But I thought it was interesting to share my findings on an aspect of the K7 that fascinated me the moment I got it.
Anyways, review and impressions for both of these coming soon!
