[darth nut]

[size=medium]STAX SR-007 (OMEGA II) … A REVIEW
AFTER 4 YEARS OF OWNERSHIP[/size]

[size=xx-small]A madman is one who ‘hears voices in his head’.
Headphone-user: ‘you calling me a madman?[/size]




In September 1999 I posted a review of STAX
SR-007 (Omega II) headphone at HeadWize.


I wrote as detailed and exhaustive a review as I
could manage at the time, with the target audience
being obsessive headphone-users who had, like
me, noticed the strange addictive joy of being
immersed in a small cranium-bound soundfield that
oddly pulsates with life; a soundfield that for all its
smallness paradoxically triggers our imagination to
‘see’ large acoustic spaces.


Four Christmases have passed since that 1999
review. Pleasant and unpleasant things have
happened in my personal life during these past
years; the chief unpleasant thing being the sheer
fact that I have aged four years, and the chief
pleasant thing (so I console myself) being that I
have grown four years wiser.


(Just in case you are wondering, I am 38 now.)


At the time of my 1999 review, I thought that the
number of interested readers could be counted
with one hand— back then I just didn’t think that
there were that many people interested in high-end
headphones who also frequented headphone
forums. Today I am gleeful to see how many fellow
headphone enthusiasts there are out there, judging
from the activity here at Head-Fi. I am also quite
amazed to observe how many owners of high-end
headphones and high-end amps there are who are
presently “visible” in the forums, compared to the
scant few back in 1999.


I have disappeared for a long time from HeadWize
/ Head-Fi. I found that writing a post, especially a
full-length review, to be quite consuming, which
was another reason why I stopped posting for a
long time. It’s simply far more relaxing to disappear
from the forums and enjoy my headphones. But
lately I came back as a forum lurker, and have
enjoyed reading dozens and dozens of threads.
There are many intelligent members here, and I
was entertained and educated by the experiments,
insights and exchanges (some heated) posted by
headphone enthusiasts from all over the world.
The folks who go back to HeadWize days may
remember me—I suspect most people here at
Head-Fi either don’t know me or know me only as
a ghost from the past. I wish to say hi to everyone.



________________________________
WHICH READER AM I ADDRESSING?


Because a headphone forum comprises of
different people with all sorts of headphone
experience levels and all sorts of listening habits,
I had to be clear in my mind for whom I was
targeting this write-up.


This essay is rather detailed, and unfortunately
may be difficult to digest. I have tried my best to
sequence the flow of this essay such that the
reader is gently, gently eased into increasingly
complex concepts. But what I’ve not done is to
dumb down the essay. I resisted the urge to
simplify the concepts because I do not want to
short-change those readers who are highly curious
about I have to share here.


Readers who listen predominantly to close-miked
music (such as rock and pop) may find the
concepts rather alien and detached. Headphone-
users who listen predominantly to close-miked
music are more apt to go “so what?” or worse
“what ******** is this?” to a large part of this article,
because the things mentioned here lie outside of
their scope of experience. If this describes you, I
hope you can suspend disbelief just for the
duration of this article, so that the knowledge
gained from this write-up would lie dormant in your
memory. In some future moment when you least
expect it, you hear something either at home or at
the audio shop (or at a Head-Fi Meet perhaps?)
that will remind you of what you read here.


Readers who habitually listen to music with a lot of
ambient cues (such as live jazz, orchestral and
choral) will more readily understand how the
spatial subtleties mentioned in this write-up relate
to headphone listening. Such readers may have
less problems diving into the intricacies elaborated
later on.


Readers of my review of the Omega II written 4
years ago may remember that I have used the
term “headstage” before, but I did not manage to
explain its meaning clearly in that review—hence
some readers may have been puzzled as to the
purpose of its inclusion then. I apologize for your
warranted puzzlement. In this current write-up I
have finally succeeded in nailing down the
meaning of “headstage” in no uncertain terms.
Additionally, I have found a way to explain the Four
Depth Cues in a clear and communicative manner.
(The Four Depth Cues first appeared in my
archived essay at HeadWize’s Library, but this
current write-up takes it one step further by having
a headphone review structured on the Four Depth
Cues.)


It has taken me years to crystallize these concepts
into a consistent framework. I am happy to share
with you today the fruits of my labour.



___________________________
OBJECTIVES OF THIS ARTICLE


The objectives of this write-up are twofold:


Objective 1: to share my feelings of the STAX SR-
007 (Omega II) after 4 years of ownership. Am I
still happy with my purchase, now that the new-toy-
syndrome has passed? A comprehensive review of
a product owned after a passage of time must
surely furnish a better indication to another
prospective buyer of that product’s worth (or lack
thereof) than a review written during the
honeymoon period. Also, it is fiendishly difficult to
accurately describe the sonic character of a
headphone—any headphone. A few of my detailed
observations now differ from those I made in 1999.
Back when I was active in the forum, there were
instances where I promoted this headphone as the
best headphone in the world. But today, as a jaded
forum lurker, I wonder about the fruitfulness and
sensitivity of such claims. There are so many
marvellous headphones out there—with a fan base
for each of them—why tell others that one and only
one headphone is the best? Is there such a thing
as a single best headphone for everyone anyway?


Objective 2: to persist in an even bigger project of
mine, which is to attempt to advance the
development of an adequate language to describe
the sound of headphones. The language we use
today has evolved through the decades within the
context of a loudspeaker-centric audio world. A
language specifically for headphones has not yet
been constructed. Some Head-Fiers construct DIY
amps—I construct here a DIY language. This is an
ambitious project; one that I started 4 years ago,
and it is heart-warming to see that a few people
have begun to use the term “headstage” since its
introduction back in 1999. In this write-up, I will be
offering a crystal clear explanation of the term
“headstage”, and then I will be adding even more
words to the lexicon of headphonespeak.


This write-up is therefore not just a simple review
of the Omega II—it is also about the creation of a
new language, new terminologies and a new
review methodology. My review of the Omega II
may at first appear sporadic and strewn all over
this essay, but actually there’s a structure: every
time a new term has been properly defined and
explained, I will subsequently proceed to review
the Omega II using the newly created terminology.
Then I will move on to the second terminology,
define what the new word or words mean, and
then describe the Omega II using the
second set of new words …and so on.


Let’s start.



________________________________
BEFORE THE FOUR COMES THE ONE


First there is the One; then there are the Four.


I will be touching on the Four Depth Cues towards
the middle of this essay, but from the beginning I
want to say that there is one sonic mechanism that
overrides the Four Depth Cues. This One is the
sense of sound localization.


We acquire the sense of sound localization
because our left and right ear each receives a
slightly different input, and by comparing the two
our brain interprets the location of the sound
source. When we put on our headphones, the
headphone transducers are positioned very near
our ears—we can locate the source of the sound,
and we are aware of this proximity of the sound
source. Every time I use the word ‘locate’, I am
referring to this One mechanism—the mechanism
of sound localization. This One mechanism is more
powerful than the Four Depth Cues.


This One mechanism gives rise to the headstage.



_______________
INTRODUCING:
THE HEADSTAGE


I am listening to a section of Beethoven’s Pastoral
symphony (andante movement), and I think there
are 20 musicians packed inside my head. Listening
to music via headphones can be a paradoxical
experience. I know that 20 people cannot fit into
my head, empty as I sometimes swear it may be
during my stupider moments. Yet the steadfast
illusion right now is that there are 20 musicians in
my head.


There are some recordings that make me go “wow,
what a huge soundstage”. But here’s the rub: I
happen to have a wall-sized mirror on one side of
my listening chair. When I look into the mirror, the
illusion of the huge soundstage is stripped away
and revealed for what it truly is: a cramp head-
hugging soundfield. In the mirror I can “see” all
those sonic images sticking to my scalp like a bad
hair-do. I look away from the mirror, close my
eyes, lose all sense of scaled reference to the real
world, re-invest my concentration into the music,
and the huge soundstage re-appears. But when I
open my eyes and look again at the reflection of
my headphones in the mirror, I once again “see”
the scalp-bound soundfield.


I call this soundfield that stubbornly refuses to take
leave of my head the headstage.


The difference between soundstage and head-
stage is illusion and reality. The soundstage is the
(desired) illusion; the headstage the (unfortunate)
reality.


Another way of stating the difference between
headstage and soundstage: headstage is about
the localization of sonic images in relation to your
head. Let’s say you are listening to a piece of
music that contains 3 sonic images. One image is
located at the right temple of your forehead,
another image is skimming the top centre of your
scalp, and yet another image is located an inch
beyond the left earcup. The arena within which all
these sonic images are located is called the
headstage. And it is a tiny arena—I estimate this
arena on the Omega II to be maybe 8” wide and 5”
tall (it could be bigger on your headphone—I’ve
always said that the Omega II has a small
headstage—but more on this later). The sound-
stage is something else altogether. The sound-
stage is the qualitative perception of ambient cues
captured in the recorded music. The soundstage
can be very big, as big as a cathedral nave, if that
was what was indeed captured in the recording.


When listening to headphones we can choose
between perceiving the soundstage or perceiving
the headstage. Your mental concentration can
swing the perception one way or the other. During
moments when we are utterly absorbed in the
recording, all you have to do is to tell yourself to
“snap out of it”, and chances are that you will “lose
sight” of the majestic soundstage. What’s so
majestic when you choose to become aware that
the whole violin section of a grand and majestic
orchestra is only 4 inches wide across your
forehead?


When listening via headphones, most of us choose
to be aware of the soundstage instead of the
headstage, in an effort to distract ourselves from
noticing the cramp head-hugging soundfield or in
an effort to lose oneself in the recording—the latter
is valid and is after all the whole point of listening
to music. But distracting yourself from scrutinizing
the head-hugging soundfield will not make you a
more discerning listener. You have to understand
the head-hugging headstage first, cramp as it may
be, before you understand the soundstage.



_______________________________________
HEADSTAGE: ANALOGY OF A PHOTOGRAPH


What is the headstage, really? First I will put
forward an analogy, then I will offer a working
definition of the term “headstage”.


Analogy: imagine a 5-inch wide photograph
depicting a sprawling mountain scene going on for
miles and miles. A photograph is nothing more
than colour pigments distributed on a flat piece of
paper. There is no mountain on the piece of paper,
nor inside nor behind the piece of paper. The
mountain is in the eye of the beholder.
Furthermore, a photograph does not need to be
mountain-sized in order to depict a mountain.
Additionally, a statement that the mountain in the
photograph is 10 miles away does not contradict
the fact that the colour pigments representing the
mountain are lying flat on a piece of paper.


The two-dimensional headstage is analogous to
the two-dimensional photograph. If a small photo
can depict a large scenery, why can’t a small
headstage portray a large soundstage? And if a
flat photo can depict distance, why can’t the two-
dimensional headstage depict depth?


This is the definition of the term “headstage”:
the headstage is a flat plane, small in size,
positioned vertically such that the plane
intersects both ears, and all sonic images are
chained to the two-dimensionality of this plane.


None of my past articles has offered such a
concise definition of “headstage”.


Please take time to digest this: all sonic images
are chained to the two-dimensionality of the
headstage, much the same way the mountain is
chained to the two-dimensionality of the
photograph.


