Audio Critic the 29 r schematic

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ISSUE NO. 29

Display until arrival

of Issue No. 30.

"Hip Boots,"

our classic column that
relentlessly waded through
the mire of misinformation
in the audio press, comes to
a reluctant but inevitable end.

Also in this issue:

A slew of unusually thorough loudspeaker reviews, by Don Keele,
Tom Nousaine, and Glenn Strauss.

Reviews of AV electronics, power amplifiers, and assorted other
electronic components and accessories.

Plus our standard features, columns, letters to the
Editor, CD/SACD/DVD reviews, etc.

pdf 1

contents

Our Last Hip Boots Column

By Peter Aczel

Speakers:
Five Loudspeakers (One a Time-Honored Exotic)
and a Headphone

By Ivan Berger, D. B. Keele Jr., Tom Nousaine, and Glenn O. Strauss
2-Way Audio/Video Minimonitor Loudspeaker:

Definitive Technology StudioMonitor 450 7

Powered Monitor Speaker: Genelec HT210 13
Floor-Standing 2-Way Loudspeaker System: Thiel CS1.6 17
Floor-Standing 2-Way Speaker: Ohm Acoustics Walsh 200 Mk-2 21
2-Way Minimonitor: B&W Nautilus 805 30
Noise-Canceling Headphones: Bose QuietComfort 2 Headphones 32

AV Electronics:

High Efficiency Meets Hi-Fi, in Analog and Digital
Embodiments

By Peter Aczel and David A. Rich, Ph.D.
2- & 5-Channel Power Amplifiers: AudioControl Avalon & Pantages . . .33

DVD Audio/Video Player & 7-Channel AV Surround Receiver:

Denon DVD-9000 & AVR-5803 35

CD/SACD/DVD Digital Disc Player/Receiver: Sony AVD-S50ES 37

Peripherals:
Four Audio Side Dishes: Two Good Little Radios, the

World's Best CD Rack, and a Switcher for Recordists

By Ivan Berger

Two Good Little Radios: Boston Acoustics Recepter Radio

& Tivoli Audio PAL 45

CD Storage: Davidson-Whitehall STORAdisc LS-576 47

Recorder Switchbox: Esoteric Sound Superconnector 48

Audio's Top Urban Legend

By Tom Nousaine

Capsule CD Reviews

By Peter Aczel

Box 978: Letters to the Editor

ISSUE NO. 29 • SUMMER/FALL 2003 1

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2 THE AUDIO CRITIC

After Ivan Berger had written the above, further unforeseen
delays took place. What's more, and worse, we lost our second-class
mailing permit, "due to nonuse" (too true, alas). The consequences
remain to be assessed. Will we continue to publish? You bet. Ad­versity just makes us more stubborn. —Ed. (RA.)

From the

Still in Transition.

This is the first magazine I've ever edited completely, and

the first issue of The Audio Critic that Peter Aczel has not.

He's neither gone nor going, just taking a step back and letting
someone else—me—handle the daily work.

In the last issue, Peter introduced me as the former Techni­cal Editor of Audio, but I feel some further introduction is in
order.

I've been writing about audio since my beard was black,
stereo was new, and everything was analog. I appreciate good
sound, maintain a healthy skepticism about the "scientific"
claims of manufacturers and designers, and realize that audio
components can sound good even when those claims do not
make sense—and sound bad even when they do.

My writings have appeared in many magazines, several lan­guages (including Portuguese and Flemish), and under a few
pen names. (At one time, I was writing for Audio, Stereo Re-
view, and High Fidelity, which the magazines didn't mind as
long as I used a separate name for each; an editor once called
me "three of the best-known hi-fi writers in America.") I've

also been an editor at Popular Mechanics, Popular Electronics,
and Video, as well as Audio. It's my editing that counts, here,
and you can judge that for yourselves.

Of the other transitions Peter Aczel mentioned in the last
issue, the partnership with The CM Group stopped progress­ing, and is gone. Progress has been made in getting us caught
up with our four-time-a-year schedule; we're far from there, as

yet, but we're continuing to move in that direction. This issue
came a little faster than the last; the next should come faster
still.

Editor and Publisher

Peter Aczel

Guest Editor

Ivan Berger

Technical Editor David A. Rich
Contributing Editor D. B. Keele Jr.
Contributing Editor Tom Nousaine

Contributing Editor Glenn O. Strauss

Technical Consultant (RF) Richard T. Modafferi

Art Director Michele Raes

Design and Prepress Tom Aczel

Layout Daniel MacBride

Business Manager Bodil Aczel

The Audio Critic® (ISSN 0146-4701) is published at
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Any conclusion, rating, recommendation, criticism, or
caveat published by The Audio Critic represents the
personal findings and judgments of the Editor and the
Staff, based only on the equipment available to their scrutiny
and on their knowledge of the subject, and is therefore not

offered to the reader as an infallible truth nor as an irre­versible opinion applying to all extant and forthcoming sam­ples of a particular product. Address all editorial corre­spondence to The Editor, The Audio Critic, P.O. Box 978,
Quakertown, PA 18951-0978.

Contents of this issue copyright © 2003 by Critic Publi­cations, Inc. All rights reserved under international and
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Some of our readers still don't understand what kind of letter is likely to be
published in this column. Zen hint to the intuitive: not the kind that begins with
"I have a Schmigehgie QX-200 amplifier-in your opinion is it. . ." Please
address all editorial correspondence to the Editor, The Audio Critic, P.O.
Box 978, Quakertown, PA 18951 0978.

to the Editor

The Audio Critic:

I hope Issue No. 28 was not the last
issue of The Audio Critic, since it shines
by an absence of the typical technical
nonsense that I find in all the other au­dio magazines. On top of that the tone
of presentation makes it so much more
readable than often in the past.

In the introduction to "Speakers"
(page 15), you point out that good
speaker design is the sum of many,
many aspects that were properly dealt
with. I agree wholeheartedly, and also
with your example of the Waveform
Mach 17 speaker system. Yet this
speaker, and all the ones that Floyd
Toole referred to in the feature article,
suffer from being caught in the box par­adigm. The ultimate performance and
accuracy of reproduction that can be
achieved within this paradigm are lim­ited, and the best of Toole's examples
have reached that plateau.

There are two fundamental prob­lems with box speakers: (1) selective re­radiation of the sound energy inside
the box through the cone and walls and
(2) a power response, or directivity in­dex, that changes at least 10 dB be­tween low and high frequencies. The
reradiation problem has been addressed
to varying degrees of success by differ­ent designers. Constant power response,
though, requires drivers and box fea­tures that decrease in size as frequency
increases, to maintain wide and uni­form polar response beyond what the
speakers in Toole's article achieve. The
result of failing to deal with these two
problems is the typical, generic box-

loudspeaker sound that is immediately
recognized in comparison to live, un­amplified sounds.

Loudspeakers end up in rooms. The
off-axis radiation therefore matters, as
Toole's findings clearly point out, but

10 dB variation in power response is too
much and limits this design approach.
The improvement beyond it is via om­nidirectional box speakers or full-range,
open-baffle dipole speakers. Some pla­nar electrostatic or magnetic designs
show the potential of this approach,
but ultimately they are limited by be­ing acoustically too large at higher fre­quencies, yet having insufficient vol­ume displacement for low-frequency
reproduction at near realistic levels.
These problems can be overcome with
conventional dynamic drivers on open
baffles. As it turns out, such speakers are
significantly less sensitive to the room
both below and above 500 Hz.

