Thanks, I'm watching the video ... but immediately he mention the Blon BL-03 I had and that frankly with music like extreme metal, faster and more intricate, they were a bloated unlistenable mess. Maybe the worst IEMs I've tried with Black or Death Metal music.
7Hz is pretty good for extreme metal. Almost as good as my MEST mkii. There are benefits and reservations with both of them, honestly. I have no perfect choice for you, sorry.
Timeless is def fast enough and layering is adequate to pretty good, and so is low dynamic range forgiveness, all good there. The planar timbre doesn't really affect metal the same way as it does rock and jazz, also good, I don't mind it. Sometimes I even prefer it.
They do have, like the MEST, a treble peak that can suck for drums
sometimes. But that is true for most of the high performing monitors out there.
You walk that tightrope between smooth listenability and the tuning higher fidelity requires to actually be "higher fidelity". It simultaneously reveals and destroys the organics of a badly recorded metal album. Usually by boosting frequencies that are so smashed its just atonal noise.
Simply though, Timeless,
for the money, are great choice for extreme metal. They almost beat out the MEST and at 1/7th the price, which is not bad at all.
When the music starts slowing down you may have more issues with the 7Hz, but for the fast hard stuff, its pretty damn good.
I also have a BL-03. And I have used it exactly twice for 5 min each time.