Why do I say that the headstage is two-
dimensional? In order to be aware that this head-
hugging soundfield is actually two-dimensional,
you have to stop yourself from being swept away
by the soundstage illusion of the recording, and
start to focus on the location of the images in
relation to your head. Your headscape offers
several landmarks that you can reference the
location of the images against. Landmarks on your
head include the front centre of your forehead
between the eyebrows, the front centre of your
forehead where your third eye would be if you
were a Buddha, front top of your forehead where
your hairline is if you haven’t started balding yet,
the left and right temples of your forehead, and the
left and right ears on your head. It may seem
unnatural at first, but try not to focus on the
soundstage cues inherent in the recording, but
instead focus on the location of images in relation
to your headscape.


Then you will realize the truth that all the images
can be located more or less on a flat vertical plane.
Average playback systems will create flatter sonic
images that resemble stickers from a child’s sticker
book. Sonic images are like flat stickers that you
can “paste” on the flat vertical headstage. Superior
playback systems create more rounded, full-bodied
images, in which case the headstage resembles
more an upright rectangular tupperware* within
which all sonic images are contained. (*tupperware
= plastic food container, just in case there’s a
cultural gap here.) But whether it is a flat plane or
an upright tupperware, the point here is that whilst
there is depth in the recording, there is no depth to
the localization of the images.)


I have read accounts of a headphone’s soundfield
as being “a clothesline stretched from one ear to
the other”, or another account describing it as
being “three blobs in the head”. My senses tell me
that both descriptions of the headstage shape are
inaccurate.


I simply don’t perceive the images being located as
if they were strung along a straight line going from
ear to ear, like so many beads on a string. There is
such a thing as height, so the one-dimensional
description of the headstage is something that
contradicts my personal experience. A straight line
going from ear to ear is actually located very deep
in my skull (a straight line going from ear-to-ear is
three inches below the top of my scalp) and the
only time I noticed images located three inches
below the top of my scalp is when I listened to
mono recordings. Stereo recordings create not just
left-to-right differentiation, but also create a sudden
upward expansion of the headstage, i.e., the
creation of headstage height. (If you have a
Stereo-Mono toggle switch on your amp you will
notice that toggling to Mono will collapse the
headstage into a tight-fisted ball deep inside your
head, while toggling to Stereo will not only provide
left-to-right differentiation but also expand the
headstage upwards.) So the description of a
headstage as a thin clothesline stretching from ear
to ear is something I take issue with.


As for the description of the headstage as being
“three blobs in the head”—on my systems (past
and present) I have not heard the three blobs
effect. Intellectually I understand what HeadRoom
is trying to say—it’s just that the three blobs effect
simply doesn’t square with what I have
experienced so far. I suspect that HeadRoom
offered such a stark model (three blobs is a very
stark model) because a more subtle explanation of
the crossfeed mechanism may potentially be lost
on laymen. In an advertisement, you need a clear,
strong message; and the three-blobbed headstage
is as clear a message as you can get: “you don’t
want the three blobs—you want our crossfeed”.
From my experience, the headstage is a smooth
continuum from left to right; and there is no distinct
separation into three separate blobs, unless I was
playing a very old stereo recording—as old or older
than myself. (This is not to be construed as a
comment on the crossfeed mechanism. I am
commenting on the accuracy of the description of
the headstage as being a three-blobbed affair.)


I am prepared to accept a description of the
headstage shape as being a spherical soundfield,
but it is a squashed sphere, more like an oblong
rugby ball: the left-to-right dimension is larger than
the front-to-back dimension. A person who insists
that the headstage soundfield is a perfect sphere
must either get his ears checked or tell us all what
super-duper headphones he is using that can
create not only left-to-right localization but front-to-
back localization as well. (Binaural recordings that
matches one’s personal HRTFs and various 3D-
processing methods lie outside the scope of this
write-up. This write-up is restricted to stereo
headphones playing stereo recordings.)


The description that most resembles my
experience of the headstage shape is any one of
the following: that it is either a flat vertical plane or
an upright rectangular tupperware or an oblong-
shaped ball or a thick fat discus placed vertically.
Whatever shape you choose to describe the
headstage as, the main thing is that this shape has
a larger left-to-right dimension and a very flat front-
to-back dimension. (But if I were to be absolutely
accurate about it, I’d say that the headstage is a
rainbow-shaped arch springing from ear to ear with
the apex of the rainbow at the top centre of the
forehead. All images are located in a smooth
continuum along this rainbow. This rainbow has a
larger left-to-right dimension and a very flat front-
to-back dimension.)


Most headphones create headstages that intersect
the ears. (Meaning to say that the vertical plane or
the oblong ball or the upright tupperware or the
vertical discus or the rainbow intersects the ears.)


But headphones such as AKG K1000, STAX SR-
Sigma and -Sigma Pro create headstages that do
not intersect the ears but instead their headstages
are located perceptibly more towards the front. I
am not so familiar with the K1000, but for the
Sigmas the headstage is about 2 inches in front of
the forehead. This is because their transducers
are, by design, angled perpendicularly and located
more frontally than in other headphones.


This is where I review the Omega II for the first
time in this essay. What about the Omega II’s
headstage?


The Omega II’s headstage does not intersect the
ears, but is located very slightly in front, such that
the headstage is in contact with the flat front of my
forehead. I guess this slightly frontal position of the
Omega II’s headstage (not as frontal as in the
Sigmas though) is due to the headphone’s slightly
tilted diaphragms, such that the headphone co-
opts the ear flaps at an angle, instead of directly
firing the sound straight into the ear canal.


The second thing about the Omega II’s headstage
is that the sonic images are so rounded and full-
bodied, such that the headstage does not seem
like a flat vertical plane, but more like an upright
rectangular tupperware into which all sonic images
are contained. The longer side of the rectangular
tupperware is touching the flat front of my
forehead. (The tupperware is not hovering outside
my forehead—the tupperware overlaps and
protrudes into the front portion of my head. The
frontal lobe of my brain is contained in this
hypothetical tupperware.)


The third thing about the Omega II’s headstage is
that it is small; shockingly smaller than all
headphones I remember hearing. Believers of a
‘bigger is better’ worldview may be in a rude shock.


The fourth thing about the Omega II’s headstage is
the precise way it locates sonic images within the
headstage. Its headstage is small, but it can
paradoxically hold a great many sonic images
without seeming overcrowded. The images are
located very precisely in the headstage—
sometimes you feel as if the images are merely
millimetres apart from each other within the
headstage, but because of the awesome resolution
power of this headphone, mere millimetres is
enough to separate those two images.


We have come to the end of the section on
“headstage”. I hope you feel that the explanation
offered about what the headstage is has been
insightful. The way headphones erect their
headstages has so far been conspicuously absent
from the literature of headphone reviews. I feel that
a review of a headphone—any headphone—
becomes more thorough and complete when the
reviewer comes to grips with these 4 things:
headstage size, headstage fullness, headstage
frontality (or lack of) and precision of image
location within the headstage. All 4 things are
about the One mechanism of sound localization.


But would the term ‘headstage’ be useful in every
headphone review? Perhaps not. The description
of the Omega II’s headstage is important because
its headstage is highly peculiar—small but highly
focused, slightly frontal and full-bodied—these four
characteristics are peculiar. Many headphones do
not exhibit all four characteristics simultaneously. If
headphone X’s headstage is unremarkable
(meaning its headstage is normal-sized and is not
frontal) then it may not be necessary to describe
headphone X’s headstage in a review, other than
perhaps a passing remark that its headstage is
that normally expected of a headphone.


One further question about the headstage remains.
If all sonic images are chained to the two-
dimensionality of the headstage, then what gives
rise to the illusion of depth? Or to rephrase the
question: how does one reconstruct soundstage
depth from the two-dimensional headstage?



_________________
INTRODUCING:
FOUR DEPTH CUES


The Four Depth Cues are the mechanisms by
which the two-dimensional headstage is given a
semblance of the third dimension. These Four
Depth Cues transform the headstage into the
perceived soundstage. The photograph analogy is
once again helpful here.


Let’s assume that you are looking at a photograph
that depicts both nearby mountains and faraway
mountains. How do you know that certain
mountains in the photograph are closer to you
whilst other mountains in the same photograph are
further from you? The photograph is a flat piece of
paper—but it communicates depth cues via five
visual cues:


Visual cue 1—mountains or objects that are small
in the photo may be interpreted as being far,
unless otherwise contradicted by other cues

Visual cue 2—mountains with lighter colour in the
photo may be interpreted as being far, unless
otherwise contradicted by other cues

Visual cue 3—mountains in the photo that have
more terrain detail appear nearer, unless otherwise
contradicted by other cues

Visual cue 4—mountains seen through an
atmospheric haze in the photo appear far, unless
contradicted by other cues

Visual cue 5—a mountain that overlaps and blocks
another mountain in the photo is perceived as
being the nearer one, and this visual cue takes
precedence over all other visual cues



The above are the five mechanisms that afford
visual depth cues in a photograph. The mechanism
of perceiving distance operates thus:
TWO-DIMENSIONAL PHOTO - ->
FIVE MECHANISMS OF VISUAL CUES - ->
PERCEPTION OF DISTANCE (DESPITE THE
FLATNESS OF THE PHOTO).


For each of the above visual cue there is a
corresponding sonic equivalent. I will re-list the five
visual cues, but for each visual cue I will now
provide its sonic equivalent:


Visual cue 1—mountains or objects that are small
in the photo may be interpreted as being far,
unless otherwise contradicted by other cues
Depth Cue #1- sonic images that are softer in
volume appear further, unless otherwise
contradicted by depth cues #2, #3 and #4


Visual cue 2—mountains with lighter colour in the
photo may be interpreted as being far, unless
otherwise contradicted by other cues
Depth Cue #2- sonic images that sound tonally
attenuated appear further, unless contradicted by
depth cues #3 and #4


Visual cue 3—mountains in the photo that have
more terrain detail appear nearer, unless otherwise
contradicted by other cues
Depth Cue #3- sonic images that have more
textural detail appear nearer, unless otherwise
contradicted by depth cue #4


Visual cue 4—mountains seen through an
atmospheric haze in the photo appear far, unless
contradicted by other cues
Depth Cue #4- sonic images swathed in a
diffused/reverberative halo appear further


Visual cue 5—a mountain that overlaps and blocks
another mountain in the photo is perceived as
being the nearer one, and this visual cue takes
precedence over all other visual cues
There is no sonic equivalent to this mechanism
because sonic images are “transparent
enough” such that one sonic image cannot
“block” another


The above are the four mechanisms that afford
sonic depth cues in a headstage. I call these the
Four Depth Cues. The mechanism of perceiving
distance operates thus:
TWO-DIMENSIONAL HEADSTAGE - - ->
FOUR DEPTH CUES - - ->
PERCEPTION OF SOUNDSTAGE DEPTH (DESPITE
THE FLATNESS OF THE HEADSTAGE).


Please note that these Four Depth Cues do not
free the images from the bondage of the head-
stage. The images are still chained to the head-
stage plane, just like the way the faraway
mountains and nearby mountains are still chained
to the two-dimensionality of the photograph. The
mechanisms only offer the facsimile of depth, but
not real depth itself. The Four Depth Cues do not
create out-of-the-head images.


