Ear Wax
by Srajan Ebaen
Click here to e-mail reviewer

Pat McGinty:
The Birdman of Watertown
Part I of II

 

Birdie

In German colloquialism, telling someone he has a bird  -- Du hast einen Vogel – means you recognize in him that rare but enviable spark of minor daftness; of a certain eccentricity; of perhaps even a little inspired craziness. Delivered in this way, your rib poking comes across as intended. It’s a good-natured jab rather than an accusation of loony bin destination.

It’s knowing that your friend enjoys riding through town butt-nekkid on a bicycle in the predawn hours of winter. It’s commemorating that time you watched him bribe a cop to waive a speeding ticket. He calmly claimed to be rushing to your wedding and invited the officer to join the fictitious party. He actually urged him to use his flashing lights since good times were probably in full swing by then and why should y’all be late.

How about his mid 90s proposal of starting a loudspeaker company that would deliver handcrafted goods while using mature well-paid American labor on US soil? You laughingly turned your friend into the proud owner of more than just a single bird. He cheerfully insisted that all this could readily be accomplished - against the established design houses no less that even then were already subcontracting for cheap labor in the Far East. Of course, when he finally claimed to be just the right guy to pull all this off, you probably lost your well-practiced patience. Presumably, you accosted him of having a whole flock of wild-eyed and chirping feathery friends and paid no more heed to his ambitious dreams.

 

Par? No, It Pat.

Know anyone like that?

I do. Talked my way into working for him and enjoyed every minute of it. His name’s Pat McGinty, and that of his company Meadowlark Audio. His firm’s stocked to the rafters with very feathery speaker models that go by names like Kite and Shearwater, Heron and Kestrel, Nightingale and Petrel. What will he christen his forthcoming subwoofers, pray tell?

More to the point, do you reckon McGinty has a bird or two?

 

Based on sheer case evidence, I would have definitely said yes many moons ago when I granted his long-term survival prospects skinny hundred to one odds. After all, speaker manufacturing has turned into a seriously cutthroat business. As a non-drinker, I’d even have thrown in a bottle of overpriced Napa Valley Kenwood Estate to make my point. I still worked in audio retail then and was based out of Sonoma County. From afar, I watched Pat’s little Kestrel floorstander make the rounds. It soon incited rave word-of-mouth applause. I felt compelled to nag my storeowner boss to order a pair so I could hear this upstart for myself while the going was good. Boss-san ended up carrying the line, too. It soon became evident that Meadowlark Audio was here to stay. I eventually moved to San Diego County to become McGinty’s National Sales Manager. Good thing I didn’t bet earlier. I’d probably picked a lousy wine to congratulate Pat on overcoming the equally lousy odds of my secretive contest. You see, it’s now quite a few years later again. Not only is Meadowlark Audio thriving despite a sluggish economy, it’s growing like one very pregnant ostrich ready to explode.

 

Backwards In Time Like An Incoherent Loudspeaker

As with any good yarn, ours starts in the crib when the tooth fairy presented li’l Pat with a gold-plated soldering gun. Dad was a WWII Navy radar man who thought that the proper age for a youngster’s first electronics lessons was just about when he turned from a quadruped rug rat into an upright biped monkey. Pat quips that he designed his first circuits in kindergarten, with a slide ruler rather than pocket protector sticking out of his jeans. He soon understood electronics the way other kids understood soccer – from the inside out, indulging it every spare moment because of sheer enthusiasm. Growing up in close proximity to the Big Apple, he raptly attended more Leonard Bernstein concerts at Avery Fisher hall than he can remember. His was also the perfect age to capture the Fillmore East in the halcyon days of late 60s Rock’n’Roll.

He moved to Southern California where he eventually transcended surfing and R’n’R to become a hobbyist cabinetmaker. In his early 30s, woodworking had turned into a full-blown career. With hands-on training under the ever-watchful eye of master craftsman Ian Kirby at the Palomar College, he designed and built furniture-grade custom cabinets and even a few challenging boats.

