B&W electronics dm70 Instruction Manual - page 6
The ideal is a solidly built ground floor room w i t h a concrete floor. In
rooms where there is a board and joist floor this will play a part in
both adding to bass gain and room colouration. The suspended floor
acts as a supplementary bass radiator operating at the main resonance
of the room. If your listening room has other than a solid floor and
you are troubled by excessive or resonant bass response as a result,
positioning your loudspeaker away from the corners will assist.
The subject of positioning your loudspeakers is dealt w i t h in section
4, but before leaving the listening room we will mention its effect on
middle and high frequencies.
The soft furnishings — chairs, curtains and carpet, together w i t h wall
and ceiling coverings are the main factors governing the performance
of a room at middle and upper frequencies. Position of cupboards,
bookshelves and other items of wall furniture also play an important
role in these parts of the spectrum.
A room w i t h insufficient soft furnishing will give a hard or steely tonal
quality to middle and upper frequencies, w i t h strings suffering especial-
ly. A room w i t h too many soft furnishings — an over-damped room —
will sound dull and lifeless, a somewhat similar effect to putting 'top
cut' on your amplifier tone control.
The ideal mid/high frequency reverberation times ( a measure of
acoustic 'brilliance' or 'dullness') are somewhat subjective, but
generally a good balance can be obtained by opposing a reflective
surface with an absorbent one. As an example ceilings are usually
bare and reflective and this can be well balanced by a fitted carpet. An
unbroken wall facing large w i n d o w areas can be broken by a bookcase
on the opposite wall.
When furnishing a new room which is to be used for listening to
reproduced music, it is usually wise initially to underdamp the room
and then add absorbent articles after the correct balance has been
determined.