The "preservation of the art" prob­lem, or the "circle of confusion," can
only be resolved by using unamplified
sound as a reference and not other loud­speakers. This will also point out the
need to reduce nonlinear distortion and
stored energy, which are at least equal
in importance to the different steady­state frequency responses.

Siegfried Linkwitz
Linkwitz Lab
Corte Madera, CA

Siegfried Linkwitz is one of the most
distinguished practitioners in audio—
what audiophile hasn't heard of the
Linkwitz-Riley crossover? He was a

Hewlett-Packard scientist before he
started designing loudspeaker systems for

Audio Artistry and Linkwitz Lab, all of

which are based on the dipole principle.

Thus the above letter is motivated by a de­signer's agenda, but that doesn't make it
less valid. The arguments in favor of the
dipole approach are powerful and not to
be ignored. We wish we could test one of
the Linkwitz-designed loudspeakers—
how about it, Siegfried? We listed you as
one of the White Hats (good guys of au­dio) in Issue No. 24, but that was based
mainly on your engineering papers and

spoken commentary, not specific products.

It's time for some hands-on. As for your

favorable comments on our publication,

they couldn't come from a more authori­tative source and are therefore especially
welcome.

—Ed.

The Audio Critic:

In response to Issue No. 28, "Sci-

ence in the Service of Art"—is Floyd E.

Toole colorblind? First picture: a por-

trait painted under a light with 3 dB too
much red versus when viewed under
natural, neutral light. I've been paint­ing for over 40 years and I never knew
light could be measured in dB.

As for the rest of your magazine,
you've done better. As far as your plan
to retire to a primarily supervisory po­sition is concerned, just retire and let
Ivan Berger take over.

Your "Hip Boots" column is sorely
missed because it keeps the crazy audio
drivel in check. Don't give that up! Tom
Nousaine's "Urban Audio Legends"

ISSUE NO. 29 • SUMMER/FALL 2003 3

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comes close but does not have the "bite"
of "Hip Boots."

Maron Horonzak
Stoutsville, MO

Marrone, Maron! You never knew

that light could be measured in dB? Well,
it seems there are lots of things you never
knew, and this is one of them. A dB num­ber can be just an expression of a ratio,
e.g., 20 dB is a ratio of 10 to 1, 10 dB is
a ratio of 3.16 to 1,3 dB is a ratio of l.41
to 1. Thus 3 dB too much red means 1.41
times as much red as there should be—
41 % too much. Your assumption that it's
Floyd Toole, Ph.D., who doesn't know
what he is talking about, rather than you,
reveals a lot about you.

Now, about Issue No. 28 not being as

good as some others, you may be right.

When there are three or more of anything,

one will be the best, one will be the least

good, and the other(s) will be in between.

That doesn't mean, however, that they
aren't all good. As for my total retirement
and letting Ivan Berger take over, it's a

staggeringly simplistic suggestion innocent

of all business/financial/professional/per­sonal considerations. Didn't it occur to

you that it just might be more complicated

than that? lastly, "Hip Boots" is back in
this issue but, as explained there, not as a
continuing feature. Thanks for all your
concerns.

—Ed.

The Audio Critic:

I was truly delighted to find Issue
No. 28 in my mailbox yesterday. It is so
good to see that someone is still out
there battling the fakes and frauds. Pe­ter, you are my hero. [Mutual admira-
tion society! See below.—Ed.]

It is most pleasing to see the excel­lent authors you have corralled and the
fine articles that you have published. In

your editorial you claim to be getting

old and tired. But cheer up. What you
are doing with The Audio Critic is such
excellent work that it must go on.

I have retired from the audio field af­ter many years and am now, 10 years into

retirement, simply relaxing with my mu­sic and other hobbies. These are gar­dening, astronomy, and mineral collect­ing. Still, I think about audio matters
very often and still do a bit of consult­ing in room acoustics and audio systems.

I have taken the liberty of sending
you a couple of photos of my listening
room as it is now and has been for 22
years. I am still pleased with it and find
no reason to change anything. It is now
the music that counts for me.

Very best regards and best wishes for
future success.

Sincerely,
Dick Greiner
Madison, WI

Dr. R. A. Greiner is Emeritus Profes­sor of Electrical and Computer Engi­neering, University of Wisconsin, and one
of my heroes, as our regular readers know.
For quite a few decades before his retire­ment he embodied the academic com­munity's most authoritative, and at the
same time most genial, voice on the sub-

ject of audio. Talk about "battling the
fakes and frauds"—he was at all times in

the font lines, patiently refuting charla­tanry with irrefutable science. My admi­ration for him is unlimited, hence his fre­quent presence in this column. We may
not have anything near the circulation of
Stereophile, but could they ever, in a
million years, have elicited a letter like the
above from Dick Greiner?

As for your music system and listen­ing room, Dick, should I be surprised
that you are not looking for a change?

What, only eight monstrous woofers? Only
24 visible smaller drivers? Only a dozen
electronic units? I have never seen a 1980
setup like yours, and very, very few 21st
century rigs like it. It really amuses me
when you say that only the music matters;
it's like a Rolls Royce owner saying that,
well, it's basic transportation. May you lis­ten to that music in good health and spir­its for many years to come—and thank

you for your compliments.

—Ed.

The Audio Critic:

Hello Peter, I have come to praise

you, not to bury you!

Item One: I received the latest issue
of The Audio Critic (No. 28) and im­mediately went to die "From the Editor"
column. Your explanation as to the rea­son for the disintegration of your rela­tionship with The CM Group caught
my attention. Wanting to hear the other
side of the story, I placed a call to The
CM Group publisher, Greg Keilty . . .

... Greg had not read your explanation
as to what happened between you and
The CM Group, so I read your expla­nation to him (verbatim). Was I sur­prised at his response! He agreed with
you completely! To be completely hon­est (which is a much better form of hon­esty than partially honest!), I was ex­pecting at least a minor disagreement
from Greg regarding your explanation.
There wasn't. Not only did he agree with
your explanation but spoke very highly
of

you!

Son of a

gun!

You get an A+ for
editorial integrity and my apology for
doubting your word. It's somewhat
humbling to admit I was wrong, but it
would be a mortal sin not to admit so
and apologize.

Item Two: I received the latest issue

of Invention & Technology magazine

(Fall 2002). Within this issue of the
magazine was an article (the cover story)
titled "The Tube Is Dead, Long Live the
Tube," written by Mark Wolverton. No
need to tell you that I couldn't wait to
read Mr. Wolverton's article. I was ex­pecting more of the idiotic subjective
audio-cult gibberish printed as fact by
mainstream publications {Wall Street

Journal, Business Week, Fortune, to name

a few). Fortunately, this time, the
cultists were shown as believing (?) and
propagating myths based only on their
emotional or financial involvement
with tube equipment—something you
have been preaching for quite a while.
Much to my pleasant surprise, you and
David Rich were quoted regarding the

(continued on page 44)

4

THE AUDIO CRITIC

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By PETER ACZEL, Editor

Our Last

Column

How come? Because "wading through the mire of misinfor­mation in the audio press" (our former subtitle) is no longer
meaningful when nearly the entire audio press is dedicated to
misinformation.