For purposes of layout clarity I will re-list the Four
Depth Cues here:


Depth Cue #1- sonic images that are softer in
volume appear further, unless otherwise
contradicted by depth cues #2, #3 and #4

Depth Cue #2- sonic images that sound tonally
attenuated appear further, unless contradicted by
depth cues #3 and #4

Depth Cue #3- sonic images that have more
textural detail appear nearer, unless otherwise
contradicted by depth cue #4

Depth Cue #4- sonic images swathed in a
diffused/reverberative halo appear further, and
this cue takes precedence over all other cues


You will notice that there is a ranking order to the
four cues, starting with #1 as the weakest of the
four cues and #4 as the strongest of the lot. This
hierarchical order was arrived at after careful
observations by listening to many recordings via
my headphones over the past 8 years.


I will now explore each of these four cues in detail.
For each of the four cues I will also touch on
qualities of the audio playback chain (source-amp-
headphone) necessary for the accurate portrayal
of that respective mechanism. I will also review the
Omega II’s ability to render each of the
mechanisms.



___________________________________
DEPTH CUE #1:
sonic images that are softer in volume appear
further, unless otherwise contradicted by depth
cues #2, #3 and #4


Hypothetical scenario: You are in the middle of a
losing cavalry battle. Hope is almost lost, but out of
the blue you hear a bugle call from afar: friendly
reinforcement is approaching. Suddenly there is
hope that you can save your cavalry division from
certain defeat. Something so soft-sounding as the
bugle call from afar has stirred intense feelings of
hope.


Great depths of romantic feelings can be ascribed
to the soft-sounding sonic image, and there are
many instances in recorded music of all types
where you find the soft-sounding sonic image
being the prime carrier of emotion and meaning
during that particular musical passage.


(Psychoacoustically, we interpret the soft-sounding
image to be far away because we have learnt from
infancy that an object making a sound or noise will
sound softer as the object moves further from us.)


The challenge that the soft-sounding sonic image
poses to the audio playback chain is this: how do
you sustain the presence of the soft-sounding
image amidst all the other louder sounds? How do
you prevent it from being drowned by those louder
sounds? Even more difficult: as those loud sounds
alternate between being loud, being soft and being
even louder, how do you prevent the soft-sounding
image from flickering in and out of existence at the
mercy of those fluctuating loud sounds?


The challenge posed here to the audio playback
system is therefore one of clarity and resolution,
and to a lesser extent, one of macrodynamics. A
system with sufficient clarity will differentiate the
soft-sounding image from the louder images.
Systems with good portrayal of macrodynamics
would allow the various instruments to go loud or
soft, and in superior playback systems, the
instruments will go louder or softer independently
of each other.


The other challenge to the audio playback system
is how to tell if the image is soft because it is far
away, or because it is deliberately played softly by
a nearby musician. The latter retains textural
intensity but not volumetric intensity. (Textural
intensity is touched on in the section on Depth Cue
#3.)


How well does the Omega II fare in the rendition of
the First Depth Cue (#1)?


In a word: stupendous. This headphone is capable
of oodles of detail, and the soft-sounding image
never gets lost even in a cacophonic jungle of
other loud sounds. Image stability of the soft-
sounding image is extremely high.


As an example, I am now listening to the
soundtrack from Mighty Joe Young. The beginning
of Track 2 has a soft-sounding image of a piano
tuned weirdly (ala John Cage-like), played
percussively but very softly, and its softness gives
the impression that it is further away compared to
the louder percussive slapping of sticks and the
soaring of violins. On the Omega II, the image
stability of this soft-sounding image is maintained
despite the fluctuations in volume of the louder
sonic images.


Another example: Princess Leia’s Theme from the
soundtrack of Star Wars. This is a sweet, lovely
slow piece, with a solo flute opening the track,
followed by a solo clarinet, then a solo horn takes
up the main theme. When the solo horn is carrying
the main melody, a background violin provides the
accompaniment. The violin is played softly as well
as played a little further away. The softness (#1)
and lack of textural specificity (depth cue #3) of the
violin provides the depth and backdrop to the
perceived acoustic space, whilst the louder and
more texturally specific solo horn is the foreground
object. The solo horn presents a high image
height—as a foreground object it “stands tall” in the
acoustic space. (That’s the lovely thing about
horns and human voices—whether solo or
massed—they tend to “stand tall” in the acoustic
space.) Princess Leia’s Theme develops slowly but
inevitably to its mournful conclusion—at the end, a
solo violin weeps its last farewell note, gently dying
into the night. (With such a sweet but sad ending
to the theme, it’s a wonder that the Princess didn’t
die in the movies.) The Omega II convincingly
portrays the layered perspectives of this theme
utilizing depth cue #1 (as well as #3—but more on
this later).


But if a sonic image is soft-sounding, couldn’t it be
that the instrument was played softly by the
musician and not because the instrument was far
away? How do you differentiate between the two?
This is how: on a hierarchical order, depth cue #1
is at the bottom of the rung, and can be overridden
by depth cues #2, #3 and #4. Depth cue #1 is the
weakest of the four cues. You will perceive a
volumetrically soft image as being far away, per
depth cue #1. But if you hear a volumetrically soft
but tonally rich image, #2 will override #1, and you
perceive the volumetrically soft image to be nearer.


Example: I am now listening to Stravinsky’s The
Soldier’s Tale (Track 6 The Three Dances). The
track opens with a violin and timpani, then a soft-
sounding gentle cymbal crash from the rear of the
stage. Or at least the soft-sounding cymbal
seemed at first listen to come from the rear of a
deep stage, due to the effects of depth cue #1. But
on closer listen, the cymbal was in fact played
softly rather than played faraway. How can I tell?
Because while a faraway cymbal would lose much
of its metallic shimmer via depth cue #3, the soft
cymbal crash I heard in this track retained a highly
specific metallic shimmer. (In talking about the
texture of an instrument I have actually gone a little
ahead of myself. Textural specificity as a depth
cue is touched on later when I come to Depth Cue
#3.) This soft-sounding cymbal crash retained too
much texture for it to be far away—implying that it
is nearby. High-end headphones like the Omega II
make it easier to differentiate between those two
situations.


Another example where the Omega II allows me to
experience depth cue #3 overriding depth cue #1:
Death Of Darth Vader (a fellow Sith, by the way),
from the soundtrack of Return Of The Jedi.
Towards the ending of this piece, when Vader
dies in his son’s arms, a gently plucked harp
softly plays Darth Vader’s Theme. (Usually Darth
Vader’s Theme is pompous and militaristic, played
by snare drums and brass instruments; but in this
scene where he dies, a harp—a harp!—takes up
the theme.) The softly plucked harp sounds
unmistakably near despite depth cue #1. The
leading edge textural detail of the plucked harp is
clearly heard—I can almost “see” the fingers
plucking the harp strings. Depth cue #3 says that
when the textural detail is high, we perceive the
image to be near. We can infer from this obser-
vation that depth cue #1 is easily overridden by
depth cue #3.



___________________________________
DEPTH CUE #2:
sonic images that sound tonally attenuated
appear further, unless otherwise contradicted by
depth cues #3 and #4


Hypothetical scenario: You print out on hard copy
the threads at Head-Fi titled “Do You Believe In
God?”, “In God We Trust?” and “Jude vs God”.
You bring the printed stack outdoors to read,
where you hope that the bright outdoor light would
conspire with your reading concentration to finally
put the question of the existence of God to rest.


You come across the part which goes “of course
God does not exist“ when the distant roll of thunder
rumbles across the sky. And then you get the hint:
He exists, and has just sent you a gentle reminder.
You think to yourself: He could have given you a
more severe rebuke by sending forth a deafening
thunder clap 10 feet from where you sit, replete
with a high-pitched transient snap, like two
Godzilla-sized kendo sticks forcefully meeting each
other in mid-air.


But no. Instead you heard….the distant thunder
rumble.


What the distant thunder roll lacked in high-pitched
proximity, it made up for in majesty, for it rumbled
across the land with a deep and authoritative
resonance. But how did you know the thunder was
distant? (The distant thunder was still quite loud;
so it was not through depth cue #1.)


You inferred that the thunder was distant because
it lacked high frequency components.


Every sound, except for pure test tones, contains
high frequency harmonics and low frequency
harmonics. When the source of the sound is
nearby, the full palette of all these harmonics can
be heard together with the principal harmonic.


But in a free field, such as in the open outdoors,
the further sound has to travel, the more it loses its
high frequency content. Which is why thunder from
afar is made up of mostly low frequency sounds.
The high frequency components have been
attenuated along the way.


In a diffuse field, however, such as in a concert
hall, it is my observation from recorded music that
as sound travels further, it loses both its high
frequency and low frequency content. It is a tough
call to judge whether the low-frequency harmonics
also gets attenuated, because I think it differs from
one recording venue to another. It depends on the
acoustic character of each venue whether or not the
low frequency component also gets attenuated. It
also depends on the microphone array, recording
equipment and the recording artist’s decisions. (But
I do observe from recordings that the high frequency
harmonics often gets attenuated in a diffuse field.)
In some recordings, hall ambience actually comprises
of low frequency harmonics.


Sidetrack: in saying that depth cue #2 is a result of
tonal attenuations, I might be putting the cart
before the horse. It might actually be the opposite:
we judge the tonal balance of a recording or a
headphone based on how far or how near
everything sounds. After all, our ears don’t behave
like frequency spectrographs—we don’t plot
frequency spectrums with our ears. We perceive
what is far and what is near—we use expressions
such as “forward-sounding midrange” and “laid back
treble”. When a certain portion of the frequency
spectrum consistently sounds nearer irrespective
of recording, we say that the headphone has an
accentuated bump in that portion of the spectrum.
It is the perception of forwardness via depth cue #2
that allows us to estimate a headphone’s tonal hot
spots.


There are two incarnations how depth cue #2
manifests itself, and this depends on the recording.


First incarnation is called tonal blandness (#2a):
there is a simultaneous attenuation of high
frequency harmonics and low frequency
harmonics. This results in the distant sonic image
sounding more tonally bland. It is very satisfying to
hear the effects of distance on the tonal character
of instruments. It seems odd to say that it is
satisfying to hear the loss of tonal richness of an
instrument—shouldn’t it be the opposite: that it is
satisfying to hear the tonal richness of an
instrument? Well, both are satisfying in their own
ways. Small works that are miked more closely will
give me the tonal richness and intimacy of each
instrument, whereas distance-miked works will
give me the satisfaction of hearing greater
distances and a grander scale to the proceedings.
Sometimes a sonic image is meant to be tonally
bland due to effects of distance.


The second incarnation of depth cue #2 occurs
when there is an attenuation of only the higher
harmonics, with a preservation of low harmonics.
This leads to what I call a harmonic shift (#2b), to
coin a new term. When the higher harmonics are
attenuated due to the effects of distance yet the
lower harmonics remain largely intact, the resultant
tonal character of the sonic image shifts towards
the lower harmonics. The sonic image seems
deeper-sounding, with more heft in the lower
regions. (It’s always a harmonic shift downwards—
never upwards. The example of the distant thunder
roll described at the start of this section is an
example of harmonic shift.)


What challenge does depth cue #2 pose to the
audio playback system?


