ok, let's start from this - I read and studied many threads&post here about VPR (so called) bass trap. Thanks to few great folks here and after some thoughts I decided VPR panels are way to go in my situation.
I want to build them myself, and before asking questions first, let me describe my situation quickly.
I have heavily trapped working space. I will drop some photos with more details asap.
Monitors I used 2 weeks ago were PMC TB2, and those sounded in my room excellent.
The outcome of REW test was also very good.
Situation has changed since I got new monitors PMC IB1 (passive). Room nodes became evident and low end became boomy:(
I mean 32-40Hz is kind of a pain now...
My room doesn't like peter's gabriel 'up' album (great album btw), and many lowest notes resonate
Well, hence it's my working space and it's my day job, I need to put old TB2 when working, and then remove them when testing setup IB1...and the latter are not very light

Anyway, after mounting additional broadband absorbers at the backwall (most offending), in the sweet spot/listening position, is almost perfect, although a little move of head (10-20cm) and the problem is there.
Situation is I work here and rent this flat, can't move walls, or even pay acoustic designer to design this room for me, as I will move out in 2 years for sure (I hope

. I have to work with what I have, space is as it is.
I can fit 2 big vpr panels at the front (between and behind monitors) and at the back (behind a sofa).
2m per 1 m, will easily fit and won't take much space (10 cm).
I thought it over and I could actually make bigger VPR panels, only thing worries me is a weight of that thing...
my question regarding building an vpr panel would be:
1. weight of 2m x 1 m build panel (steel+foam)
2. I am still not sure should I go for 1mm steel or 2.5mm or maybe both for 2 panel
3. I know I need to ask DanDan about purchasing the foam (Iso Bond right ?)
4. what kind of steel to buy ?
5. where buy steel in uk/babylondon ?
6. prices for foam (2m x 1m x 10 cm, I presume ?), steel sheet, transport, anything else (price per 1 2x1m panel)
7. why there's no sticky about VPR panel? - wiki about it, sort of
if anyone who build them have anything to add, to encourage me or warn me - please go ahead,
I need those panels very badly asap!
peace