B

efore we stopped running our
"Hip Boots" column three issues

ago, its subject was almost in­variably the ignorant and/or irresponsible
subjectivity of certain audio reviewers,
more often than not Bob Harley (igno­rant) or John Atkinson (irresponsible) or
Harry Pearson (ignorant and irresponsi­ble). Occasionally we addressed purely
technical errors in various publications,
sometimes even the mass media, that a
good fact checker could have corrected,
but most of the time our target was the
absence of accountability in one or the
other of the same three or four audio
magazines. That's where the mire lay that
only hip boots could wade through.

Lately the ground has shifted—or,
rather, it has expanded, spread out, in a
totally engulfing mode. We have reached
the point where virtually the entire au­dio press is in tacit denial of the realities

of electrical engineering and electro­acoustics. All debate on the subject has
ceased. The false assumptions we used to

attack have become the self-evident

givens of the audio journalists. Fiction is

now accepted fact, mindless misinfor-

mation is unquestioned mainstream.
So—what's the point of singling out in­dividual examples of this sad state of af­fairs? Whatever nonsense reviewer X
writes is echoed just as unthinkingly and
self-assuredly by reviewer Y and reviewer
Z. Why "hip boot" X but not Y or Z?

Do you think I'm overreacting or
exaggerating? Then tell me which
equipment reviewer refrains from as­cribing a personality to amplifiers, pre­amplifiers, and CD players. They all do
it, except David Ranada, technical ed­itor of Sound&Vision, the one maga­zine that is at least a partial exception
to the rule—but their other reviewers
are not as careful and tend to fall into
the trap of characterizing the sound of
electronic equipment.

For our newer readers I should per­haps point out all over again the pa-

thetic fallacy of talking about the

soundstaging, or front-to-back depth,
or open/closed quality, or graininess,
or any other sonic characteristic of
purely electronic signal paths that are

less than, say, 20 years old. What the

human ear can differentiate are fre-

quency response, level, noise, and to a
lesser extent distortion. That's all.
Since all modern audio components,
from a $15,000 rip-off amplifier to a

$69 portable CD player, have flat fre­quency response, negligible noise, and
negligible distortion, their sound has
no signature, no personality. Any two

of them—two amplifiers, two pre-

amps, two CD players, etc.—will
sound exactly the same, as long as their
levels are matched within ±0.15 dB. I
solemnly guarantee it. There has not
been a single properly conducted lis­tening test—double blind, at matched
levels—to contradict that statement.
This will surprise only some of the
aforementioned newer readers and
elicit a chorus of denial from the more
obstinate of the high-end reviewers,
but it is an ironclad truth. Think about
it. There is no such thing as an effect
without a cause, and what could cause
a sonic difference except a skewed fre­quency response, a high noise floor, or
unusually high distortion? What you
are told in Stereophile, The Absolute
Sound, and other such publications is

ISSUE NO. 29 • SUMMER/FALL 2003 5

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6 THE AUDIO CRITIC

arbitrary effect without an explainable
cause—"Hip Boots" material over and
over again.

I'll grant maybe a rare exception to
the above in the case of the most eccen­tric "retro" vacuumtube designs, which
depart so radically from the flat/low
noise/lowdistortion model that, for all
I know (and I don't care), they sound dif­ferent. The gullible are welcome to these
electronic abortions. I'll also grant that
matching levels within ±0.15 dB (prefer­ably within ±0.1 dB) is a fussy, sweaty,
boring process, requiring some instru­mentation, and for all those reasons not

done when it should be. That is un-

questionably the main nonideological
reason for all the stonewalling denials of
the soundalike outcomes. (Larry Klein,
former technical editor of Stereo Review,
Sound & Visions predecessor, once sug­gested a delightfully ironic solution to
this problem. He said you don't need
any instrumentation to match levels

within ±0.1 dB; all you need to do is fuss
with the volume controls until A and B
sound exactly alike, at which point the
levels will be perfectly matched. Bingo!
I love it!)

Let us also address the opposite end
of the spectrum, where there are always
large differences in sound—loudspeakers.
Every loudspeaker ever made is at least
slightly different in frequency response
from every other and therefore necessar­ily sounds different. Unfortunately, this
creates another likely "Hip Boots" situa­tion. The various subjective equipment
reviewers have no clue as to how to re­late the measured performance of a loud­speaker—if indeed they have measured
it—to its sound. Let us say it has rapidly
falling lowfrequency response below 60
Hz. In that case they would probably
praise its superior bass. Or it has almost
deadflat highfrequency response over a
large angle. In that case they would com­plain about its attenuated treble. If it has
a huge suckout in the crossover region at,
say, 1.8 kHz, they would praise the highly
accurate upper midrange. And so on. It

isn't just one or two reviewers that do
this. I look at the subjective highend
magazines and find absolutely no corre­lation between measured performance
and listening appraisal. Not that more
than one or two of them do any meas­uring at all, but I do and I can't find a sin­gle loudspeaker reviewer whose percep­tions agree with mine and track my
measurements. (Tom Nousaine of
Sound & Vision is an exception, but he
doesn't count because he also writes for

The Audio Critic.) Since none of them do
an orderly, logical, disciplined job—like
Don Keele or David Rich or me in this
publication—what's the point of "hip
booting" one or two of them?

My conclusions from all this actu­ally go beyond the futility of continu­ing "Hip Boots." I am beginning to
think that all comparative (A/B) lis­tening tests have become unnecessary.

What? How can an audio equipment

reviewer possibly be saying this? Bear

with me for a moment. Since all mod-

ern electronic signal paths sound the

same, why go through the motions of
A/Bing them? I can guarantee that the

results will be the same over and over

again, and therefore the exercise is a
waste of time. (Don't misunderstand
me. I'm not suggesting that we stop lis-

tening to and enjoying music through

the various components. I'm talking
about A/Bing.) You can try it, as I have,
with a multikilobuck highend ampli­fier (A) and a dirtcheap Japanese mass
market receiver (B). You'll see.

But that's not all. I'll go further. Why

A/B loudspeakers? The flatter they are

in frequency response and the lower
they are in distortion, the more nearly
they will approach total neutrality, to­tal transparency, which is both the goal
and the reference point. Conversely, the
more they deviate from flat and distor­tionfree response, the more they will
deviate from neutrality/transparency.

These relationships, as I have found out
over the years, are linear—the approxi­mation of the ideal sound is exactly pro­portional to the degree of perfection ob­tained from the measurements. In other
words, there are no surprises in the lis­tening tests—in which case why bother
with them? The only reason to do so is
that our measurements are incomplete;
we would need the 72 different meas-

urement points in a 4π space that Floyd
Toole uses at Harman International to
be sure that we have characterized each
speaker completely. If we had the labo­ratory facilities to do that, I wouldn't
A/B test anymore (although Floyd still
does). We have reached the point in au­dio where the laboratory instruments
know it all and tell it all, much as the
goldenear boys hate to admit it.

All of the above considerations are
made more complicated by surround
sound, which has its own rules. It is
not easy to understand that the audible
differences between Dolby Pro Logic
(I and II), Dolby Digital, DTS, Home
THX Cinema, 5.1, 6.1, 7.1, etc., etc.,
are not a matter of signal paths but of
algorithms. The differences are deter­mined mathematically, not acoustically.
(There are also differences in bit rate be­tween Dolby Digital and DTS, but
none that I consider to have audible
significance.) Listening tests, therefore,
are quite limited when it comes to sort­ing out the inherent audible character­istics of each configuration, because ba­sically the sound is determined before
it reaches the amplifier/speaker stage. It
could actually be better studied from a
block diagram. Again, remember that
I'm talking about comparative listening,
not musical enjoyment.