The challenge that the Second Depth Cue poses
to the audio playback system is two-fold: tonal
neutrality and harmonic diversity, to coin a new
term.


The first challenge is tonal neutrality. If the
headphone is not neutral, i.e. if there are segments
in the frequency spectrum that are spotlighted at
the expense of others, this would create havoc to
the sense of perspective afforded by the Second
Depth Cue. I suspect that the headphone that
portrays depth cue #2 just right is the Grado HP-1;
but I’m saying this from memory. (See sidetrack
below.) The second challenge that #2 poses to the
audio system is harmonic diversity. Nearer images
sound tonally richer, while further images sound
tonally blander. You need an audio system that
can portray tonally rich images and tonally bland
images simultaneously. The ability to portray
differing tonal richness fosters a sense of differing
depths between images.


Sidetrack: To be sure, tonal neutrality is a complex
issue for headphones because almost all
headphones are voiced for what is called “diffuse
field equalization”. Due to complexities in the
coupling between earcup and ears, specific tonal
adjustments have to be introduced for a
headphone to sound tonally neutral. A headphone
with a ruler-flat frequency response would sound
awful. But I can swear there does not seem to be a
single consistent execution of diffuse field
equalization, because I observe that almost all
headphones purporting to be diffuse field
equalized sound so tonally different from each
other.


How does the Omega II fare in the rendition of the
Second Depth Cue? Awesome, but with one point
of weakness.


First the awesome point: the Omega II has a
prodigious low frequency weight. You would never
expect an electrostatic headphone to have so
much heft in the bass regions. A weighty low
frequency is critical to the portrayal of depth cue
#2b (harmonic shift), which is one of the two
incarnations of depth cue #2. The Omega II
portrays harmonic shifts convincingly. For
example, right now I am listening to Track 10 (The
World Spins) from Julee Cruise’s Floating Into The
Night (which features the Main Theme from The
Twin Peaks). Did you know that a cymbal, which
most of us would expect to be a high-frequency
instrument, can actually sometimes portray low-
frequency harmonics? The squeezed-air cymbal
on Track 10 sounds as if it comprised more low-
frequency harmonics than high-frequency
harmonics—a surprise to me when I became
aware of it. That the squeezed-air cymbal sounded
this deep contributed greatly to its sense of
distance, via depth cue #2b (harmonic shift).


The Omega II’s weakness in portraying #2?


The Omega II’s overall tonal balance errs on the
side of warmth. (Warm = clockwise tilt of the
frequency balance about the fulcrum at 1kHz—
definition from Stereophile) In other words, this
headphone’s treble is restrained (but much more
on this in a later section of this write-up). The result
of this treble-shy tonal balance is that the
attenuation effects via depth cue #2 occur at a
faster rate than what I suspect is accurate. We
know that high frequency harmonics of an
instrument gets reduced over distance (#2), but it
seems to get attenuated a tad quicker via the
Omega II.



___________________________________
DEPTH CUE #3:
sonic images that have more textural detail
appear nearer, unless otherwise contradicted
by depth cue #4


Hypothetical scenario: You have been a RS-1 user
for years. You swear by its clarity and textural
immediacy. Your friend who owns a HD600 invites
you over to his house to try out his headphones.
You have never auditioned the HD600, so you
trudge over to his house with a clutch full of your
favourite CDs.


You go “what!?”, when you finally get a handle on
the HD600’s character. You complain of its distant
mid-hall perspective. You even complain that the
HD600 sounds “veiled”.


When you get back to your home, you start a new
thread at Head-Fi titled “Shocking news! HD600 is
veiled and distant-sounding”, thereby starting yet
another argumentative thread.


For the previous two depth cues, I started off with
wacky scenarios to give a humorous touch to the
proceedings. For the Third Depth Cue, I can think
of no other better anecdote than one that involves
the RS-1 and HD600, which had been the topic of
many previous feuds at both HeadWize and the
early days of Head-Fi. I wish to provide here a
fresh angle on the differences between these two
headphones.


Depth Cue #3 says that sonic images that have
greater textural detail appear nearer.


The RS-1 is the more detailed headphone—it
portrays more sonic information on the textures of
instruments. Via depth cue #3, this creates the
impression that the instruments are nearer to the
listener. Depth cue #3 is the reason why we
customarily say that HD600 is more mid-hall, while
RS-1 is closer to the stage. One criticism of the
RS-1 that I am hesitant to agree wholeheartedly
with is that it is coloured—it has become too
commonplace for audiophiles to accuse a
component of being coloured when the only sin
that that component ever committed was to be
texturally specific.


(I made the same mistake 4 years ago in my
review of Omega I vs Omega II, when I referred to
the Audio Note DAC2 digital-analogue converter
as being coloured, when what I actually meant was
that this lively DAC was texturally specific. My
apologies to Peter Qvortrup, who did give me a
gentle rebuke on this matter and insisted that his
DACs were not coloured when I e-mailed him to
inquire whether the ultrasonic grunge emanating
from his DAC3.1X zero-oversampling DAC, which I
subsequently bought, would fry my T2 amp. It just
shows that when we don’t have the words to
describe something accurately, we end up using
whatever available existing descriptions, however
erroneous.)


In the case of the RS-1, it is less a matter of
coloration than it is of the headphone’s rendition of
mechanism #3. Headphones that render textures
vividly sound more up-front. The language that
audiophiles use in describing sound has become
too dependent on descriptions of tonal balance. If
a headphone is more up-front—blame it on the
coloured tonal balance. If the headphone is more
mid-hall, ascribe it also to the tonal balance.
Everything becomes simplistically reduced to a
matter of tonal balance. The effects of textural
portrayal (#3) is not mentioned or not noticed.


Two tonally neutral headphones can sound
different, despite their similar tonal neutrality. The
headphone that renders #3 more vividly will sound
more up-front and closer to the stage.


What challenges does #3 pose to the audio
system?


Depth cue #3 requires that the audio system be
capable of portraying textures vividly when the
occasion calls for it, as well as portraying textures
less vividly when another occasion calls for it. The
challenge posed to the audio system is therefore
textural range, to coin another new term. If
“dynamic range” means the ability to portray the
gamut of dynamics from fff to ppp, then textural
range means the ability to portray the range of
textures from less texturally specific to extremely
texturally specific. Textural range means the ability
to portray a highly textured sonic image alongside
a not-so-highly textured image, such that a sense
of depth is portrayed. It is not easy for audio
systems to portray textural range accurately.
Lesser playback systems tend to homogenize the
sound, such that all textures tend to appear equally
textured. Superior playback systems do not
homogenize the sound, allowing textures of
various instruments to come across as being
texturally specific or texturally non-specific,
independently of each other. Textural range is a
key performance indicator of an audio system,
especially in a headphone-based system where
headphone-users have to rely on comparative
texture as a means of gauging spatial depth.


How well does the Omega II portray the Third
Depth Cue?


Stupendously. The textures portrayed by this
headphone can range from highly texturally
specific to texturally non-specific, depending on
what was in the recording. This headphone also
does not homogenize sound, allowing a lot of
breathing space for each texture to develop
naturally and independently of each other. The
textures of voices and instruments sound very
different from album to album, which should be the
case, as each album was recorded differently. And
within the same album and same track, the
textures also sound very different from one sonic
image to another. Simply fantastic. Much of the
spatial depth portrayed by the Omega II can be
ascribed to its fantastic handling of textural range.


For example, I am now listening to the Track 20
(You Win Again) from The Very Best Of The Bee
Gees. The insistent drum-beats sound distinctly
further away due in large part to depth cue #3.
(Drum-beats appear nearer when the textures of
both the rattling drum frame and the taut dry drum
skin being hit are abundantly present.) In the
absence of both these textures, like for instance in
this You Win Again track, the drum-beats seem to
be further away, which is what I am hearing now
via the Omega II. I hear the texturally less specific
drum-beat to co-exist with the more texturally
specific voices. The texturally less specific sound of
synthesizers creates the backdrop against which
the texturally specific voices of the Gibbs become
the foreground object. I have found that rock music
often employs synthesizers to create the backdrop
against which foreground objects (typically voices)
stand out. It has to do with the way synthesizers
roll out smoother textures, and as #3 would have it,
smoother textures sound more distant and can
readily serve as soundstage backdrop. A handy
little tool, the synthesizer.


Another example: Track 2 of Ali Farka Toure / Ry
Cooder’s Talking Timbuktu album. This CD is the
collaboration between Ry Cooder who plays
various sorts of electric guitars and Ali Farka Toure
who sings and plays acoustic guitar and the njarka,
accompanied by his team of Timbuktu percu-
ssionists. This album is filled with catchy melodies
infused with pure and simple forms of rhythm. In
Track 2, the percussive shaker is positioned dead
centre of my forehead, but it sounds perceptibly
distant. (The recorded sound of a percussive
shaker placed up close to the microphone has a
distinct texture, like the sound of many metal
beads being agitated either by shaking or rubbing.)
But in Track 2 of this album, the shaker definitely
lacked such a high degree of textural specificity,
implying the shaker’s greater distance.


Another example: Track 5 (Amandral) from the
same album includes a western drum kit, but the
way it is played is deliberately subservient to the
African percussive instruments during the opening
and closing section of this track. The opening and
closing of the track has the drum kit played such
that the textural specificity of the air-squeezed
double-cymbal and stick-hit cymbal is reduced.
The reduced textural specificity of the air-squeezed
double-cymbal and stick-hit cymbal contributes to
their sense of greater distance, whilst the textures
of the calabash and congas remain highly
texturally specific. This makes the western drum kit
seem further away, and therefore compositionally
subservient to the nearer-sounding African
percussions. Then in the middle section of this
track, the western drum kit acquires equal status to
the African instruments. In this middle section, the
leg-operated tambourine rips through the acoustic
space with its clear vivid texture, appearing as
forward sounding as the African percussions.
Altered depth is used as a compositional element
in this track, and this altered depth is achieved by
altering textural specificities (#3).


Another example: 1st Movement of Shostakovich’s
Piano Concerto No.1—the piano-trumpet duet
sounds nearer to the listener than the accom-
panying orchestra. When the cello starts to play, I
infer that it is further away because I hear neither
the typical resinous purr of a string being bowed
nor the typical woody resonance of a cello’s body.
Both the piano and trumpet are perceptibly more
texturally specific than everything else, the piano
more so than the trumpet. (It is after all a piano
concerto.) The texture of the piano is highly
specific—I am very aware of the percussive nature
of the piano, its leading edge transients coming
across sharp and clear. However, because the
leading edge lacks the sharpest of bites, I also
infer that I am not that close to the piano—I am not
on the stage with the piano. I can understand the
mental calculations involved in the recording
engineer’s mind when capturing this piece. On one
hand, he must have wanted the piano to sound
quite close because Shostakovich experiments
here with “off-key” tonalities, and off-key tonalities
on a piano sound best when captured near-field.
On the other hand, he had to make the piano “gel”
with the rest of the orchestra and cannot afford to
have the piano stand out in too stark a relief
against the accompanying orchestra. Hence the
near-but-not-too-near perspective of this piano.


