Changed Drivers Still Not Happy

I got a Bugera 210 cheap so I changed the drivers to Delta Lite II 2510s, based on the specs I gave US Speaker, and their recommendation but it's too punchy and bright. I have a Markbass 210 combo that's nice and full, is it the speakers Markbass uses, the cabinet dimensions or Italian magic?
 
The results is the sum of many inter-related factors. Throwing a speaker in a box isn't going to work if the speakers parameters (including voicing) are unsuitable.