I've got a decent amount of noise floor with mine. It's not audible while music is playing. But any time they aren't playing something else I can definitely hear jt

I mean yeah if you're listening to extremely compressed stuff or super loud then if you won't hear it. But I absolutely hear the noise floor during quiet passages.

It's not. I wasn't a huge fan of the tuning, but my main issue is that it has an audible noise floor.

Basically you plug it in and it starts going shhhhhhhhhhhhhhhhhhhhh

Great bargain, but not a replacement for anything high end

The answer most ppl aren't talking about, is that it adds cost and complexity to do it well. The added complexity is part of why tws only ever last a couple years before croaking.

Also, most tws use anc to compensate for their awful sound isolation. Most quality iems just block the noise passively and call it there.

Massively over estimating the number of audiophile headphones that get sold

The problem with the Fletcher Munson curve is twofold.

Sound engineers mix on neutral monitors, which have a very flat response. because of this they compensate for human sensitivity in the 5k region by dropping it down naturally.

The second problem is that by definition the Fletcher Munson curve changes with volume. So equing to it only works at 1 specific volume. The real way to compensate for it is with loudness controls, which boost the bass and treble at low volume.

Yes. You bought the fiio K9 already, why wouldn't you use it?