Strangely, as distance increases, different
instruments lose their textural specificity at differing
rates. For example, I am now listening to the 3rd
and 4th movements of Beethoven’s 5th
Symphony—the part where sunshine bursts on
stage when the brass section rejects the C Minor
key in favour of the C Major. It is my observation
that massed strings acquire a smooth texture
whereas massed brass still retains a slight hint of
the “brassy” texture. Maybe the higher harmonic
textures of some instruments get attenuated faster
than the textures of other instruments?



___________________________________
DEPTH CUE #4:
sonic images swathed in a
diffused/reverberative halo appear further, and
this cue takes precedence over all other cues


Hypothetical scenario: You are jungle trekking at
night when you suddenly find a strange entrance in
a stone cliff, covered by vines, into what you
suspect might be a tunnel through the stone cliff.
You adventurously go into the dark tunnel without
any torchlight, relying only on your sense of touch
and hearing to guide you. You have gone some 30
feet into the pitch-black tunnel (well I did say you
were adventurous) when you suddenly realize you
have passed from the tunnel into the belly of a
large cave. Even in pitch darkness you knew you
have progressed into a cave because you hear the
fluttering of a thousand bat wings echoing off the
walls of the cave. The echoes of the fluttering
wings “light up” the cave walls, and for that short
duration when the echo could be heard you can
“see” the extent of the cave walls.


Music is tied to architecture. I am not talking of the
metaphorical relationship between music and
architecture (that music is architecture in motion,
or that architecture is frozen music). I am talking of
the literal relationship between music and
architecture —that some forms of music are so
inextricably connected to the venue it is played.
Choral and orchestral music are better heard in
halls, and best heard in certain halls. Such music
played in the open outdoors loses its usual sense
of lushness.


Reverberation in recorded music occurs when
sound is reflected off the walls, floor and ceiling of
a recorded venue, and the microphones capture
both the direct sound and the reflected sound that
comes milliseconds after the direct sound. When
you are nearer to the instrument, the amount of
direct sound overwhelms the amount of reflected
sound. When you are further away from the
instrument, the ratio of reflected sound to direct
sound gets larger. This gives rise to depth cue #4:
whenever a sonic image is diffused with a
reverberation halo, you perceive that that image is
further away. I have consistently found by listening
to recordings that depth cue #4 takes precedence
over all the other three cues.


Depth cue #4 comes in two incarnations—
overlapping reverberation (#4a) and impulse
reverberation (#4b).


Overlapping reverberation (#4a) tends to occur
with continuous sound sources, such as blown or
bowed musical instruments as well as choir voices,
whereas impulse reverberation (#4b) tends to
occur with struck or plucked musical instruments.


Overlapping reverberation (#4a) is the reverb-
eration that overlaps with the direct sound of a
blown or bowed instrument whilst the instrument is
still playing. The net result of this overlap is that
the sonic image of the blown or bowed instrument
acquires a certain “halo of diffusion”. Depending on
the type of instrument and the hall characteristics,
there might a core at the centre of the halo. Some
diffused images do not have a central core; some
do. I find that instruments that give off high-pitched
textures tend to retain this core. Amazingly,
sometimes the core can be so sharply delineated
(because the core is texturally specific) that the
core appears nearer (via depth cue #3) while the
halo appears further. Curious.


(Because the overlap between direct sound and
reflected sound causes a diffusion of the sonic
image, I also call this type of reverberation
“diffused reverberation”. Overlapping reverberation
and diffused reverberation are one and the same
thing.)


Impulse reverberation (#4b) is when the transient
sound starts and then stops quite abruptly, with the
reverberation quickly following in its wake. This
occurs mainly with struck or plucked musical
instruments. There may even be a very brief gap
between the end of the direct sound and the start
of the reverberation, similar to what you find in an
echo. The reverberation also starts and stops quite
abruptly, hence the name “impulse reverberation”.
During the short duration of the impulse reverb-
eration, the edges of the recorded venue “lights
up” momentarily but dramatically. Nothing, and I
truly mean nothing, “lights up” the recorded venue
quite as dramatically as impulse reverberation
(#4b). It is as if you were a blind person but for a
brief miraculous moment you were given the gift of
sight. Quite wondrous really.


An example of impulse reverberation can be heard
at the conclusion of the 4th movement of
Beethoven’s 5th. The whole orchestra concludes in
the C Major key in simultaneous syncopated
bursts. Each burst is very brief, but very intense
(because the whole orchestra contributes to the
burst). A short moment after each burst, the hall
“answers back” with an impulse reverberation
burst, almost as if the reverberation note was on
the composer’s score sheet. At those moments
when the hall “answers back”, I can “see” the limits
of the acoustic space.


Sometimes reverberation can be applied
electronically, but I have found post-event
reverberation to sound odd at times, and at rare
occasions, truly hilarious. (The most comical
application of electronically-added reverberation
was in this particular piece where the female voice
came from extreme left and the reverberation of
her voice came from extreme right, and all through
this piece there was a pretension of simulating a
real acoustic space.) I find it acceptable to hear
electronically-added reverberation if it was done in
a witty manner or if there were valid compositional
reasons. Certain music forms like rock, which is a
form of amplified music, have no pretensions of
being played in a natural acoustic setting, and if
rock employs electronically-added reverberation I
have often found that rather acceptable. The
electronically-added reverberation was just one
more electronic manipulation in a series of
electronic manipulations like the judicious use of
equalization and heavy mixing of multiple close-
miked sources. I’m all right with it so long as there
is no failed pretension at simulating a real acoustic
space. (If it were a successful pretension then I
won't know it's a pretension.)


What challenges do depth cues #4a (diffused
reverberation) and #4b (impulse reverberation)
pose to the audio playback system?


The proper portrayal of #4a and #4b requires that
the headphone playback system be (i) transparent
such that there is little or no loss of ambient
information contained in the recording, (ii) highly
resolving such that each sonic image has ample
breathing space and (iii) nimble-footed with quick
transient response so that you perceive a
heightened sense of real instruments playing in
real acoustic environments.


How well does the Omega II portray depth cues
#4a and #4b?


STAX headphones have a great tradition of being
able to reproduce hall ambience excellently. There
is an ethereal magical chemistry between STAX
electrostatic headphones and reproduction of hall
reverberation. STAX headphones have a light
nimble touch that gives us the sense of real
instruments hovering in real acoustic spaces.


The Omega II does not significantly depart from
such pedigreed lineage. But the Omega II does not
portray depth cue #4a (diffused reverberation) as
vividly as other STAX headphones like the
Lambdas and the Omega I. The restrained upper-
midrange and treble of the Omega II prevents the
upper-midrange harmonics of ambient air from
being “lit” brightly enough. There is no lack of
transparency and resolution—via the Omega II you
can hear right to the very rear of the soundstage,
but it’s as if all the lights had been turned off and
the recorded venue is plunged in darkness. The
Omega II offers a superbly transparent window
to the acoustic hall—it’s just that it is an utterly
transparent window to a darkened hall, rather
than a moderately transparent window to a more
brightly-lit hall.


Sidetrack: For this reason, I frequently turn off all
the lights in my listening room when I listen to
headphones—the actual darkness of my listening
room complements the apparent darkness of the
recorded venue. If I had a wish list for the new
Omega III (if and when it comes out), it would be
that the Omega III shines a little more light on the
middle-midrange and upper-midrange spectrum of
ambient air. Just a little more, but no more than that;
or else the presentation would sound a little too
“hi fi-ish”. It is a very tricky balance to get right.


Other than this slight gripe, the Omega II is clearly
superb in rendering hall reverberation and depth
cue #4. For example, it is able to afford me an
instructive demonstration of depth cue #4a
(diffused reverberation) in Johann Strauss’s
Explosions Polka 4th movement (Banditen Galop).
The first explosion at 0.07sec seems reasonably
nearby, while the second explosion at 0.11sec
sounds further away than the first explosion
because there is a greater reverberative diffusion
(#4a) around the image of the second explosion.
Coupled with this, there is also a sense of
harmonic shift (#2b) with the second explosion
that was absent in the first explosion. The third
explosion at 0.19sec sounds even slightly further
than the second explosion; this sense of greater
distance was contributed by greater degrees of
both #2b (harmonic shift) and #4a (diffused
reverberation) relative to the second explosion.
The location of the image of all three explosions
remained the same: they were all located just
beyond the left temple of my forehead.



_______________________________
#2 + #3 + #4 + Air btw instruments:
THE SENSE OF PERSPECTIVAL AIR


Now I want to share with you something really
magical called perspectival air.


When two or more of the mechanisms combine,
you get a greater effect of depth. Most convincing
is when a single sonic image demonstrates #2, #3
and #4 simultaneously, coupled with a strong
sense of air around the image. This combination of
#2 + #3 + #4 + Air offers a devastating sense of
perspectival air (played over the right headphones
and set-up)—perspectival air to die for.


For example, I am now listening to Chris
McGregor’s The Brotherhood Of Breath (a VTL
Recording using an all-Manley recording set-up).
Pinise Saul sings into the mike (of course—how
else would it have gotten into the recording?), but
her voice is not fed into the mix yet. Her voice
plays through a public address system, then the
reproduced voice travels through 12-15 feet of air
before being picked up by the main microphones.
The acoustic ‘haze’ surrounding her voice is a joy
to listen to, as is her singing. This ‘haze’ is
achieved via mechanisms #2, #3 and #4, meaning
to say that her voice sounds a little “tonally
washed-off” (#2), loses quite a bit of textural
specificity, for example the pronunciations of
consonants are not as sharp compared to if her
voice had been directly fed into the mix (#3) and
the image of her voice is surrounded by a diffused
halo of reverberation (#4). The combination of
these 3 operative mechanisms plus the sense of
air around the image of her voice gives rise to a
tremendous sense of perspectival air—I am very
much aware that the public address system from
which her voice emanates is located some
distance from the main pick-up mikes. Excellent
stuff. Perspectival air to simply to die for.


Likewise, the plucked bass guitar in the same track
is not fed directly into the mix, but played through
the guitar speaker; the reproduced guitar sound
then travels through intervening air before reaching
the main mikes (the same main mikes that picked
up her voice). This results in the bass guitar
sounding airy, which may strike bass junkies as
being odd—how can bass be airy? Bass is
supposed to be solid and punchy, isn’t it? Not
really. (But more on this later.)


What is the difference between perspectival air
and soundstage depth? After all, both occur in the
z-axis (x-axis being left-to-right and y-axis being
height).


Air may be the medium of transmission of sound,
but air is also the medium of resistance to sound.
The further sound travels through air, the more its
volumetric (#1), tonal (#2), textural (#3) and
reverberative (#4) character changes. Perspectival
air is about the heightened aesthetic awareness
that air is a medium of resistance to sound. The
difference between “soundstage depth” and
“perspectival air” is that the former is (merely) a
perception of the z-axis, whilst the latter is about
perceiving that the sound of instruments had to
surmount an obstacle (air) in order to reach the
microphones.


Perspectival air is a more acute and intense form
of soundstage depth. You perceive soundstage
depth when a sonic image displays any one or
more of the Four Depth Cues. But when you get a
potent combination of #2 + #3 + #4 + air around
the instruments, you perceive glorious bountiful
perspectival air. Without the fourth ingredient (air
between the instruments) perspectival air will also
be lacking. When only #2, #3 and #4 are present
but the sense of air between instruments is
lacking, what you get is soundstage depth, not
perspectival air.