By his late 30s, the three predominant forces in his life began to converge: his firm background in electronics and the sciences; his by now sharply honed cabinet making skills; and his love of music. Like a renaissance man born into the wrong century, he began building speakers on weekends. This turned his garage into the proverbial mad scientist’s lab from where he cranked out a large number of designs that included the weird and the wacky, the funny and the purely experimental. Spreading repute soon had him emerge as the King of the One-Off in Southern California where he fashioned custom loudspeakers for discerning audiophiles who had the Jones for something unique and exclusive. Having delved into the accessible literature on speaker engineering, McGinty initially espoused the Gospel of the latter-day apostles – steep 4^th order filter topologies wedded to closed and vented box alignments with vertical baffle boards.

 

Perfect Measurements Sound Imperfect
If You’re Looking At The Wrong Measurements

He chronicled his major turning point as the arrival of the first Melissa spectrum analyzers. Capable analyzers until then had been the sole providence of the professionals, priced way out of reach for even the serious hobbyist. These new Melissa units at $3,000 to $4,000 leveled the playing field. A euphoric McGinty could now properly outfit himself to produce speakers with stellar measurements and beat the world - or have the world beat a path to him. He developed an extensive analog and digital bench and engineered speakers whose measurements compared favorably with the very best published in Stereophile at the time.

Still, he couldn’t fail to notice that his new creations sounded pretty darn nasty – fatiguing and irritating, not musical. This begged the obvious question: why, despite nearly flawless measurements, couldn’t he stomach his own offspring?

A secret mentor who had guided our budding cabinet and now speaker builder through the more overlooked and obscure corners of applied Physics provided the first clue. A sonic signal is a transverse wave that can be described entirely in the amplitude and time domain. Imagine ripples on a pond. By knowing their amplitude (the height of the waves) and time function (how many peaks arise in a given period), one can accurately depict this event in its entirety. Frequency response, McGinty’s prior textbook concern and main focus, really was just a derivative measurement extrapolated from these two core variables. Henceforth, he was to regard a speaker’s job as the correct reproducer of time and amplitude data derived from the preceding amplifier. Getting those right would force frequency to lock into place. Concentrating on frequency and amplitude instead as is convention had already proven that time as the senior denominator did not automatically follow suit.

To implement his new course of action required implementing 1^st order networks that are only casually documented in the major tomes on speaker design. It also meant physical time alignment of the drivers. While the latter can be achieved with stepped or sloped baffles, McGinty decided on the angled option for aesthetic reasons. Between the two available filter choices – parallel or series – he settled on parallel circuitry but was quick to point out that phase coherence can be achieved with either.

 

Epiphany

To McGinty’s astonishment, careful implementation of phase and time alignment now produced loudspeakers that consistently put a smile on his face. They finally did justice to that overworked but I-know-it-when-I-hear-it musicality term - the ability to emotionally connect with the music. This is McGinty’s self-professed mission. Even if all the audiophile checklist traits were to be successfully crossed off  -- soundstage precision, subterranean bass as quick as Sugar Ray Leonard and as pounding as Joe Frazier, airy treble, seductive midrange, blazing transients, the works – it’d all amount to naught in the Birdman’s private black book if the emotional response was absent. Since time domain fidelity had proven to be the door through which he could meet his muse time and again, Pat dedicated his new company to the 1^st order credo. In Part II next month, we’ll take a closer look at another important design philosophy, transmission-line loading, an intrinsic ingredient to his Meadowlark recipe and incorporated into every single loudspeaker model he makes. For today, let’s consider phase-and-time coherence. It could make you smile like Pat or wince in horror. That’ll depend on your sympathies for and appreciation of the subject matter.

