Still tweaking (Patreon)

I finally need to keep you updated, as I had several setbacks recently which somehow made me lose motivation to post something. One setback was Earfun who withdrew their cooperation offer for the Free Pro 3. This made me lose a big source of potential income that I need so urgently right now because we are currently in the process of exchanging our old oil-heating for a heat pump with necessary investments higher than €10.000, which I can hardly cover now. I already counted on this cooperation although I was not satisfied with the result for the Free Pro 3 with only some simple EQ. At least I would have earned some money which would have allowed me to cover all current costs. I started to build a foundation for the heat pump on my own to save some additional expenses which cost me lots of nerves and took me several days to finish as I am not a very skilled construction worker, but I hopefully managed to build a decent paving which should also accommodate the heatpump.

Next setback was when I tried transforming my IEM target over to other units of the Free Pro 2. For the most precise results I re-measured my current unit I was using for all my adjustments so far. I measured the raw response of both left and right unit repeatedly and despite carefully trying to achieve the same 6000hz resonance for the measurement every single measurement turned out different deviating several dB in the upper frequencies like you can see below, blue colors left, red colors right:

All measurements for both sides averaged and again averaging those was my starting point to achieve a final graph.

I also measured a brand new unit using the same procedure, applying my EQ settings to both my original unit and the new unit, you can see that both deviate a lot which also makes them appear to sound quite different:

Next I tried to re-adjust my settings based on the response I achieved for my original unit as good as possible and although the final graphs align quite nicely the new unit still sounds considerably different, lacking the nice smooth character I achieved for my original unit:

Last week I had to visit my otologist again to let my ears clean which tend to get blocked after repeated swimming and getting wet all the time. Unfortunately this screwed up my hearing completely. It needed several days to come back to "normal" again. At the same time I started to re-adjust my original settings for the Free Pro 2 to come up with an even more natural response for my original unit but I am a bit hesitant to continue any work with the experience I made so far. The measuring procedure can take several hours to achieve the same exact resonance for a single unit, while still resulting in big deviations. I think the more measurements, the more variance I can achieve which I also noticed is happening during everyday listening. I accustomed myself to always start listening to pink noise every time I insert the earbuds, and it tends to sound somehow different depending if I listen in the morning or in the evening or what I was listening to before. Sometimes it sounds super smooth and natural while other times it can sound artificial and strange. When being in a noisy environment for longer and listening to pink noise afterwards it can definitely appear different than when listening to some particular music before, or immediately after waking up. I also noticed that it can change a lot when swallowing, which obviously opens up the eustachian tube and can change the acoustic properties of the ear canal, I can open that tube consciously without swallowing and often do so if I perceive something to sound strange then suddenly the ear can open up and this also changes the perceived frequency response of an IEM significantly, so many factors can have an impact on the end result that it’s really frustrating, with IEMs this is particularly extreme as the ear canal is the only sound forming factor consisting of a single resonating chamber thanks to its particular shape or condition having the biggest influence on how the resonances shift.

As an experiment I also let my son detect his own resonance as carefully as possible with the new unit I had measured before and he achieved a value of around 5650 which I then had to measure again at his particular resonance. Then I tried to achieve my original graph I measured for my own resonance and let my son listen which he thought sounded more natural to him, also comparing to pink noise played over the speakers and he clearly preferred the setting I had created for him, he claimed mine to sound harsher and metallic. He is no sound expert and I cannot believe 100% in his claims as I have no idea what he really perceives, but to some degree it proves that i cannot be completely wrong in what I am doing.  

With my current personal settings for my original Free Pro 2 unit I am really enjoying music and love to listen in any spare moment. I enjoyed it already before but I managed to achieve an improvement over time which was just the result of achieving a more correct and natural frequency response. Not a result of better hardware, better drivers, amps or whatever. It would seem that affecting the frequency response directly in a controlled manner gives better and more predictable results than trying to change the frequency response indirectly by different components, “better quality drivers” etc… Tiny adjustments which hardly show up in a graph and can be smaller than some measuring errors like shown above, can nevertheless have a big impact on the final sound. How smooth and natural it appears let alone your ear condition or how consistent you manage to place the IEMs inside your ear will make the sound appear different.

I need to invest more time into this, especially achieving a better generalised setting for my own which should still sound correct to my ear regardless of when I listen, and then trying to measure this particular response as precisely as possible, also finding out why different units can still sound so different while measuring more or less the same. It won’t make sense to publish any new settings which won’t even sound correct to myself.

Once I figure out where the key frequencies are that make the sound appear false or correct, I can hopefully achieve a valid average to offer acceptable results over several different units and I can also offer custom tuned units towards other’s resonances hoping that they will perceive the sound in a similar manner like me. It’s just very time consuming achieving perfect results which seems nearly impossible for my own and makes it frustrating at the same time. With all those repeated failures especially not being able to find some reliable cooperation partners dampen my enthusiasm for the audio business. It would seem as if only promotion and advertising making consumers buy every new released shit was the key to success. Earfun proved again that they do not really care about sound quality at all. Despite their slogans “better sound & better life”

I just need to repeatedly thank all my supporters here who at least manage to keep my head above water.

Thanks guys!