[Driano]

I stumbled upon the KZ ATR, which I bought back in 2018 for roughly 5$. If you look at the frequency response graph, until about 700 Hz, it looks just like a Sennheiser Ambeo Smart Headset, which is pretty nice sounding and was also praised by Oluv's Gadgets:

From 700 Hz until about 4 kHz, the graph is almost exactly a Sony MH755, one of my all-time favorite IEMs:

Only after 4 kHz, it starts getting a little weird and shrill sounding. So I quickly applied some peak filters in EQ Apo starting from 5 kHz and the graph is now looking like this:

I really like how it sounds. If you have a KZ ATR laying around, you can test the filters and give some feedback. I have ordered another unit of the KZ ATR to see if the tuning is still the same in 2022.

The following filters were used in Equalizer APO:

Filter: ON PK Fc 5000 Hz Gain -7 dB Q 5.8
Filter: ON PK Fc 6000 Hz Gain -4 dB Q 3
Filter: ON PK Fc 7000 Hz Gain -1 dB Q 1
Filter: ON PK Fc 10000 Hz Gain -6.5 dB Q 2.4
Filter: ON PK Fc 11800 Hz Gain 2 dB Q 2
Filter: ON PK Fc 17500 Hz Gain -4 dB Q 2.0999
Filter: ON PK Fc 19000 Hz Gain -3.5 dB Q 2.9
Filter: ON PK Fc 18341 Hz Gain -1 dB Q 7

 

[BrownBear]

This is cool, EQ is something I've been reading about for years and never got into mostly because I'm a weirdo and also because I don't fully know how to use it. Mostly because I'm a weirdo though.

 

[Old_Snake]

I stumbled upon this week but haven't tried it yet. https://github.com/jaakkopasanen/AutoEq

 

[Driano]

I stumbled upon this week but haven't tried it yet. https://github.com/jaakkopasanen/AutoEq

Really interesting tool, hadn't heard about it before

 

[Driano]

I also measured the KZ ZSA, which seems to be a little more bass boosted version of the MH755 until 1.5kHz:

So I trimmed down the "harshness" to resemble the upper midrange and treble of the Earfun Free Pro Oluv Edition, which seems to be more fitting here than the MH755 target:

Compared to the MH755 again, it looks like this:

IMO, the initial tuning seemed even worse than that of the ATR, but when removing the harshness, it has a very interesting sound with nice extended bass and subbass.

The following filters were used in Equalizer APO:

Filter: ON PK Fc 10700 Hz Gain -9 dB Q 2.7
Filter: ON PK Fc 2600 Hz Gain -5.5 dB Q 2.6
Filter: ON PK Fc 12300 Hz Gain -5 dB Q 2.8
Filter: ON PK Fc 4200 Hz Gain -3.5 dB Q 3.7

 

[Driano]

P.S. I've added two more filters to tame the boosted bass a bit:

Filters are:

Filter: ON PK Fc 10700 Hz Gain -9 dB Q 2.7
Filter: ON PK Fc 2600 Hz Gain -5.5 dB Q 2.6
Filter: ON PK Fc 12300 Hz Gain -5 dB Q 2.8
Filter: ON PK Fc 4200 Hz Gain -3.5 dB Q 3.7
Filter: ON PK Fc 100 Hz Gain -2 dB Q 0.3
Filter: ON PK Fc 165 Hz Gain -0.7 dB Q 2

 

[Driano]

So I received my second pair of the KZ ATR, which was produced in November 2020. The general signature looks the same as the one from 2018. Sadly, the channel matching is just as bad as before.
Also, there seems to be quite a bit more treble and upper treble, but I guess thats all just due to bad QC and slightly different insertion depth. For the price, you still can't complain that much.

You just have to try if the EQ works for your unit.