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Reviewer: Srajan Ebaen
Source: Zanden Audio Model 2000P/5000S; Ancient Audio Lektor Prime; AMR CD-77 [on review]
Preamp/Integrated: Supratek Cabernet Dual; Wyetech Labs Jade; ModWright SWL 9.0SE; Bel Canto PRe3; Melody HiFi I2A3; ModWright LS 36.5 [on review]
Amp: 2 x Audiosector Patek SE; First Watt F3 and F4 [on review]; Yamamoto A-08S; Fi 2A3 monos w. JJ 2A3-40s
Speakers: Zu Definition Pro with WLM Sys V active crossover; Mark & Daniel Ruby with OmniHarmonizer; DeVore Fidelity Nines; Mark & Daniel Maximus Monitor [on loan]; Esoteric MG-20 [on review]; Zu Presence [on review]
Cables: Crystal Cable Ultra loom; Zanden Audio proprietary I²S cable; Crystal Cable Reference power cords; double cryo'd Acrolink with Furutech UK plug between wall and transformer
Stands: 2 x Grand Prix Audio Monaco Modular 4-tier
Powerline conditioning: 2 x Walker Audio Velocitor S fed from custom AudioSector 1.5KV Plitron step-down transformer with balanced power output option
Sundry accessories: GPA Formula Carbon/Kevlar shelf for transport; GPA Apex footers underneath stand, DAC and amp; Walker Audio Extreme SST on all connections; Walker Audio Vivid CD cleaner; Walker Audio Reference HDLs; Furutech RD-2 CD demagnetizer; Nanotech Nespa Pro; Acoustic System resonators for room tuning
Room size: 16' w x 21' d x 9' h in short-wall setup, with openly adjoining 15' x 35' living room
Review Component Retail: $1,995/pr

PIO. Usually that stands for paper-in-oil. Capacitors, not pickles. But in the case of super tweeters, engineers and thinking audiophiles, it becomes Pissed Intensely Off. Male middle-aged hearing is good for between 14-17kHz. The ubiquitous RedBook standard brickwalls at 22.1kHz. Your average single-ended triode amp is happy to make it to 20kHz at minus 3dB. Why should added ultrasonics up to 105kHz be audible, preferable and relevant over the entire audible spectrum, not just its uppermost harmonics? How is it that a passive device leashed to a CD-based signal chain containing no >22.1kHz data obtains such data in the first place? If it really does. That the concept should work as is on broad record here and elsewhere can piss off thinking folks something fierce. It's worse than why cables sound different.


On first blush, wide bandwidth amplifiers to 200kHz aren't intuitive either. Then what about Goldmund's Job 5-based circuits? They are good out to several MHz. Spectral's DMA-360 too is spec'd +/-3dB from DC to 1.8MHz. Accompanying rationale is speed (slew rates up to 1000 Volts/microsecond, rise times better than 300 nanoseconds) and phase coherence in the audible band's top for time-correct sweetness. Perhaps the same rationale (limited bandwidth causes phase problems) is behind super tweeters as well? Not actual ultrasonic activities intermodulating back into the audible range but simply phase-correct performance in the audible band? Or is one causing the other? Even though such devices often kick in high, say at 15kHz, their electrical or mechanical filters aren't ultra steep. Actual coverage stretches rather lower than such figures would indicate. Shouldn't that heat up any speaker with good native treble extension by a few dB to make for a bright forward sound? UK speaker stalwarts KEF and Tannoy, neither of which could be accused of flavor of the monthing, both have their own super tweeters. There's also Townshend and Tonian Acoustics, the latter with ribbons. Now explode operational scales well beyond audio. Enter muRata of Japan.
As Michael Lavorgna presented it in his excellent review of their ES103A device, "The muRata Manufacturing Co., Ltd. is not your typical audio manufacturer. They're not even your atypical audio manufacturer. "muRata as an 'Innovator in Electronics' supports the infrastructure of our electronic society by developing new electronic components and technologies." Don't believe it? muRata was formed in 1944. Their revenues for 2004 were roughly 4 billion US dollars. If you want to find their super tweeters in the company's annual report, you'll have to look in the "piezoelectric components" category - and I suspect we're talking a tiny fraction of income. You see, the ceramic spherical diaphragm that is the breath of the ES103A was an offshoot of some R&D into a core product line - piezo-electronic ceramics. We are talking high-tech and high budget R&D to the tune of $300 million plus last year. The notion that someone within the muRata ranks thought to spin off a line of super tweeters amidst the millimeter wave radar modules and piezoelectric vibrating gyroscopes is pretty darn fascinating."


