Wer viel misst, misst Mist...

this is a popular German saying which plays with the equal sounding words "misst" which stands for "measuring" and "Mist" which means crap. Thus "someone how measures a lot, measures a lot of crap" which unfortunately is true when trying to analyse my measurements of the Free Pro 2 to have something which I could quantify. I did some tests recently especially as I am trying to get some kind of final "target" which not only will be used for compensating the audio samples for IEMs I am planning to offer but also be a valid base for my future tuning work. 

I can create the smoothest and best sounding tuning for myself, but if I am not able to actually measure what I am hearing and demonstrate that in a graph, it becomes nonsense. When looking at all the IEM graphs every reviewer is posting with a fixed resonance at 8khz or no particular resonance at all, these graphs are completely useless, they show how an IEM would measure at a particular ear canal resonance with this particular coupler, but that's it. Ii will never tell you how the given graph will sound to you. If even swapping for other tips gives such drastic differences as visible from my measurement above. I measured my current personal tuning for the Free Pro 2 with the default medium tips, I always use these smaller tips for measurements as it's close to impossible to fit the bigger ones inside the couplers although I personally use these. But I did some tests and managed to do measurements with both tips, just differing in size: on top again the raw response, below the final tuned sound. In black are the biggest tips, in green the smaller ones at exactly the same well not insertion depth, but rather the same resonance. I need to insert the smaller ones deeper to achieve the same resonance, at least it would seem so, as the bigger ones stick out definitely more, but maybe they just stick out more because they are bigger, who knows. But when looking at the measurement you can notice that the final results are significantly different. With the bigger tips I could clean up the mid region which always appeared quite jagged above 1khz and I always dispatched it as measuring error which it really was. It was simple not possible to achieve a stable rigid system with the smaller tips to get a smooth curve in this region. The bigger tips on the other hand seem to have more stability inside the couplers or whatever which prevents this vibration how I would call it. What suprised me more though are the differences in treble mainly the 13khz dip which I always measured before and tried to recreate that in the same way for every other resonance. With the big tips this area represents way better what I am actually hearing. I never heard a dip but rather a peak in that region and tried to reduce it to such an amount so that it would blend into the overall spectrum. I have no idea if the measured difference is really just a result of different tips, or different insertion, and if someone using the small tips would really hear a dip, which he won't if using the bigger tips, but the black measurement would now look quite plausible to me and would result in a smoothened rough target like shown below. I also overlaid my previous target I used for the "smooth" tuning of the Free Pro in blue. You can see that they do not look that different overall. 

They also sound pretty similar if compared side by side although from the graph it would seem as if the original Free Pro tuning had way more treble which to my ear it doesn't really have, just that treble sounds different, not as defined as the one from the Free Pro 2. I am still not sure if this is due to different drivers or other internals, or simply different tuning, but when I tried to achieve the same response for the Free Pro 2 in the very beginning that I tuned the Free Pro for, it sounded crappy and I had to sit down and start completely from scratch to achieve a result which would again satisfy me to the same degree. I was really fully satisfied with the sound of the Free Pro until I achieved a better one for the Free Pro 2. But why does it really sound better? I hear no peaks from either of them, just some areas differ in some details. This is quite a complex topic and I would like to investigate more what is going on here by trying to recreate the tuning of the Free Pro 2 for the Free Pro and check if they would still sound similar, or even the same. Where does the difference in sound come from if both units measure exactly the same. (I already mentioned this issue before with one of my tunings, that 2 completely equal measuring tunings which were achieved by different filters, will also sound different.

What still bugs me though is this resonance visible from bass. Oratory1990 once claimed that the tips are to blame as they obviously move or are not 100% stable when the driver is moving during the measurement and he suggested to fill up the tip with some material. I finally tried this now with some standard glue which I let dry over night, and although the glue was too stiff and didn't really stick well to the tip, I could at least perform some measurements which show quite a difference:

You can see that the blue curve is missing this dip above 60hz, but it somehow shifted higher to 150hz now. I am pretty sure I can get this area even smoother if I managed to give the tips some additional mass, therefore I ordered some fluid silicone now and will try to play with this a little bit. This way I hope to achieve more reliable results which hopefullly will also help to improve the results for all other tunings which I need to deduce solely based on measurements.

I can imagine that many are eagerly waiting for some videos, but I am simply not in a mood to do any videos right now as there is not that much content I would like to waste my time with. Some first reviews about the new Soundboks Go are out, and I am surprised but also gleeful about their honest verdict, because this is also what I was always claiming regarding Soundboks.

On top of this my recent purchase of the KH80 turned out to be a fraud as I just received an empty envelope and lost more than 500€ this way. I don't have the funds to order a new pair and don't want to take the risk finding and purchasing another used pair again. Sorry, but shit happens, I always believed in the goodness of man, but obviously there are tons of wankers out there.