OK, so my original idea is down, because the second big tube is for lows (as reported by rusnak above).
However, I still have an interesting results from a few experiments I´ve done..
I´ll take Brooko´s measurements as baseline, because his rig is much more accurate:
We see a 2k peak which some people don´t like and 7k peak which was for me personally more disturbing than the 2k one.
I wasn´t able to tame 2k yet, because damper with smaller diameter would be needed, not sure
if we can buy them somewhere??
BUT, I managed to target the 7k peak and bring it down a few dB, which sounds good imho.
purple = stock
yellow = stock grey damper replaced by brown damper
Then I put the stock grey damper in the big tube for lows.
This is the configuration I´m currently testing: green = grey damper for lows + brown damper for highs:
In case there are some trebleheads
stock vs grey damper removed..
I don´t have time to make any comments now, but I think most of you will find the graphs informative.