GRAND ILLUSION - PART I
by Steve Deckert
of us have different criteria for judging and enjoying high fidelity
playback systems. For some it is overwhelming volume and dynamics
- trying to re-create the live performance in it's proper scale.
For others it's imaging and soundstage - trying to re-create the
live performance in it's original space. For some it's both.
paper will deal with observations relating to the desire and ability
of all audiophiles to re-create the original performance as close
as possible on their playback systems. It will discuss imaging,
soundstage and recording techniques as well as try to determine
what is reasonable to expect and what is not.
enough we all admit to wanting to create the illusion of live music
in our living rooms, but each go about it in different, usually
unsuccessful ways. A reason for the lack of consistency in technique
could be a lack of understanding of what it actually is that you're
trying to re-create. Obviously before you can make any serious moves
in the progress of your playback system or it's setup, you have
to know exactly what it is you are trying to accomplish.
of the first things to consider are the types of performances you
wish to re-create. Live Rock Concerts, Small Jazz Clubs, Live Classical
works or perhaps small instrumentals?
order to increase your chances of success, you might want to choose
one that has some chance of being recreated in your listening space.
Naturally if you have a small listening room in your home, it's
going to be difficult to actually recreate the live pressures, and
space of a large rock concert or classical symphony.
is very much a room size issue and a listening style decision. For
example, given most peoples idea of a proper listening room setup,
it would be rather difficult to re-create a full orchestra in your
16 x 24 listening room. Even more difficult would be a 12 x 15 room.
goal is to hear the recording and nothing else. To do that you must
make pain staking efforts to NOT hear your room, or artifacts generated
by your speakers and electronics. Well right there you're screwed
because your listening room is responsible for altering 60% of what
you hear from your playback system. Low level ambiance cues and
harmonic trails that give a recording it's sense of space will be
drowned out by the tones and resonance's of your listening room.
your room is going to be the biggest key to your success or failure,
you want your room to be generally as large as possible, and of
course acoustically compatible with your intended setup. If you
were to dedicate your room to your playback system and one listening
chair and got very serious about acoustic treatments that started
with the basic architecture of the room you could get fairly close
to the grand illusion some of the time.
if not, you have to make some choices as to how you set up your
listening gear. Most of us would like to have it sound like the
musicians are actually there in the listening room between and behind
the speakers, while we sit 8 or 12 feet back (a psychologically
safe distance). This only works in rooms that are around 500 square
feet or larger unless you don't care about scale. It is possible
to create a miniature scale illusion of the performance that is
very pleasing but it will never give the illusion of being real
because the scale is off.
smaller or normal size rooms, you have two ways you can setup your
speakers and listening chair for the grand illusion. One works and
one doesn't. The common way, where you try to bring the performance
into your room can be replaced with a near field setup that largely
reduces the negative effects of your listening room acoustics on
the recording. In a near field arrangement, you are transported
to the performance and the size of your room has little bearing
on the illusion. In this setup, any kind of recording can be properly
Grand Illusion is what every audiophile and high end manufacture
chases. Few actually master one, as they seem fragile and hard to
maintain with consistency. That doesn't keep us from trying though,
and it is the intent of this paper to help people understand what
it is that they're chasing. Most audiophiles chase their tails because
they've never actually considered what is possible and what is not,
let alone how to correctly judge results.
speaker manufactures have concluded that the evils of your listening
room acoustics will always be a reality and try to use your room
acoustics to enhance the sound. Obviously the perfect way to listen
would be to hear only the direct sound from your speakers, not the
reflected sounds of your room. Headphones being the closest thing
I can think of to that ideal. However, the delivery system of headphones
is incapable of creating the illusion of depth from a sound stage
that exists in space in front of you (vs. inside your head).
stands to reason then that if you're listening to your speakers,
the louder you play them, the louder the reflections and other nasty
acoustic issues of your room become. In contrast, if you were to
listen to your system set up in a near field arrangement late at
night when the noise floor is lowest, you would be about 100 times
more likely to witness the grand illusion.
