Glad you are very satisfied with your setup and thank you for sharing this, @Totomo. This can help for those who have the same equipment.
It is a subject to which attention is paid very regularly. The conclusion is almost always: what sounds good to you, sounds awful to someone else. In other words, whether something sounds 'good' is very personal. I guarantee that if you give 10 other people the opportunity to set up your studio setup to their liking, you will see 10 different setups. There are dozens of variables between sender <> receiver. But perhaps that's why it remains an interesting topic. Btw. I often use the SX900 internal speakers, even in my home studio, which sound great to MY ears.