Hi Diki

The SD2 is effectively the sounds of the SD 5 Arranger minus any hardware controls and backing, so it’s probably around 6 or more years old now, thus its hardly surprising it does not do any better than your BK9, however it is still a great sound set that can expand any arranger keyboard beyond what the manufacture provides. (The SD4 is basically 2 x SD2 in a box with physical controls, so may be the better option with arrangers that have limited Midi capabilities)

The SD1000 is supposed to be the new kid on the block (The SD 2 bought up to date) however design wise it looks like it was built in someone’s back shed, rather than having the professional look of the SD2.

Bill