Dear Patrick: As Restock point out there is no clear problem on the Rega/XX2 matching but I think it is not the best tonearm match.
I have a friend that have the same tonearm/cartridge in an Avid TT ( different electronics and Avant Garde speakers. ) and never really like it.
I owned the XX2 and I think s a very good cartridge with very decent tonal balance and certainly not a lack of bass not either in the other side but neutral.
I think that that cartridge deserve a precise VTA/Azymuth set-up in a better matching tonearm.
In the other side the Sunilda has a subsonic filter at 20Hz this makes that the roll-off in the bass start at around ( depend on the choose of filter order. ) 80-100 Hz.
So, IMHO ( at least ) you have these two different subjects where my experiences tell me " you are in trouble ".
Now, I don't know which speaker/amplifier you own and how good are integrated to your listening room, specially in the bass response subject.
If I was you first I will try to borrow ( somewhere ) a different tonearm and try in the audio system.
Regards and enjoy the music.
Raul.
I have a friend that have the same tonearm/cartridge in an Avid TT ( different electronics and Avant Garde speakers. ) and never really like it.
I owned the XX2 and I think s a very good cartridge with very decent tonal balance and certainly not a lack of bass not either in the other side but neutral.
I think that that cartridge deserve a precise VTA/Azymuth set-up in a better matching tonearm.
In the other side the Sunilda has a subsonic filter at 20Hz this makes that the roll-off in the bass start at around ( depend on the choose of filter order. ) 80-100 Hz.
So, IMHO ( at least ) you have these two different subjects where my experiences tell me " you are in trouble ".
Now, I don't know which speaker/amplifier you own and how good are integrated to your listening room, specially in the bass response subject.
If I was you first I will try to borrow ( somewhere ) a different tonearm and try in the audio system.
Regards and enjoy the music.
Raul.