Most recordings give you soundstage depth, but
not all recordings give you perspectival air. To give
you perspectival air, the album has to be well
recorded, most preferably minimally-miked, with
ample ambient cues captured by the pick-up
mikes. However, not all minimally-miked
recordings give you perspectival air—production
labels such as Clarity Recordings for example offer
a rather close perspective lacking in perspectival
air despite their productions being minimally-
miked.


Binaural recordings feature a lot of perspectival air
by virtue of the minimalist approach of placing
miniature microphones at the opening of the ear
canals of a plastic dummy head. But I have yet to
hear a binaural recording that gave me out-of-the-
head imaging because I have yet to find a binaural
recording that utilized a dummy head whose
specifications exactly matches my personal HRTFs
(Head Related Transfer Functions). But despite the
usual in-the-head headstage that I experience with
binaural recordings, such recordings gave me a
soundstage filled with a marvellous sense of
perspectival air. No regrets there in having bought
a total of 20-odd binaural CDs, even if I did not get
the out-of-the-head experience that I thought I
would get.


Labels such as VTL, Chesky, Mercury Presence,
Telarc, Stereophile and Reference Recordings
(amongst many others) feature recordings that
have perspectival air. I have always thoroughly
enjoyed the recordings released by such production
labels when played over my headphones, but it
surprised me to read at least 3 posts at Head-Fi
that consistently complained about “the sense of
distance” captured in such recordings. I cannot
remember the threads or the persons who posted
such a comment—but I was extremely perplexed
by this consistency with which “sense of distance”
automatically deserved criticism and rejection.
Why would a headphone-user complain about
recordings that portray depth cues or a lush sense
of perspectival air? One answer might be that the
audio system they own is not transparent enough
to make sense of such recordings; another
explanation might be that they have not yet
acquired the experience to enjoy such recordings.


I have found STAX headphones to make me
peculiarly aware of perspectival air—when it is
present in the recording. I have owned five STAX
headphones over the past 11 years (Gamma Pro,
Sigma Pro, Lambda Signature, Omega I and
Omega II), and can attest to the unique
presentation style of STAX headphones. All the
observations you read here in this essay have
been slowly gathered by me over the past decade
based on what I hear via those five STAX
headphones, especially the Lambda, the Sigma
and the Omegas. (The other headphone that
presents an unsurpassed sense of perspectival air
is the Sennheiser Orpheus.) I am not a recording
engineer and I have not done recordings in my life
before, nor am I a psychoacoustician, so it is highly
curious that I can articulate several sonic
phenomena that one would expect to be within the
province of recording engineers or psycho-
acousticians. This says something about the
transparency of STAX headphones, which allows a
home-user in the comfort of his listening chair to
reconstruct the spatial characteristics of the
recorded event.


Sidetrack: This may also explain STAX’s choice of
calling their headphones “earspeakers”, because
this term “earspeakers” more greatly carries a
connotation of distanced air than the term
“headphone”. However, I think that the deference
to a loudspeaker-centric terminology may be
unnecessary and potentially misleading, because a
pair of loudspeakers creates an intervening
distance between its “headstage” and the listener,
whilst the effects of perspectival air is about the
intervening distance between musicians and the
microphones. Seen from this angle, the fact that
STAX headphones are prodigious portrayers of
perspectival air should not make them deserve the
epithet “earspeakers”. Perhaps by “earspeakers”
STAX meant that their headphones co-opt the ear
flap the way loudspeakers do, and not that STAX
headphones are prodigious portrayers of
perspectival air.


How well does the Omega II fare compared to
previous STAX models when it comes to portrayal
of perspectival air?


I would describe Omega I’s soundstage as being
especially charged with the sense of perspectival
air and that Omega II’s soundstage, while not
lacking in the portrayal of perspectival air, is
not as super-charged. The slightly brighter middle-
midrange and upper-midrange of the Omega I
shines the light on the midrange spectrum of
ambient air, making the sense of perspectival air
super-charged, as if the air molecules above and
around the musicians and between the musicians
and the microphones were frenetic with vibration
energy. (This occurs only if the correct recordings
are played via Omega I—recordings that have a lot
of perspectival air.) But what the first Omega
lacked relative to the second is the sheer
effortlessly relaxed clarity of its successor.



(Summarizing the essay so far: Before going into
my next section I just want to pause and take stock
of what we’ve covered so far and what still lies
ahead. We’ve covered the headstage, the Four
Depth Cues and this incredibly lovely thing called
perspectival air. I will now need to complete my
review of the Omega II. I reviewed the Omega II
using a review methodology structured on the Four
Depth Cues, but an assessment of a headphone’s
depth portrayal is not enough—there are other
things to evaluate. I will be touching lightly on six
additional aspects: Background Blackness,
Portrayal of Details, Bass, Midrange, Treble and
System Matching. The reason why I am lightly
touching on these aspects is because I do not wish
to usurp the significance of the headphone review
methodology based on the Four Depth Cues.)



____________________________________
ADDITIONAL REVIEW ITEMS OF OMEGA II


BLACK BACKGROUND


All too often with lesser headphones, you become
aware of the black background only when the
music becomes less complex—the transition from
the passage with many instruments to the passage
with few instruments seem also to be accompanied
by a transition from ‘busy’ background to a quieter
background. With the Omega II, you never transit
from busy background to quiet background—the
background is always quiet and black, no matter
how many instruments there are.


I believe that the Omega II’s refined black
background is due to its near-zero distortion. I
have gotten so accustomed to the absence of
distortion that I have become sensitised to it. After
getting used to the Omega II, I suspect that there
must be many types of insidious distortions
exhibited by other headphones. I am not talking
about the obvious sort of distortion where the
amplifier clips or something like that. I am talking
about subtle forms of distortions, and there must be
more of such insidious distortions than we have
names for them. When such subtle distortions are
at vanishing low levels, you get this incredibly
velvety black background.



PORTRAYAL OF DETAILS


The Omega II is a refined headphone. It portrays a
lot of details—but it does not shove the details in
your face. Rather, it is relaxed and casual about its
rendition of detail. It’s quite a paradoxical
experience—there’s oodles and oodles of details,
yet the presentation seems very relaxed.


After having lived with this headphone for 4 years,
I have come to the conclusion that its supremely
natural and relaxed rendition of details is the result
of 3 co-existing qualities:
(i) ample dynamic headroom, such that there is no
sign of stress and strain,
(ii) ultra-high resolution, such that images are
clearly distinguished from each other, and
(iii) a velvety black background out from which
images emerge effortlessly



BASS


Can you believe that the history of STAX
headphones had been primarily motivated by the
search for true deep bass? Yet it seemed to be so.
Years ago I read somewhere that in the mid-80s,
when the Gammas used to be the top-of-the-line
STAX headphones, the makers of Mercedez Benz
cars needed a transducer that could tell them
precisely what sort of low-frequency chassis
resonance was happening in automobile frames.
Thus was the first Lambda born—for a non-
audiophile, non-recording industry purpose.
Subsequently the Omega I appeared in 1992. The
pamphlet for the Omega I says this: “large circular
transducers…can effortlessly reproduce the lowest
conceivable notes”. Then the Omega II appeared
in 1998 and further ups the ante on bass
reproduction: “a new gold-plated electrode that
attributes to increased bass response”. Every new
model had been primarily about further improving
the bass reproduction.


I have a feeling that with the Omega II, STAX
designers felt that they have finally cracked the nut
on how to make a headphone go really deep. Back
at HeadWize I called the Omega II “the heavy-
weight bass champion of headphones”, and I
wasn’t excluding dynamic headphones. (But
please note I didn’t say heavyweight bass-slam
champion of headphones.)


There are 3 aspects to bass reproduction—bass
slam, lower harmonics of voices/instruments and
lower harmonics of ambient air. (But why do
people keep thinking that there is only one aspect
to bass performance, which is bass slam?) The
Omega II excels in all three.


Bass slam—this headphone displays tremendous
bass slam, when the recording calls for it. It is not
a trade-off between weight and definition—the
Omega II’s bass slam is both weighty and tight.
(But because of its restrained treble, the
perception of bass slam via the Omega II may not
be as hard-hitting as compared to a brighter
headphone. The sense of a hard-hitting drum is
attributed more to the presence of high frequency
textures and/or a more forward midrange than to
low frequency weight alone.)


Lower harmonics of voices and instruments—this
is even more important to me than bass slam
because not all recordings call for bass slam but all
recordings will benefit from a rich reproduction of
lower harmonics. A deep, rich bass makes the
tonal character of voices and instruments so much
more authoritative and weighty. No headphone I’ve
heard sounds as authoritative and weighty as this
one.


Lower harmonics of ambient air—this is also very
important to me, especially when I play albums
that feature a lot of perspectival air or albums that
feature harmonic shifts (depth cue #3b). No other
headphone I’ve heard tells me so convincingly that
hall reverberation also comprises of low frequency
harmonics. People say that bass is matter of
solidity, but I beg to differ. Bass to me is a matter
of air as well. There is such a thing as a low-
frequency ambient air—when you play large-scale
orchestral works, it is the lower harmonics of hall
reverberation that gives a sense of architectural
scale to the music. The sense of weight and
gravitas to music—this is Omega II territory.



MIDRANGE


The all-important midrange, where most of the
music is. Magical is how I would characterize the
Omega II’s midrange. I really dislike the phrase
“smooth liquid midrange” because it is so
overused, but I cannot think of a better phrase to
describe the Omega II’s midrange. There is
nothing to dislike about the Omega II’s midrange
and everything to love. (Although in direct comparison
to the Omega I, the Omega II's midrange sounds a
little more reticent.)


Also, it is never just how this headphone portrays
its midrange, but how the supporting bulwark of
qualities such as velvety black background, ultra-
high resolution and casual clarity come together to
offer a clean, clear and sweet midrange.


One important thing to mention about the Omega
II’s midrange is that it is so fused with its treble and
bass, that all the sonic images seem cut from the
same cloth. The differentiation into bass, midrange
and treble is in fact an artificial division. When you
hear a trumpet via the Omega II, you don’t just get
midrange richness—you get the sound a trumpet
that comprises the midrange principal harmonic
plus upper harmonics plus lower harmonics all
fused together to make the complete sound of a
trumpet. “What midrange? I only hear a trumpet.”



TREBLE


The treble of the Omega II is difficult to describe. I
have not read any review whether in HeadWize or
Head-Fi or any professional magazine that
accurately described the Omega II’s beguiling
treble (including my own review in 1999).


Quantity-wise, the treble of the Omega II errs very
slightly on the side of insufficiency. Quality-wise,
the treble of the Omega II packs oodles of clarity
and resolution. Calling the headphone “dark” is
somewhat true, but only half the truth. “Dark”
carries the connotation that the treble is soft-
sounding, and this is true of this headphone to a
certain extent. But “dark” also carries the
connotation that the treble is muffled or not clear
enough, and nothing could be further from the
truth, for the Omega II is capable of resolving very
finely textured treble detail. Its treble seems finer
than silk—so fine that you can journey between the
super-fine grains all the way down down down to
the noise floor of your amp and source
components.


