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These reader contributions first appeared in the January and November 2010 issues of hi-end hifi magazine of Germany. You can also read these reviews in their original German versions here and here. We publish their English translations in a mutual syndication arrangement with the publishers. As is customary for our own reviews, the writer's signature at review's end shows an e-mail address should you have questions or wish to send feedback. All images contained in this review are the property of fairaudio or HighEndNovum.
Readers unfamiliar with this category of audio tweaks might think of them as secondary passive sound sources by way of deliberately resonating objects made from various metals. Related ones are also made by Acoustic System Int. and Synergistic Research among others. - Ed.

Contributor: Frank Hakopians
Review component retails: €970 for PMR, €379 for three MKT

The big bowl
: After 20 years of involvement with high-end audio, one might conclude that real innovation is rare whereas old wine hawked in new bottles seems quite common. Even so I sustain a healthy curiosity about interesting products and unusual solutions. One of those is the passive multivocal resonator—henceforth PMR—by Michael Jungblut of HighEndNovum. The name suggests esoteric equipment used to treat water or entire homes against negative geopathic disturbances. It seemed worthwhile to try how something like it would affect a hifi.

After a longer phone call with Michael Jungblut, my curiosity was further piqued by learning that the PMR works by enhancing specific upper harmonic bands. I’d sat through previous demonstrations of the well-known acoustic resonators to know their positive effects, albeit without  personal must-have reactions. Their operation and that of the PMR was supposed to be similar in effect, with Jungblut’s assumption being that the recording process somehow strips away important harmonic content which the use of such resonators can offset.

More important to me than theory was an unforgettable concert in the Golden Hall of the Vienna Musikverein of the Vienna Symphony under Georges Pretre performing Mahler’s 1st. It had convinced me that specific added secondary harmonics can make for an especially involving and nearly magical experience. That particular venue accomplishes this trick with hollow bronze figures which are incorporated in its wall construction to exhibit significant resonant activity when triggered. That’s certainly not the only unique construction detail of this famous hall which to me has a truly exceptional sonic signature. But then this brief report is really about the PMR. My thinking was simply that if such sympathetic resonance works so well on real music, why shouldn’t a derivative PMR create similar magic in my own listening room?

Jungblut’s device is a metal bowl of ca. 30cm diameter and 12cm height. The appearance suggests origins in Bronze Age or Medieval times. The weight is 5kg and according to the creator consists of high-quality bell bronze. Careful, the edges are quite sharp! Manufacture is by sand casting. This implies that each mold can only be used once. The next casting requires a new sand form. It also explains the surface variations/imperfections which make each PMR unique. Hand labor the old-fashioned way is my kind of thing.

I had opportunity to experience a demonstration of the PMR in Herr Jungblut’s high-end but far from excessively priced system in the town of Siegen. The addition of two PMR created sufficient sonic advantages to believe he’d instead upgraded his hardware chain with a rather more expensive one. Particularly treble and dimensional realism improved and the general sonic action appeared more energetic. Bass and tone colors showed gains too. I thought that the majority of these changes occurred already with the first PMR installed which altered the high-frequency bands and improved stage height for greater realism. The second PMR wrapped up these positive changes with a bow of more timbre saturation and greater bass energy. The overall results were very agreeable and I was grateful for an impressive demo.