Positively dB’s Feedback: RoomTune, Kimber, Nordost, & VansEvers
Doug Blackburn

Time for another issue of Positive Feedback, and again there are so many things happening there will barely be enough room to cover half of what has been going on. There’s another visit to the eastern Ohio high-end capitol, New Philadelphia, to have another talk with Michael Green about new developments since the last trip there 19 months ago. And: New and renewed Kimber cables are making an impression…Nordost sends a stunning cable package…and then there’s the VansEvers power cords and Power Line Conditioners.

The July 4th weekend found me in Ohio again, just a short commute from Michael Green’s New Philadelphia headquarters. A perfect reason to spend another day seeing what new things have come from Michael’s continuing work on tunability and mechanical resonance. Since my last visit:

* The factory moved to a much larger space.

* In-wall tuners have gone through several revisions before landing on a design that seems to reliably do what Michael set out to do when he started investigating in-wall tuning.

* Michael has entered the commercial acoustics arena designing new and retro-fit tunable concert halls and church sanctuaries.

* There are projects either just completed or in progress to provide manufacturer (Klipsch) and recording (Mobile Fidelity) facilities with tunable rooms.

* PARA audio and home theater dealers are rapidly adopting tunable demo rooms with 15 complete now and 25 more expected in the not too distant future.

* There are projects to fit symphony instruments (tympani, piano and bass so far) with tunable bases that improve the performance of the instrument. The San Francisco Symphony and others are driving this work.

* The first attempt at applying tunability to a commercial loudspeaker product failed to meet Michael’s design goals. The correct/corrected tunable speakers began to be available in September.

* Michael now has in-house numerical control lathe and milling machines which are permitting him to refine the performance of AudioPoints. There will eventually be new ones with different profiles that improve performance and sound quality, naming for the new cones/points is not firm yet, though "MTD" (mechanical tuning device) will likely be part of the name.

* A new line of acoustic treatment devices, "PZC" or Pressure Zone Controllers, use a completely different approach to room tuning.

* New production methods coming out of the search for better tuning of shelves for the rack products (Justarack, Clamp Racks, etc) have led to a "Signature" series of racks and platforms with appearance/finish standards (and performance standards) that have never been as high.

As I delve into a little more detail about these topics, you will begin to see how what may, at first, seem like "working in too many different areas" really isn’t that at all. What is happening as M.G. explores mechanical tuning in one area is that new things learned about refining the performance of a speaker or instrument tuning device, has direct applications in other areas like room tuning devices or improvements in shelves/racks. It is a juggling act to try to keep the latest and greatest information applied to each product area. I have organized the following list to try to clarify the areas M.G. is focusing his efforts on:

* Mechanical Tuning Devices (MTD), brass cones for under, or above when clamping, components with threaded variations for bottoms of rack legs and under speakers.

* Room Tuning devices for home systems, stereo and home theater, with a strong focus on "Tunable Room" technology.

* On-wall, floor standing, & corner mounted for existing rooms

* In-wall, under floor, and above ceiling tuning devices and techniques for new construction or remodel jobs

* Acoustic ceiling moldings for existing or new construction

* Room design and acoustic treatment using tunable room technology applied to church sanctuaries, performance halls, recording studios, speaker manufacturer facilities, audio equipment dealer demo rooms.

* Using mechanical tuning technology, developing support platforms for acoustic symphony instruments which permit them to sound the same (or better) as they are repositioned within their usual performance venue or moved to less familiar performance locations.

* Applying mechanical tuning, musical instrument building techniques, and tunable speaker technology to a line of loudspeakers which meet M.G.’s performance goals and working with other speaker manufacturers to bring tunable speakers to their existing products or new products.

* Create high performance audio and video component support/rack systems using tunability and mechanical resonance control.

Let’s look at how the evolution of AudioPoints is tied to M.G’s work with the San Francisco symphony. Changes to the original AudioPoint design resulted from work on tuning bases for symphonic instruments. M.G. found that everything he placed under the various instruments gave a different decay profile. Take tympani as an example: ideal performance would be a nice long decay after the initial whack with no increase or decrease in pitch as the decay progresses. Under the instruments, each different material produced a different decay profile. Some materials, like sorbothane, produced a short but linear decay. The shortness of the decay deadened the sound of the instrument. Other materials produced longer decay times but the pitch of the decay would begin rising or falling at some point during the decay. AudioPoints provided a fairly long decay time, but Michael found the frequency would not remain linear throughout the decay. Using new numeric control machining equipment, new brass cones were made with profiles that were different from original AudioPoints. In fact, the machine tools used to produce the original AudioPoints cannot duplicate the profiles that the new equipment is capable of doing. The design and properties of this new line of brass-cone feet is still being finalized as this is being written. Perhaps the fall will see them begin to appear in quantity. MTD will be part of the name to indicate the changes that resulted in ‘perfect’ linear decay profiles with no pitch changes during the decay.