That's putting it mildly. muRata isn't a cottage industry mosquito that clings for bottom feeder survival to a rotten stalk of audiophile voodoo and hopes for the occasional sucker to walk past and get bled. Rather, muRata adds to the growing chorus of why bother if it's bullshit? Why should Big Corporate bother with devices that can't work? Why should engineering driven electronics companies like Goldmund, Spectral and many others bother with MHz amplifier bandwidth? Why should established serious speaker companies with feet in Pro like Tannoy bother with their own super tweeters? As a prosecutor would put it just about now, "that's all very interesting, sir defense attorney, but are you telling me that your client is actually alive and committing this mischief or is all of this nothing but heated imagination and third-hand hearsay?"
Today's super tweeters are most certainly alive and full of mischief. I ran a set of Crystal
Cable Ultras straight from the wide-bandwidth FirstWatt F4 to a pair of muRata ES105s, at the identical volumes the DeVore Fidelity Nines had fed off the same amp before. In the listening seat, I could clearly discern the harmonics of female vocals, remnants of lyricizing and the rhythmic, pitch-modulated tingles of the accompaniment's uppermost harmonics. Very bandwidth restricted for sure, mere sizzle and glinty pixie dust but unavoidably audible. Why this data, once mixed into the far louder output of the main speaker, should do anything save for perhaps adding a skoch of zing to transients is a very good question. Regardless, the answer won't yet account for the 90,000 cycles above what I heard but which the ES105s (nomenclature indicative of kilohertzian extension) are supposed to recover. Let's rephrase this last bit though. To my knowledge, none of the super tweeters actually claim to play back at 100kHz - just that they're capable. Is part of the confusion surrounding their workings the implicit assumption that such specifications mean these tweeters put out such signals? Would you expect any ultra wide-bandwidth amp to show ultrasonic output signal on the bench when fed a CD music signal rather than ultrasonic test tones?


Sticking one muRata straight to my ear while the DeVores were playing, still at the same volume, it was impossible to make out anything definitive. Yes, there was some golden gossamer and you felt the air inside your ear excited by something but the main speaker's output completely overshadowed the narrow details audible when the muRatas alone were tizzing away.


The whole thing is mysterious. In his follow-up to Michael's review, John Potis too concluded that the muRatas were efficacious, particularly on vinyl where he noted very obvious across-the-band improvements. Alas, the high costs of the cylindrically enclosed ES103As of $2,495/pr don't exactly support popularizing this outlandish concept.
Today's muRata ES105 review came about because I'd loved the tiny Micropure Kotaro
which wears an OEM'd muRata gold dome on its li'l two-way sleeve. It too employs it for just minimal conventional tweetering at 15kHz before entering 'super' coverage. When one backs out retail margins and the costs of its fancy musical-instrument enclosure plus wideband main driver, the Kotaro at $3,100/pr demonstrated that muRata'ing didn't have to be so expensive once higher sales volumes from stock speaker installation were on hand [btw., the 105s sport a threaded insert to be mounted on microphone stands or equivalents if a speaker's top won't allow placement].

Michael Lavorgna laid out the corporate structure and specialized R&D at the heart of muRata's piezo technology. It explains why this tiny sub division inside a huge keiretsu has to justify its existence by, we assume, at least breaking even. Considering the global non-volumes of add-on super tweeter sales, economics dictate why muRatas cost what they do.


