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"My cousin is a Ph.D micro-mechanical engineer. He works in a university research department in Germany. He came to see me with a NASA-kind of software to do a simulation. I asked him to first listen and feel, not to music but to the difference of the room ambience with and without the resonators. I told him that if he couldn't hear and feel the difference, how would he know which parameter to key into his computer? These parameters are pretty complex. But many people who leave school with an advanced degree believe they know everything there is to know about their specialized field."


Was it possible to be a text book engineer and not hear the difference? Would it take a bit of time to acclimate and get sensitive to the changes - like having pointed out the ringing endemic to high-order loudspeaker networks which you never heard before but once identified, can never not hear thereafter? There are other factors at work as well. One user had reported that room temperature played an effect. Franck replied to my concomitant query that yes, air temperature does affect acoustic energy transmission. Temperature drops raise air density due to humidity and a bit of sonic compression results. "Just raise the resonator up by half a centimeter and everything should work fine again."


It's such empirically derived answers that could get Mr. Tchang into trouble. That's why the basic instructions for a set of 9 resonators don't mention the refrigerator or other seemingly outré applications. After all, it's taken three long years for his resonators to be taken just serious enough for a tiny bit of press. Plenty of resistance remains. Just how far things can be taken with this system is probably not something revealed in any formal instruction manual soon. It'll be for the adventurous to find out for themselves. The inventor will merely silently grin as feedback begins to arrive in Paris.


Just to throw a major curve ball, he did let on that the resonators are also electromagnetic receivers. "Their small size creates 'poles' but because the devices are passive, it takes time to set up the associated pathways This explains the settling-in cycle during installation. Once the cycle has completed itself, electromagnetic energy in the room connects with the poles and the room is cleaned up. When a resonator is removed, the electromagnetic energy will try to reach another pole. If the original resonator is put right back, the established channel may still have an effect but if too much time passes, it'll have to be recreated again. If different resonators are swapped out from wooden base to wooden base a number of times, the electromagnetic field in the room will confuse and there'll be some audible compression by comparison."


Franck doesn't have his own website. He doesn't hawk his wares. You have to seek him out via e-mail. Very unhucksterish of him. If you really want to know, he'll warn you straight up that "with the resonators in place, you can control the air and cancel the walls in the house - virtually of course. After you treat the full house, you can adjust any one resonator in any room -- even the one in the fridge -- and bring the energy to a higher level. Or vice versa. Yes, you will have a strange feeling for a very short time but our body and mind adapt very fast. One thing is for sure. You cannot go back. No one can." Terminally tchanged? I was ready for my very own acoustic treatment though I was by now way out of my depth. But first,
Franck's personal speaker - prototype

Marja & Henk's further franckly unbelievable adventures
HVT Acoustic System resonator workshop
It takes courage to stick your neck out when dealing with something controversial in audiophile surroundings. After our initial article on the Acoustic System resonators, many postings on the various forums and message boards were negative. When we published the article on a Dutch website, the reactions were plain hostile and personal. Common to all forum participants, mailers and criticasters was the fact that none of them had ever seen the resonators in person nor listened to the effects in a room treated with these tiny bowls.


When we met Dutch HVT magazine's editor Theo Wubbolts and discussed the positive experiences we had with the resonators and the negative feedback over publishing our findings, he was immediately intrigued. Theo is not the person to jump on any wagon. He is the kind of man who thinks things through before reacting. His magazine HVT reflects his vision on audio. Music comes first. All the equipment is just a necessary means to bring the music to the listener. Theo in this respect is a typical Dutchman. Acting normal is strange enough. Why add to it with bizarre behavior? And now he wanted to know more about Franck Tchang's crafts. Hey, he asked for it. A brave and open-minded man he is.


HVT magazine has its offices on the premises of the well-known recording and post production company Polyhymnia, formerly known as Philips Classical. This location facilitates HVT with a dedicated and acoustically treated studio for its formal listening tests. The studio can seat up to 10 listeners. Some years ago HVT began to organize small regular weekend workshops in this studio. Readers of the magazine were invited to attend whenever something really special was on hand. The subject could be a novel recording technique, a very special set of equipment or something that would interest music lovers. Such a workshop was held three to four times a day, each time for a small group of attendees who had subscribed to the event. Admission is free and Theo provides coffee and tea.


To enable a group of people to get hands-on experience with the resonators, Theo Wubbolts offered to facilitate a workshop on the subject. We contacted Franck in Paris and Theo contacted the Dutch distributor of the resonators. Franck was interested and so was Rannel de Cock of RA Vision. A date was picked and in the next issue of HVT -- short for Hifi Video Test -- an ad was placed to alert interested readers about the workshop. When the date of the workshop arrived, over 30 persons showed up. Four groups were formed so every attendee was able to enjoy good seating in the studio.

RA Vision provided a system with Ascendo C7 loudspeakers, an Acoustic Signature turntable, behold CD player, behold PSD192 phono stage, behold APU768 preamp and behold BPA768 amplifier. The German electronics make for a complete digital system since the analogue signal of the turntable is almost immediately converted to 192/24 digital.


At the beginning of each of the four workshop sessions, music was playing while the attendees picked their seats. Theo very aptly chose Paganini's "La Campanella" with Salvatore Accardo on violin. Before the workshop started, Franck and Ranel had been sticking nine resonators to the walls of the studio, plus an additional diffuser. This meant that all attendees entered an already treated room. Franck did this since it is easier to experience a difference when you subtract rather than add something. Before Theo Wubbolts welcomed everyone, they had a chance to listen to Paganini's little bell to become accustomed to the room acoustic and system. Only a few of the resonators were visible, most of them hidden behind the curtains that line the walls.


