I am a (custom) IEM addict. I think this is the future of sound. I also like (portable) closed headphones and only rarely use fully open types for critical listening.
My preference in tonality is studio-neutral with a very moderate low-end compensation for loudness. My second preference are W-signatures as long as the midrange sounds detailed. I less tolerate but much prefer balanced (v-shape) over very warm and bassy tuning.
Oppo PM-3 are perhaps my favorite set of headphones. Dry, tight and fairly neutral signature that only lacks in the upper treble. They are extremely efficient, well-built, beautiful and comfortable. They serve formidably as a main pair for use at home and on-the-go. It is saddening to hear that Oppo ended the production.
Sennheiser HD 660 S are great open headphones and extremely underrated due to the competitive pricing of the Massdrop HD 6XX. However, with little help of an equalizer, the HD 660 S actually can make near-field monitors obsolete. Even without EQ, these are very well tuned and their speed and precision is more than worth the price.
Sony MH1 are god-tier if you consider the price as low as 10$. Measurements look very bassy but the low-end has a silky smoothness that doesn't drown out the remaining frequencies. The midrange is nicely compensated and the treble lacks just a little bit detail. If you replace the stock cable, this is a easy recommendation to start the hobby.
Final E2000 are a good step up from the MH1 in regards to tonality and overall balance. They're slightly v-shaped but it works well with the half-open design and low isolation. I love the cable and the ear tips. These are a must-have as a backup pair or for a quick fix on-the-go.
MoonDrop Kanas Pro managed to land a spot on my list of favorites due to the very well tuned low-end and midrange. This is an exceptional sounding dynamic IEM that hits deeper than any BA ever could at this price range. The treble quantity is where it needs to be with just a slightly bright tilt but high resolution. This is a great allrounder.
InEar StageDiver SD-2 are absolute classics and they do well with what matters most: superb comfort, great build quality, high sensitivity, extreme isolation and all with an overall warm-ish neutral signature. One of the easiest mid-tier IEMs to recommend.
As an alternative I like to recommend the Etymotic ER4 XR. It's perhaps even more neutral but has a forward midrange that makes the SD2 perhaps more enjoyable for long listening sessions. For monitoring I would prefer the ER4 XR, though.
NF Audio NF6i are an underrated beast of a CIEM! Production quality doesn't match high-end tier, but the treble response above 6 kHz is easily the best I've ever heard from any IEM - insane extension and no peaks whatsoever. These sound fully open while having great isolation. The tonality isn't linear per-se, but a very well equalized W-shape that sounds more dynamic.
InEar ProPhile 8 are a godsend for monitoring. The linear frequency response is almost perfect for very critical listening. I wish the bass were tighter (probably vented BA receivers) and treble extension better. If so, they would make everything else obsolete.
qdc Gemini are my pick for the high-end category. The tuning focuses more on the extreme ends of the frequency response, meaning sub-bass and very high frequencies are somewhat boosted. However, the well-separated mids sound forward and lush. Also, my pair is the most beautiful set of CIEMs I have ever seen.
Headphone Amp Inventory:
RME ADI-2 DAC or Pro is perhaps the best D/A converter for the serious audiophile. The fully balanced design was built to use as a benchmark for other gear and to use for measurements by RME internally. It's all about transparency and nowhere else will you find so much use in the functionality of a DAC.
Chord Hugo 2 is a killer portable device that can replace most high-end audio chains in a small package. Genius engineering with an extremely durable battery were trapped inside this attractive device. If you travel a lot and are serious about big cans, this is a good investment. It might be directed at higher earners, though.
Chord Mojo should be powerful enough for most users and it comes with great sonics in a much smaller package. For IEMs I would even prefer it over the Hugo 2, though it lacks the superb connectivity overall.
The Apple iPhone was always meant to replace the iPod. Next to iRiver and Cowon, Apple held its own. It is more about the convenience although ironically the headphone jack was moved to the end of a dongle. I had almost all of them, from 3G to X. Although I miss the iPhone 4 most, the 6 and 6S also sounded more than decent. The latest generation focusses more on Bluetooth and streaming.
Shanling M0 thus makes a great addition to the iPhone. Not only can it pair via Bluetooth, but it also stores all my music on a mounted 400 GB microSD card. The device is so tiny that there is no reason not to carry it with you every day. It also serves as a great source for other DACs like Hugo 2.
I am not the one who invests a lot into cables. I think many underestimate the influence of impedance and ground wires. Of course I don't mind a flexible cable with great looks and 8 wires, but I don't think it is recommendable to spend 20% or more for a cable.
In my collection are Forza Audio Works (FAW) Hybrid, Linum BAX Balanced and NF Audio 6N cables.
It seems my power supply at home is fairly clean and does not limit the audio quality audibly.
Other Audio Equipment:
XiVero MusicScope is a great software tool to analyze audio files in real time and easily uncover HD dupes. It tells you a lot about bad mastering and why 16 bit resolution probably isn't the limitation many people think it is.
Sonarworks True-Fi is a very easy way to enhance the frequency response of supported headphones. I don't use it on a regularly basis because I find the target a bit fatiguing, but True-Fi is a good tool for those looking for an easy solution.
JRiver MediaCenter is an extremely powerful audio playback software. The macOS version is poorly ported but the functionality is too great to miss out on. Blind testing audio files, converting formats, resampling, analyzing, tagging, renaming, and more make this an extremely powerful core center for any music library.
I am a huge fan of most releases on ECM Records and ACT Music. I like Avant-garde and Contemporary Jazz with high dynamic recordings.
For reviews, I add a wide selection of Concerto & Chamber Classical, all kinds of Metal, Alternative Rock, Vocal, Soul, Pop and some Rap or Electronica.
Depending on my mood I can enjoy any genre.
I love photography but I don't have a favorite brand. I use what works for me and whatever seems reasonably priced. For now, my main camera is an Olympus OM-D E-M5 Mark II with the M.Zuiko 12-40mm F/2.8 Pro lens.
I have been member of the trade before. I have accumulated profound insights into the business, distribution and creation of headphone-related gear.