In my book, the wee Kotaro, off axis, had produced the finest treble my crib had yet witnessed. In a few subsequent reviews, I'd referenced it as such with a certain nostalgia. Apparently muRata noticed. It wasn't too long after the Kotaro review that Swede Hans of Subas Audio rang my bell once again. Would I be interested to revisit muRata's gold dome? He'd safely received back his Kotaros and muRata now had a cheaper add-on version available. He'd be pleased to send me a pair from his personal distributor inventory for testing. Ah, it's good to have friends around the globe looking out after your audiophile Jones [Kotaro below]. Over the Kotaro, the ES105 adds about a one inch-long horn in front of the same hyper dome.
One thing I'd forgotten to confirm before accepting this assignment was what "cheaper" constituted over the ES103As. As it turns out, just $500. We're still talking the price of a good Canadian floorstander - for two after-market gizmos of trapezoidal cross section that contain one pinky-tip size piezo tweeter each and sport a simple though quality pair of aftern binding posts to jumper off your main speakers' terminals. If their bindings posts be low and their profile tall, you'll need rather long jumpers but considering the bandwidth involved, skinny and cheap is all you'll need. muRata efficiency is 90dB, impedance 8 ohms and power handling 50 watts. Curiously, the ES105s sport no provisions for signal cut or boost as though matching the output to the main boxes was considered redundant. The DeVore Fidelity's 91dB rating suggested a nearly perfect match. Their special ¾" dome tweeters good to 40kHz didn't necessarily, producing perhaps too much overlap 'up there'. But wait, considering how my hearing nose-dives at 17kHz sharp, why should I be bothered by double -- or even quadruple -- coverage between 20-40kHz? Bring it on.
As it turned out, the muRatas on the DeVores eventually caused a bit of inner ear pressure which I always equate with the presence of low ultrasonics. I prove such inaudible stuff to myself by removing such effects when powering down the perceived culprits, in this case the muRatas. My ears may be deaf above seventeen kay but an extra spread of twenty to forty presence isn't completely harmless after a while. Conversely and before this effect became bothersome, I had to admit that the presentation in general clawed up a few notches on the "it's live" pretendo-meter by creating better soundstage focus and slightly deeper tone colors - nothing drastic but still welcome. Because this particular inner ear reaction had not accompanied the Kotaros, I laid the 'blame' on DeVore's unusually endowed tweeter neither needing help nor booking competition. There were plenty of other speakers in my digs to hopefully get the goods without this side effect. The latter isn't so dissimilar
from flight landings. You want to close your nose and blow from the inside to relieve the pressure against your ear drums. It's proof positive that out-of-range sounds do register on our nervous systems. Needless to say, the military would abuse that fact in the low end to design infrasonic ray guns and incapacitate people.
Back on track. As its review chronicled, the mighty Mark & Daniel Maximus Monitor is hung so elephantine in the bass that it takes away from overall transparency and openness (a recent factory adjustment of driver suspension and network tweak addresses this). While not overturning the resultant heaviness of the former stock voicing entirely, the overall presentation did lighten up when the optional Omni Harmonizer was added. That's a 7kHz+ upfiring small air-motion transformer. It injects air and extends to a claimed 35kHz. On my older units, three hot speaker terminals allow for 0, -2.5dB and -5dB output while the latest Omni sports a stepped attenuator instead. With the 85dB sensitivity of the Maximus, the muRata's output would automatically lead by 5dB. I was curious how it'd compare to the synthetic marble unit.

As current-hungry 4-ohm loads, the Maximii were powered from 900 watts worth of available Coda CX monophonic power on loan. This wide bandwidth amplifier circuit would additionally avoid the treble phase shift endemic to valve designs that struggle to make 20kHz.

Defeating the muRata merely involved undoing one WBT locking banana per side on the Crystal Cable custom jumpers. Swapping in Mark & Daniel's omni could be done while losing less than 30 seconds in the hot seat.


No inner ear pressure. Adding the muRata otherwise made a small difference in focus and by creating a fine glistening sensation all over - as though looking at subtly wet objects. On the instrumental CD I tried first, guitar and cello duettize before soprano sax and background voice enter and finally a high flute. In line with super tweeter commentaries I'd read, the unexpected benefit really did occur in the midrange, particularly noteworthy on the con arco cello. Its presence locked in a bit more and there was a tad more on-the-bow action. But on this track, I'd not call it a profound hallelujah transformation save for turning a $3,000 into a $5,000 speaker.


Hello came knocking with the title track of Dulce Ponte's Lagrimas, one of my flames at her finest. I audiophiled my wife for a spell and she heard it instantly. "Smoother, softer, like silk - very sensuous". Indeed and as such, the exact inverse of what any expectation of 'more treble energy' would suggest. This was a more profound difference, like MSG in food.


"More depth" was my wife's reaction to the omnis. And tears. "This is more profound" she whispered as she recovered. Lo and behold, the tears came again when it was the omni's second turn after the muRatas and stock Maximii had interjected their turns. To my ear/brain, the omnis were more spacious and the soundstage increased in depth while focus softened a tad. The general effects of add-on tweetering were related, however. Smoothness increased and things got more intense though it's hard to pinpoint what intensified, exactly - tone color? Still, both add-on solutions were different in flavor. On this particular speaker, Mark & Daniel's own was preferable (and cheaper by half to compound that preference). While you think hogwash, Luke Manley, in his interview for Mike Malinowski's review of their VTL 7.5 Mk2 statement preamp, shared how extending preamp bandwidth from 60kHz to 100k to above made a noticeable difference during R&D - though like everybody else on this subject I've been able to find, Luke did not offer any compelling explanation as to why.