 

It’s A Toasty Blur

A good initial example for visualizing time domain fidelity is a four-slice toaster. Let it represent a four-way speaker, each slice the signal from one of the four drivers. Ideally, all four perfectly browned slices should pop up from our toaster at the exact same moment when the alarm rings This would signify the arrival of a single unified aural event at our ears, just the way it was produced in the live venue. But unless the speaker/toaster was time-aligned, the slices instead pop up at different times, and not even in sequence either. What should be a synchronized wave launch -- of a single signal divided by the crossover into four parts sent to four separate drivers -- becomes in fact discombobulated. Rather than arriving at your ear as a composite and recombinant waveform of four drivers working in concert, “it” arrives in pieces, the woofers and tweeters like self-absorbed prima donnas each doing their own thing. What else to call that but “it” since it certainly is not the original signal? To the further horror of 1^st order proponents, some of these fragments, never mind being tardy, aren’t even the right pieces. Instead, they’re upside down, out-of-phase mirror images.

A simple measurement that demonstrates this inchoate effect is called step response. A speaker is asked to instantaneously go positive, like hooking up a battery to its terminals. This should cause all drivers (if wired in-phase) to push out and produce a compression airwave. A properly engineered coherent speaker will create a measurement that looks like a step – going from zero to full excursion up in a straight line in one split millisecond, with the drivers retracting back to zero in a sloping line because of real world woofer response. Incoherent speakers without regard for phase and time alignment cannot reproduce this simple step response. They generate a more complex, jagged and convoluted response curve. They introduce phase rotations that invert and superimpose parts of the positive-going signal into the negative domain. They transpose outgoing compression into retracting rarefaction (those previously dubbed wrong pieces). They store portions of the event and release it delayed in time (the tardy late-arrivals). Plainly put, a very simple input signal of a milli-duration click becomes confused. Instead of being rendered with the precise and devastating impact of a single bullet, it turns into ricocheting buckshot salvo scattered in time.

Would it surprise you that one of the claimed audible advantages of time and phase coherent loudspeakers occurs with percussive transients that are reproduced without telltale blurring scars? Or that images and their positioning in the soundstage are more accurate because tones that are reproduced between multiple drivers (the fundamental in one, certain harmonics in another) have all their constituent parts timed coincident and correctly to lock into crisp focus without fuzzy outlines or unrealistically bloated sizing?

 

This step response was taken during regular Shearwater QC
and shows perfectly synchronized compression without delays
or transposition into rarefaction (going negative)

 

This - not particularly bad - step response was taken from
a competing design that claims to be time aligned by virtue
of a stepped baffle but uses a higher-order filter. Note the large
amount of high frequency signal that’s delayed and
inverted (undershooting the center line). What should
have been compression has turned late rarefaction. Some of
the low frequency signal arrives late and inverted as well.

 

The impulse response measurement applies a full-frequency click to a speaker to track how it settles. The ideal impulse response curve spikes up, crosses zero, goes negative (the driver moved out, then back past its original rest position) and phases out very rapidly thereafter. This demonstrates how quickly and cleanly a speaker system comes to rest, i.e. stops to produce sound beyond the actual signal. Perusing just a handful of past Stereophile review measurements of highly regarded and expensive speakers will show that most are far from this ideal impulse response. Instead, many go on ringing far past the actual aural event.

The question that any 1^st order proponent would now likely ask of his higher-order colleagues is this: why do their speakers render such a simple aural event with such complexity - shouldn’t the output signal reflect the input signal? After all, isn’t that the precise meaning of High Fidelity – remaining faithful to the signal without taking liberties?

 

Audibility? 

You might have heard the persistent argument that while time and phase coherence is admirable in theory, it’s in practice inaudible and an unnecessarily vexing bother to contend with. Familiar with this notion, I asked Pat to describe the first rudimentary test that determines the proper baffle angle of physical time alignment for an upcoming new Meadowlark model. On a test tone generator, he programs an infinitely short clicking signal pulse and feeds it to a woofer and tweeter on a mock baffle board mounted on a horizontally rotating axis. Armed with his ears, a microphone and an oscilloscope, he assumes position at the far end of the room, triggers the signal and sends it via the microphone to the scope. Until he arrives at the correct baffle board slant, his equipment will register two signals – click, click. It records the tweeter and woofer signals delayed in time. While the ear/brain can’t discern such closely spaced sounds as two distinct and separate events, it perceives this timing discrepancy as blurring. Once adjusted properly, the blurring becomes a razor-sharp, cleary defined and pronounced “pop” rather than a “pppopp” (or should that be “poop”?). McGinty claims this is clearly audible to anyone who’d bother with such an experiment.

