How does the Canon 2 compare with the newly released Thieaudio Hype 4? I'm wondering if I should go ahead and get the Canon or wait a couple of months until the Hype 4 is available. I'm gonna use them for listening to rock, metal, rap and will use them for gaming as well.

Speaking on EQ, this is what I'm using (and loving) on the HD660S:

I've been playing with EQ and I really liked this subtle curve below: Gives a bit of extra oomph on the bass side and brings vocals a tiny bit forward. Loving it.

Agree. The 660S2 looks great, but I wouldn't pay more than $300 when the 6XX exists and sells for $200.

How do you like your 660S? I've seen a bunch of people critical to them, saying they're not on par with the OG 600/650, and other people that say it's a clear improvement. For a normal person that just loves to listen to good music, what to take from all this?

Amazon has the 660S for $275, just snagged a pair

Do you have an EE or electronics academic background?

If you need an LED to tell if an audio device is working or not, maybe it doesn't make that much of a difference at all?

Subjectivity is not a bad thing. What is a bad thing though is buying devices that have no impact whatsoever in audio quality for large sums of money. Don't twist my words.

Since you have the gear and the skills, why not settle the argument once and for all and run a proper randomized double blind ABX test?

Timbre can be measured, since it's basically our own interpretation of frequency response. Dynamics? Of course, mics have a considerably higher dynamic range than our ears. Psychoacoustic effects like soundstage are harder to measure of course. Regardless of all that, it goes against my simple...

In this case even electrical measurements at the DAC/Amp level should tell how much of a difference this device makes.

A fat joint can improve significantly the sound quality of any system.

https://www.silvertel.com/images/appsnotes/ANX-POE-Isolation-Barrier-explained.pdf

As they say, the shoemaker's son always goes barefoot.