I absolutely will check out both Grado & Koss. Used to have a Grado cartridge on my turntable, and wore the hell out of a Koss Porta-Pro (paired with my portable MiniDisc which I also beat into the ground) back in the mid-late 90's.
The Porta-Pro is actually still in production! I was trying to think of "other Koss headphones" and that one eluded me however...
At $15 the KTX-Pro are kind of a knockout, but honestly I'd say "spend more" if this is something you're going to use with any regularity - my biggest gripe with the KTX Pro was the flimsy build and resulting funky fit. Something like the DJ/100 is a lot more solid headphone, and sounds better too. Frankly I think both Koss and Grado make cans that'd do great with your listening tastes, but they do make fairly different sounding headphones. Fortunately, none of their "entry to mid range" models are horrifically expensive, so you could realistically try both if you so desired.
Was asking about Chinese brands as I know very little first-hand except for my Pistons. Actually, one of the reasons I bought my ZTE Axon 7 was its strong audio performance.
Honestly I've never really gotten into IEMs or other in-ears, and from what I read that's really where Chi-Fi has taken off. Not sure what to tell you as a result.
Thanks for the quick feedback. Let me ask you one more thing--what would you recommend as far as music players/EQ apps for Android and Windows? I have a little Agptek MP3 player which basically replaced my old Sandisk Clip, but I could use some advise on Windows gear: do I need a better Bluetooth dongle? Is there something that works better than VLC and/or MediaMonkey for playing and organizing my digital music? I have heard great things about Viper for Android but I believe my phone must be rooted to use that? What do you use for all this?
I don't do much of anything with mobile devices - I bought a Sony Walkman back around 2009 and haven't had any inclination to upgrade or mess with it (and anymore it spends its life in a drawer). So I don't really have any good advice on the Android front - I'm not sure I've ever plugged headphones into a mobile phone to be quite honest.
On the PC side, I would say "wars have been fought over those kinds of questions" - there's as many opinions as there are stars in the sky when it comes to doing PC audio. Personally I come down on the side of convenience and "good enough" quality (meaning I have no interest in spending a thousand hours fighting for "bit perfect" or other extremes) - sure I rip my CDs to lossless with EAC, but I don't bother with esoteric media players and never-ending plugin configuration and all that. VLC is fine for playback but it doesn't have much in the way of library support, so that'd be a no-go for regular use IMHO. Anymore I'm just happy with Windows Media Player, but Foobar2000 is also a popular choice (and free), and there's other options beyond that if you're unhappy with Foobar or WMP, such as: iTunes, Winamp, JRiver, Amarok, etc. Some are paid some are not. IME/IMHO there's not much to be argued about with media players in terms of sound quality (some would disagree, some would disagree vehemently) - bigger arguments are to be made for UI/functionality, codec support, and how well they rip and/or tag content. If you rip with EAC that removes one big question from the board, and codec support is pretty standardized these days (and there's easily had freeware packages that will give you access to whatever esoteric containers you like - this is more commonly needed with video than audio though), so that takes that off the board too, and leaves basically UI/functionality as a big determinant. If you have something that you like the workflow with, stick with it.
Now as far as the audio from the PC itself - Bluetooth isn't really the greatest thing for audio due to the amount of compression it requires. I'm not sure a different dongle will improve sound quality, but it may improve connection stability or range. The bigger places to futz around here are with the actual output hardware for the PC - while integrated audio (at least in some areas) has made big strides, it's still hard to beat a quality soundcard (be it internal or external), and there's so many options out there these days (especially when you get into USB-based audio). From there its off to your gear via analog ICs, and all of the "more typical" audiophile discussions can come into focus - cable quality, power, amplifiers, etc etc. Basically I'd say if you want to do PC listening on headphones in a really "hi fi" way you should probably look into the output hardware on your PC (and potentially upgrading it) as the link between the PC (and your digital files) and the amplifier driving your headphones.
Something else that may or may not be obvious: the quality of the files themselves is a really big deal. What I'm saying here is three-fold:
- Quality rips matter, if you're starting with CDs or similar. I'd go straight to lossless these days, given how cheap storage is. That isn't to say quality lossy encodes are bad, but really storage is so cheap anymore that it's just not worth arguing about the 4:1 space saving or whatever when you can get a 1TB hard drive for like $40-50 to your door. EAC is a great utility and very easy to use (and its free).
- How the music is recorded/mastered/etc is also important. "Digital" isn't a cure-all, and the loudness wars are still in full swing for some producers. So it may be the case that whatever you want to listen to just isn't available in a "high quality" way as a result.
- Digital streaming services are not created equal, and some of them are frankly pretty bad. Like audible compression ringing bad. Sure there's a huge convenience factor, but frankly with a lot of digital streaming services, despite all their bluster about "HD this" and "HD that" its really similar to the differences between HD broadcast cable and Blu-ray - sure they're both 1080p, but one of them is actually sending out the proper surround sound mix and doesn't even know what "macroblocking" means...
(Speaking of "hi rez" you might also find this useful:
https://xiph.org/~xiphmont/demo/neil-young.html)
Personally I'm still of the mind that if I really like an album and want to own it, I'll go buy the CD. In many cases its cheaper than buying the lossy download, and I can rip it myself (which is quick and easy), and still have the CD for playback on my equipment if I should ever want it.