A very interesting thread this, as I have just brought back into use my speaker based system after listening through cans (Senn 650s) after nearly 5 years.
We are renting an old house here in France until I can find a farmer that will sell us a piece of land in a good position. It has all the classic negatives of an old stone built house, including sloping wooden floors and internal walls made of the awful cavity red clay blocks - 2.5 inches/6cm.
KlausR says that he had an extension built and then complained 'that he knew it would be a nightmare to set up his sound rig'
KlausR why did'nt you research building materials as deeply as you researched room acoustics or did you just accept what the builder chose
Tako is the only poster to mention building materials and even he does'nt really know what materials are used in Dutch construction - I worked for a Dutch company in Rotterdam in 79/80 renovating old houses and on new build as well, I am a qualified builder with lots of experience in both old and new construction and know well construction methods used in most European countries.
The OP presented a lot of possible ways to deal with setting up speaker systems but totally failed to address this most important point - what are the floors/walls and ceilings made of in the listening room.
KlausR - why did'nt you specify - aercrete blocks - de Jong (or used to be) Netherlands; Durox (Tarmac) UK; Xella International - Germany/France/Spain.
These blocks are thermally very efficient, so much so that on the Xella sites it featured one man using a blow torch against one of these aercrete blocks with another man whose hand is against the other side of the block. Now the bit that should interest all those who want to maximise their listening experience - they are acoustically superb.Each block contains millions of air pockets which explains their lightweight but also load bearing ability. They also are impervious to insect attack and wil only absorb around 3% moisture.
Xella also make aercrete flooring and roofing beams - I intend to use all three products not only for our personal listening/sanity centre rooms but for the whole house and guess what - the materials maybe more expensive than crap traditional materials but it actually costs a lot less to build a house because the whole process is so much quicker. The irony is that they were invented by a Swedish architect
and this in 1924.
For those not familiar with construction in mainland Europe and for Europeans who blindy accept what builders or architects
Dense concrete blocks, solid or cavity - soak up water like a sponge are very heavy and with only a finish coat of plaster - thermally useless and will give a hard cold dead sound. With the new planning regs that came into force this year here in France - to acheive a sufficient U value, these rubbish blocks need a 4 stage process, which includes using plasterboard and a skim coat of finish plaster - resulting in an awful acoustic performance as well as costing a lot of money to create ( great for the builder).
Cavity clay blocks - these are used all over Europe for internal walls and are the principal cause along with re-inforced concrete (dense concrete again) floors covered with ceramic tiles for the awful ringing that is the norm with homes on mainland Europe. These homes offer zero privacy for those that live in them.
So, KlausR you could have specified aercrete materials for the floors/walls and roof of your extension - be far warmer in winter/cooler in summer. battened the flooring beams and used tongue and groove pine or oak as floor covering.
There is no rational reason to use any kind of plaster finish on aercrete blocks - they can be painted directly - do not use vinyl paints of any kind, they are all very carcinogeric, in Denmark there is a recognised condition known as 'painter's dementia'. Or, as in the UK - lining paper (1200 grade) which I may or may not use. I shall decide after initial listening tests. I may use tongue and groove wooden panelling for the walls upto approx 4ft/120cm. I aim for a neutral sound rig but with a warm vibrant room - it's all about personal choice.
Quite frankly if you have rooms with stud and plasterboard walls - don't bother get into using cans and h/amp.
If as a European you are contemplating having a house built - there is only one material to use - aercrete blocks and don't let any builder use anything else other than 'the thin joint' system.
If you own an existing house you should be able to take down any internal plasterboard walls and put up aerecrete walls instead - they are so easy to use that anyone can use them.
So here I am having to do the best I can in this rented house with two external walls made of local stone - very deep and p/poor insulation - hot in summer and bloody cold in winter and two other cavity clay block walls.
I'm sure that experimenting with the various methods expounded by the OP and others I maybe able to get rid of 'congestion' that happens sometimes in the upper mids but I will never acheive a result that satisfies me because of the materials used in constructing this house.
As so often in the hi-fi world, very few actually start at the beginning - imagine even attempting to build a house without proper foundations - room acoustics start with the materials used in the room construction - everything should follow from there.