I use the S1 pro with my tyros 5 keyboard. Great speaker but I do have a problem when I connect the Bose to the Tyros. If the bose volume is at 12 o clock I hear a buzz or hum in the speaker. I first had an unbalanced (TR) cable and then tried a balanced (TRS) cable but the buzz or hum remains. Do you have the same problem when connecting your L1 compact to the Tyros 5 ?