He then recalled a long-ago demonstration he had hosted for an audiophile club meeting. His 1^st order presentation sported a two-way speaker with a tweeter mounted onto a drawer slide. Via a long skinny stick from the listening position, each participant could freely alter the physical offset between tweeter and woofer by about 1.5 inches to and fro. Without exception, every single music lover not only heard the differences but also independently adjusted the tweeter to the same final position. This proved to everyone present McGinty’s prior audibility contention. What really were rather minor timing discrepancies of the treble signal in a misaligned 1^st order two-way versus the rather more obvious broadband midrange errors a misaligned 3-way would have elicited – these relative subtleties were cleary and repeatably audible. More importantly, they were discerned and correctly accounted for by average listeners who weren’t trained to consciously recognize time domain perturbations as any serious engineer of 1^st order loudspeakers obviously would.

 

Now Prove It

However, outside such an ingenious demonstration, real world customers comparing 1^st order loudspeakers against any other types in retail or trade show environments are always comparing apples to oranges. They are never empowered to isolate the effects of accurate time alignment between two speakers that in all other regards are absolutely identical. This lamentable fact gave rise to the popular notion that time coherence is an unnecessary and inaudible luxury. This retort simply cannot be disproved in any such settings. It’s something I imagine must ruffle the feathers of numerous 1^st order designers who have no associations with winged creatures at all.

After speaking with many music lovers over the years, I’ve learned that those who have “crossed over” into the camp of phase and time coherent loudspeakers can never retract. Once their hearing mechanism has identified the artifacts of time domain disturbances for whatever reasons, they can never not hear them when present - as they are by design in any loudspeaker that’s not 1^st order.

McGinty is obviously very sensitive to this aspect. He has trained himself to recognize the higher-order sonic signature he refers to as ringing. Capacitors and inductors store energy and release it later – that’s their whole raison d’être. Higher-order designs use a larger number of these devices, hence suffer from pronounced time-domain smearing. Segments of the signal are spread out in time and arrive sequentially. That’s plain ringing. McGinty hears it readily on piano, in the impact of the hammer on the string. What should be a sharp “clack” attack turns into an extended “boiiiinnnng”. He easily perceives it in soundstage precision, too, and in what he simply calls naturalness and musicality. For those not attuned to what he’s listening for, those are vague terms to be sure. But for those who relate, these qualities are as plain as day. Jim Thiel, incidentally, pointed to the very same recognizable time-coherent reproduction traits when I interviewed him earlier for another publication.

 

Plucking A Feathered Myth

What caught McGinty’s attention when he explored his first matured 1^st order design were greatly improved dynamics. Dynamics refers to the linear scaling or tracking of increased input signal versus output signal. Does doubling the input voltage at the speaker terminal produce double the output level for all drivers? Do output levels scale proportionally as input voltages are increased? Is this balance maintained not only with steady-state signals but transients as well? When does compression set in?

Pat’s findings aren’t entirely surprising - simpler systems scale more smoothly than complex ones. Their filter networks insert less reactive, energy-absorbing components into the signal path. He pointed out that comparing two identical woofers attached to 1^st and 2^nd order filters respectively would prove the dynamic superiority of the simpler filter in a heartbeat.

Then there’s the prevailing myth that 1^st order designs are inferior snake, ahem power handlers. Power handling in a bass driver is a combined function of excursion and heat. Maximal excursion – hitting the physical stops – occurs only at a woofer’s lower reaches, in the octave of 20-40Hz where the effects of its low pass filter network aren’t operational. This plainly removes the crossover components from the power handling equation. Thermal limitations arise from overheating. The glue holding the voice coil in place melts. Meadowlark drivers employ glue that liquefies at 800°F. While prolonged excessive power into a woofer will cause self-destruction, this once again is unrelated to the circuit’s filter network. Rather, it’s a function of irresponsibly overriding the effective voice coil’s cooling mechanism.

