The
Legacy Aeris is a great speaker by any standard, and I can see why
Robert Harley recommended it so highly after a listening session
at the Rocky Mountain Audio Show [Issue 230]. It is a truly full-
range speaker, with bass deep into the subwoofer region, outstanding performance at
every frequency to the limits of hearing and beyond, excellent denition, outstanding
dynamics, and a visual image that might win it an entry to the Museum of Modern Art
in New York.
It comes with separate 500-watt ampliers dedicated to each bass driver with a
crossover point low enough that you can still get the best sound out of your regular
power amplier, and it has a very well chosen mix of drivers that provides a coherent
and naturally detailed sound at any reasonable listening distance, as well as enough dipole
radiation to widen the stage and reproduce more natural ambience.
And yet, these are only half of the reasons I’m excited about the Aeris. Bill Dudleston,
Legacy’s chief engineer, has produced some other excellent speakers, but the Aeris
breaks new ground in what for me is the most important frontier in high-end audio:
It comes with the Aeris Wavelaunch processor that allows you to tailor the frequency
response to be as musically realistic as possible in a real-world listening room.
The Aeris Wavelaunch processor is an electronic unit that goes between your preamp
and amplier. It gives you up to 30 settings that you can use to adjust the sound of
the speaker to correct room-interaction problems, partly correct for over-bright, close-
miked older recording, and even—if you are fanatic enough—compensate for the
different equalization curves in LPs.
Music vs. Technology
Most experienced audiophiles will already be well aware of just how serious room-
speaker interaction problems are with more conventional speaker designs. Back in the
1960s, Roy Allison pointed out that low-frequency response in any normal listening
room will look like the Alps no matter how accurate the speaker is in an anechoic
chamber, or when measured so neareld that room interaction problems are minimized.
There are always peaks and valleys well in excess of 5dB, and almost always serious
colorations from such peaks and valleys in the midbass, where the impact is clearly
audible. There also are smaller response and reection problems that affect the rest of
the upper bass, midrange, and upper midrange. These can be corrected to some extent
by adjusting the location of the speakers and listening position and by room treatment.
I have never measured anything approaching a normal home listening room, however,
where such preventative measures eliminated such response problems.
Moreover, “at response” measurements inevitably create a musical sound that is too
hard and bright. A single response or target curve also cannot correct for the fact that
recordings differ sharply in timbre. This is particularly a problem for classical music fans
because today’s all-too-typical close-miking, while dramatic in apparent detail, produces
an upper-midrange hardness that is often a cause of listening fatigue when a speaker is
voiced for “at” response and placed in a real-world room.
Designing individual components for at measurements and then voicing them for the
best musical performance has severe limits. First, technical measures cover only a relatively
limited part of the “error budget” of problems detected by the human ear. Second, any
front-to-back walk-through in a concert hall will tell you immediately there is no one “at”
response—and that what you hear on stage is not what you hear live. Third, no one lives in
a concert hall. Even a custom-designed listening room is susceptible to signicant speaker-
room interaction problems unless the system can be equalized to deal with them.
The good news is that we have learned to be tolerant of such colorations, and speaker
designers now almost universally use the crossover in their speakers to act as a passive equal-
izer to both improve frequency response and musicality. The bad news is that audiophiles
as a breed are far less tolerant than others. This helps explain why audiophiles often talk
about speakers as the most colored component in a stereo system, why they keep changing
speakers, and why listening to a speaker in a large showroom where the speaker is precisely
matched to the room doesn’t guarantee that it will sound as good when you get it home.
No one can solve these problems
simply by changing speakers or listening
rooms. Our perceptions are not shaped
by the character of the speaker or
the listening room per se, but by the
interaction between them. Moreover, this
same interaction means no combination
of front-end gear, no matter how good,
will be voiced with the nuances that best
correct for these problems in speaker-
room coloration. As a result, the search
for the best high-end sound inevitably
means consciously or unconsciously
tailoring the system around the speaker-
room interaction problem as well as
nding the best-sounding individual
components.
In the past, most equalizers that tried to
reduce these interactions created as many
problems as they solved. Older analog
equalizers could partly solve truly critical
room problems, but were often badly
colored themselves. They also altered
dynamics, and took some of the life out
of music. Furthermore, they could only
affect timbre and not the other problems
in getting the best signal at the listening
position like phase and time.
A few pioneers have addressed such
problems with considerable success.
Richard Vandersteen, for example,
designed speakers with built-in
subwoofers that could be corrected to
deal with many real-world problems in
the bass below 100Hz without coloring
the rest of the speaker’s response. Firms
like TacT Audio and Audyssey developed
digital equalizers that address most of the
problems in response, make automatic
room corrections, and adjust some
aspects of time and phase.
Manufacturers like Rives have
improved analog equalizers to the point
where any colorations are so inaudible
that the benets outweigh the drawbacks.
As Robert E. Greene points out in a
recent review, the DSpeaker Anti-Mode
2.0 Dual Core room-equalization system
provides the rst truly affordable room-
correction system that can be inserted
into any normal home system, although
it has some limits in digital headroom and
input exibility.