During the development of the brass parts for the in-wall tuners and new MTD brass-cone feet, Michael learned that how the brass parts were cut affected the sound of the final part to a significant degree. There was a significant sonic difference between using hardened steel cutters and diamond cutters. There was a significant difference depending on rotation speed and feeding speed (cutter motion along the part and depth-of-cut). All of these parameters affected the finish of the surface of the part and that surface finish is apparently what causes the sonic differences. By finding the best rotation speed, feeding speed and cutter material for each part, the sonic performance of each device can be maximized. This is something that was not possible using previous production methods because the equipment being used was not capable of producing the profiles and surface finishes that the new equipment can produce.

Tuning symphonic instruments (tympani, piano, bass) lead to the discovery of ways to further improve the sound qualities of the shelves used in all Michael Green equipment racks and in tunable speakers. Part of the improvement is from years of research into finishes for the shelves. The finish is one of the most important elements that goes into creating a fine musical instrument. It turns out that finishes for audio related items is just as important. All of the experimentation with finishes has given M.G. a whole new appreciation for the role of finishes on everything from speaker enclosures, to equipment shelves, to studs and joists in tunable rooms.

Using amazingly up-to-date equipment and with fanatic attention to detail, Amish craftsmen are now making shelves for M.G.’s new upscale Signature rack series. The new shelves have exceptionally musical sounding tonal characteristics when given knuckle taps progressively from center to corner. I was very surprised at just how musical the tone of an mdf shelf could be and by how modernized Amish craftsmen are. My image of the Amish as a technology-shunning people was thoroughly shattered on this visit. It turns out that only a minority shun all modern technology. Most have adapted. They may have a generator but no connection to a power company, or a satellite dish but no connection to cable TV. They will use telephones, but often not allow them inside their homes or businesses.

Part of the improvement in the performance of the new shelves comes from the hand gluing of the two 3/4" pieces of mdf that make up each shelf and the new method used to create a perfectly round radius on the outside edges of the shelf. The prototype I saw was finished in amazing looking transparent dark purple over silver metallic called "Midnight Rose." The round recessed top nuts for the legs are highly polished brass as are the new-profile bottom cones and the 2 locking nuts.

All in all, the appearance of these shelves is stunning. If I could afford them, I would have them, absolutely no question. Gloss black and a couple of other colors will be available also, but Midnight Rose is incredibly elegant looking, especially with the polished gold appearance of the metal parts. The single shelf amplifier platform will sell for about $275.

Michael’s home, which I dubbed "Tuner Villa" in the last installment, was in the process of having the original tunable room re-done using the latest tunable room devices that Michael has developed. New 2x4 studs are going in which are ‘treated’. Michael found out that applying a certain type of varnish with the right ‘weight’ (viscosity of the varnish in the can) changes the vibration transmission properties of the 2x4s to a startling degree. An impromptu demo using a treated 2x4 and one as-delivered from the lumber yard proved instantly that the varnished 2x4 did indeed have a musical quality to the resonance that was totally lacking in the duller and fuzzier sounding untreated 2x4. So the tunable room was right in the middle of the remodel. No listening freakouts for me this time, but I will be going back when the room is finished to see what third generation tunable room technology offers. Michael had second generation tunable room hardware in another room at Tuner Villa, but there was really no reason to spend any time listening to Gen 2 on this trip when Gen 3 would be along soon enough.

