The M-50 Loudspeakers
by Tom Warnke
| Mt. McKinley
on the summit
from the top
speakers usually fall into two
camps. The first is that of the
overachiever — something like
the Vandersteen 2 series or the
Magnepan 1.6, speakers that each
time you hear them leave you
shocked that such quality can
be had for so little outlay.
The second is the cost-no-object,
statement speaker. The first
time I heard the $85,000 Dynaudio
Evidence or the $67,000 Kharma
Exquisite Reference 1B, I had
my expectations of the possible
seriously and permanently altered.
But there is a third, more elusive
camp, namely those speakers that
aspire to and nearly reach the
state-of-the-art yet cost fractions
of the likes of the Evidence.
While harder to categorize, being
neither a budget speaker with
finesse nor a budget-be-damned
assault on the highest peaks
of the audio art, the rare speaker
that does fit into this category
is truly memorable. One that
does, at least to these ears,
is the Merlin VSM-M. At $7050
(with battery BAM), it offers
performance from about 40 cycles
on up that is truly state-of-the-art.
Sure, that $7050 is a lot of
real-world dollars, but in state-of-the-art
audio dollars, thats not
even a generous per diem. And
its the combination of
these two traits, true first-rank
skills for relatively modest
cash, that place it in the elusive
Of course, if $7050 is per diem, then the $35,000 USD
that the Wisdom M-50 costs is, at least, a nice weeks trip in the state-of-the-art
sweepstakes. Since were looking at the M-50, a good question to ponder
is what does a near $35k speaker have to do to be worth the money, and perhaps
merit inclusion in the third camp of memorable speakers? Obviously, a lot. It
needs to offer world-class sound from somewhere close to 20Hz on up. It needs
to offer a transparent, detailed and lifelike window into the recording, but
without losing emotional context. It needs to be dynamic, both on the micro and
macro levels. It needs to reward system upgrades without punishing unfairly other
system components that might lag behind them. It needs to offer full-scale harmonic
color. It should stage with accuracy, but not to the extent of turning an audio
event into a visual one. And it should also be flexible enough to stay with you
should you move or change listening rooms. Oh yeah, one last thing. If you want
the Significant Other to approve the purchase — after all, sliding almost $35k
on the credit card isnt quite as simple as hiding the purchase of the next
Miles Davis boxed set is — it should look like high-quality furniture as well.
Looking back at that list, Im glad Robin had the
sense not to compile an equivalent one before she married me. While not quite
of Everest proportions, its a list of at least McKinley proportions —
an awesome sight, for sure, but terrible as well. And it's far beyond the skill
of the average climber, or speaker designer, to summit. Yet thats exactly
the peak that Tom Bohlender at Wisdom Audio has set out to conquer with the M-50.
back to top
Planning the expedition
Wisdom Audio was born out of Bohlender-Graebener,
a speaker and raw-driver company founded and co-owned by Tom Bohlender.
The reputation of B-G rides on their planar midrange-tweeter, and its
quite a reputation, being the OEM supplier to, among others, Genesis
and their line of statement speakers. But, like many of those possessed
by a keen and restless mind, Bohlender was only partially fulfilled by
the Bohlender-Graebener experience.
So in 1997 he formed Wisdom Audio with the express purpose
of creating the best speakers in the world. The current embodiment of that thought
is the $95,000 Adrenaline Rush. Using a highly modified 75" B-G midrange-tweeter
per side and a separate low-frequency cabinet housing four 12" woofers per
side, these monsters are aptly named. Every time Ive heard them my inner
urge to bungee jump Royal Gorge for the hormone kick has been slaked. On
the other hand, not every adrenaline junkie has the cost of a weekend cabin
rattling round the cookie jar, so the Adrenaline Rush is joined by the modest
luxury-car-priced M-75 (a Rush mid/high unit with a separate woofer cabinet
with two instead of four drivers a side and priced at $55,000), and also the,
by comparison, affordable M-50.
In contrast to the big Wisdoms, the M-50 uses a 50" midrange-tweeter
in place of their 75" units. The main reason for this is to allow a single-cabinet-per-side
design, as the woofer, a single 12" unit per channel, is mounted in its
own enclosure below the midrange/tweeter. The two sections visually integrate
quite nicely. The midrange/tweeter, although a natural dipole, is mounted in
an infinite-baffle cabinet that slopes backward at about a 20-degree angle to
absorb the rear wave. The elegant shape of this cabinet flows down to the square-but-deep
woofer chamber so that it looks more like a sail on an Americas Cup yacht
than a speaker.