This strange combination of a superbly fine-
textured treble, yet shy treble, results in a
headphone that is revealing-yet-forgiving. Because
the treble is very finely textured, you can hear
upstream nastiness like sibilance and smear, even
in small amounts, but because the treble quantum
is subdued, the upstream treble nastiness loses
much of its sting, which accounts for the
headphone’s forgiving nature. Revealing yet
forgiving: the secret is in its treble.


This type of treble is a slight departure from
absolute tonal neutrality. It errs on the side of
warmth. But one good turn deserves another: I am
willing to be forgiving of the Omega II’s tonal
warmth, because it has been forgiving of my less-
than-stellar recordings (of which I have plenty as
well). Its revealing-yet-forgiving treble goes a long
way in making my entire collection of CDs
listenable and also in reducing listening fatigue to
near-zero levels.



SYSTEM MATCHING


Tricky issue to deal with. If you are a long-time
owner of previous STAX models, you would
welcome the Omega II’s non-fussy coupling with
all sorts of source components and cables. This is
because the Omega II does not sound as bright as
previous STAX models such as the old Lambdas,
which were more fussy about the tonality of system
matching.


But if you are new to STAX headphones and you
belong to the category of people who prefer up-
front immediacy, then system matching becomes a
more pertinent issue. When I first bought the
Omega II, I was using the Muse Model 2 as my
digital-analogue converter, which I would
characterise as a little laid-back. I thoroughly
enjoyed this partnership. (I’m a transparency freak,
and I don’t really need up-front immediacy.) Then I
bought the Audio Note DAC3.1X non-oversampling
DAC. Audio Note DACs are musically lively,
possibly due to the zero oversampling design, and
it transformed the Omega II’s presentation into
something more musically lively. I would say that
the Omega II + Muse would not have appealed to
people looking for greater immediacy, but Omega
II + Audio Note—now that might rock your boat.


The type of equipment you absolutely don't want to
partner the Omega II with are averagely-transparent
equipment that are simultaneously dark-sounding.
You'll be in for a lot of trouble if you do so, because
you will get a presentation that veers towards
being annoyingly difficult to "see through".


Partnering it with highly transparent equipment
that are also slightly warm-sounding is not much a
problem if you are, like me, a transparency freak.
But this just means that during those moments
when your mood is "on the fence" (not really
looking forward to music but not averse to it
either--we all have such moments) then you
might find that the slight darkness may make it
more difficult to "get into the music", unless you
are careful in selecting a music type or recording
type that off-sets the slight darkness.



_____________________________________
CONCLUSION (FOR REVIEW OF OMEGA II)


The Omega II is a beguiling headphone. It has
unique headstage characteristics (slightly frontal,
small-sized, fulsome, hyper-focused). It portrays
the Four Depth Cues well, in particular it has a
most amazing textural range (#3), which
greatly helps the listener in using comparative
textures as a means of gauging spatial depth. It
portrays diffused reverberation (#4a) and impulse
reverberation (#4b) well, with a sense of real
instruments playing in real spaces, but the upper-
midrange spectrum of hall ambience could do with
a little more illumination. It portrays perspectival
air (#2 + #3 + #4 + air) well, when it is present in
recordings, although previous STAX models
render perspectival air more vividly. It presents
sonic images that emerge out from a quiet black
background. It has an unbelievably prodigious yet
tight bass, and it often portrays ambient air filled
with low frequency harmonics, which imparts a
sense of architectural scale to music. It has a
magical see-through midrange that is uncannily
cohesive with lower and upper ranges. It has a
treble that is a little restrained but highly-resolved
and refined. And the quality I cherish the most: it
has a resolution and clarity so effortless as to
become casual and relaxed.


The Omega II is a long distance runner. It is such a
fatigue-free headphone that it can be used in an
intensive manner by a compulsive headphone user
(ahem!) who wears his headphone for a minimum
of 4 hours at a single sitting, twice or three times a
week, week after week, year after year (but with
intermittent periods of complete rest, lasting 1-2
months each, to give the ears a necessary break
and also to give myself a rest from too much of a
good thing).


Is the Omega II the best headphone in the world?
That’s a very broad question, as there are many
aspects to consider. But four aspects of the
Omega II strike me as being possibly unsurpassed
by any other headphone, dynamic or electrostatic.
First is its clarity and resolution—no other head-
phone I’ve heard portrays such effortlessly casual
and relaxed clarity. (There may be other head-
phones that match the clarity of the Omega II, but
not its sense of relaxed clarity.) Second is its
prodigious spectral weight—no other headphone
I’ve heard sounds more authoritative and mature
as the Omega II. Comparing all other headphones
to the Omega II is like comparing the prepubescent
voice of a boy to the voice of a matured man.
Third, its midrange is so coherently integrated with
the lower and upper reaches. Fourth, I have never
heard a more finely textured treble from any other
headphone.


So back to the earlier question: is the Omega II the
best headphone in the world? My feelings now
about this matter is: so what if it is and so what if it
isn’t? It is an irrelevant question for me now. This
headphone has made me thoroughly enjoy a
diverse range of music forms. It is as comfortable
with classical as it is with rock (although I wouldn’t
describe it as a dedicated rocker’s headphone that
can play rock and only rock superlatively). It
renders various forms of music with a great sense
of ease and musicality and has kept me enthralled
in this headphone hobby for 4 years (and running).


Talk about an extremely worthwhile investment.



______________________________
CONCLUSION (A UNIQUE LANGUAGE FOR
HEADPHONES)


Listening via headphones offers a different realism
from that offered by a pair of loudspeakers. A
different reality requires a different language to
describe it. A language that specifically describes
the sound of headphones has hitherto been
either absent or under-developed. This essay
seeks to fill that void.


The set of new words elaborated in this essay may
be utilised to describe and review any headphone.
The only reason I used this new language to
describe and review the Omega II was merely one
of convenience—the Omega II is after all my day-
to-day headphone.


People who scoff at headphones for not portraying
depth have not been listening alertly enough.
While it is true that loudspeakers portray depth
more convincingly, headphones DO portray depth,
and they do so via four cues—volumetric (#1),
tonal (#2), textural (#3) and reverberative (#4).


Granted, through a pair of loudspeakers you not
only hear the Four Depth Cues, you can actually
localize the externally located sonic images as
well. In headphones, you do not have the benefit of
externally located images, but you can train your
ears to be more perceptive of distance cues
inherent in recordings. Headphones are not
deficient when it comes to portrayal of the Four
Depth Cues, as I have been at pains to illustrate in
this essay. (But headphones do lose out to
loudspeakers when it comes to the One
mechanism of sound localization.)


Come to think of it, the fact that the Four Depth
Cues have been articulated as a coherent
paradigm within the headphone world first and has
not surfaced yet within the loudspeaker world
suggests a possibility that headphones make us
more aware of these depth cues than speakers do.
Perhaps loudspeakers’ localization ability is at
once both an advantage and a handicap. If you
have the convenience of externally-located images
to give you the perception of depth, then would you
be so acutely aware of the Four Depth Cues?
Whereas a headphone-user who does not have
the mechanism of localization at his disposal is
forced to maximize his perception of the Four
Depth Cues to grasp the spatial world of the
recorded venue.


Will this essay be successful in instigating the
growth of a language peculiar to headphones? I
can only hope so.


May I politely request that Head-Fiers use some of
the new words introduced here in their own posts
and reviews? I have introduced many new words
in this essay, but I wish to make the strongest case
for only a few. Headstage is a word we cannot do
without, once you understand what it means—what
else are we headphone-users going to call that
head-hugging soundfield that has kept faithful
company? Perspectival air offers so much
pleasure via headphones that it deserves to be
used more often in order to describe those
recordings or headphones that portray the sense
of depth with such haunting airy realism. Textural
range is a key performance indicator of a
headphone’s ability to portray depth via depth cue
#3—what other more appropriate word can we find
to refer to that ability to portray spatial depth via
comparative textures ranging from the non-specific
to the highly specific? The term ‘textural range’ is
as appropriate and useful as the term ‘dynamic
range’.


There is really a chance here for the headphone
community to craft a language peculiar to
headphones. But someone has to first volunteer to
produce the ‘first cut’ for everyone to debate and
discuss. This essay is such a ‘first cut’.


I’ve finally come to the end of this essay. Have a
good day, everyone. I will be taking a long break
after this exhausting write-up. Enjoy this wonderful
little hobby of ours. Bye!




________________________________________


Footnote-essay no.1:
HOW TO PERCEIVE DEPTH CUES BONDED TO
THE HEADSTAGE


Play music via your headphones, and close your
eyes. In your mind’s eye, draw a rectangle, approx
8” wide and 5” tall, with the bottom of this rectangle
resting on an interpolated line that connects both
ears. You will find that all the sonic images
portrayed by your headphone will “fit” into this
abstract rectangle that you have just drawn in your
mind’s eye. This abstract rectangle is the
headstage.


All the sonic images are resting on this abstract
vertical rectangle. (“Resting” is a strange word to
use when music is dynamic.) Think of the sonic
image as a child’s sticker book sticker—in your
mind’s eye you paste this “sticker” on the flat
rectangle. Sometimes the “stickers” may overlap
each other, but don’t be too bothered about this—it
is natural for two or more sonic images to
sometimes occupy the same space. If you own
high-end equipment, it becomes increasingly
difficult to picture the sonic images as flat “stickers”
because the images seem so full-bodied and
rounded to you. In which case, do not fret—think of
the headstage as the vertical plane that intersects
through the centres of all those full-bodied “balls of
sound”. Or think of the headstage as an upright
rectangular tupperware that contains these
rounded sonic images.


Concentrate on one sonic image. Precisely where
on the rectangle is it located? Is it located nearer to
the right edge of the rectangle? Is it located nearer
the top edge or bottom edge of the rectangle? On
lesser playback systems, it can become difficult to
pin-point the precise location of the sonic image—
the image seems to be smeared over a larger
area. On superior playback systems the image
location is precise and can be effortlessly located.
Once you have determined the location of this
image on the rectangle, you can proceed to the
next stage. Of this sonic image you picked, ask
yourself: is it soft-sounding? Then go the next
question: is the image you picked tonally washed-
out? Then: is it texturally washed-out? Then: is it
swathed with a reverberate halo?


When you have run through all four mechanisms
for the first sonic image, proceed to the next sonic
image of your choice. Run it through the same
checklist of five questions (its location on the
rectangle and the subsequent four questions).
When you are done with the second image,
proceed to the third.


It all sounds very tedious, but it isn’t. It is actually
simpler than it appears in this write-up. (Either that,
or I’ve had a lot of practice.) It isn’t really a chore
because you have to remember: you are bobbing
your head up and down to the rhythm and melody
of your favourite music. (Either that, or you’re
waving your imaginary baton in empty air.) How
can that be a chore? If anything, the awareness of
each image’s portrayal of the mechanisms only
serves to deepen the enjoyment of music.


After some practice, the awareness of the planarity
of the headstage and the perception of the Four
Depth Cues come quite naturally. With practice
the enjoyment of the music is integrated with the
perception of depth cues. It seems counter-
intuitive—the idea that in order to hear depth cues
better you need to first focus on the planarity of the
headstage plane. But keep practising at perceiving
the planarity of the headstage and its Four Depth
Cues and you will become a more discerning
headphone listener who can quickly and accurately
decipher the depth cues inherent in recorded
music.



