There is a you tube video out there somewhere about modifying / hacking your boot screen. It also tells you how to change the mp3 sound file that is that very loud boot up sound you refer to. It is not for the faint of heart but not impossible by any means. Any how what I did was use the instructions to "extract" a copy of the sound file to my pc then ran the sound file through a free shareware program called mp3gain. If you analyze it first you see it is at over 100 dB if I recall correctly. I set the gain to something like 60 dB then pushed it back into the ST10+ and now have a far more reasonable sound level at boot up. However, you have to redo this everytime you upgrade the ST10+ firmware because your modified file gets overwritten on an upgrade.