Based, and double checked. Blues for the Red Sun for example sounds perfectly fine without the EQ, maybe a bit piercing if anything.

Watain’s debut doesn’t gain too much from the EQ either.

Pestilence’s Consuming Impulse I feel does benefit from the EQ, it becomes a lot meatier (IMO as it should).

Ahab’s The Call of the Wretched Seas also benefits more as it’s a more atmospheric album and uses that bass headroom quite well. Without the boost in the low end, it sounds a bit weak.

Again it all depends 😳 I also have a EQ profile where all the changes are 50% of what they originally are. So it’s kind of between that EQ profile and without EQ.

What kind of metal, bands genres etc.

Check out the Headphone Show youtube video on EQ’ing headphones. That’s essentially what I’m using.

I don’t doubt that, but the XS and those planars are at completely different price points.

Again, I’ve totally fixed that with EQ, planars take it quite well.

I wouldn’t say it lacks substance, just needs more oomph from the bass range.

I’ll also add, the headphones benefited a lot from a good DAC and Amplifier

Yup, you bet I'd rather listen to Steely Dan on my 660S.

I think it's because they don't try to be something they're not.

They're not really price constrained, they do all they want to do regardless of price.

I suppose they don't go for other things like speed / bass response etc. What they do have is universally liked midrange capabilities and really good timbre.

It entirely depends on the kind of music you listen to. Jazz sounds fine without any EQ.

The Edition XS lacks bass for me and it doesn't have the midrange prettiness of the HD6 series to make up for it. Again, I listen to mostly metal so the XS is near unusable to my ears that way, obviously not everyone feels that way.

The Headphone Show has a tutorial on how to EQ (in general) and in that video they give the Edition XS as an example, with an example tuning. I've modified it a little bit, smoothing out the midrange peak and reducing the bass shelf.

I would really never ever use the Edition XS without EQ. It sounds very weak and shrill.

BUT, with EQ they are my preference over the HD6 series and its cousins. The XS will never have the timbre of the HD6 series, but for the music I listen to (mostly metal) the Edition XS are an obvious winner, but that's just me.