Footnote-essay no.2:
NON-CARTESIAN CO-ORDINATES


If I were asked to paraphrase the headstage and
its 4 depth cues into a computer programme code
for processing of depth cues via headphones, I
would create the following 8 variables:

(x, y, z, r) + (a, ,b, ,c, d)

where

x = left-to-right location of image
y = up-down location of image
z = 0, which will create a flattened headstage
r = radius or roundness of images

a = loudness of image (depth cue #1)
b = tonal richness (depth cue #2)
c = textural specificity (depth cue #3)
d = reverberation amount (depth cue #4)


You might notice that (x, y, z, r) are variables that
arise out of the One mechanism of sound
localization. And (a, b, c, d) are variables that each
arise out of the Four Depth Cues.


Assigning z = 0 will create a flattened headstage.
Variable x is simply about stereo panning and
should be easy to programme for a pair of stereo
headphones. Variable y is difficult to programme—
what gives rise to the sense of up and down
placement of images? Variable r is difficult to
programme—what gives rise to a sense of
roundness of images? Variable a is easy to
programme—it is simply a matter of volume
control. Variable b is simple to programme—it is
simply a matter of equalization. Variable c is
difficult to programme—how does a computer
programme increase and decrease the
“trumpetness” of a trumpet? A computer cannot
recognize the texture of a trumpet simply from
wave analysis. Variable d is simple to
programme—it is a matter of feeding slight delays
to the original sound. But using a computer
programme to simulate good hall ambience must
surely be an art form.



Footnote-essay no.3:
CAN YOU INCREASE HEADSTAGE SIZE?


To increase the headstage size means to create
images that are located further from the head,
even to the point of creating out-of-the-head
images.


The only way to significantly enlarge the
headstage is to listen to binaural recordings, but as
I’ve noted previously, it’s unlikely for the your
personal HRTFs to coincide with the dummy head
used in the recording. Consequently, most of us
will still experience an in-the-head headstage when
listening to binaural recordings.


But there are some options open to you if you wish
to slightly increase the headstage size. (Keyword =
slightly.)


The headstage is the result of the transducer’s
location in relation to your ears. I have not
auditioned them before, but I would imagine that
Jecklin Float headphones create slightly larger
headstages than most other headphones, simply
because the left and right transducers in a Jecklin
Float (and AKG K1000 as well, come to think of it)
are about 2 inches wider apart than almost all
headphones. This increased distance should
create a slightly larger left-to-right soundfield, i.e.,
a wider headstage, but I’m not speaking from
firsthand experience of the Jecklin Floats here.
Swivelling the K1000’s earpieces frontally should
create a most amazingly frontally-located
headstage, unrivalled by any other headphone
probably except the STAX Sigmas.


The tonal character of a headphone has a small
but perceptible effect on headstage width and
headstage height. Brightness in the middle-
midrange and upper-midrange results in slightly
taller headstage heights when playing distance-
miked recordings, but results in a solidifying of
sonic images when playing close-miked recordings
with no apparent effect on headstage size.
Brightness in the upper treble has the effect of
slightly increasing the headstage width in close-
miked recordings, but slightly increasing the
headstage height in minimally-miked recordings. I
am generalizing here—not all close-miked
recordings sound the same and not all minimally-
miked recordings sound the same. But my central
point here remains valid: the tonality of a
headphone or recording slightly affects the
resultant headstage size, either in width or height
or both. I must emphasize the ‘slightly’ part.


But a larger headstage is not necessarily better
than a smaller headstage. It’s bit like saying that a
6” photo is better than a 5” photo. Is it really? Of
course it is nice to have a larger headstage (in the
same way it is nice to have a larger computer
monitor), but how about comparisons between
clarity, resolution, texture and colour saturation?
Size of headstage is only one consideration out of
many. Moreover, the differences between
headstage sizes of various headphones are not
that significant (at least from my experience), so it
really becomes less important to compare
headstage sizes. If the difference between the 5”
photo and the 6” photo is only 1” (if my math isn’t
rusty), and the 5” photo has better clarity and
colour saturation, then why not go for the 5”
because more significant factors outweigh the
small gain in size?



Footnote-essay no.4:
WHAT DOES “LARGE SOUNDSTAGE” MEAN?


Now and then I come across posts at Head-Fi that
says headphone X when coupled with headphone-
amp Y creates a “large soundstage”. What does
the phrase “large soundstage” mean in perceptual
terms? In abstract terms we all know what large
soundstage means—it means that the soundstage
is large. Duh. But what exactly did the person
perceive that prompted him to use the term “large
soundstage”?


It could be any one of five possibilities that
prompted him to use the term “large soundstage”:


(i) the headstage itself has increased in size, i.e.,
meaning that a sonic image instead of being
located in its usual position touching the left temple
(for instance) has now suddenly acquired through
happy accident an illusion of being located 3
inches in front of the left temple (for instance). By
happy accident I mean a freak coincidence where
your personal HRTFs and the phase/frequency
peculiarities of the recording and phase/frequency
peculiarities of a headphone system commingle to
result in a binaural-like illusion of an externally-
located image hovering 3 inches beyond the left
temple. This occurs very rarely. It is extremely rare
for images to drift away to some out-of-the-head
location.


(ii) the recording he heard had a deep soundstage
and he could hear to the very rear of the
soundstage. The backdrop of the soundstage is
created by a sonic image that portrays a depth cue
or a combination of depth cues, and the depth of
the backdrop is further emphasized by the
presence of a foreground object. The foreground
object is tonally richer or texturally richer or
reverberatively poorer than the backdrop image.
Experiencing this clear background-foreground
relationship may account for another possibility
why a person would say he hears a “large
soundstage”.


(iii) the recording had ample reverberation cues
and his headphone is transparent enough to
render such cues. Reverberation diffuses a sonic
image and makes the sonic image acquire a halo
around the image. The presence of this halo of
diffusion results in a perception that the sonic
image has increased in size as well as making the
image sound further away (#4). The bigger and
subjectively further sonic image leads to a
subjective perception that the soundstage has
correspondingly increased both in lateral size and
depth.


(iv) strangely, some instruments tend to “stand tall”
in the acoustic space. Choir voices and horns tend
to do that. I have no idea how or why this occurs.
The Four Depth Cues only work in the z-axis, and I
have not been able to account for mechanisms
that work in the y-axis. So another possible reason
for a person to say that he hears a “large
soundstage” is because he hears an image
standing tall in the acoustic space, which
contributes to his illusion of a larger soundstage.


(v) smeared sound is mistaken to be a wide
backdrop or a wide sonic image. This smear may
be inherent in the recording or may have been
introduced by the audio component.



A LEXICON OF HEADPHONESPEAK

Headscape: the contours and landmarks of your
head that you can reference the location of sonic
images against

Headstage: the head-hugging soundfield resulting
from the One mechanism of sound localization

Soundstage: perception of width via left-to-right
differentiation, perception of depth via Four Depth
Cues and perception of height via an unknown
mechanism

The Four Depth Cues: the four mechanisms based
on the principle that the further sound travels
through air, the more its volumetric (#1), tonal (#2),
textural (#3) and reverberative (#4) character
changes.

Depth cue #1: soft-sounding images tend to
appear further.

Depth cue #2: Tonally attenuated images tend to
appear further. Occurs in two incarnations—tonal
blandness and harmonic shift.

#2a: tonal blandness. Both higher harmonics and
lower harmonics are attenuated, causing tonal
blandness that makes an image appear further.

#2b: harmonic shift. Only the higher harmonics are
attenuated but the lower harmonics are intact,
causing an image to sound deeper and appear
further away.

Depth cue #3: Images with reduced textural
specificity appear further.

Depth cue #4: Images surrounded by a halo of
reverberative diffusion appear further. Comes in
two incarnations—diffused reverberation and
impulse reverberation.

#4a: diffused reverberation. Reverberation that
overlaps with original sound. Occurs with bowed
and blown instruments as well as voices.

#4b: impulse reverberation. Reverberation that
starts and stops quickly in the wake of the original
sound’s demise. Occurs with struck or plucked
instruments.

Textural range: an audio system’s ability to portray
differing depths by portraying the whole gamut of
differing textures

Perspectival air: a more acute (and more
enjoyable) form of soundstage depth when
mechanisms #2, #3, #4 and the sense of air
around instruments come together to form a
heady mix




__________________________________________________

 

[Snufkin]

Holy wordwrap batman, that's a lot of scrolling!

It's going to take me a while to absorb all that!

 

[andrzejpw]

I skimmed through it a second ago: serious reading will have to take place while I'm awake. Extremely interesting!

 

[Uncledan]

woow, this is a nice review!! I will save it when I have time to read!!

Nice job!

 

[dd3mon]

I read the vast majority of this letter, and I only have two things to say.

1) This essay would feel so right as the introduction to the pilot issue of the world's first Headphone related magazine. You've obviously spent considerable time on this, and it shows. I've not read another piece of audio prose that this piece would not stand up against.

2) Try some Sony R10's

Although I have not been fortunate enough to hear them for myself, many who have been agree that they are the world's only headphone that presents a realistic soundstage.

-dd3mon

 

[grinch]

Quote:

Originally posted by dd3mon 2) Try some Sony R10's Although I have not been fortunate enough to hear them for myself, many who have been agree that they are the world's only headphone that presents a realistic soundstage.

hahah wow are you dumb. try and keep the useless comments quiet until you've actually heard the gear you're talking about.

darth nut: wow. thanks for coming back.

 

[dd3mon]

Quote:

Originally posted by grinch hahah wow are you dumb. try and keep the useless comments quiet until you've actually heard the gear you're talking about.

Flametastic grinch - living up to the name again I see. My very small comment was, although not based on personal experience, far from irrelevant or 'useless'. Good contribution.

-dd3mon

 

[SteeleBlayde]

Still munching away at this thread at the moment....

 

[Vertigo-1]

OH...MY...GOD.

Darth Nut is back.

And with one hell of a post to start things off.

WELCOME BACK!!!

 

[spritzer]

Speachless...

Thanks very much for the review Darth Nut. Now it is even harder to wait for my Omega's to arrive

 

[HanssoN]

Marvelous, the pinnacle of reviews! Your review will be remembered and treassured for years to come

VERY nice

 

[kcits]

wow... a masterpiece of a review.. definitely some very good points brought up. especially the perceptions of "air" around instruments and headstage -- very interesting.

 

[kaiwei]

Great review, as usual from the HeadWize days.

Used to be there was only like 3 of us from Singapore in the HeadWize days but there's even a SG Headphones forum now.

Great to have you back!

 

[SteeleBlayde]

Wow. Simply spectacular. I've been reading your amazing review, the whole night! (Went for dinner a bit earlier.

) You bring up a vast amount of information with just as many pertinent points, and it is extremely apparent you have put a lot of effort into this "review", it definately shows. You've covered every single aspect of the headphone listening experience that I can think of, which is an amazing feat in itself. I must acknowledge you as a true pioneer in critical headphone listening! This "post" of yours definately deserves to be in a Hall of Fame.

I salute you, Sir.


Thanks for turning on the lights Daddy!!!

 

[HappymaN]

Lovely reading. It's the next best thing to strapping the headphones on yourself.