Wallpaper will make a very small difference, unless it's 100mm thick!

Overall it achieved my goal of reducing the echo in the room. Naturally it
was not 100% efficient so I went for further treatments as outlined.

While many of your suggestions is something I've heard mentioned before it
does not make a front room, home friendly! In the past I've used carpeted up
right panels filled in behind with loft insulation installed behind speakers
to reduce/eliminate echo. These did a fine job but when they were removed
from the room it was amazing how fresh & spacious the room became so I doubt
that method would be used again.


What do you think will be achieved by standing the 'speakers on
breadboards?

Before they were on breadboards I experienced some bass mudiness & thickness
which I would say was contributed by extra reverberation through the floor.
They were also very difficult to get stable as aligning 4 spikes to sit
correctly was not easy. I guess I am trying to rid the speakers of this bass
anomalie without attracting other anomalies in upper frequency areas. With a
solid base it is also very easy to get 4 spikes to sit correctly.
Having experimented with them for quite sometime I would say they have done
the trick but I feel they sound a bit light weight now so I'm not sure which
I prefer.

If you have suspended wooden floors I would isolate the 'speakers by
mounting them on rubber.

The floors are concrete but I like that suggestion for wooden floors :-)

Alternatively, you could use mass, but you'll need
an awful lot more than a marble slab ( a couple of tombstones might work!
I'd like to hear the discussions with one's wife over than suggestion....)

I'd like to see someone whom would use that suggestion let alone go and pick
them up (I do hope they liked music).