Youtube review: Photos: http://dalethorn.com/Photos/iPhone7p/Headphone_B_O_H4_01.jpg http://dalethorn.com/Photos/Audioforge/B_O_H4.jpg Sources: iPhone7-plus, iPod Touch, iPad Pro Mini, Macbook 12-inch, AudioQuest DragonFly Red. I bought 4 of the B&O H6 for the full price (different editions/colors) before it was reduced to $300 USD. Those were fairly good for sound, but had a strong peak around 9 khz (common in closed headphones) and a recess around 4+ khz, which is less common. The H4 Bluetooth headphone definitely inherits its sound signature from the H6, which most people will probably like. The H4 has a ~4 db recess between 300 and 700 hz, and a ~4 db emphasis between 30 and 70 hz, giving it a warm and slightly soft low end, which most users will also like I expect. The really surprising thing about the H4 is the price for a quality Bluetooth headphone, which is comfortable, looks very durable, and is aesthetically pleasing. The perception of the peak-to-recess differences in the treble will vary among users, and will not likely be a problem in portable/outdoor use. An emphasis in the bass is usually welcomed for outdoor use, since low frequencies get absorbed in the outdoors, particularly in automobile traffic areas. You can see the test/EQ curve I did for the H4 at the above link, or on my dalethorn Website. Basically, this is a pretty good sound with bass impact that users will like for portable/outdoor use, but if I were recommending it for at-home hi-fi use, I'd suggest trying an equalizer to get the best possible tuning. I have not found any problems with the Bluetooth connection from my iPad Pro Mini, iPhone 7-plus, or iPod Touch. Everything plays perfectly, but if you were to walk past a source of strong electrical interference, you could get interrupted in a case like that. The quality of the Bluetooth sound is excellent in my view, but that applies to playing 320k CBR MP3's on the players I noted above. For maximum quality playback on a good DAC/headphone amp, you'd want to use the cable with the Bluetooth turned off, and try CD rips, FLAC files, etc. To check out the Bluetooth capability, I paired it with my iPhone 7-plus, and placed the phone at one end of my apartment. I walked into several other rooms including laundry and bath rooms, closets, A/C enclosures etc., up to 35 feet from the phone, and the signal was always clean and perfect. I've used a few other wireless headphones, and most were 100 percent in that regard, so I wouldn't expect any surprises with the H4. I haven't found that where I am with the headphone makes any difference, unless such a difference (interference etc.) were caused by my cellphone attempting something that I'm unaware of. I don't hear a significant difference in the sound between wireless and wired modes in most situations, but if getting the very best sound is important, wired use with a good DAC and headphone amp would be the way to go. I use the DragonFly Red for those occasions. The H4 has one input for wired use on the bottom of the right earcup, and one Mirco-USB input for charging next to it. The on/off/pairing and volume switches sit next to the charging port. These controls are easy to manipulate, but they blend in so well that they don't distract from the overall aesthetics. The earpads are large, soft and squishy, and are a very comfortable around-ear fit for my average size ears. There is no carrycase included, but this is a B&O wireless headphone at a very low price point (for B&O), and so for people who need a good case, the Grado-type cases available online for less than $20 work well, since the H4 earcups fold flat. I don't use a case unless I'm traveling, because the earcups pull down far enough and fold flat so I can wear it around my neck all day if necessary, without any bother. The headband's range of adjustment is about 1/2 inch larger and one inch smaller on each side compared to where I use it on my average-size head. The H4 does not have a noise canceling DSP, just the Bluetooth DSP, and so the isolation is moderate - good enough for most outdoor use, but it may not be enough for commuters on jet planes, buses, or trains. There is some leakage, so if playing the H4 in a quiet office or library, the volume would have to be kept below audiophile levels. In previous reviews I've included music examples with comments about how the headphones sound with each track. My suggestion is instead of reading each one as an absolute unto itself, you could compare my notes here to other reviews and see how the H4 compares to other headphones with each track. Note: At the outset of this review I expected the tracks listed below to sound pretty good compared to playing on my other headphones, but I'll give a special nod to the H4 here for exceptional Bluetooth sound - especially the bass which has great impact and detail. Above & Beyond - We're All We Need (feat. Zoe Johnston): A very nice tight but strong-impact bass with crystal clear vocals - the H4 plays this with great ambiance. Anamanaguchi - Planet: A complex mix of percussion sounds and hummed vocals. The bells and other high-frequency percussion are highly detailed, the bass line has good impact, and the bass detail is surprisingly good. Armin van Buuren - J'ai Envie de Toi (Orig Mix feat Gaia): Strong bass impacts, breathy vocals, lots of fun noise - the H4 plays this perfectly. Avicii - Feeling Good: Classic female vocal in movie-theme style - the H4 brings this to life like very few Bluetooth headphones - very impressive. Carl Kennedy-Tommy Trash ft Rosie Henshaw - Blackwater (Original Master): Nice strong tight bass impacts, female vocal, rendered delectably by the H4. Crystal Castles - Wrath of God: Atmospheric tune with vocal sound effects and strong bass line, plus some unique treble percussion sounds. The H4 brings these unique sounds to life. Digitalism - Pogo: A driving beat with a detailed bass synth and great vocals ("There's something in the air...") - the H4 makes this very enjoyable. Dino Lenny-Lino Di Meglio - We Will Make It: Atmospheric tune with good bass impacts and mixed vocals - the female vocal is a special treat with the H4. DJ Shadow - Building Steam With A Grain Of Salt: High-pitched tones and strong deep piano chords with a hummed female vocal - ultra-cool with the H4. Fairmont - Poble Sec: Awesome detailed bass impacts with some nifty pingy guitar and synth effects. I discovered this tune at the time I purchased a different headphone, and the H4 makes this even better. Giuseppe Ottaviani - Lost for Words (On Air Mix feat Amba Shepherd): Strong bass impacts behind a female voice - a large-scale sweeping sonic image reminiscent of epic adventures in an exotic land. I can't imagine hearing this any better than with the H4. Hecq - Enceladus (With Skyence): Prodigious deep bass and clean at that. This tune's melody is more abstract than most of the others here, but the H4 makes it a real adventure. Katy B - Crying For No Reason (Tom Shorterz Remix): Oh myyyyy, I love Katy B. The vocal mix here is awesome and the bass is solid. This is the H4 at its best. Ladytron - Destroy Everything You Touch: I first heard this in The September Issue film and soundtrack, as the backdrop for the opening catwalk (watch Andre grinning at 1:51 - all you need to know) - the H4 plays this tune perfectly, with an amazing soundstage. Lee and Malinda - Truth Will Set You Free (V-Moda Mix): Lee Kalt is the master, this is the masterpiece. The drum (or tom-tom) hits here have a very realistic skin-tone, the female vocal is seamlessly integrated into the driving beat, and the synth effects also blend well - the H4 just owns this. Markus Schulz - Mainstage: The granddaddy of bass is in this track, and the H4 plays it smooth and clean.