are wondering what specifically I mean by near field so let me site
an example. In a 13 x 15 dedicated listening room, you would place
your speakers around 6 to 7 feet apart and your listening chair
about 3 to 4 feet back from the speaker plane. The speakers would
be toed-in to intersect at an imaginary point just in front of your
nose, or just behind your head. When you sat on the very edge of
your chair and reached forward you would be just about able to touch
your speakers. There would be about 4 to 5 feet between your front
wall and the speakers.
that use your room, or more specifically the walls in combination
with direct radiation often are more successful in getting close
the grand illusion than conventional designs. Bipolar and or panel
speakers being a good example of this, create their own illusion
of space and size using your room dimensions to dictate the accuracy
of the results. Any sound you hear from your room is not sound true
to the recording because it becomes imbedded with new spatial and
timing cues. If you are the type who feels secure only when perfect
accuracy is achieved, these types of speakers would insure that
it never happens. But, as you will someday discover, the grand illusion
has little to do with perfect accuracy, or the specs of your playback
the perfect illusion requires much more than the right speakers
and room setup, it is in fact a fragile balance of your entire audio
chain and always in the hands of the weakest link. This can be cables,
amplifiers, preamps, sources, speakers, room, listening style, dirty
power lines, ambient noise levels, or the most common of all, the
interaction of all the gear in your audio chain with each other,
better known as synergy.
the weak link is usually all but impossible unless you take suspects
one at a time and do careful documented replacements of each and
analyze the changes.
that you have a playback system and room that stands a chance at
creating the illusion, you need to start thinking about a way to
measure the results so you can continue to tweak things in the right
direction. This is where many audiophiles who've been fortunate
enough to have the money to buy great gear get lost. They get lost
because they have no real reference.
simple grand illusion would be to set a stool between and behind
your speakers and record a singer or musician playing an acoustic
instrument in your room. The recording would be done using a stereo
pair of good ribbon microphones and recorded live onto two tracks.
The recording would then be played back using the two track machine
as your source. This simple recording would carry the acoustic signature
of your room, so when it is played back IN your room it pending
the quality of the gear involved could become the grand illusion.
that ideal as an example, you need to have a long hard think about
what you're listening to. Recorded CD's and LP's from major or popular
artists are an illusion in themselves in that you'll never know
if what you're hearing is accurate or not.
is a large contributor to the fact that audio playback systems are
judged subjectively. If playback systems were all setup and optimized
to transport you to the performance and we all had the same live
two track recording to listen to, and we all had been to the actual
performance at the exact time it was recorded and all sat just below
the microphones it would be about a 1000 times easier to judge the
quality and accuracy of high fidelity playback systems. It would
certainly be nice from the perspective of reviewers in magazines
who's information is usually all but worthless in letting us know
what that same gear will sound like in our homes.
the first high fidelity playback system was married with the concept
of stereophonic recordings it was demonstrated and measured in an
auditorium where live classical works were performed for a live
audience. The recording technology of the day was inferior so they
wired the recording to another auditorium in real time. The second
auditorium was outfitted with speakers on the stage arranged in
a stereo array and played to a live audience. That was the first
Grand Illusion, and was very enthusiastically received.
it is neither practical or possible for most to create live recordings
in their own listening rooms, or listen to recordings that they
themselves have made in world class studios it is all but impossible
to accurately rate the accuracy of your playback system. That is
not to say it is impossible to create a good illusion, just difficult
to know if that illusion is fictitious or based solely on the merits
of the recording.
most of us have only CD's or LP's to listen to, and most of us have
not had the luxury of attending multiple live performances, the
better we understand exactly what we're listening to on a recording
the better chance we'll have of tweaking our systems to achieve
a consistent and accurate illusion on all good recordings.
you're in a small untreated listening room, sitting far away from
your speakers you have no chance of creating the illusion regardless
of the quality of your gear, so don't waist any more money trying
to get there. Learn to listen in the described near field arrangement
and do it on gear that is conducive to lucid soundstages. Don't
expect to chase the grand illusion in a family room with all the
associated comforts of home, or in a home theater/stereo system.
The grand illusion is the summit for only serious climbers who are
willing to dedicate a room to the task.
part II of this paper we will discuss recordings and how they effect
imaging and soundstage accuracy, and or how they effect the illusion
of imaging and soundstage accuracy. Once you discover what a recording
is, you can learn to hear what's probably right, and probably not
right with your playback system on most decent quality recordings.