NH1 - work in progress (Patreon)

Hi guys, I have been suffering from some otitis lately as a result of a longer flu, therefore please apologise my absence here on Patreon.

Finally I am stating to feel better again. But as this had changed my hearing properties I wasn’t able to do anything audio related. Now I am hearing normally again and it was interesting to perceive the changes in sound due to a swollen ear canal, which allowed me to simulate having a different ear canal. This affected the perception of sound in general, thus not only headphones started sounding different but also the sound around me appeared to have changed. My usual “reference” to know if I am hearing normally is the sound of my toilet flush, it has a particular harsh sound which I immediately notice if that has changed. Then I usually know that either my ear got clogged by ear wax or there must be some other issue. My headphone measurements are performed at the entrance of my ear thus the effects of the ear canal are omitted, but apparently a different ear canal shape seems to simply add its effects to the sound around you, be it headphone or some other sound source. Everything around me started sounding off to the same degree, a bit more dull, a bit more metallic, but usually the brain will adjust to the given change pretty quickly, just like it does to all the different sounding headphones. My goal for the NH1 is to offer you an as natural as possible headphone, so if you are listening to music over your speakers, the difference in sound to the headphone shouldn't bee too drastic. But as sound perception is so complex and is also accompanied by psychoacoustic effects, and being used to some particular sound over time, it’s hard to judge what the end user will really hear, therefore I can only speak for myself, when talking about sound and how I perceive it.

I had to readjust my tuning for the bigger pads as these change the sound quite a bit. At the left you can see the original pads, at the right the new bigger ones, these are definitely more comfortable for me and should also work well with bigger ears.

Below you can see the effects of the different pads measured with my very 1st reference unit. Grey is my target derived from my HD58X tuning, black the sound measured with the small pads and green with the bigger pads. Although the difference may not appear big it’s actually pretty noticeable and makes the headphone sound off. Biggest difference is some boost around 1khz and a reduction between 2-5kHz.

Instead of trying to adjust the sound for a single unit I tried to create an average over all units I own and use this curve for the final adjustments. Below you can see the results for all my usable units. Black was the unit I used for listening when doing the adjustments. Although all units are quite close they still differ a lot which results in a strong audible deviation from what I would regard as perfect to my ear. Some sound more off than others.

Just to give you an idea of about the tuning process here some measurements how I tried to approximate the optimum with black being the final result and light blue being the first attempt, the darker colours being later attempts. Keep in mind that this process took several days as I needed to retire after some hours of tweaking and what I regarded as decent one day didn’t sound decent to me the other day. Trying to match some measurements just by some graphs leads to unpredictable results, therefore I am only keeping my target as rough reference and always adjust by ear.

Although the differences do not seem too drastic, every further approximation is an audible improvement. Therefore different units even just deviating by 1-2dB will sound worse to me. In the end we are talking about changing filter values by some 0.1dB or adjusting their frequency by some Hz to achieve something which I perceive as more or less smooth and natural sounding. To finally have some representative samples, I decided to readjust every single unit and will request separate firmwares for each of them. So far this process took me quite a while for only 2 units and I will need further time to adjust the other 2 units. What makes it hard is that different units have different areas that need special adjustments and the filters need to be set differently. Below you can see the difference between both units with their individual tuning in blue, and the averaged one in red.

In the end it's the finest nuances which make the difference if the headphone sounds natural, even though 2 different units may sound slightly different, the balance of the overall spectrum can still be perceived smooth for both if adjusted individually. Unfortunately approaching this optimum is a bit of a trial and error and hard to achieve which makes the entire procedure quite frustrating for me let alone for several units separately, but this way I can at least regard these individually tuned units to be representative of what the final sound will be.

If finished my plan is to send 1 demo unit to Resolve from headphones.com to get his feedback and in case he finds it worthy let him prepare some first video maybe. Another unit will be sent around starting with my friend in Berlin who is sound engineer at Teufel, I also highly value his opinion and I hope he can perform some measurements on Teufel's HATs. He will forward this unit to the next volunteer after that. The next one will just need to send him the amount that is needed to ship that unit to you. I am still not sure how we can handle this best, if you have some idea please let me know. Maybe I will prepare some list, where everyone interested can fill in his data and I will try to organise the journey. I would like to cover nearby places first and in the very beginning cover Germany before sending the headphone somewhere else.

The 3rd unit will be given away to one of my supporters as promised and 1 unit I will keep for myself as reference.

I am still in discussion with the factory how to minimise sample variation even more as with the current difference between all units I simply cannot guarantee the results I am after. Although all units sound decent and the ear gets used to the small differences pretty quickly, how can I expect them to sound right to someone else, if they don't sound 100% perfect to myself? I will also need to request further samples in which comes with additional costs etc. Therefore I am just thankful for your continuous support, as this allows me to continue trying to achieve something decent. The factory requests a high amount of order quantity which is just ridiculous to handle for me especially if the final result won't be as expected. Only if I am fully satisfied and get positive feedback from others, I will start preorders so that I can finance the mass production.

Besides I already started working on an alternate headphone model from another factory which may be a better candidate but so far I am having issues achieving the same result I achieved for the current units I own, therefore it’s quite a dilemma for me currently to release something not being sure that I can stand for the results.

Thanks to all for your patience, but I can only stand towards my own product, if I can be sure that it meets my own standards. I hope you understand.