[Greg Wormald]

In article , fid
wrote:

Thank you for your replies and suggestions. Finally I start to
understand something...

snip

Obviously I have standing waves bigger than I can handle. If I
increase the sub level even at the lowest crossover setting it will
increase proportionally also those peaks.

I understand that moving the speakers around would change things, but
my living room is cluttered, that's why I need to learn alternatives,
if there are any.

The bass energy in a room is much harder to tame than treble, and
increasing it by using sub-woofers makes room dynamics more critical.
IMO the best way to tame resonant frequencies (either reinforcements or
cancellations) is by shifting speakers and furniture. Standing waves
depend on the shape and size of the room as well as the use of large
furniture to break them up or absorb bass.

Sound in general does not respond well to speakers in corners, this
gives great reinforcement to bass frequencies. I prefer to block the
corners with chairs, book cases, etc.

As sound leaves a speaker, it spreads out depending on the frequency.
High treble beams almost straight out in a narrow path, often only 10 or
15 degrees wide. Lower bass goes around corners easily and will leave
the vicinity of the speaker in almost 360 degrees.

So putting your speakers in the corner reinforces the bass up to 4 times
with reinforced frequencies dependent on the distance to the side and
rear walls (as well as to the floor and ceiling). There used to be a
good computer program (BestPlace) that calculated all these
reinforcements.

Taming the bass, and the reflections of all frequencies from flat hard
surfaces, does mean rearranging, but changing room acoustics does make
for dramatic differences.

Have fun.

Greg