In general, the paradigms have
shifted, journalistically, electroacousti
cally, psychoacoustically, every which

way. You can't take the old perspectives
for granted. We are well into the 21st
century. Or perhaps I should say, dis­comforting as it is, we aren't in Kansas
anymore.

pdf 7

ISSUE NO. 29 • SUMMER/FALL 2003 7

By Ivan Berger, Guest Editor

D. B. Keele Jr., Contributing Editor

Tom Nousaine, Contributing Editor

Glenn O. Strauss, Contributing Editor

Five Loudspeakers (One a Time­Honored Exotic) and a Headphone

Definitive Technology, 11433 Cronridge
Drive, Owens Mills, MD 21117.

Voice: [phone]. Fax: (410) 363-

9998. E-mail: [e-mail].
Web: www.definitivetech.com. StudioMoni-

tor 450 shielded audio/video minimonitor

loudspeaker. $329.00 each ($658.00 the
pair). Tested samples on loan from the
manufacturer.

A 10-inch, side-mounted woofer in
a full-range speaker this small? Not
quite. It's something Definitive Tech­nologies calls a "planar-technology pres­sure-driven subwoofer"—in other
words, a passive radiator (sometimes
called a PR, drone cone, auxiliary bass
radiator, or flapping baffle). Typically,
passive radiators substitute for vents,
or ports, in small speakers designed to
deliver substantial bass output. That's
a good description of the StudioMon­itor 450, a member of Definitive Tech­nologies' "Monitor Series" of modestly
priced home-theater loudspeakers.

Using a ported cabinet instead of

a closed box extends a speaker's low­frequency response and reduces its
distortion. It does this by coupling an
acoustic resonant system (the enclo­sure and a port—usually a tube—that
vents its output into the room) to the
rear of the speaker's diaphragm. This
sets up an acoustic resonance between
the mass of air moving in the port
and the stiffness of the air in the en­closure. By matching the enclosure
and port sizes to the characteristics of
the driver, this resonator is typically
tuned to a frequency near the lowest
frequency the system is intended to
reproduce, and radiates low frequen­cies over a range of roughly two-thirds
of an octave around its resonance. If
the system is properly designed, far
more sound comes from the port
(within its operating range) than from
the driver. Because the ported enclo­sure's acoustic resonant system is typ­ically more linear than the mechani­cal resonant system of the speaker, its
distortion is lower. Below its reso­nance, unfortunately, the port's out­put is essentially out of phase with
the loudspeaker's, which makes the
system's bass output roll off much
faster than that of an equivalent
closed-box system.

pdf 8

There is, however, a catch to all
this: At high volume levels, the air in
the vent can move fast enough to gen­erate significant turbulence, which
causes extraneous noise and limits the
port's output. This turbulence can be
tamed by increasing the port's area,
but that calls for lengthening the port
to increase the air mass within it. Oth­erwise, the box resonance, and hence
the shape of the speaker's response
curve, will change. For small boxes
that are tuned to low frequencies and
designed to radiate a lot of acoustic
power, enlarging the port's mouth
would call for very long port tubes
that take up a lot of space in the box;
sometimes, tubes that are long enough
won't fit!

Using a passive radiator sidesteps
these problems. Typically, a passive ra­diator is a speaker (frame, cone, sur­round, and sometimes spider) without
a magnet and voice coil. Here, the
ported-box resonance is a function of
the mass of the passive radiator and
the compliance of the air trapped in the
enclosure. Because it is shallow, the ra­diator can be made large enough to
avoid turbulence while taking up
hardly any space within the cabinet.

And because the radiator's mass is in-

dependent of its area, any size will do
as long as its air-moving capability (area
times stroke) is sufficient. A properly
designed passive radiator requires
roughly two to four times the air-mov­ing capability (1.5 to 2 times the di­ameter) of its companion driver and
must have a self, or free-air, mechani­cal resonance at least an octave below
box resonance.

In Definitive Technology's com­pact, two-way StudioMonitor 450,
the companion driver to the 10-inch
passive radiator is a 6½-inch cone
woofer/midrange, used with a 1-inch
aluminum-dome tweeter. Both active
drivers are mounted on the front of
the cabinet, with the tweeter on top
and offset about an inch to one side.
The speakers are provided in mirror­image pairs, with black, white, or
golden-cherry piano-gloss finishes on
the top and bottom. The front, sides,
and rear are covered in a wrap-around
grille cloth, held in place by the re­movable top and bottom pieces. Con­nection is through a single pair of
gold-plated multiway binding posts,
spaced for double banana plugs, on
the bottom rear of the cabinet. Cabi­net construction is quite heavy-duty
for a speaker system of this size and
price: The medium-density fiberboard
(MDF) front panel is a full inch thick,
and the remaining panels are ¾-inch
MDF. The cabinet is well braced and
quite solid.

The magnetically shielded, 1-inch
aluminum-dome tweeter is essentially
the same as that used in Definitive
Technology's top-of-the-line systems.
The 6½-inch bass/midrange driver, also
magnetically shielded, has a cast basket.
The 10-inch passive radiator is simply
a rigid circular plate with an attached
surround.

The SM 450's crossover is wired
on a small PC board mounted near the
speaker's input cup and can be reached
by removing the cup. The crossover,
a second-order design, has an iron-

8 THE AUDIO CRITIC

core inductor connecting the
woofer/midrange, an air-core inductor
in the tweeter circuit, four power re­sistors, and three capacitors. That's
one more resistor and capacitor than

usual; the extra components probably
act as an impedance-compensating
network.

As in my previous reviews, I used
two different test techniques to meas­ure frequency responses. I used nearfield

measurements to assess low-frequency

response, and measured response at
middle to high frequencies with win-

dowed in-room tests (my test micro­phone was centered between the

tweeter and woofer/midrange axes, 1
meter away). The test signal for these

measurements was the usual 2.83 V

rms, and the curves were subjected to

one-tenth-octave smoothing.

The on-axis response of the Studio

Monitor 450 is shown in Fig. 1, in­cluding smoothed and unsmoothed
responses above 10 kHz. Only the re­sponse with the grille on is shown, be­cause the grille cloth is not designed to
be removed; fortunately, the grille had
essentially no effect on the SM 450's
response except for very small devia­tions of less than ±0.5 dB between 8
and 12 kHz. The smoothed curve is
quite well behaved and fits a tight (2.5­dB) window from about 95 Hz to 12
kHz. At higher frequencies, the un­smoothed curve exhibits a sharp dip of
about 10 dB at 12.9 kHz followed by
a less energetic peak of about 4 dB at

14.5 kHz, both presumably caused by

a resonance in the tweeter's metal
dome. At low frequencies, the system
rolls off slowly, reaching -3 dB at 83
Hz, -6 dB at 63 Hz, and -9 dB at
about 50 Hz (which is near the SM
450's vented-box resonance). Below

50 Hz, the system rolls off rapidly,

about 24 dB per octave, as is common
with vented-box systems. However,
this curve was measured in free space,

pdf 9

Fig. 3a: Frequency response above axis.

ISSUE NO. 29 • SUMMER/FALL 2003 9

Fig. 2: Horizontal off-axis frequency response.

