Room treatment plans - special basstraps??

I've moved to a new place and trying to figure out how to get the basement room usable for music hobby.
It's not a good room, and I don't have money to spend. 7mx 5 m (23'x17'), only 2,04 m high (6,9'). Maybe I'll send the layout drawing later. Anyway, exactly half of it must be left for normal basement storage, full of carton boxes and other stuff, 3,5m x 5 m is left for my use. The walls and floor are all concrete and lightweight blocks (I don't know what they're actually called in english, light bricks made of groil-kind-of stone material).
 
I'll separate the storage part from the room with a 2,5 (1') cm woodfibre wall (the other side of which will be covered by clothes in hangers), leaving a doorway covered by a molton curtain. Also, I'm planning to cover the walls with the 2,5 cm woodfibre plates as well, and put the same material on first reflection points on the ceiling. I've also reserved some thick and heavy plasticfoam mattrasses to make movable absorbers.
 
I was thinking of different kind of basstraps instead of the traditional stone-wool ones. If the basstrap is made of, say, 3-5 layers of
2,5 cm woodfibreplate with 2-3 cm air gap between them, would it work? The total weight would be equal or bigger compared to stone wool, and the material is rather porous, though much harder compared to fabric covered stone wool. What if the fibreplates have holes in them?
 
I'm not very happy with the room, but I suppose it can be made tolerable. The big question mark is the effect of the storage side, as I can not separate it from the room fully. It's full to the ceiling with shelves full of stuff, only a 4 foot wide gangway from the outdoor to the room. I just can't imagine, how much the sound can wander amongst the stuff, or will it be absorbed to a non-disturbing level.

 You know Kalle I have wondered why someone hasn't come out with more solutions especially for bass control in small spaces. I use ARC2 and after setting it up it notches out a lot of my bass. Of course it does a heck of a lot more than that by controlling the timing of the sound waves with regard to when it reaches my ears. Software like ARC can be really helpful but probably not completely make a block room sound perfect. It can get you a long way towards a better listening environment. 
 
  Having worked with some of the materials recommended for sound absorption I can attest to how itchy it can be. You are working with fiberglass and rockwool. If you don't sneeze or itch after the experience you are one lucky man. Everything has a price I guess. The commercial foam isn't bad to work with. Done correctly you can have your space looking like the bridge of a Klingon vessel in no time. I have seen some neat things done with the dense foam. 
 
 At the most basic the low end energy that needs to be tamed is directly dependent on the volume. If you mix at lower volumes the energy is obviously not as much. The whole idea is to trap the invisible sound energy and not let it back out into the room to mix with other incoming sound energy causing a distorted sense of perception and setting up what they call "standing waves".....so any material that is semi dense (like insulation) seems to work well. The thicker it is the better. The sound hits the corners of a room and bounces, then tries to move into the room but the density and thickness of the rockwool won't allow that...so anything of a similar nature will help reduce the effect. It doesn't need to look pretty to do its job. In my studio I have a small closet and it is full of coats and other junk and it has a heavy curtain over it. This makes a wonderful trap but unfortunately it isn't enough to completely remove all the bad waves.My desk has a lot of angles and panels in it acting like a large wooden baffle at certain frequencies. Honestly  a person on the cheap could probably get away with a few sleeping bags rolled up length wise in the corners and even that would help if dense and packed tightly..Mostly materials that are porous and dense like certain fabrics and insulations are good for this....your imagination is the limit here.
 
  Like Bit said, applying wave stopping substances with an air gap behind is a big help. The wave passes through, slows down and tries to rebound but can't get though the material a second time, usually used to control higher frequencies.
 
 Ceilings and floors also reflect and usually need some kind of treatment. I'll bet that pile of stuff at one side of the room will help tame it some.

I need to do some studying. I'd like to do the job the simple and fast way, as it may be I'm moving house again in 2-3 years.
 
I know the  traditional, framed rockwool/fibreglass elements are good.
I tried to find info regarding the acoustic qualities of the woodfibre plates I'm planning to use, but did not find any for that particular brand. I know it's widely used for it's pleasant acoustical properties in general, but studio environment is another thing. As I don't know any similar foreign products I can't find useful info on the net elsewhere. It weighs 280-300 kg per cubic metre (different wools around 30-80 kg ?) so I think my bass trap idea doesn't work, after all (?). It's too dense I believe.
 
I'm starting to doubt if it's ideal for the walls either, or worth the work. When painted it would reflect high frequencies anyway, but how much....Would it be better to leave the lightweight brick uncovered and just position some absorbers in good places? I assumed the woodfibre would just soften the general acoustics, and leaving concrete (mostly) uncovered in the ceiling and floor would give enough "bouncing surface" for high frequencies. There'll be shelves enough to do the diffusing part, and two big sofas.