Most cost-effective upgrade for my Kan's

Just got me a demopair of Kan-ll's last week.
Together with my Nait-2 and CD-3.5 + f/c they bring a smile on my face and I can't hold still
when these babies are swinging.

There's only one little thing...
"What !?!? nag,nag,nag, why aren't you enjoying the music,instead of complaining on the forum",
I hear you say,haha..

well, I know the bass could be a little tighter,
and there can be 3 things that can be the cause of this.

Wadda ya think is the nr-1 factor for this:

1. The Nait-2 can't keep control over the Kan's.
2. They're standing about 40cm next to a
fireplace. (sligh corner effect?)
3. They're on (top-and bottom spiked) Target-HR
stands instead of the dedicated Kan stands.

Don't get me wrong, I'll keep the Kan's anyway,
because I love all the thing the Kan's are doing right!
It's just curiosity,maybe in the near future..
What would be the best
(or for now the most cost-effective) upgrade for
my Kan's to get a little more control over the bass.

I can get a s/h 140 from my Naim-dealer for
50% discount.
Could I convert my Nait-2 in a pre-amp and buy only the s/h nap140?

or should I just STOP wanting too much, and START
saving money or enjoy the music !?

Well, see ya'

Greetings,
Alco.