Oops. I did not mean to say splitter. It is a Presonus box that takes output from the interface and provides four independent headphone outs. My mixing headphones are pretty high impedance (160 or 180 ohm). The Focusrite cannot drive it, but the Presonus has no problems.
it looks, like I have the same box, but didn't use it for a while. yeah, it's louder than Clarett's headphone outs. really not sure if Clarett's HP pres are better than the Scarlett's, but the Presonus headphone amp is a great little box.