In building the cabinets, Bohlender uses true artisans
to assist in his assault on the mountain. His cabinet builder is David Kunkle
of custom-guitar fame and is located several miles down the road from Wisdom.
Cabinet building is a reiterative process between Wisdom and Kunkle, who contributes
his vast experience in woodworking and music. After Kunkle is finished with the
cabinet, it moves several blocks away to another specialist, Mike Martin, who
paints and bakes the cabinets. From there they move back up the road to the shop
of Yves Stillmant, a musician, recording engineer and former Steinway finisher,
who completes the cabinets to a "better than Steinway" gloss. The
result really is a work of passion, skill and art.
The planar drivers, while sourced from Bohlender-Graebener,
are a unique design to Wisdom Audio only. Tom Bohlender completely customizes
them, with the result being what Wisdom calls the SMART planar, a driver
that has better high-frequency extension, the removal of a resonant mode, and
is easier to drive. The bass drivers (low-frequency regenerator, or LFR in Wisdom
parlance) are massive. Each weighs over 40 pounds, 32 of which are the weight
of the magnet assembly. This underhung driver (a short voice coil in a long magnetic
gap) allows for three inches of excursion, with full control over the complete
Controlling everything is the Active Brain. A complex,
hand-built active crossover, it has something like 4000 possible internal settings.
These are best set by Tom Bohlender himself, and indeed they are: first at the
factory to dial the M-50 in to match the performance of the reference model exactly,
and then again in your home. Thats right — when you purchase any Wisdom
Audio speaker, Tom Bohlender comes to your house and refines the various
internal switches on the Active Brain and then teaches you how to best use the
four external controls. Those external controls allow you to adjust the Q of
the woofers, the volume control on the low-pass side of the 24dB-per-octave
crossover, the damping factor into the crossover, and the volume on the high-pass
side of the crossover. In all, these controls allow Wisdom to match virtually
any combination of room, amplifiers, and musical taste.
Yes, I did say amplifiers. The M-50, like all Wisdom
speakers, requires four channels of amplification, one for each bass channel
and one for each planar panel. To make sure that there was no compromise
there, Bohlender arranged for a pair of Jeff Rowland Design Group Model 112 amps.
These were well suited to the Wisdom speakers, and Tom Bohlender has used them
at shows in the past.
I also needed two separate sets of speaker wires (not
internal biwire) as well as three sets of balanced interconnects. Fortunately,
George Cardas has an accommodating soul and sent me a full set of Neutral
Reference. Once again, Tom at Wisdom has used this setup at shows and so was
quite comfortable with the Cardas wire, but more importantly, so am I. Cardas
wire is always my first choice, and I know the Neutral Reference quite well,
so there was no change to my reference system when using it.
After I had the necessary pieces, setup went smoothly.
I first placed the speakers with the fronts of the woofer cabinets in almost
the exact same place where my Merlin speakers were, about four and a half
feet from the front wall and separated by nine feet. I sit about nine feet back
from the speaker plane. Over time I found that sliding the speakers in a tad
and toeing them in just a scoosh more than I do with the Merlins resulted in
a wide, deep, and stable image. Even though nine feet is pretty close to speakers
that are six feet tall, the relatively slim cabinet and high-gloss champagne
finish gave them an elegance that remained upscale without becoming imposing.
Finally, with the size of the M-50s, setting them up
in the office system to break in was not feasible. So, to break them in without
breaking me in as well, I set them up on a Friday morning, hit repeat on
the CD player and took Robin camping in the mountains until the following Tuesday
evening. Since Tom had run the speakers in before they left the factory,
the 100+ hours of break-in was primarily for the new amps and wire and did a
thorough job as the sound of the system underwent only minor changes during the
back to top
Assault on the summit
Ive been listening in on the Wisdom line
since their first showing at HI-FI '97, and so I had some idea of what
to expect when Robin and I got back from our camping trip (by the way,
I mean camping in the real sense: no RV; no pop-up tent trailer; no condo
in the Rockies; nothing but a tent, a sleeping bag, a Coleman lantern and
stove, a cooler of food and real fires at night to make smores).
But expectations and reality often have a way of diverging, so I was quite
surprised when the first sounds I heard were quite similar to what Wisdom
gets at shows: full range, very detailed but with a full harmonic palette,
dynamic, and exceedingly clear. The speakers sounded so good that I spent
several weeks just listening before I began to play seriously with the
room placement and the Active Brain settings. Im glad I did. As enjoyable
as the first listening sessions were, the M-50 is so sensitive to setup
issues that my round of tweaking was the most important week I spent with
the speakers. Each turn and twiddle of a knob made an immediately discernible
difference. And the challenge of balancing the speaker with my room was
an education in itself.