Fig. 1: On-axis frequency response.

without reflecting surfaces to augment
the bass; in a room, reflections from
the walls would enhance the bass con­siderably. Averaged between 250 Hz
and 4 kHz, the SM 450's sensitivity
was high (89 dB), just 1 dB less than
Definitive Technology specifies. The
left and right speakers matched within
+ 1 dB, with most of the difference oc­curring in the tweeters' range.

The SM 450's horizontal and ver­tical off-axis frequency responses are
shown in Fig. 2 and 3. Fig. 2 shows
the horizontal off-axis curves, in 15°
increments out to ±45°. Between 1
and 3 kHz the response shelves down­ward, the dip worsening as the off­axis angle is increased. There are also
significant high-frequency aberrations
above 8 kHz at extreme off-axis an­gles. These aberrations include a dip
above 10 kHz, followed by a peak at

about 13 kHz.

That high-frequency dip and peak

are also seen in the responses measured

above and below the tweeter's axis. The
above-axis curves (Fig. 3a) are quite
well-behaved, except for a dip in the

3 kHz crossover region that deepens

progressively as the listening angle in-

creases, and the previously mentioned

aberrations above 10 kHz. Response

below axis (Fig. 3b) is significantly

smoother. Between 3.5 kHz and 7 kHz

the output below axis slightly exceeds

the on-axis output, which indicates that

the SM 450's response is smoothest a bit

below axis. This implies that these

speakers should be aimed above ear

level, or possibly be mounted upside

down to provide the smoothest re-

sponse for seated or standing listeners.

Luckily, the cabinet bottoms are fin-

ished like the tops, although there are

four small bumps that serve as feet. Un-

fortunately, the logos on front of the

speakers are upside down when the

speakers are inverted.

The input impedance magnitude
of the StudioMonitor 450 (Fig. 4a)
drops to a low of 3.2 ohms in the lower

pdf 10

midrange (at about 200 Hz) and

reaches a high of about 14 ohms
slightly below crossover, at 1.6 kHz.

The two impedance peaks that mark

the 450 as a vented box are clearly ev­ident; the impedance minimum (3.7
ohms at about 55 Hz) shows where the
box is tuned. The impedance phase
(Fig. 4b) is well behaved and varies

only moderately, about ±38°. The SM
450 should be an easy load for any
competent power amplifier or home­theater receiver.

To measure the distortion of the
450 (Figs. 5a and 5b), I used some soft­ware I recently wrote that works in con­junction with Igor Pro 4.0, a graphics
and data-analysis program (available for
Mac and PC from www.wave­metrics.com) and an external audio in-

terface with 24-bit A/D and D/A con-

verters, the Sound Devices USBPre

(www.sounddevices.com). In this setup,
test signals generated by Igor are fed
through the USBPre and my amplifier
to the 450s, while signals from my test
microphone are fed to the computer
through the USBPre, then analyzed and
plotted on graphs by Igor.

Fig. 5a shows the sine-wave har­monic distortion of the 450, evaluated
from 40 to 500 Hz at frequencies 1/12 oc­tave apart. The distortion was evaluated
at each frequency by applying a sine

wave to the system for one half second

and then evaluating the harmonic dis­tortion of the system's output, meas­uring the total energy of the 2nd
through 5th harmonics by using FFT
(Fast Fourier Transform) to compute
the frequency spectrum of that out-

put. (Results are expressed as a per-

centage of the fundamental's signal

level, not as a percentage of the total
output. Note that this calculation

method allows distortion levels above

100% if the energy of the harmonics
is greater than the energy of the fun­damental.) The harmonic distortion at

each frequency was evaluated at three
different power levels, 6 dB apart. (The

10 THE AUDIO CRITIC

Fig. 4b: Impedance phase.

Fig. 4a: Impedance magnitude.

Fig. 3b: Frequency response below axis.

pdf 11

Fig. 5b: Intermodulation distortion versus frequency and power level.

0 dB level was 2.5 V rms, or 25 watts
assuming a 4-ohm impedance.) Mea­surements were made with the speaker
on its side on the ground plane, passive
radiator facing up, and the test micro­phone at the ground plane, on the
woofer/midrange driver's axis and 0.25
meters away.

For frequencies above 125 Hz, the
harmonic distortion percentage stays
roughly constant and generally dou­bles when the input power does. Be­low 125 Hz, the distortion reaches a
maximum at about 70 Hz, falls to a

minimum between 50 and 55 Hz, and
then rises rapidly at lower frequen­cies. The dip in the vicinity of 50 Hz
coincides with the system's vented­box tuning frequency, where the pas­sive radiator is producing most of the
sound. (As you can see from the slight
shift in this dip when the power level
changes, box tuning varies slightly
with the test conditions; this is why
the impedance measurement, above,
indicates 55 Hz as the tuning fre­quency.) At the highest power level, 25
watts, the maximum distortion is a

When I first unpacked the Stu-

dioMonitor 450s, I was quite impressed

with their overall appearance, especially

the cabinets' piano-black top and bot­tom panels. At first, I could not figure
out how to get the grille cloth off so I
could see the drivers, but I soon deter­mined that the top and bottom panels
could be removed, as they are attached
to the cabinet with four pegs that en­gage holes in the panels. When a panel

is removed, it uncovers the grille cloth,
which is tightened around the cabinet
with a captive drawstring. The grille
wraps completely around the cabinet

and has a cutout at the rear for the in-

put-terminal cup.

ISSUE NO. 29 • SUMMER/FALL 2003 11

moderate 16% or so, occurring at 70

Hz. At the power levels I used for this

test, the distortion did not become ir-

ritating until the test frequency

dropped below 45 Hz.

The SM 450 woofer's intermodu­lation distortion (IM) was measured
with the same power levels and test

conditions as in the harmonic distor­tion test but over a slightly different
range of frequencies. For this test, I
applied two tones of equal level, one
fixed at 440 Hz, the other varying
from 31.6 to 100 Hz in half-octave
steps. The dual-tone test signals were
applied to the speaker for one half sec­ond each. The test results, expressed
as a percentage of the energy of the
two original test tones, represent the
total energy of three intermodulation
sidebands above and three below the
higher test frequency. The IM (Fig.
5b) varies slightly over the tested fre­quency range and increases as the
power level increases. At the highest
test level (25 watts) the IM rises to
roughly 10% at the lowest test mod­ulating frequency. While 10% har­monic distortion is not annoying,

10% IM distortion is. At power lev­els of-6 dB (5 watts) and less, the IM
remains below 3%.

Fig. 5a: Harmonic distortion versus frequency and power level.

pdf 12

When uncovered, the speakers and
cabinet had a meticulous, no-non­sense look that showed careful crafts­manship and attention to detail. Un­der the grille cloth, the enclosure was
finished in an attractive satin black.
The SM 450s are provided with wall­mounting brackets that screw into
routed-out holes on the rear panel—
a nice touch.

The large passive radiator essen­tially takes up one whole side of the
cabinet; in an enclosure this size, it

looks like a monster woofer. The ra-

diator is inset " to protect it from
damage. When energized by high­level sine waves, the speaker sounded
quite clean down to 40 Hz, but dis­tortion was audibly significant at
lower frequencies. At the box tuning
frequency, the woofer's motion almost
ceased and the passive radiator's ex­cursion became quite large. The deep
null in the woofer's excursion showed
that the box and the passive radiator

work extremely well.

