PM sent. Meanwhile, I had the unique chance to visit the local Technopolis store, where they stock Xperia 1 IV and 10 IV. Top-placed headphones jack, but anyway... Both phones have a music app with no settings for the sound, that is very similar to the one in LG phones. Once I gave access permition for my Sandisk 400GB mSDXC, songs were loaded into the library, easier and faster on the 10 IV.
I brought my CCA C12 and Focal Listen Pro - when I plug their cables first in my LG V10, and then the headphones, both activate AUX mode. I also brought the open-back, bassy HD 599 SE (black). Since Focal Listen Pro has less bass, but a pronounced, pleasantly detailed sparkling treble, I knew I was in for a lot of fun. I brought numerous different styles of music, ranging from Eurodance mixes in Youtube mp3, to other files in DSD 128. The result will shock you and I am quite happy to be able to contribute to this community, that has teached me for a decade how to be an audiophile. This post will be very informative and very long, I spent a lot of time, and got quite tired from trying to concentrate on the sound - too many noisy people were at the smartphone stand, I even gave some recommendations, and some people were particulary disrespectful and even interrupted my listening to ask questions, not to mention they talked loud for a long time next to my ears. I tested all phones with all my 3 headphones, with different tracks that I know very well (this is essential).
Lucky for me, the store attendant has Xperia as her personal phone, so she was quite shocked how competent I was (she said it) and let me put my mSDXC in both Xperia 1 IV and 10 IV. First - between those two phones, the difference was minimal will all three headphones. Both phones are tuned differently, while maintaining the typical Sony sound, more so on the first one. Whathifi strongly recommends the flagship as a clear step up - I stronly disagree. Both phones are warm, more pleasantly so on the 10 IV, which also has much better bass in every way - deep, pronounced, well controlled, you name it. It is shocking, since the 10 IV costs around 3x less than the flagship, and also has a "gargantuan battery life", according to GSMArena. I did not like the Xperia 1 IV, so I did not test it much. It is very difficult to compare differently tuned phones in a loud, noisy store, but it was clear that the 10 IV best it in almost every way, there is no comparison. Both phones show a yellow "HR" symbol for high resolution files. The screen on the 1 IV was punchier and clearer, but in a cartoonish way. I did not spend much time with it, but the white balance on the 10 IV was impressive for an OLED (I hate OLED). There is no info yet on PWM for this model.
For the test, I listened for a minute on every song, since I remember where are the complex instrumentals. So, I listened to hard rock, power metal, techno (Music Instructor), and Russian foklore song that are incredibly well mastered in studio, and incredibly tough for the audio to process, since there are multiple high-pitched instrument, specific for the Caucasian region (violins, bagpipes, whistles), all in the same orchestra with big drums. This is where I knew the ESS 9018K2M would best both Sony phones, and I was right. Since I was not impressed with the 1 IV at all, because it was too different sounding than the other Sony and my LG V10, I will only discuss the 10 IV. Not only better treble extension, but more forgiving on poor recordings as well. Analogue, mellow sound. The 10 IV is instantly engaging, very rich, very dynamic, surprisingly close to the V10 (which was in AUX mode). The CCA C12 immediately show that any of those 3 phones deserve higher end headphones, so the testing was brief.
The 10 IV is warm, very warm. After very hard listening with extreme concentration (to the point I got dizzy), I figured out it reminds me of the HTC 10, with better treble extension, detail, and less muddy sound. Think HTC 10 on steroids. It is very hard to believe that this conclusion took me so long - this is where I started to appreciate the forum that I read for a decade now. Information is the new petrol oil, they say. XPERIA 10 IV WAS VERY INCONSISTENT WITH DIFFERENT SONGS. To the point I could not decide anything. It sounded so different with different tracks and headphones - sometimes low bass, sometimes plenty of bass, and it processes the audio files very different from LG V10. At first, because both are warm-soundung, I thought they are similar. I could not be more wrong. I tried to be merciful, as I knew the ESS DAC will easily show unique treble extension. This is why the Focal Listen Pro sounded remarkably good with the warmer 10 IV, to the point that I tought it matches the LG V10. It doesn`t. Wider soundstate, more fun-sounding, neutrally detailled, treble that blends very nicely with the upper bass (NOT BLEEDING INTO IT). The 10 IV sounded a bit muddy like HTC 10 does, when listening to rock songs, and more digital on tracks like "Electric city" from Music Instructor. V10 sounds pleasantly analogue, fun and detailed at the same - an audiophile heaven, and I will keep repeating that. Battery went flat, so I changed it with a fully charged one (much to eveyone`s surprise in the store). On complex Russian folk tracks, 10 IV showed unique bass, rich, deep in big quantities, but the typical Sony bass. Refined, but not so much - here the LG V10 was better, and it also is consistent with different music styles, where the 10 IV sounded from warm, to neutral, bassy, flat...almost if I used a different equalizer preset on every different style of music. Still, very close to the V10, but not close enough. The promotional price of 460 EUR was quite tempting...but the awkwardly narrow and tall screen, a fingerprint magnet, made me think twice. The soundstage is narrower than V10, but close to it, and bigger and wider than HTC 10. Treble is significantly better than HTC 10, but on some tracks, it sounded too warm. The Sony sounded engaging, rich, dynamic...it instantly grabs you and makes you listen critically, but not "in your face" grabbing.