While that sounds like it work, it wasnt. The Active
Brain is actually quite simple to use. The first rule, according to Tom, is to
avoid adding gain on either side of the crossover, but rather to cut gain to
balance out the sound. With that rule in hand, and by making slight adjustments
to the Q (which controls LF extension) and damping (controlling the crossover
blend) I was able to get +/- 1 dB frequency response from 60 hertz on up, +/-
2dB from 40Hz, and was down 3dB at 20Hz. What I learned from this experience
is that J. Gordon Holt may be right: flat in-room frequency response is not always
the best or most realistic sound. I eventually shelved the top down about 1dB
and found my personal sweet spot. The result was still the flattest response
Ive had in my room, even if not quite as flat as the speakers are capable
of. The real lesson here is that the M-50 is adjustable both for flat response
and to taste.
Lets get to the details of that final sound. The
first characteristic of the M-50 is its near-perfect driver integration. Anytime
you put dissimilar drivers together, as Wisdom does with their dynamic woofer
and planar midrange/tweeter, the transition is where the trickiest waters lie.
Navigating them requires the usual care with crossover issues, but more importantly,
it requires special consideration in selecting drivers that correctly complement
each other. The Wisdom planar driver is fast, open, uncolored and transparent;
thus the woofer needs to offer the same characteristics while adding deep bass
and dynamic power, all without having an obviously different tonal character.
Score one for the Wisdom assault on McKinley. With only the most minimal of tonal
shifts — the bass being just the slightest amount richer in tone than the planar
driver — the M-50s sound of one piece. To these ears it is the remarkably overbuilt
woofer that deserves the credit for the match, as it is blindingly fast, free
of distortion and compression, but also rich in nuance while extending all the
way down with tremendous punch. The driver combination results in a harmonious
flow of musical waters.
Second, the M-50s offer the feel of unlimited resolution.
On recording after recording I heard more deeply and accurately into both the
performance and the recording session. To take a simple example, on the title
track of Joni Mitchells Court and Spark [DCC GZS 1025], Joni is obviously
in a separate booth, while the rest of the band (and what a band: Tom Scott on
reeds, Larry Carlton on guitar, Joe Sample on keys, Max Bennett on bass, and
John Guerin on drums) is spot miked, but in a common space. This is easy enough
to hear on even entry-level high-end speakers, but what the Wisdoms do is draw
out the individuality of each player and not just place Joni in different air
from the rest, but give a sense of the volume of that air, even though it is
an acoustically dead recording booth.
Better still than the amount of resolution and detail
is the way the M-50s handle this resolution. Unlike the school of hyped and etched
detail, which takes musical and sonic detail and blows it up and out of proportion
to the actual event, allowing things like fingering on a guitar to assume greater
import than the sound of the guitar itself, the M-50s reveal the smallest detail,
but in proportion to the actual event. Thus, in the above example, the recording
details serve not to distract or to isolate events, but to make it easy to see
the session taking place before you with musicians spread right to left and Joni
just left of center in a booth, listening to the feed on headphones and singing
Third, along with that resolution, the M-50s present music with a full and accurate
harmonic palette. Ive mulled this over and think that this may be the main
reason these speakers are able to maintain such a sure grip on perspective. When
each instrument is drawn in full, with body, range and depth, details are easily
seen but not at the loss of the whole. The facts of both the playing and the
recording come through unimpeded, but the emotional context remains rock-steady.
This is done so well that Keith Jarretts vocalizing, something that never
bothers me the several times Ive heard him live but is almost always a
distraction on recordings, really sounds like a guy sitting at a piano and humming
in ecstasy while playing, rather than the disconnected, annoying buzz that most
high-end speakers make of it.
Fourth, the control of the Wisdoms is impeccable. From
the very lowest octaves all the way out to dog, cat and bat range, the M-50s
are steady and composed. Sure, when playing something like Matthew Sweets "Girlfriend" at
high volumes (from the album of the same name [Zoo 72445-11015-2]), the music
careens around the edges of control, as it should, but the speakers are never
stressed or unbalanced. What comes through is the feel of a musical event, with
everything from bass-drum whacks, to guitars and vocals, to cymbals splashes,
the M-50s reach top to bottom with joyful abandon and don't augment the chaos
in the recording.