At and near the system's tuning
frequency, maximum clean excursion

was about 0.3" peak-to-peak for the
woofer and a healthy 0.4" peak-to­peak for the passive radiator. The ef-

fective radiating diameter of the pas-

sive radiator is about 8.35" and that

of the woofer about 5". This makes
the drone cone's radiating area ap­proximately 2.7 times that of the

woofer—and with its higher excur­sion capability, it can move roughly 3

to 3½ times as much air as the

woofer. As I said above, this is good

design practice for a passive-radiator

system.

For my listening, I placed the sys­tems on 24" stands (which raised the
tweeter to about 34½" above the

floor) about 7 feet apart and well
away from room's side walls. I drove

them with my Crown Macro Refer­ence power amplifier and Krell KRC

preamp. The SM 450s are smooth-

sounding speakers, and their sensi­tivity is quite high, especially as com-

pared to my reference B&W Matrix

801 Series 3 systems. In A/B com­parison tests, I had to attenuate the
input to the Definitive Technology
speakers by about 4 to 4.5 dB to
match their levels to the B&Ws'. The
LED level monitors on my power am­plifier showed that the amp was
working noticeably less hard when
driving the SM 450s. The Definitive
Technology speakers performed well
as long as the deep bass levels were
modest, but were no match for the

B&Ws in the low bass. Otherwise,
their overall balance was quite simi­lar to the B&Ws'.

The SM 450s performed ad­mirably on recordings with high peak
content, which profit from high play­back levels—big-band material with
prominent brass sections and drum

rim shots, for example. With the peak­exercising special effects on Ein
Straussfest (Telarc CD-80098—one of
my favorites, even though it dates
back to 1985!) I could actually get
slightly more volume from the De­finitive Technology speakers than
from the B&Ws, because the latter's
lower sensitivity caused my amplifier

to clip before they reached the 450s'
maximum level. However, when I got
carried away with the volume control
on some of the Telarc CD's very loud
low-bass passages, I could overload

the 450s severely. The 450s' bass re­sponse was quite adequate on most of
the material I listened to. On shaped
tone bursts, bass response was quite
acceptable down to 50 Hz, with us­able output at 40 Hz—but not at
lower frequencies. Teaming the 450s
up with a subwoofer improved the
sound significantly, putting the 450s
on a more equal footing with the
much larger 801s.

On well-recorded female vocals,
the 450s did exhibit some slight upper­midrange irregularities, but on high­frequency sibilants they did quite well,
reproducing them without harshness,
strain, or spittiness. After my lab tests
revealed high-frequency response aber­rations caused by the tweeter reso­nance mentioned earlier, I listened to
the speakers again, but could hear no
problems caused by this. (Although
my hearing, at this point, is rolled off
in the range of this resonance, I some­times can detect the subharmonics of
such resonances.) The 450s were the
full equal of the 801s on male speak­ing voices.

On the stand-up/sit-down pink­noise test, I heard moderate upper­midrange irregularities when I stood
up. With the speakers turned upside
down, the sound heard from a stand­ing position matched the on-axis
sound more closely. I did perform side­by-side A/B mono listening compar­isons between an upright and an up­side-down speaker. Differences were
much less evident with music than
with pink noise.

The imaging and soundstaging of
the 450s were excellent. Mono center
images were quite stable and did not
shift when the recording's frequency
content changed. The 450s did ex­tremely well on classical a cappella
choral music, reproducing the voices
and the room's reverberant sound with
great precision.

Considering their reasonable price,
good looks, and great sound, I highly
recommend the Definitive Technol­ogy StudioMonitor 450 speakers for
stereo use or for a home theater setup.
With a competent subwoofer, they
provide real competition for many
much larger systems. Their high sen­sitivity and smooth response will be

welcome in any music system.

—Don Keele

12

THE AUDIO CRITIC

pdf 13

ISSUE NO. 29 • SUMMER/FALL 2003 13

Genelec Inc., 7 Tech Circle, Natick, MA

01760. Voice: [phone].

Fax: [phone]. E-mail:
[e-mail]. Web:
www.genelec.com. Model HT210 2-way
active loudspeaker, $2800.00 each in

black; other finishes optional. Tested sam-

ples on loan from manufacturer.

No audio component is perfect,

and speakers are the least perfect of all.
The imperfections of other compo-

nents can be too small for anyone to

hear, but speakers—all of them—have

readily audible deficiencies. The virtue

of "active," or powered, speakers is that

their electronics can make those de-

fects far less audible: Dedicated elec-

tronic equalizers can minimize the

speaker's frequency-response errors.

Built-in amplifiers can provide the ex-

act power that the speaker (or, better

yet, each driver) requires and, if each

driver is powered separately, precise ac-

tive crossovers can be employed instead

of cruder, passive ones. What's more,

protective circuitry can be custom-tai-

lored to the drivers it safeguards.

Despite their obvious potential for

improved performance and reliabil­ity, active loudspeakers have never
taken off in the home market, proba­bly because most audio consumers al­ready have receivers with a full com­plement of channel power, or even a
stack of amplifiers. Why buy power
again?

The complexity of modern audio
and home theater systems may change
that. In the days of stereo, all you
needed was a record player, a tuner, a
tape deck, a preamplifier, and a stereo
power amplifier, plus five shelves to
hold everything. Today, you might
have seven source components, a pre­amplifier, satellite receiver, and an
equalizer (well, I do). Who has rack
space for an additional seven or eight
channels' worth of amplifiers? I sure
don't.

So I use active speakers through­out my 7.1-channel reference system;
they perform better, conserve space,
and (because of their driver-matched
power levels and protective circuits)
let me leave my system in the hands
of a friend without coming home to
fried tweeters and the smell of melt­ing voice-coil glue.

Genelec is a fairly new name in
the consumer market, but this Finnish
company's active speakers are highly

regarded and widely used in pro
sound, where active speakers have
long been common. Now, the com­pany is angling for consumer sales,
with several series of active home-the­ater speakers. The HT210 is the larger

two-way speaker system in the Inti­mate Home Theater series (there's also

a three-way system), recommended

for rooms of 3,000 to 4,200 cubic

feet; other series are designed for

rooms of under 3,000, 5,000 to

10,000, and over 10,000 cubic feet.

The line also includes an in-wall

model and two subwoofers.

The HT210 has a 10-inch woofer,
which is unusual in a two-way speaker.
The primary reason you don't see

many 8-, 10-, or 12-inch two-way de­signs is that the directivity of large
drivers narrows rapidly as they reach
the crossover point, which is also the
frequency where a tweeter's directiv­ity is widest. Passive crossovers can
have little or no influence on direc­tivity, especially while retaining
smooth response off axis. Better-per­forming satellites use 6- or 6½-inch
woofers at most, because such drivers
are the largest ones capable of offering
both a reasonable low-frequency ex­tension and a woofer directivity that
closely matches the tweeter's near the
crossover (1.8 kHz). With electronic
crossovers the designer can play a few
little trade-off games regarding direc­tivity; in the case of the HT210, how­ever, the excellent directivity over the
entire operating range from 42 Hz to
22 kHz, despite the comparatively
large woofer, appears to be due to the
shallow, hornlike "Directivity Con­trol Waveguide" surrounding the
tweeter.