The in-wall tuners going into the remodeled tunable room have a 16" wide steel bracket, painted black. This attaches to studs with Phillips head screws. The heavy brass part in the center is fixed to the steel bracket with 2 brass screws. The brass screws turned out to be one of the key components in achieving maximum performance of the in-wall tuners. So much so that these screws are being made in-house because a commercial version could not be found with the right profiles and finish. Each wall in a tunable room requires a number of tuners. The number required depends on the size of the wall. When all the tuners are in place, a layer of a specific type of plywood goes over the studs. A hole is drilled so that the tuning bolt can pass through the plywood into the heavy brass anchor. 3/8" drywall goes over the plywood. A hole has to be drilled into the drywall to clear the tuning nut. The tuning nut bears down only on the plywood. This leaves a hole in the drywall everywhere there is a tuning nut. The ugly holes are dealt with by using a small cover, something like a switch plate cover.

Of course in-wall tuners are not the only things that make for a tunable room. Tuning the ceiling and floor will further improve the performance of the tunable room. This can be done several ways, using the Gen 1 method of staggered 3/4" threaded rods connecting 2 joists at a time and applying appropriate amounts of pushing or pulling tension. Or by using the Gen 3 method... in-wall tuners and varnish on the joists which will operate the same way as when they are used in walls.

The tunable room is not complete without the latest in-room tuning technology. In this case that is the PZC series of tuning devices. Pressure Zone Controllers improve room acoustics by working on the sound that travels along walls. M.G. focuses on the sound flowing on/along walls so much because in his experience, this is the major contributor to the acoustic problems that make home audio rooms sound bad and which cause the worst problems in larger rooms and halls. The roughly 4" thick PZCs mount on the wall or can be floor standing against a wall if wall mounting meets with spousal disapproval. The frame of the PZC is open on the sides, bottom and top allowing the ‘laminar sound’ to enter the PZC easily. The ‘back’ of the PZC rests against the wall so it is not an active element of the design. The outside surface of the PZC faces into the room. It is a hard mfd board with a single tuning nut in the center. The tightness of this tuning nut controls how the ‘laminar sound’ collected from the sides, top and bottom of the PZC is dealt with by the PZC. Properly setup, the PCZs eliminate slap echo, and unevenness in room response.

PZC effectiveness was demonstrated stunningly by a field trip to one of Michael’s commercial installations. We visited a church sanctuary. The lobby area was shaped like 1/2 of the sanctuary and had the dreaded "gymnasium" acoustics. Huge amounts of echo and long resonance/decay period. This would be one of those difficult to converse-in spaces if there had been a lot of people in it. In the sanctuary, the results of the treatment of the room with PZC devices was clear... the sound was stunning in this room. Every seat heard the same thing at very close to the same sound pressure level. There were no peaks, valleys, or odd echo effects anywhere in the seating area. This was a stunning achievement in this space. You could tell just by looking at the room that it would be a sonic disaster. Yet walking around the room was a convincing demonstration that not only was there no disaster, there was an amazing uniformity to what was heard everywhere around the 600+ seats.

PZC treatment of the sanctuary was not the only M.G. addition. The stage was designed to be as "horn shaped’ as possible. This helps the sound travel out into the large seating area very efficiently. Sound pressure levels of unamplified speech did not suffer a rapid decrease as you moved away from the front toward the rear of the room. The sound reinforcement was supplied by an array of 8 tunable speakers built in M.G.’s shops. These were mounted high near the ceiling and angled downwards. Voicing of the tuning was done on-site after installation. Several men and women with voices in different registers would take their turn at the microphone then walk away from the microphone while still talking. When every voice sounded the same at the mic and away from the mic, they knew they had the speaker dialed-in for that space. Not having tunable speakers would mean that the only sound that could be achieved in that space would be the sound of the ‘fixed’ speaker and how it interfaced with the room. If voices did not sound right, there would be nothing that could be done other than trying to fix it with equalization which will not achieve the same degree of fidelity as tuning the speaker.

In addition to the sound reinforcement speakers, M.G. provided tunable stage monitors so that speakers, singers, and soloists could hear themselves. If their voice or instrument does not sound quite right to them, the tunable stage monitor speaker can be modified to bring the right tonal quality to the voice or instrument. Working on church and performance hall acoustics has provided acoustical insights that would not have been possible had M.G. never stepped outside the home arena. What should be getting clearer to you about now is how the seemingly non-related activities of room tuning devices, working to improve the sound of symphonic instruments, designing and installing large halls, and equipment racks are all actually inter-related.