After Theo's introduction of Franck, the designer started taking all the resonators off their wooden supports. Then he restarted "La Campanella", now in an untreated room. That is, the room as always treated by the Polyhymnia crew. The body language of every attendee was very clear. Everyone noticed the difference. From an open, light and very dynamic sound, the little bell now sounded somewhat muffled as though a blanket covered the musicians. From the reactions we'd overheard prior, we could make out that about 50% of the attendees were skeptic that the devices would work. The other half was just curious to learn more.
Franck gifted Theo with a Special Gold resonator for his private listening room

As Franck took to stage, he first explained that we do not listen to the system -- the equipment -- but to the room. To demonstrate, he hit one of the walls with his hand. Like in many treated listening environments, the walls are drywall on 2 x 4s with insulation between. His knock on the wall produced a dull sound. But a sound it was, not a no-sound. This, Franck explained, is what you hear when he takes off the resonators. You hear the room because it is too small to recreate the original room of the recording venue. There simply wasn't room for the room. At certain locations, the air pressure got too big and compression resulted. We all listen to the air that surrounds us. Air is everywhere as it should be or we'd die.


We need to remove the compression at key points. We need to intercept air pressures and create more listening space. With the resonators, we can control the listening space to mock up a virtual space that seems bigger than the actual room. The resonators do that by means of introducing their own damping factor as a result of the materials used to forge them, from the lowest density of the basic copper resonators to the highest in the pure platinum version. Low frequencies displace more energy than treble frequencies, hence the need for various materials with their dissimilar damping factors. They are all passive and only react to certain frequencies. Others will pass unattenuated.


The compression in room corners is high and overpowers treble energies. Franck talks of the air's own damping factor. Where high frequencies die out and are smothered in the corners, lower frequencies with their much greater energy will reflect and create the dreaded room boom.


Now, our demonstration facility at Polyhymnia was pretty big. Let's make it smaller. With the help of Rannel, Franck lowered the four highest resonators with their wooden supports. All wooden blocks are easy to attach and detach from the walls with a sort of blue tac. After the adjustment, the highest resonator on the front wall and the two on the sidewalls sat at about 1.60m instead of 2.20m. The second resonator on the front wall was now roughly 1 meter above the floor. As Franck explained, the top resonators made of gold have a rather high damping factor and control the height of the virtual room. With the virtual ceiling now lowered, more music was played. All attendees confirmed the subjective sensation that the room they listened to had vertically shrunk. Franck didn't like the sound and raised the block and resonator on the right side only. The virtual ceiling tilted and it was fun to see almost all attendees tilt their heads in response. This reaction said more than a thousand words.


Next the top resonator at the front wall was put back in its original location and the sound grew livelier. All this was done while the music played on. Finally the resonator at 1 meter on the front wall was raised to its original height of about 30cm above the tweeter. This simple move opened up the soundstage and the midrange acquired more air. With this change, all attendees began shifting in their chairs and looking at each other.

When all resonators had been put back in their initial locations, Franck addressed the listeners that sat behind each other in the center aisle. Only they'd be able to hear his next demonstration. He predicted that the center of the music would collapse and only hard left and right remain - "dual mono" just for three listeners. He achieved this by rotating the resonator behind the tweeters so that one of its wings was pointed at the listeners. Franck called this the Closing Of The Window. And the listeners admitted that they experienced a gap in the normal center fill. By turning the resonator again, the window was reopened and true stereo restored.


Just to give the listeners further impressions, Franck and Rannel removed all resonators once again and played more music before putting the resonators back on their supports. The differences were very apparent to all attendees. On a question why these small cups rest on the bigger wooden blocks, Franck answered as follows. Each resonator has its own damping factor as a result of the material used. Each wooden block is either made of soft of hard instrument-grade maple. He passed a block around and let us all knock on it. The block together with the bowl forms the resonator just like a stringed instrument where a wooden body and some strings connect through the bridge. With the Acoustic System resonators, the maple block is the body, the metal bowl the strings and the silver tripod the bridge.


Theo recently discovered a 45RPM Bert Kaempfert LP (Image Hifi LP007) with the song "A swinging safari" on it. In this song, the bass line goes really deep and is an ideal demonstration piece to see -- or better hear -- what resonators can do to low frequencies, a problem almost everyone battles. Once again, all resonators were removed and the Kaempfert track cued up. The room was filled with powerful bass - too much for the room. Or in Franck's words, the room was just too small. After adding the resonators back to the walls, the room -- with the same playback volume -- was now perfectly capable of supporting all the bass the Ascendos dished out.


With a smile Franck explained that your room is the real loudspeaker you listen to. The woofers and tweeters are just the mechanical means to push the air in the room. You cannot look at the air playing the music but you can see your transducers. So choose nice looking ones...


From the questions asked, the most common were two. A few listeners wanted to know if the resonators had to be visible to work. Franck explained that they are reacting to the air in the room, thus as long as there is air surrounding them, they work, even behind curtains, cupboards or doors. Next was the question of how many resonators are really necessary. Franck admitted that there is a real -- not virtual -- price to pay when all nine resonators are put to work to give optimal results. However, one can start with the most important locations by using just two resonators. Just put a basic copper resonator a few centimeters above the floor and a silver slightly higher than the tweeters on the front wall. This will smooth out the bass response, unlock soundstage depth and improve clarity and intelligibility of the music.


After four demonstrations to four groups of HVT readers, we confirmed that of 30-some participants, not one left with the impression that he or she had been duped or was the victim of a mass hypnosis. Even the most skeptical listener was convinced that what he heard and saw was real and repeatable.