I just got myself the Between Pro earbuds. I will test to run an Ultima tomorrow and report more but they have quite a good flat response, much flatter than most earphones. They sound absolutely amazing and while they are not artificially „bass boosted“, they have the most amazing bass I ever heard through their physical triple speaker driver setup. Just played a loop of „Bad guy“ and it felt like on a fucking concert.
Here the link if anyone interested.