Loudspeaker Room Placement -- Part 2
Dear Wes,
I am an audio enthusiast from Athens, Greece. My listening
area is quite small (13 square meters) and I have placed the speakers on the wide wall.
The room is covered with wall paper and a lot of paintings
My listening position is at two meters and the speakers are
about 85cm from the back wall and one meter from the side walls. I have tried to apply the
"rule of thirds" to the best possible outcome given the limited space available.
The speakers are not toed at all and there is no space behind the listening position, only
a big painting covering the wall behind me.I know the room is almost a disaster, almost
anechoic with very little to none reverberation. Now comes the problem:
I mainly listen to classical music. Romantic composers, but
in addition, small ensembles and Lieder, plus ECM Jazz and the glorious Miles. I like the
music to be laid back and very transparent without loosing anything as far as dynamics and
involvement are concerned. The problem is that currently what is missing is the
"flesh" and "juice" of music. Any recommendation on changes of
interconnects, speaker cables or speaker positioning would be of great help.
Just a last comment. Before my Mini's I had the B&W
Silver Signatures and the effect was quite the same.
Please help
Regards,
Dimitris Lykouressis
In Part 1 of Loudspeaker Room
Placement, I wrote about a way to calculate speaker placement in a fairly sizable
room. However, as Dimitris points out, not everybody has a big room to work with. What to
do?
One approach is put forward on Immedia’s website (www.immediasound.com) and is based
upon the combined set-up experiences of Immedia’s Alan Perkins, Audio Physic’s
Joachim Gerhard, and a number of Immedia’s dealers who have mastered the arcane art
of speaker placement. For their version, check the website, what follows here is my take
on the basic technique, which varies slightly from theirs. This approach, based upon the
Haas effect, calls for the listener to sit within two feet of the wall.
The Haas precedence effect involves the way the brain
processes sound, specifically the way the brain determines the localization of sound. If a
short transient sound, say a click, is perceived by one ear, and then milliseconds later,
by the other, then the brain will determine the sound to have been located on the side of
the head where the first sound originated. If a sound arrives at a listener’s ears
from two locations -- as happens in concerts with multiple speaker columns or in a room
where direct and reflected sound reaches the ear at extremely short intervals to one
another -- the sound will be perceived as coming only from the location (the speaker) from
which it arrives first. The sound from the other speakers (or the reflected sound) will
not be perceived at all. Perkins and Gerhard maintain that this will happen -- that is,
the brain will ignore the arrival difference between the direct and reflected sound --
when the distance from the reflection to the ear is no greater than the circumference of
one’s head. You can measure for the exact distance if you want, but two feet is a
good rule of thumb.
This method works best if you align the speakers and your
listening position along the room’s long walls. Start with the listening chair at the
room’s halfway point, two feet or less from the rear wall. Now quarter the front wall
and mark the 1/4 and 3/4 points with masking tape. Quarter the room’s width and again
mark the 1/4 point from the front wall. Where the marks intersect, set up your speakers.
You now have the two loudspeakers extremely wide apart -- so much so that it will look
wrong.
But you’re not done yet. Now you need to feed a mono
signal to one speaker at a time and listen as you adjust its position inch by inch toward
the wall. Any solo instrument or unaccompanied voice will do the job nicely. As you move
the speaker toward the wall, you’ll hear it lose clarity and sound thick. Stop. Mark
that position with masking tape. Now move the speaker toward you and continue listening --
when the speaker develops a "hollow" sound, stop again. Mark it with tape. Now
move the speaker inch by inch toward the side wall until you hear the sound thicken, and
mark that point. Move the speaker toward the center of the room, listening for the
hollowness to develop again and put down your final marker. You now have a box that
defines where the speaker sounds its best. Work within it to get the best sound you can
and go through the entire process with the other speaker.
Once you’ve established their room positions,
reconnect both speakers and listen to the same solo recording while adjusting the speaker
toe-in. When the sound pops into focus and you get a solid sounding instrument or singer
in the middle, you’re done.
You might consider draping a towel or some curtains on the
wall behind your listening position to further mask reflected sound. RPG Abfussors also
work a treat, if you can afford them and your current lifetime companion will allow it.
The soundstage will be huge and incredibly solid with this
placement scheme -- another plus in a small room.
Now we’ve covered two fundamentally different
placement schemes, but they both assume you have a symmetrical room. What if you have an
open-living plan household, or an ell-shaped room? We’ll cover that in Part 3, which
will go up on September 15th.
...Wes Phillips
wes@onhifi.com
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