The way different applications of tuning interact and feed improvements in various Michael Green Designs and Room Tunes products should also be getting clearer. One good example is how the PZCs, equipment shelves and tunable speakers all benefited from learning things while designing each device. The highly musical tone of the PZC tuning board arose from improving the walls of the tunable speakers which also spawned resonance improvements in the shelf boards. Production practices, surface finishes, shape/profile and material content all were important elements that may never have been so highly optimized if M.G. had developed only one product/application rather that working in a range of different applications.

I’ve made several references to improving the musical qualities of several materials by controlling the surface finish. Wood and wood products like mdf are affected a lot by the finish. Certainly the material, mdf, itself is important. But the qualities of the material, mdf or wood, are changed by what is applied to the surface. This is one of the secrets of the old hand made musical instrument masters. Restoration of Stradivarius violins is a very dicey proposition because a bad guess about the properties of the finish used at the completion of the restoration can make or break the sound quality of the instrument. When M.G. was working on the tunable speaker design, it was discovered that premium grade 3/4" and 1" mdf do not all sound alike. They are very different sounding depending on the origin of the wood used to manufacture the mdf. By origin, I mean not only the type of wood used but the actual physical location the wood was grown in. In other words, a specific species of hardwood grown in, for example, central Canada and the eastern U.S. will sound very different when pulverized to fine fibers and turned into hardwood mdf. M.G. found that for his speakers, one variety of mdf used by a Canadian assembler produces a sound quality unmatched by any other mdf encountered so far. "Conventional wisdom" (M.G. would probably say "conventional myopia" or if he was in a more testy mood "conventional ignorance") says the speaker cabinet should be as dead as possible. Manufacturers damp the insides, brace the heck out of the cabinets, use lots of hot glue on components on the crossover network, and stuff the cabinets full of wool, poly-fill, foam or fiberglass. M.G. believes he can design and build a speaker using minimal damping, minimal stuffing, no hot glue, thinner mdf, and no glue or sealer around the drivers that will exceed the performance of anything out there at similar prices.

But M.G. finds the audiophile mindset on matters like tunable speakers and even room tuning, surprisingly intractable. He believes that far more non-audiophiles will embrace tunable speakers than audiophiles. He wishes this were not true, but after so many years dealing with audiophiles, M.G. has become disappointed in their inflexible fixation on electronic components. So few audiophiles consider the room and equipment supports/system tuning to be critical when, in reality, they account for 2/3 of the system’s overall performance. For the most part, audiophiles are ignoring the sound of their rooms and are not paying attention to tuning their system using appropriate hardware like racks, feet, support devices. If you have been reading Positive Feedback for a while, you have read about my experiences. I have heard what proper tuning of components does and I will never again be without the means to do it in my system. Whether you use M.G.’s products or not is not so much the point — and he will agree with that statement. What is important is that audiophiles stop being so tied up in tradition, habit and poorly thought out logic that has been reinforced in the high end press for decades. There is a whole other class of audio/music buyer out there, non-audiophile music lovers, who listen, try and buy room tuning and equipment tuning devices to the great betterment of their systems. They do not read high-end publications and are not subject to the same limited value system that is perpetuated by what have become "mainstream" high-end magazines, dealers and industry "personalities."

The whole speaker-as-musical-instrument philosophy came to M.G. as a result of his experiences with room tuning and tuning electronic components to make them sound better. If room tuning and component tuning work so well, why not speaker tuning? Critics have 2 ‘problems’ with tunable speakers... 1) If they are adjustable, how do you EVER know when they are ‘right’? and 2) If they are resonant on purpose, they are by definition, messing up the music. M.G. understands the questions and finds #1 trivially easy to answer. Take the case of the traditional speaker. It is designed by one person, who may have help, to sound a certain way. Typically, it will be optimized in a listening room with specific properties that, like most listening rooms, are unique. This non-adjustable speaker is guaranteed to sound somewhat different in every different listening room it is placed in. If the speaker were adjustable, it could be tuned to adjust the sound to work with the room it is installed in. This, of course, assumes the owner has the wherewithal to determine where/when it sounds best. Audiophiles seem to have trouble believing that they or non-audiophiles could achieve this ‘correct tuning’ for a given room. M.G.’s experience suggests otherwise... it isn’t all that hard to do. Get a tunable speaker in a room, get familiar with the sound for a while. Make a few adjustments. Get used to what each one does. Within 1 afternoon you can settle on settings that work well in your room. He’s confident this will work for you even if you aren’t an "audiophile" or maybe in spite of your being and audiophile.

