Thanks for the suggestions guys, lots of filters available to narrow it down but I don't see any wider filters available. My radio has all four filters in it, but I find the 2.4KHz filter just a bit too muddy for my liking. Used to the Kenwoods I guess!
2.4 is plenty wide. Nice thing about analog IF rigs is that you can usually use IF shift to center bandpass to your liking. I think your audio sound is more the product of a 990 receiver than the filter width. It will never sound like a "kenwood"