I sweat like a pig in headphones! If I have to play silently for practice I use Sony earbuds of an unknown quality.

I have a Korg Pa800, and it sounds great to my ears. The Korg Pa1X had a great and powerful sound as well, but at 50 lbs what an unwieldy beast! Never opened it up or looked into the specs for the internal amp(s).

The TRS-MS05 speakers sold as a companion to the Tyros 5 are lousy; I don't recommend them. When I got my BK-9 I invested in a Roland CM-110 2.1 monitor setup. This system is rated for 50 watts. I think the original MSRP was around $700, so not high-end at all. But they sound much better than the TRS-MS05.

I don't play pro gigs and I have no experience EQ-ing for a room. But when I play a MIDI on the BK-9 it sounds great to me!