Question #2 is the more difficult to answer. Most audiophiles and manufacturers believe that the driver should do all the talking and the rest of the speaker should be silent. M.G. finds this to be an overly simplistic view of sound reproduction. In M.G.’s view, the drivers, crossover, and speaker enclosure are parts of a musical instrument. Real musical instruments have to resonate a certain way or they sound less musical than the instruments that get resonance right. Instrument makers, whether the factory-type or individual craftsmen spend a LOT of time perfecting that resonance. That special resonance is rarely identical from instrument to instrument. Expert guitarists, violinists and harmonicats can tell the difference between virtually any 2 different instruments, even if they are only 1 serial number apart and tuned as closely as possible to being identical. A grand piano sounds bad if the resonant properties of the wood are not correct.

M.G. believes that these same musical instrument sensibilities should be applied to speakers also. The speaker driver needs resonances from the cabinet to make music convincingly. A musical instrument requires the resonance of the instrument body and other parts to sound correct. The proper tuning and sound of the cabinet will help the drivers produce natural musical sound, not add inappropriate resonances to the sound. Take a conventional speaker with conventional build techniques and try to make it work like a tunable speaker and you will get a bad result. Take a conventional speaker and apply tuning techniques to it and you can be successful.

M.G. has done this very thing with other manufacturers’ speakers at the request of the other manufacturers. I saw one of these modified speakers while I was at Tuner Villa, but I am unable to reveal the manufacturer involved. To apply tuning to an already built speaker required specific modifications: removal of much stuffing; removal of most of the bracing; removal of sealer around drivers; removal of hot glue and excess amounts of any other glue or damping material. In addition, the mdf of the cabinet is subjected to the router... it is thinned from stock dimensions in specific areas inside the speaker. The final step is to install the tuning devices. This approach to tuning an existing product is apparently very successful. However, M.G. feels that designing for tunability from the ground-up achieves even better results. Perhaps on the next trip I’ll get to hear how much of an improvement the tunability changes make when ‘stock’ speakers receive the ‘tunable speaker’ treatment.

In spite of M.G.’s ability to repeatedly demonstrate how well tuning techniques work, there is a lack of appreciation among manufacturers and the buying public for how interactive the music making process is at the speaker level. This lack of willingness to understand or lack of interest in listening to a ‘new voice’ in speaker design frustrates M.G. He finds people and dealers outside of the high-end/audiophile realm to be more receptive to the new ideas and new approaches to getting better sound. Reality for Michael Green Designs / Room Tunes is: a small mention in a home theater magazine about Room Tunes being a source for products to improve the sound of audio or home theater systems generates thousands of sales; ads in audiophile magazines generate 10s of sales. What stings even more… .compared to the non-audiophile customers, audiophile customers are a pain in the hindmost parts because of all the second guessing and lack of faith in what they are being told on the phone by people who are trying to be as honest as they can be.

M.G. had a final version of the smallest of the tunable speakers, the Rev 5 ($900 to $1050) on hand. It was a pretty little mini-monitor-size speaker. Very well finished with real wood veneer, solid cherry quarter-round corners, and a high quality satin finish. The unimpressive looking binding post plate is a plastic part with gold plated all-brass posts. There is a paper-y resonance to the plastic panel when thumped. M.G. says this is not problematic and that damping the part to remove that resonance makes the whole speaker sound worse. As with all tunable speakers, a minimum of glue is used. Drivers are precision fitted to the enclosure without sealers or glue. The drivers are mounted with screws that were selected for sound quality from 40 different types. Change those screws and you suffer a significant loss of sound quality. The cabinet is finished to maximize the musical instrument-like tonal quality. Tapping the sides from corner to center produces a sound that is musical, unlike rougher sounding conventional speaker enclosures.

M.G. says these speakers are not built to be the best audiophile speaker in the world. The design goal is different. They are produced to be the best music reproducing instrument possible. There is far more hand work in these tunable speakers than in typical high end speakers. They are built as musical instruments. Each one will very likely be slightly different in tonal quality, just like real musical instruments. M.G. says the sound of this first series of tunable speakers is modeled on Martin guitars... each unique, yet each identifiably "Martin-sounding." Larger tunable models will also be available. Other companies make physically larger "audiophile" speakers available for the same price, but M.G. is confident that people will find the properly built tunable speakers superior to those speakers. M.G.’s tunable speakers were available beginning in September 1997.