Fifth, the dynamics of the M-50s are superb. Placed in
a system with the First Sound Presence Deluxe Mk II preamp, dynamics from the
speakers took on Mohammed Ali-esque tones, floating like a butterfly in the quiet
and subtle passages, and stinging like an Ali hook on crescendos.
Sixth, these things stage with Denali permanence. Images
are life-sized, lifelike, layered and anchored. I love Bernsteins DG Mahler
recordings and often scare the hell out of myself with the Sixth Symphony [Deutsche
Grammophon 215076]. The first movement begins with a rush and then settles to
a nervous twitch scattered amongst the strings. With the Wisdom speakers, each
player is firmly placed — right to left, front to back, and with a precision
I hadnt known was on the recording.
And lastly, besides sounding the part, the M50s look
it as well. Any thing six feet tall will occupy a significant part of the visual
space of the room it's in. And on looks alone, the M-50s can justify their price
tag. Polished to the overused jewel-like cliché, they are, indeed, fine
pieces of furniture that even Robin found satisfying.
And there is another point worth mentioning, especially
to music lovers (and I hope thats what we all are). The recordings Ive
cited above are not, on the whole, sonic blockbusters. Oh sure, the M-50s handle
the Super Disc list recordings just fine, drawing out every nuance in the grooves
or bitstream, but where they really shine is in making music, not just sounds.
So all those great performances that are found on run-of-the-mill recordings
— remember Holts Law, the better the performance the lesser the recording
quality — are as listenable as the insipid but beautifully rendered audiogeek
stuff. This is, indeed, a rare, valuable and often overlooked skill.
Perfect? Right. Of course, there are drawbacks, but many
of them are ancillary to the speakers themselves. First, four channels of high-quality
amplification raise the cost of the speakers beyond their list price, as few
of us already have four channels of power. Second, besides the amps, youll
probably need new speaker wire, as internal biwire cables dont work. Third,
while Ive heard of the M-50 (and its larger sibling, the M-75), being used
in a 14' x 12' room, to get the most out of your investment, youll need
at least a medium-sized room. Id say at least 15' x 20'. On the other hand,
the woofers suck up the juice, so the M-50 is probably not right for a large
room. As for the speakers themselves, I suppose that in absolute terms the two
dissimilar drivers pose a small issue. On the other hand, Wisdom integrates these
dissimilar drivers better than 99.96% of audio companies integrate similar drivers.
I also heard my upstream components with clarity beyond what Im used to.
While not punishing per se, the Wisdoms will certainly let you know the true
skill of the rest of your rig. Other than that, about the only other drawback
is the aforementioned need for juice, so if you are a SEThead or use OTLs (please
see the TAS review of the M-75 for details on the writer's experience with the
Atma-Sphere MA-2 amps), you will definitely be changing amps, and probably to
solid state. Finally, I guess that all your audiobuds clogging the listening
room may be a drawback as well, unless they spring for the munchies.
back to top
The closest competitor Ive had in for
review to the M-50 is the $10k Kharma Ceramique 2.0. My system was considerably
different when it was here, and its been a while as well. Still,
it left an indelible impression of smooth response, extreme musicality
and deep, articulate bass. Compared to the M-50, it was a slightly softer
on dynamic peaks, didnt reach as deep in the bass, and had a few
more issues with driver integration. It also had a slight tendency to a
dark presentation and was a tad less revealing. Of course, we are talking
about subtle differences as both these speakers are very near the edge
of the possible.
back to top
View from the top
But the real story is that the Wisdom is sui
generis. The large bass driver, coupled to an extended and detailed planar
midrange/tweeter, controlled by an infinitely adjustable active crossover
that can be tweaked to fit both room and amp, add up to a unique product,
as the M-50s truly stand apart from the crowd. While no casual purchase,
even for those whove avoided investing in a dot bomb company, the
M-50s also fall short of the small-condo category of speakers. But just
like H. L. Mencken, who said he could write better than anyone who wrote
faster, and faster than anyone who wrote better, the M-50 is better than
anything thats cheaper, and far cheaper than anything thats
better. In my world, that makes it a truly memorable speaker, one worthy
of inclusion in the third camp of the "affordable" state-of-the-art
product. Sure, $35,000 is a helleva lot of cash, and certainly beyond what
we call inexpensive here at the Warnke Snowshoe and Music Lodge. But when
you are making a play for the best possible sound, nothing is cheap, and
in that chase, the M-50 can be considered affordable. Kudos to Tom Bohlender
and his assault on McKinley. He made it with ease and in style.
back to top