Earfun Free Pro - 5900Hz tuning (Patreon)

I finally managed to create a tuning for everyone who hears the resonance lower than average at around  6000Hz and below just like me right now.

I think this is my best and most consistent one so far, I would even say this is the most convincing result I managed and I am enjoying it for as long as it will last,  because after my ear cleaning next week I will perceive the sound again completely different when I will get back to my "normal" response. 

But I hope at least all others with longer ear canals will get a decent result. I would also like to experiment with longer eartips maybe to try if I afterwards I can still achieve the same result like. I will immediately start my work on my existing tunings as I also need to adopt them to my new target. This time I took a completely different approach to create this EQ, because I wanted the final balance to be as correct as possible. What does this mean? A neutral headphone should sound like a neutral speaker in front of me and the Earfun should sound like the neutral headphone and then again back checking with a speaker the result is just stunning. It's not equal, there are differences and I tuned it overall a bit more airy, but the timbre is quite similar between all sources just way smoother, it sounds so real because of this. It's the first time that I really wanted the balance to be as perfect as possible. This took a bit of time as I needed to recreate the spectrum I am hearing from my equalised HD600 with the Earfun by hearing and comparing and wasting hours. All exisiting targets could only be used as a rough guide, as all of them are just way too generic, therefore I had to rely on my ear by listening to the HD600, and comparing back and forth. A huge help for me was to use Equalizer APO with additonal filters on top of my existing tuning and also adding a graphic EQ to get at least the basic sound as close to what I was hearing from headphone, speaker and IEM, while my existing tuning rather dealt with the details. After having created that target I needed to adjust my tuning towards my new found curve by just using the exisitng 10 filters, this was the hardest of all. I tried an autoEQ based on the measured difference between raw tuning and my new target and although the EQ was usable, it needed 18 filters and still sounded worse than my final manually adjusted one. Finding the right balance between all frequencies is the hardest and a real pain in the ass, adjusting just one filter can change the whole tonal balance. It took me again hours to fine tune and opimise and having some dozen different variants I was trying to create one as close and as similar as possible to the "neutral" spectrum I was hearing from the HD600. With music the fine nuances are not even noticable, with some songs the "worse" EQ could even sound "better" somehow, but this time I wanted to avoid this "overequalizing" and stick to the target I created as close as possible, this is something I didn't do back then when I worked on the OE. I just tried to get a smooth overall response by reducing all obvious peaks, but at the same time I also reduced peaks which are simply there and appear obviously natural in a spectrum. I can hear or maybe concentrate on particular peaks when listening to pink noise which I tended to remove when I did the OE. Although the resulting response was very smooth for anyone with a simiar resonance frequency like mine (I tuned it for 6500Hz back then), I didn't check the overall balance at the end, thus comparing the Earfun Free Pro OE to some speakers either the speakers appeared somewhat resonant in the upper mids, or the Free Pro OE a was lacking in this area. It depends a lot which sound you were used to. That's still one of the biggest problem in the entire audio world. The human ear can get used to any response and will try to "filter out" most peaks and pretend this to be the new "neutral". This is the only explanation I can have that so many horrid sounding headphones can exist at all, because the brain will get used to the sound after some time, while some call this "burn-in", in fact it is just the brain getting used to the sound, which can happen within some minutes but can also take some hours or even weeks, but as soon as you listen to a really neutral reference speaker or headphone you should notice that something is wrong. If a neutral headphone sounds muddy to you or lacks bass, then it's just your brain being used to a way boomier sound. When I listened to the new Free Pro 2 for the first time, I immediately perceived it as way too bassheavy, but I kept listening and did some work in the background, then I took the Free Pro with my current tuning and the first reaction was: "where the hell is the bass?"

To avoid these problems and overcome this circle of confusion I needed to finally sit down for some days and create a reliable target, a curve which I perceived to some degree as neutral of course with some errors here and there which were simply to bothersome to sort out. I could imagine the more critical listeners to have some complaints in some areas, but it was the best I could come up and didn’t want to spend even more time on it as I am not sure I can manage to improve it even more.

I did some measurements of this tuning with the Free Pro inserted at different depths like 5500, 5800, 6000, 6200 and also averaged all which you can see as the thick black curve. It looks definitely weird and I was wondering why it became so edgy, but this seems to happen exactly at the resonance frequencies 3K and 6K and maybe it needs these “kinks”… It lookds different than most IEMs I know but overlaid with the most recent Harman target from 2019 (grey) to my surprise the final result is following the target quite well just the area around 9khz is not defined well with that target. Funnily most IEMs have this area filled up which results in a very harsh sound.

You can also see how much the results start to differ just by varying the insertion depth about 1mm maybe. That's the biggest problem with IEMs and I assume that none sounds really correct because they are either tuned towards some wrong target without even taking the ear canal resonance into account. 

That's the best I could achieve and I prefer it over any other headphone especially now as the timbre is way closer to other neutral sources than it was before. There is still lots of work to do as I want to use the remaining days before ear cleaning to check the Free Pro 2 and Air Pro 2 and try getting something usable out of them using the same target I already prepared now. 

After all these nights full of listening I am tired now, good night!