The Room Tunes business continues with all existing products. The PZC (Pressure Zone Controller) devices are an addition to the Room Tunes product portfolio. Due to more complex assembly, the PZC devices are a bit more expensive than previous Room Tunes devices, but they are still less expensive that other devices from other companies. The PZC line includes small devices analogous to Corner Tunes and Echo Tunes called Corner Controllers and Echo Controllers. The larger PZCs are 36" or 48" high. PZCs all work on the same principle… the collect sound from the open sides, top and bottom while the PZC is flush against the wall. For those who cannot wall-mount PZCs, floor standing models are available also. The tuning board on the PZC front surface has a tuning bolt in the center so that the tuning of the PZC can be matched to your room.

Based on what I heard at M.G.’s commercial installations, these devices are truly amazing at eliminating room response problems. All PZCs are available in several matching finishes ‘to blend with any decor’. As with other Room Tunes devices, PZCs need to be customized in number and placement for each room. The Michael Green Hotline, 1-888-ROOMTUNE, can assist with determining numbers of PZCs needed and where to put them.

PARA audio/home theater dealers are accepting tunable rooms as ‘required equipment’ at exponential rates. They and their customers are finding tunable rooms invaluable in achieving good stereo and multi-channel audio for video/surround systems. When customers hear how good the rooms sound, they actually BUY equipment. Unfortunately, the typical high-end dealer is probably still using some room treatment they bought years ago which has been surpassed by orders of magnitude by more recent developments, whether M.G.’s products or products made by others. Of course M.G. believes there is only one ‘technology’ for improving room sound. Products that rely on absorption of reflections and diffusion of reflections are NOT the ‘correct’ approach in M.G.’s opinion. What you want are products that work with what is happening in the room and not against what is happening in the room. If you’re a dealer and not keeping up with advances in room acoustic products, you are falling behind the curve and will continue to be outsold by competitors who are paying attention to advances in room tuning.

Some people will find room treatment devices that do not absorb, trap or diffuse ineffective — or think they are. This will usually be because there is something inherently wrong with the audio system in the room being treated. Some systems will indeed sound bad with devices like the PZCs or Argent Room Lenses in the room. This is not because the PZCs or Room Lenses are not effective tools. It is because the systems’ flaws are reduced in magnitude by absorbing, diffusing, or trapping devices. The PZCs and Room Lenses will require that the system be a good one from the start. The PZCs and Room Lenses will improve the sound of the room without altering the sound of the system — this is a good thing. I’m finding that every time I enter a heavily treated listening or demo room, the first thing that enters my mind is "What kind of problems is all of this supposed to be trying to hide?"

I have a feeling that most audiophiles, manufacturers and dealers probably have some pretty strong mental images of the lifestyle of M.G. These mental images are probably a function of M.G.’s appearance in the ads. Possibly the enthusiasm for what he has learned about mechanical tuning and room acoustic treatment has made an impression. M.G.’s ability to maintain significant press presence over the years certainly keeps peoples’ awareness high. Think what you will about M.G., his goals, ideas and products, but know that you will probably be wrong. People very likely assume there is a big ego behind Room Tunes and Michael Green products because he places himself so prominently in advertising. My take on this is yes… and no. Yes, there is a lot of ego involved. But not the type you probably assume. M.G. is more interested in a recurring fantasy of sitting at a table with Mozart, Edison, Alexander Graham Bell, Beethoven and Bach. Having them look at, listen to, and understand his products and tell him that what he did was a good thing for music. That does indeed sound egomaniacal. But the baggage that you might assume goes along with it just isn’t there. The BS-ometer remains on zero most of the time. Occasionally there will be some flickers off zero when he gets overly excited about something that seems unlikely to be right/important, but these are nothing compared to what happens with many other ‘high-end authorities’. He seems to just lay himself out there for you to accept or reject. Sure, he’d rather find acceptance, wouldn’t we all?

