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Peter Wieck Peter Wieck is offline
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Default Subwoofer in phase ...with only one speaker

On Nov 17, 8:56 pm, Greg Wormald wrote:
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


Greg:

All good stuff.

Fid:

There is one quick-and-dirty expedient you can try to help focus on
the direct causes of your problem without ripping your room apart.

Obtain a square piece of 3/4" (20mm) plywood or MDF with its main
dimension about 1.25 x the diameter of the main speaker woofers. Line
both sides of it with either a deep-pile carpet or a dense foam
rubber. Make it on a stand so that you can put it somewhere and it
will stand vertically without additional support.

Place it at several points adjacent to your SW or main-speaker woofers
or between them and see how/if anything changes. It is just a baffle
to break up the sound waves and give you an idea of what is going on.

Best of luck with it. You may have to defer to the Decorator Entity in
your household and beg for a Dispensation to get things moved about.
Been there, done that. A pair of AR9 speakers went by the wayside as
they simply *did not fit* into the room in such a way as to be
tolerable for listening. The pair of 3as fit nicely but are of a very
different nature.

Peter Wieck
Wyncote, PA