| Video Noise September 2007
 Is Audyssey the Next Big Thing in Home Theater Audio?
I am currently getting my first exposure to Audyssey Laboratories’ automatic
calibration and equalization system. My new Onkyo A/V receiver includes MultEQ XT,
Audyssey’s current top-of-the-line software for consumer products. MultEQ XT uses the
DSP already built into a receiver or surround processor to run the Audyssey calibration
and equalization software.
In recent years there has been a steady trickle-down of
features from expensive home-theater AVRs or processors to lower-priced models. You once
had to spend $2500 USD or more to get a machine with very basic auto-calibration
capabilities. Today, many $300-$400 AVRs have more auto-calibration power than those early
models.
Audyssey MultEQ XT improves on simple auto-calibration by
adding room-response corrections, time-domain error correction, and the ability to
properly analyze measurements taken at three to eight different positions to optimize a
system’s overall response for all of those locations. Other systems simply
average the errors, often leaving you with little or no correction for many problems.
Audyssey says their system uses "fuzzy logic" to improve every measured location
as much as possible.
I was skeptical about this -- until I learned that one of
the Audyssey principles is Tomlinson Holman, who first hit my radar when he worked with
Henry Kloss at Advent. Holman then founded Apt, designing and manufacturing highly
regarded solid-state stereo preamps and amps. After that he joined George Lucas at
Skywalker Ranch, where his work to improve cinema and home-theater audio became THX (whose
name includes his initials). In addition to his position with Audyssey, Holman is now a
professor of sound and audio at USC’s School of Cinema and Television. The other
Audyssey principles, too, have outstanding professional and educational backgrounds.
The goal of Audyssey’s calibration and equalization
system is to improve the audio experience possible with any home-theater system, from the
modest to the elaborate, and to do so not just for the "sweet spot," but for
every seat in the room. The MultEQ XT’s room-EQ capabilities remove the worst
room-response problems: frequency bands that are too emphasized or too de-emphasized by
room dimensions, surfaces, or furnishings, and/or by speaker placements. Audyssey also
improves the listener’s audio experience by analyzing sound in the time domain,
looking for strong delayed reflections that need to be diminished or removed to let all
the detail come through.
So far, I am mightily impressed. My room was already far
beyond average for a home theater in terms of acoustic setup and treatments. It is in a
basement -- the floor and three of the walls are "flex-free" because
they’re backed by the concrete floor or foundation walls. The ceiling uses very stiff
engineered joists. I use 14 Pressure Zone Controllers (PZCs) -- acoustic tuning products
that hang on the walls, in corners, or at ceiling/wall junctures. Each PZC is tunable via
a bolt in its center. I also use four Argent Room Lenses, which are Helmholtz Resonator
room-tuning devices. Despite all that tuning, simple SPL readings with a handheld meter
make it clear that the room is still not perfect. Nor is any room perfect, even those
designed from the start for good sound.
Using Audyssey MultEQ XT to calibrate three positions takes
less than ten minutes for the measurements, and another five minutes or so for the
software to calculate the proper level, equalization, and time-domain corrections. Once
that’s done, you can use your receiver’s menu to turn MultEQ XT on and off to
hear the differences.
With MultEQ XT turned on, the sound quality of my room is
freaky good. The "echo game" sequence in House of Flying Daggers
(Blu-ray, uncompressed LPCM) is dramatically improved: Individual drum sounds are much
more distinct, with no boom. When the bowl of beans is thrown, the surround effect is far
superior, with much more detailed locations, and sounds that are far more individually
distinct than is possible in my room without MultEQ XT. Overall, the change in sound
quality is significant but difficult to quantify. My system, which includes seven speakers
and five subwoofers retailing for about $15,000, sounds significantly better with the
Audyssey software turned on. Bass-response problems have simply vanished -- I now
experience levels of bass detail and impact I’d never been able to achieve before.
Audyssey MultEQ XT can be used with any surround or stereo
mode your AVR or processor has, with the exceptions of signals from any analog inputs that
have not been redigitized (such as some analog stereo inputs, and many multichannel analog
inputs from DVD or hi-def disc players).
Keep your eye on Audyssey. Their MultEQ XT is so good, I
now can’t envision using an AVR or processor without it -- until something better
comes along. But that’s likely to be years down the road, and when it does come
along, it may very well be from Audyssey itself.
...Doug Blackburn
db@hometheatersound.com |