The HT210 has two internal am­plifiers: a woofer amp with a "short­term" power rating of 180 watts, and
a tweeter amp with a 120-watt "short­term" output rating. Genelec doesn't
say what the hell "short-term" watts
are, but who cares? Amplifier power

ratings for active speakers (powered

subwoofers included) have no signif-

pdf 14

14 THE AUDIO CRITIC

icance. We need to know how much
energy comes out of the speaker, not
how much energy goes in to produce
that output. (Of course, if manufac-

turer X gets 120 dB SPL with a 2,000-

watt amplifier and manufacturer Y

does it with 20 watts, I might prefer

the latter because it's easier on my
electric bill.) What is significant is
that Genelec specifies peak output for
a pair of HT210s as 124 dB SPL at 1
meter with "music material."

Unlike the controls on passive
speakers, the Bass Tilt, Bass Roll-Off,
and Treble Tilt controls in the
HT210's electronics work almost ex­actly as specified, even at low fre­quencies. An "Autostart" function
turns the unit off if no signal has been
present for 5 minutes, but restarts it
immediately when a new signal is re­ceived. Additional controls on the rear
panel (wouldn't remote controls be
cool?) include an on-off switch, a

110/220-volt mains selector, XLR and
RCA input jacks, and a rotary control
for matching input sensitivity to the

output levels of upstream compo­nents. Units currently in production
have two additional features: a set of
contacts for on-off switching using

12-volt trigger signals, and switches

that control the LED indicators.
(Users will be able to select whether

the LEDs remain off, show only yel­low for standby and green for opera­tion, or also show red for overload.)
The speaker is magnetically shielded,
so you can use it near a TV set or
other cathode-ray tube (CRT) display.

The HT210 is relatively large for
a satellite speaker. (With its bass re­sponse specified as -2.5 dB at 42 Hz,
the HT210 could conceivably be
used without a subwoofer, but I think
few would use it that way.) Although
it has a small, 1-foot-square foot­print, the cabinet occupies 2.8 cubic
feet of space in a listening room, and
its 48-lb. weight means that you
won't be hoisting these speakers off
their stands with one hand while
dusting with the other. The MDF
cabinet of my samples had a flat black
pro-style finish, and lacked the op­tional ($79) grilles. In speakers sell­ing for $5,600 a pair, the utility
finish and the extra charge for grilles
were disappointing. However,
HT210s are now available in glossy
piano black and three wood-veneer
finishes, all complete with grilles
(prices not established at press time).

As I did not have the grilles, I could

not measure what effect, if any, they'd
have on the sound.

The tweeter waveguide plate can
be removed and rotated 90° so the
Genelec logo will be upright if you
mount the speaker horizontally. The
electronics panel on the rear is re­siliently mounted, a pro-sound carry­over that protects the system against
rough handling on tour. The enclosure
seems relatively tourproof, too: when I
accidentally knocked the HT210 off
my measurement stand, the 6-foot
drop left only a -by-2½-inch gouge
on the rear corner of the cabinet and
did not affect the speaker's operation.

How did the Genelec HT210 meas­ure up? Let's discuss how it performed

in the lab first. Basic measurements
were taken at 2 meters in my large,
7,600-cubic-foot, room; maximum
output for a stereo-arrayed pair was
measured at 4 meters in the same room.
All measurements were taken with a

DRA Laboratories MLSSA acoustic an-

alyzer and an AudioControl SA-3050A
third-octave real-time analyzer and
sound-level meter.

The horizontal response graph
(Fig. 1) shows that the HT210 is in-

credibly smooth out to 60° off axis.
Directly on axis, its response fits in
a ±3 dB window from 55 Hz to
20 kHz, shelved up by approximately
2 dB between 1 and 10 kHz. Hori­zontal directivity is remarkably smooth
and wide. This is not due to some kind
of electronic trickery; there is no sug­gestion to that effect in Genelec's specs
and literature. As it is most unusual for
a 10-inch two-way system to work this
well off axis, the explanation probably
lies, as I suggested earlier, in the shal­low, hornlike baffle ("Directivity Con­trol Waveguide") of the tweeter.

Vertical radiation patterns (Fig.

2a/b) are less uniform. Below the axis,
there's a sharp, deep notch at 1.6 kHz,
followed by irregularities at greater ra-

pdf 15

Fig. 1: Horizontal on- and off-axis frequency responses.

diating angles. Above-axis response is
smooth to about 20°, with notching
near the crossover frequency as the an­gle increases. (These problems are com-

mon when multiway speakers have

drivers placed side by side or when ver­tically arrayed systems are used hori-

zontally. I beg people with multiple lis-

tening seats to use a vertically arrayed
center channel.) The HT210 should be
used vertically whenever possible, and

when used for a center channel should

preferably be placed below the screen.

The response alterations imposed
by the Bass Roll-Off and Bass Tilt
switches followed almost exactly the
curves printed in the manual and on the
electronics panel on the back of the en­closure, although the magnitude of ac­tion was only about 65% of that indi­cated. For example, the DIP switch for
Bass Roll-Off (a highpass filter whose
slope increases from 6 to 12 dB per oc­tave in small steps) indicates cuts of 2,
4, 6, and 8 dB for frequencies below

100 Hz, but setting the switch at -8 dB
only cut response by only a little more
than 5 dB. Likewise, the Bass Tilt
switch (which should cut 2, 4, or 6 dB
below 1 kHz, depending upon its set­ting) produced a 4 dB reduction when
set in the -6 dB position.

On the other hand, the action of the
Treble Tilt switch, which cuts in at
about 8 kHz and was indicated as +2,

-2 and -4 dB at 15 kHz, matched the
printed graphs exactly. The tweeter and
woofer can be turned off individually
when the Mute position on the driver's
DIP switch is selected—while this is a
fantastic feature for nearfield measuring
it is of no use I can think of for home
listening.

For a two-way satellite, the
HT210 delivered a healthy output,
though not quite as healthy as sug­gested by Genelec's specification (124
dB peak per pair at 1 meter, with mu­sic). Using the most challenging
recordings I have, I got the HT210s
to crank out a clean 102 dB SPL peak

Fig. 2b: Vertical off-axis frequency response above axis.

Fig. 2a: Vertical off-axis frequency response below axis.

ISSUE NO. 29 • SUMMER/FALL 2003 15

pdf 16

(no audible amplifier clipping, lim-

iter action or speaker distress) at 4

meters in my large room, which trans­lates to 114 dB at 1 meter. Turning the
gain up from the default setting (-6
dBu) to its maximum (+4 dBu) en­abled the speakers to deliver 105 dB

SPL at 4 meters; however, limiter ac­tion and/or amplifier clipping was
clearly evident at sound pressure lev­els above 102 dB; this surprised me,
as most active speakers will not allow
themselves to be driven into overload.

The HT210's low-frequency abili­ties were similar to those of many "full­range" floor-standing loudspeakers I've
used. Speakers seldom have the low­frequency dynamic capability that ref­erence measurement levels imply. Fre­quently, full-range models whose
measured low-frequency extension
seems impressive exhibit an upward
spectral balance shift at high output.
This shift occurs because the low-fre-

quency driver lacks the displacement

to keep up with the mid/tweeters; the
highs keep getting louder while the lows
stall out as the system's output level in­creases.