On my wife's Zu Druid Credenzas, the muRata once again did its smoothing business, albeit not as pronounced, this likely due to the higher output mismatch between it and the speaker. On my big Definition Pros, the difference was down to hairsplitting, perhaps because they're even more efficient. On Esoteric's MG-20 with their proprietary pure Magnesium domes claimed good to 44kHz, the muRatas sweetened things once more but also caused the ultrasonic inner ear pressure. I still wondered: If the add-on effect was due to increased output in the top octave, couldn't the same effect be achieved with a standard tweeter that remained linear through the critical presence region but then took a steep turn above 10K to be up, say 6dB at 15,000Hz? After all, isn't that the type of response you'd expect to measure with a piggybacked super tweeter? Stereophile's John Atkinson would probably question any speaker that measured admirably linear throughout its bandwidth but then featured a built-in and significant hike at the very top. Or is super tweetering independent of treble energy plateaus but instead an absence of phase shift operative well below the top band to improve midrange lock and soundstage focus because there's less time shift between fundamentals and their overtones? If so, you'd expect a superior ribbon tweeter to be impervious to add-on charms. Rather, a ribbon with native extension to 60 or 100K might echo DeVore's small ¾" dome or Ohmachi-San's Magnesium unit. It should prefer to run solo, being of 'super' status already.
No matter, the muRata ES105 clearly doesn't operate in any imaginary realms. In fact, it can get too much on speakers with at least a solid spare octave of extension on top. It's easy to write off the entire topic because logic doesn't seem to add up. Once you actually experiment with these devices however, the trouble of trying to understand what you hear -- and why -- will be just one price to pay for letting them into your house. The most ideal speaker to sell the muRata effect from what I had on hand was Mark & Daniel's Maximus Monitor. The muRata difference on the Maximus was substantial, readily demonstrable and unambiguously preferable, i.e. better. Gonads will shrivel merely over the financial hit. That part is a tuff sell. Had I the change to buy a Maximus + muRata combo in one fell swoop, I'd buy a Volent VL-2 instead, killer ribbon out to 60kHz built right in for integration and keeping it simple.
Esoteric MG-20s in the 2.0 video system during their break-in before moving into the big rig

Where the muRata might come into its own financially is for those who already own a good speaker. Selling that for maximally 50 cents on the dollar, then applying a $2000 savings on top of the proceeds to a new speaker should be a downgrade. Speaker technology hasn't matured that much over the last half decade. Should your system be dialed elsewhere to squarely focus upgrade funds on the speakers, the ES105 might be a sensible proposition that let's you keep what you have and improve it. I still wish it'd be only $800/pr though...


To recap, everything you've read about the strange broadband effects of super tweeters is quite true. It does seem important that super tweeter and main speaker sensitivities be reasonably well matched. A mismatch in favor of the tweeter appears more benign than logic would dictate but the opposite can diminish the effects to barely noticeable if speaker sensitivity leads by a sufficient amount. If your main speakers already extend to 40kHz, super tweeting could be more than gilding the lily and actually induce ultrasonic discomfort in your inner ear (this is likely also age-dependent and how far out your hearing still extends). In a well-matched case, you'll enjoy a smoother, sweeter, silkier presentation with more overall color, more staging definition and better focus. Or simply call it higher overall intensity yet reduced edge 'n' etch - unexpected to be sure but what to do? This review is merely the last in a long line to say so. According to our own John Potis, these effects rather compound for vinyl listeners - in which case, the must-have factor compounds equally. On that tempting note, over and out.
P.S.: My listening room and the entire remainder of the house are tweaked with Franck Tchang's Acoustic Resonators. 6moons reviewers Marja & Henk use as many or more themselves. Reading my above findings, they commented: "When we have been out of the house for some time, say a full day or more, we have to readjust to the extra pressure inside. It's like in an airplane when the pilot is fooling around with the air pressure. It has a direct correlation to the abundance of Franck's resonators in the house. ( Deactivating them removes that pressure sensation). That's exactly what you noticed when there was too much high frequency energy when the DeVores were combined with the muRatas." For further reading on the subject of ultrasonics and hearing thresholds, here are three links from M&H: 1 | 2 | 3.


Quality of packing: Big cardboard box with plenty of internal cardboard spacers.
Reusability of packing: Can be reused multiple times.
Ease of unpacking/repacking: Very easy.
Condition of component received: Flawless.
Completeness of delivery: Includes owner's manual and warranty card.
Quality of owner's manual: Perfectly adequate.
Website comments: Informative, with good photography and downloadable catalogue PDF and manuals.
Warranty: 3 years from muRata, 5 years when purchased through Swedish distributor.
Global distribution: Company manufactures in Japan and distributes in Asia, Europe, North America and Africa, with a complete list on the website.
Human interactions: Dealt with Swedish importer exclusively who responds promptly and courteously.
Other: Can be screwed to mic stand, camera tripod or equivalent.
Pricing: Very expensive.
Application conditions: Lacks output trim to make best match with speakers close to its own 90dB rating. Likely redundant on speakers with tweeters good to 40kHz or higher.
Final comments & suggestions: A real and efficacious product despite niche status though not universally applicable. Lower pricing would be nice but sufficient sales volume probably doesn't exist to make that feasible.
muRata website