If all things were equal, a steep order tweeter would outperform the identical unit in a 1^st order circuit during a loudness abuse contest since a shallow slope treble transducer extends considerably lower in frequency. But clearly, things aren’t equal. A 1^st order designer could and would never use the cheaper, narrower bandwidth tweeter his 4^th order colleague could get away with. While the latter must spend extra funds on additional crossover components, the former will spend those dollars on a better tweeter that can withstand the extended bandwidth demands of his preferred network. Such budgetary considerations between both camps tend to balance out in the end, with the steep-order design perhaps saving a few dollars overall. By way of case evidence, McGinty can’t recall ever replacing a single Shearwater Scanspeak tweeter due to power failure. With literally thousands of Kestrels in the field, tweeter warranty repairs for his entry-level floorstander are less than a handful, something he attributes to conservative design and fanatical parts QC.

 

Prototype of new Kite model in new factory -
1.25" excursion custom woofer, 1000-watt internal amp
with bass contour controls, Scanspeak Revelator midrange
and 9800-series tweeter - bass flat to 20Hz, 90dB sensitivity
for hi/mid module.

 

At the end of the day, power handling is determined by how loud a speaker can play before it blows up. Pat invites disbelievers to compare any of his speakers with higher-order designs of equivalent specifications. He predicts such folks would notice the exact same thing with either speaker: beyond a certain threshold of excessive and prolonged decibel levels, both would blow their woofers. Having built 4^th order speakers for close to 20 years, he knows what he’s talking about.

 

The Health Food Connection

At this juncture in my interview, I reflected on the curious status quo which occasionally forces 1^st order proponents like John Dunlavy, Pat McGinty, Jim Thiel and Richard Vandersteen into having to defend their engineering approach in the face of stalwart prevalent opposition. It reminds me of pre industrial revolution society. They didn’t practice biotech genetic engineering on crops then. Radiation, homogenization, pasteurization, preservatives, pesticides, artificial colors and foods with zero nutritional value were still a mere glimmer in the imagination of future exploitation corporations. Our early ancestors would have been hard-pressed to conceive of the mere idea of health foods since this very notion suggests the existence of foods that are actually bad for your physical health. Who but 21^st century man would even consider calling poisons food? 

But many obviously do. This turns those who embrace vegetarianism, health foods, organic and biodynamic produce into cranks, fanatics, weirdoes and outsiders. Doesn’t it seem more appropriate to call consumers of Coca Cola, McDonalds, processed American cheese and pop tarts to the stand? Aren’t they the very ones needing one rocking explanation as to why they so blatantly trespass against common sense and the temples of their own physical shells?

I wonder then. Rather than attacking 1^st order loudspeaker designers for preserving the fragile phase and time relationships of the music signal as it is passed on from source to amplifier – and may I add, correctly even by the cheapest CD player or preamp – shouldn’t it rather be the establishment of non-1^st order practitioners who owe us an explanation for why fidelity to timing isn’t as important as their reasons for disregarding it? What possibly could those reasons be?

 

Part II

Practicing good cliffhanger routine, we’ll bow out of these explosive questions for today to revisit Meadowlark Audio next month. We’ll explore transmission line loading, talk about Pat’s recent relocation to Watertown, Upstate New York, his new in-house cabinet shop and a productive new way to overcome traditional operating constraints. We’ll also check out forthcoming products like his Heron and Nightingale center channels, two subwoofers and the Kite, a modestly sized 8-inch 3-way that can be adjusted to extend to 18Hz at +1dB – and that’s not a typo.

 

Meadowlark Audio Inc.
800 Starbuck Avenue
Suite A-103
Watertown, NY 13601 

Voice: (315) 779-8875
Fax: (315) 779-8835
E-mail: meadowlarkaudio@meadowlarkaudio.com
Website: www.meadowlarkaudio.com

 

Postscript

A combination of personal and other issues has postponed my planned interview with Joe Fratus of Art Audio by a few months – expect it around May or June.