To measure the Genelec's low-fre­quency abilities, I used a technique
adopted from Don Keele: I fed the
speaker ramped, 6.5-cycle tone bursts at

-octave frequencies, and used a
MLSSA acoustical measurement system
to determine the maximum low-fre­quency SPL the speaker could deliver at
2 meters (a truly practical listening dis­tance) before distortion reached 10%
or overload protection cut in. While a
distortion figure of 10% seems quite
high, a speaker still sounds clean at that
level. This is because the speaker is just
leaving its linear output range at that
point; as the level increases further, dis­tortion will begin increasing exponen­tially. (Technically, this happens when
the driver's motor BL product, a meas­urement of magnetic field strength, has
fallen to 70% of its rest-position value,
or when the suspension has stiffened by

I listened to the HT210 as a stereo

pair. The sound was clean and clear, al-

though somewhat aggressive. With the
Treble Tilt switch set to 0 dB, there
was excessive sibilance when playing

Suzanne Vega's recording of "Tom's

Diner" (on Solitude Standing) and per-

cussion sounded somewhat overem­phasized. When I set the Treble Tilt
switch to -4 dB, however, voices and
acoustic instruments were rendered
with natural timbre and excellent de-

tail and clarity, although the speaker
still sounded slightly aggressive.

The Genelecs delivered a wide,
moderately deep soundstage, with ex­cellent image placement and separa­tion. The wide, smooth radiation pat­tern provided an excellent sense of

ambience, positioned images outboard
of the left/right speaker pair, and
clearly rendered reverb and ambient
effects in the mix. Center images fol­lowed me when I moved off axis; this
is normal for two-channel systems, and
the Genelecs do a better job of dis­tributing ambience and retaining far
left/right images than speakers typi­cally do in stereo setups. I believe the
HT210 can be successfully used as a
left/right, center, or surround speaker
in a multichannel system.

The Genelec HT210 will reward
any listener with high-quality, high­output playback in mono, stereo, and
multichannel music and film systems.
It has more output capability than any
other two-way home system I've ever
used, and more than many 12-inch
towers. As a satellite speaker, it's a lit­tle on the large side. As a full-range
speaker, it's moderate in size but with
the impact of many larger floor-stand­ing systems. Like all satellite and most
full-range systems it will benefit from
a subwoofer if you like high-impact
low-frequency programs.

Some people will consider the
Genelec HT210s pricey (a 5-channel
system would run you about $14,000)
Others, though will see them as a bar­gain, considering current speaker­price trends and the fact that a full set
of high-performance electronics with
useful precision operating controls is
included in the deal. As far as I'm
concerned, these Genelecs would be
welcome in my house anytime.

—Tom Nousaine

16 THE AUDIO CRITIC

a factor of four.) I define a speaker's bass
limit as the lowest frequency and high­est SPL it can deliver within the 10%
distortion threshold. For a single
HT210, the bass limit was 75 dB SPL
at 40 Hz at 2 meters.

Surprisingly few two-way satellites

(or even full-range speakers) can deliver

such usable output at 40 Hz. However,

the HT210's usable output at 40 Hz
was nearly 25 dB below its maximum
clean output at higher frequencies,
which occasionally caused the spectral
balance shift described previously. If
you want full-bandwidth dynamic ca­pability, you'll need to use the Genelec
with a subwoofer.

Dynamically, the HT210 plays
damn loud, yet retains its clarity when
the music gets soft or is simply played
softly. There is some, but less than
usual, upward spectral shift when
playing full-range recordings at very
loud levels. When played at full gain
with ultraloud, dynamic, or ultra­compressed program material (Ra­diohead's Amnesiac, Fugees' Blunted

on Reality, Jay Leonhart's Salaman­der Pie) the HT210 could play

roughly 3 dB beyond its clean limit.
At such high levels, the Genelec's lim­iters keep turning on and off and the
sound is sometimes grossly distorted.

(I used hearing protection when
checking this.) But when you're fin­ished abusing the speaker, there will
be no burned or bottomed voice coils,
and the system will play as if it were
still new.

pdf 17

Thiel Audio, 1026 Nandino Boulevard, Lex­ington, KY 40511-1207. Voice: (859) 254-

9427. Fax: [phone]. E-mail:
[e-mail]. Web: www.thiel­audio.com. Model CS1.6 coherent source
loudspeaker, $2390.00 per pair in black
ash, cherry, maple, oak, or walnut
($1990.00 the pair painted black). Tested
samples on loan from manufacturer.

The CS1.6 shares the distinctive
look of Kentucky-based Thiel Audio's
other floor-standing speakers: a finely
finished cabinet with a raked-back,
rounded, black front panel. That look
is part of Thiel's "Coherent Source"
design, which, the company says, aims
to eliminate "time and phase distor­tions that cause alterations in the re­produced musical waveforms of most
loudspeakers." Raking the front panel

moves the tweeter farther from the lis­tener, so its output will arrive at the

same time as the woofer's. The front
panel is claimed to reduce parasitic res­onances, and its rounded corners min­imize diffraction. Thiel also uses wide­bandwidth drivers and true, first-order

crossovers to maintain phase coher-

ence. The result, says Thiel, is enhanced

realism, clarity, transparency and im-

mediacy, as well as improved imaging

and a deeper soundstage.

The CS1.6, the second smallest of
Thiel's six CS-series speakers, is a two­way bass reflex system with anodized

aluminum diaphragms on both drivers.

The woofer's construction is un­usual. Instead of placing a small voice
coil at the apex of a deep woofer cone,

Thiel gave the CS1.6's woofer a large

(3-inch) coil attached about midway
between the cone's outer surround and
its center. This design distributes the
driving force over a larger area and, by
reducing the unsupported span be­tween the coil and the cone's edge, re-

duces cone breakup. According to
Thiel, it also moves the diaphragm's
spurious resonances to a much higher
frequency, and hence raises the driver's
high-frequency cutoff.

As a result of this driving system, the
woofer's cone is quite shallow and its
dustcap is distinctively large. The large
voice coil enables Thiel to place the
neodymium magnet inside the pole
piece rather than outside it. This topol­ogy provides magnetic shielding; when
I set a CS1.6 right next to my com­puter's monitor, it caused no color dis-

tortion of any kind.

The woofer's extended response is a
necessity, because of the CS1.6's first­order crossover. The virtues claimed for
first-order crossovers, which have gen­tle slopes of 6 dB per octave, are sim­ple construction (typically, one capac-

itor and one inductor) and "phase
coherence" (the elimination of phase
changes at the crossover frequency).
The theory is that a first-order crossover
keeps the two drivers in quadrature (90°

apart) at all frequencies, and conse-

quently the sum of the two drivers'
acoustic outputs is theoretically a per­fect replica of the crossover's input. The

importance of this from the standpoint

of audibility has long been debated and

belongs in another discussion.

It's not enough for a first-order
speaker system to have crossovers with
6-dB/octave slopes. It's also necessary
to have loudspeaker drivers that op­erate cleanly for two to three octaves
beyond the crossover point. This is
because moving-coil drivers are sec­ond-order devices, which roll off at

12 dB per octave outside their natu­ral passband. Only very wideband
drivers allow the system's roll-off to
start well before the drivers'. A first­order crossover's gentle slope also does
little to suppress any irregularities in
the driver's response outside its pass­band. So using such drivers not only
requires an extended upper range for
the woofer, but also a downward ex-

ISSUE NO. 29 • SUMMER/FALL 2003 17

tension of the tweeter's response. Thiel
says quite a bit about technologies
that extend the response of the
CSl.6's woofer upward, but nothing
about the low end of the tweeter's re­sponse. Nonetheless, I neither heard
nor measured any of the anomalies I'd
expect if the tweeter lacked low-end
response or had insufficient power
handling at low frequencies.

Despite the appealing simplicity of

basic first-order filter design, it often

pdf 18