How to Pick the Right Stand Height for Your Small
Speakers
I tend to prefer smaller speakers -- usually for aesthetics
and convenience, but often for performance, too. This means that, in the ten-plus years
that I’ve been reviewing audio equipment, I’ve come to be known as "the
minimonitor guy," and that many people come to me with questions about this breed of
speaker. Something that comes up often but is rarely written about is how to pick the
right stand height for a minimonitor. As any shopper knows, stands come in many shapes and
sizes -- but which will give you the best performance?
Listening axis
When determining the correct stand height, you must first
find out where your speaker’s listening axis is. This axis is the point on the
front baffle of the speaker that the designer intends to be at the listener’s ear
height. In fact, when a speaker’s performance is measured, it usually produces the
smoothest, most linear frequency response when the measuring microphone is aimed at this
point.
Unfortunately, the listening axis is not something
that’s usually published in the speaker’s specifications, or even much talked
about. It is, however, something that the manufacturer, or a knowledgeable dealer, should
be able to provide if you ask about it. Barring that, there are some general rules you can
go by to figure it out.
Most small speakers are two-way designs, meaning that they
have two drivers: a tweeter and a mid-woofer. Occasionally, I see three-way stand-mounted
designs: a tweeter, a midrange driver, and a woofer. In both cases, though, the most
common driver configuration places the tweeter highest on the front baffle. That’s
important -- in many speakers, the tweeter height is the listening axis.
But, fairly often, the listening axis is a little below
the tweeter: for example, in a two-way design, the midpoint between the tweeter driver and
the mid-woofer. Likewise, I’ve seen speaker designs where the listening axis is a
little above the tweeter. In such cases, as you’ll see below, it means that the
speaker is designed to go on a short stand, and thus be less likely to be obtrusive in the
listening room. Never, though, have I seen a two- or three-way design with tweeter on top
where the listening axis was at the woofer height. If a designer did that, it would mean
that the speaker would have to be placed on quite a tall stand to sound right. I have seen
one speaker whose listening axis was at the mid-woofer: PSB’s Platinum M2, in which
the mid-woofer is over the tweeter and the listening axis is, indeed, at mid-woofer level.
However, designer Paul Barton did special things to get the correct response at the
mid-woofer height; otherwise, the M2 would have needed an awkwardly tall stand to get its
tweeter at ear height.
But speakers such as the Platinum M2 are the exception, not
the rule. As I said, for the most part, the tweeter height is usually the listening axis;
if you don’t get any information from a manufacturer or dealer that says otherwise,
that’s as good a place as any to start.
Ear height
The next thing to determine is your seated ear height at
the listening position. Some may be tempted to sit in their favorite listening chair and
measure the distance from their ear canals to the floor, and that might indeed be the most
accurate way to go about things for your particular setup. But using an average ear
height is often just as good, particularly if the speakers will be listened to by more
than one person.
In my experience, based on all the speakers I’ve
reviewed over the last ten years, that average height is 36-38" from the floor. But
in preparing to write this article, I polled a few designers as well. All said that they
design their speakers for a listening axis 37" above the floor -- the exact midpoint
of my average range. I also measured two floorstanding speakers that I happen to have in
my room right now. Sure enough, the height of the listening (tweeter) axis for both was
37".
The goal, then, is to use stands that lift the speakers
high enough to get the listening axis at the proper ear height.
Stand height
Let’s put this together with an example. We’ll
aim for a 36" listening height, at the low end of my range, and we’ll assume
that the speaker’s listening axis is at the tweeter height.
First, measure from the center of the tweeter to the bottom
of the speaker cabinet -- let’s say that dimension is 12". Second, subtract that
number from the ear height: 36" - 12" = 24". Therefore, you’ll need a
24"-high stand to raise that speaker high enough to place the tweeter (listening
axis) at ear level, or 36" above the floor. You could use a 26"-high stand,
which would put the tweeter 38" above the floor: 26" + 12" = 38".
That’s still within the average-listening-height window and, in my opinion, is wholly
acceptable: With a well-designed loudspeaker with good lateral and vertical dispersion,
you don’t have to be that exact.
However, if the cabinet was shorter, there was only
11" from the tweeter to the bottom of the cabinet, and you used 24" stands, that
would mean the tweeter would be only 35" above the floor. While that might still be
acceptable for some, it might be far enough out of the average range to -- depending on
the speaker’s design -- cause problems. For example, when the tweeter is too low, the
top end might sound dull and the soundstage too close to the floor. In such a case
I’d opt for 26"-high stands to get the listening axis 37" above the floor.
On the other hand, if the speaker’s listening axis is, say, an inch or two above
the tweeter, that means it’s designed to sit closer to the floor, and should sound
fine on a shorter stand. Therefore, a 24" or even a 22" stand might do.
That’s why you need to know what your speaker’s listening axis is.
Conclusion
Unless you place your small speakers on a bookshelf or
mount them on a wall, stands are a necessary evil. However, there are plenty of good
stands on the market, in a variety of shapes, styles, materials, and, of course, heights.
When you buy, though, don’t go by looks and design alone. Instead, get the stands
that will not only fit your décor, but will allow you to get the most performance from
your speakers by placing them at the right listening height. Asking a simple question
about listening axis and making a quick calculation is all you’ll need to do to get
it right.
...Doug Schneider
|
