Nardoni, I listened to the Tyros w/ its original speakers & subwoofer last Saturday and they sounded good to me. Maybe they sounded a bit weaker then the AL's but that might have been because of the surroundings. I'm not sure about their output power, somebody here might know. The AL's I hooked up to my keyboard produce about 140W @10% and peak at 200W. That's quite a bit of sound if you only use them at home imo. They're bigger than the Yamahas and I'm not sure if you can mount them onto the Tyros. I prefer having them at least a foot or two away to the left and right anyway.
ev