You don't mention anything of the acoustic characteristics of the space you're working in. If it's a lively boomy room then any low end element in the sound will rocket around the room uncontrolled, giving the impression of wooliness in the bass. If this were the case the Titans would sound better simply because there is no bass in them.
You also don't mention if you are using any kind of EQ to take account of the room.
I'm no fan of the Mackies but I'd usually take them over the Titans.
Thanks for your comment, the room is reverberant but doen't seem to have any horrific bass peaks.
We tried eq but just seemed to end up with greater or lesser degrees of muddy. I wouldn't agree that the Wharfedales have no bass, although they don't seem to go as deep as the Mackies they haev a reasonable amount.
I've never liked a solo violin, you need at least five for a proper fire.