Putting on the open-back and warmer Sennheiser HD 599 SE was not the best idea. It did not match well with the Sony, as the treble instantly lacked. Bass, on the other hand - extended and pleasant, although slightly dull and muddy, due to the worse lower/upper treble. The phone benefits from open-back headphones, and shines on better studio-mastered tracks, but not so universal and pleasant as the V10, that just sinks you in the music, and does not make you evaluate or criticize like an audio-analyst. The timing on both phones was very, very good, on all types of music - electronic, , classical, or drum-paced power metal, you name it. As a critical listener, after a while, I could only hear the shortcomming in the Sony, compared to V10, and stopped enjoying it. If I have to recommend a phone, I am definitely doing it for the 10 IV. It was a shock that the 3x more expensive 10 IV did not cut it, it was obvious from the start, I did not even have to push my hearing to the limit.
One very important thing, the amps in both Sony phones seemed weak. I maxed out on my Focal Listen Pro, it was not even uncomfortable, while it was slightly for the HD 599SE, but still one can endure it. I do not have hard to drive headphones for testing, but...my V10 in AUX mode could easily drive the Focal to unbearable listening levels. Still, I enjoyed slow guitar riffs on the 10 IV, like Baton Rouge`s "The price of love" or Gun`s cover of "Word up". I rarely enjoy those songs on the HTC 10, that I own 4 of those, two HTC 10 are brand new (for my collection), and I think I will have to start selling. Music Instructor`s "Electric city" was the only song that sounded fuller and wider on the 10 IV compared to the LG V10, but...a bit more digital. Still, an excellent result. Normally, I do not audition that much - I instantly prefered V10 to the LG G7 at home and did not think twice, although I spent days auditioning them, out of curiosity. I was going to buy a Realme 8i for the battery life to use it as a cycling GPS phone, but the Xperia 10 IV made me think twice. A father in the store wanted a cheap gaming phone for his 8-year old sound, so I enlightened him about the great battery life and display without PWM, and he was happy to buy the ex-display phone with a 5% discount. Most store staff was looking at me strangely, not in a good time, for spending hours in the store with the phones. The OLED displays on both Sony phones were so much better than the crappy Scamsungs, it was no comparison. Pleasant whites, acceptable blue and purple...(I will never like those on any OLED.) Some employee started arguing with me on that, and upon hearing that I am a pro photographer, electrical engineer, and I have studied for an optometrist, stopped arguing. The staff became notably unfriendly, some beta-simps started coming and nosing, trying to hear what I was saying to the middle aged female employee (as if they could stop me, if I wanted anything from her), and at this point, my mood was ruined and I left the store. We all know how neutral and easy-minded must one be when comparing things. By the way, she warned me from the start that the 10 IV comes without a charger or headphones. I remember back in the days, the W-series, fifteen years ago, came with surprisingly high quality in-ears, much better than the competition. She also said that her Xperia 10 II has battery optimisations (charging to 80%), which was nice. I tried to search for DC dimming options in both Sony phones, but there was none. If it is present, I guess one must go in Developper options, and I have no idea if this could be added via an update. Still, one must have a very trained ear to decide which phone to get, so even demanding amateurs will be more than happy with the 10 IV (I would not, because of the OLED). But having audio this impressive, unbelievable battery life, everything top-notch, for this price?! I have never seen anything like this in the recent years. And yes, I tried to spend more time with the flagship Xperia 1 IV and tried to prefer it over the 10 IV, but I did not prefer it in the end.