I too have the Lovan Sovereign 2+2 rack. I prefer this one to the "classic" rack offered by Lovan because the shelves are supported on all 4 sides vs. a triangular shelf for the classic design.
I have not filled mine with anything so far & the performance is just fine to my ears.
I thought of stuffing the tubular shell with R-9 or R-11 thermal insulation but have not done so just yet.
I seem to subscribe more to the "light-weight, rigid" theory as I feel that it has more merit in damping resonances. Heavy stuff seems to have a low resonance freq. of its own & *could* bloat the bass. Then I disobey my own convictions & use a sandbox under my TT for added isolation!!
Almost all my equipment doesn't touch the shelf as I use DH Cones or a DIY symposium shelf. Only my preamp is sitting on the shelf on the recomendation of the designer.
One other thing I like is that the whole rack is open on all 4 sides. This heavily reduces the reflections of the music signal should you place the rack in between the speakers (like I do).
I also like its modular design - add pieces as you expand.
Anyway, I feel that this rack is very good for the money paid.
I have read on AudioAsylum that some people (Kal Rubinson included) use damping sheets on the underside of the shelves. Seems to help further. I might try that one day.
My 2 cents worth.
