Thanks Stub Mandrel and yorks5stringer for your advice and comments.
I must admit that I was thinking whether to sell the 802 and get a higher wattage bit of kit, as on half to three quarter volume I get ‘fart-out’ from the speakers when VPF is set at max. I do like a real thumpy bass, so I’m probably expecting too much from the 802!
I shall look up the CMD121P, as I do quite like the Markbass products.