Playing stage piano using YSP-800

I have a Yamaha CP33 stage piano. It is a good instrument, but does not come with speakers, so I invested in a used YSP-800 sound bar. The piano and the speaker system share a sleek and sober style and keeps the installation and wire mess to a minimum. As expected, 30W (82W peak) is plenty for me and the response over the whole spectrum is good even if slightly limited in the lower range. My deception is that this speaker unit delays its output. I would say something in the range of 100-200ms. This really spoils the playing experience, especially with sounds with a sharp attack (like piano). I could not find in the user manual any indication to eliminate or at least reduce the annoying delay. Is there anything I can do? I don't even mind open the unit and doing some soldering as I cannot return it.