Loudspeaker Room Placement -- Part 3
Wes,
I wanted to thank you for your reply to my question about
speaker placement and I will look forward to the further parts of your response because my
room is definitely not a simple rectangle! Which is one of the reasons I could never use
the Golden Mean process found at the Cardas website (great reading btw).
I have an open floorplan, with the speakers on the short
front wall which is the low point of the ceiling -- just as Bob Harley recommends in his
great book. I sit about 1/3 of the way into the room from the back wall (sounds the best
here although aesthetics also counted for something). In a room like this I guess there
just isn't going to be any pat formula to utilize because the variables are just too
great. But still, putting the speakers close to the front wall does seem to clash with the
consensus (as I read it) that speakers must be out into a room to sound their best.
Regards,
David W. Hoffman
Well David, this time out, we’re going to be working
with actual room boundaries, so here’s where all of us with ells and open-plans get
to play.
This placement scheme is a variation of the placement
method used by David Wilson -- I learned it from Mark Goldman when he visited my old
apartment in Brooklyn with a pair of WATT/Puppies. Although it can be carried out by one
person alone (more on that later), it’s easier if you have a friend to help you.
Choose an orientation -- probably you’ll want to place
the speakers along one of the short walls if your room is rectangular. However, don’t
hesitate to try the long wall if the short wall doesn’t work, or if it makes the room
work better for your non-audio activities. Now choose a rough seating position somewhere
between halfway into the room and two-thirds into it.
Here comes the easy part: sit down in your listening chair
and have your friend stand against the wall you are facing, smack dab in the middle. While
he or she is talking, have your assistant take half steps out from the wall. When you hear
his or her voice "clear up" -- that is to say lose its chesty, near-boundary
affect, mark that point with masking tape. Have your assistant continue walking into the
room while talking until his or her voice loses clarity and develops an echo-ey tinge.
Mark that spot too. You have now designated a band that runs from side wall to side wall.
Have your assistant stand within that band against either
side wall and repeat the process of taking half steps into the room while facing you and
talking. Mark the "clear" point and the point at which the sound goes
"swimmy" on you. Repeat on the other side.
You are not looking for symmetry here -- you are trying to
determine two zones where the speakers will sound their best. Since your room isn’t
perfectly symmetrical, there is no reason to assume your speaker placement will be.
You can, if you wish, lay out a grid within your two zones.
If you’re a meticulously anal-retentive type, you can lay out a half-inch grid (and,
being audiophiles, of course we all are); otherwise, go for one-inch or two-inch
increments. Set one speaker down at the rear line of your grid and play a recording of a
solo instrument or voice through that channel only -- Mark Goldman used a recording David
Wilson had made of a honk-tonk (tack) piano, which worked well, but any solo instrument
will do.
Sit in your listening chair again and have your assistant
move the speaker toward you square by square on the grid. This is time consuming and
boring, but you will hear subtle changes in focus over the grid area. Choose the location
where the instrument is most clearly focused and then repeat with the side to side
placement within your zone until you’ve optimized that as well.
Unplug that speaker, and repeat the process with the other
channel. When both speakers are placed as well as you can manage, plug both channels back
in and play the disc again. You should have an incredibly solid center image of your solo
instrument now. But you’re not quite through -- now you need to adjust toe-in. After
the ordeal of determining solo speaker placement, this is a breeze. You just wait for the
image to "snap" into focus and you’re set.
What you will probably end up with is a wide isosceles
triangle that encompasses the two speakers and your listening chair, with the speakers
toed-in so their faces are pointing almost directly at the chair. When you’re seated
there, you’ll see little, if any, side wall.
David Wilson once described this to me as "eliminating
the room from the equation," which isn’t possible, of course. But what you have
done is ensure that your first arrival is all speaker -- by placing your listening chair
away from boundaries and focusing the speakers away from their adjacent walls, you’ve
controlled the boundary effects about as much as possible (just as we did in Part 2). And, since you’ve used the speakers themselves to
make the boundary adjustments, it works just as well with stand-mounted speakers as
floor-standers.
Oh yeah, I did say that you could do this solo, didn’t
I? Well, you can do the early zone determination by placing a single speaker in your
listening position and walking out from the walls while listening to it. Since room modes
are symmetrical, you’ll hear the same effects and be able to mark your zones without
an assistant. But you’ll have to do the fine tuning of the speaker placement by
placing the speaker on the grid, moving it, sitting in the chair and listening -- and
doing it again and again. Tedious? Yes, but possible.
And when you’re done, you’ll have a huge
soundstage with a lovely openness and timbral accuracy. You haven’t so much
eliminated the room as worked with it. And when you’re not fighting your room, you
can hear precisely why you bought your stereo in the first place.
...Wes Phillips
wes@onhifi.com
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