One impression of M.G. that I am sure is out there is that he’s a super-slick money-makin’ mosheen. Selling simple but effective products made from common materials for enough money to be leading a luxury life-style that feeds the big ego. The reality that I see is nothing like that pre-conceived idea. M.G.’s lifestyle in New Philadelphia, OH is not out of the ordinary, except for the frequent travel he has to do. His home and its furnishings are the same things you would expect from friends of yours who earn comfortable incomes. The factory is what I am finding typical for a lot of high end companies. A no nonsense, kind of unfinished look and feel in the manufacturing and assembly areas. Office areas are modest, functional and well equipped. One interesting twist here is that all the offices have "desks" made from equipment rack components… threaded rod legs, granite-look paint, the whole deal. Corner Tunes, Echo Tunes and Tuning Strips are fitted in many offices even though there were no audio systems in evidence in those rooms. Nothing like the luxury of a tuned office. M.G.’s home is being remodeled, but all the remodeling is for rooms related to tunable room technology. Their primary use will be as a showcase for visitors who want to hear the latest in room tuning. I’m not sure I’d want to use MY house that way, it certainly doesn’t help the market value of the property. There’s nothing particularly lavish anywhere. Everything is comfortable and functional. If M.G. is raking in all the money people might suppose he is and if the ego involved is as big as people assume it is, there is an excellent chance that things would be more Audio & Video Interiors-like than what is really there.

The point here is, the life of Michael Green, high-end magnate, ego-driven entrepreneur, idealist, self-promoter, takes on a whole new perspective when you see the reality. What is really there is not what you might expect. Instead you find someone working longer and harder than you would probably find acceptable for the rewards achieved so far in the close-to 10 year history in audio-land.

The future for M.G. and Room Tunes/Michael Green Designs looks better than ever. M.G. continues to push the envelope of improved sonics in home audio, "hall" acoustics, recording studios, audio & home theater dealer demo rooms, and symphony orchestras. Some of the payoff for the years of hard work and promotion is now starting to be rewarded. M.G. believes that making the products he knows can be made requires keeping a hands-on approach. M.G. has set a course that keeps him in control of his own products and gives him all the power and all the responsibility for the success or failure of those products. He’s giving it his best shot, which is what the high-end is all about… people giving the improved reproduction of music their best shot.

Having recently acquired U.S. distribution of WBT products, it was only logical for Kimber to replace their RCAs with WBTs. I returned two pairs of KC-AG interconnect to have the original RCAs removed and the new premium WBT 108 RCAs crimped on. The crimping process produces a true "cold weld" that forces the metal of the connector and the metal of the wire together with such high force that they become 1 piece of metal. What a difference! A significant upgrade and the only thing changed was the RCAs. Earlier versions of KC-AG were praised for being open, dynamic, transparent, and detailed. The KC-AG with WBTs is a whole new ballgame. The upgraded KC-AG is very neutral sounding, very quick, very clean, dynamic and now the sound is much better balanced. Some people have characterized silver wire in general as having too much energy in the upper midrange. KC-AG has had this emphasis attributed to it in the past and I have heard it in my system too. After hearing KC-AG with the WBTs, people may have to stop pointing at silver as the culprit. This interconnect does not have the "sound of silver" that many assume is a characteristic of silver interconnect or speaker cable. The premium WBT 108s bring a slight price increase to the KC-AG interconnects, but you’ll really want this ‘new’ sound if you are a KC-AG fan. While KC-AG performance is up all the way across the board, there are more expensive interconnects that will perform better than KC-AG. But within its price range, KC-AG is definitely one of the stronger performers.

Using the new WBTs with their threaded locking collars can be a pain if the component’s RCAs are closely spaced. But high-end gear usually gives you plenty of working space. When you tighten the collar, the outer shield portion of the connector is tightly squeezed against the outside of the female RCA for a very positive connection.

...interconnect, that is. Their PBJ has been one of the "easy choices" in affordable interconnects for a long time. But recent upstart competition has been giving PBJ a hard time. Enter the HERO. HERO has 4 copper conductors in a black mesh jacket. Quite a different appearance form the more familiar exposed Kimber braid we are used to seeing. Less expensive solder-on WBT 144 RCAs are standard, but these still have the threaded locking collar. Priced at $110/meter/pair, HERO/144 battles in one of the most competitive interconnect price points. Performance moves way up from PBJ still having the original RCAs. I found HERO to be a very pleasant cable. Music had a nice ‘golden’ feel to it, yet I would hesitate to call this any kind of coloration. It was more of a feeling than an obvious deviation from neutrality. But this is a consistent observation. Others I have spoken to who have heard HERO agree that "golden" is the right word. HERO has a very balanced sound. Top to bottom there are no emphasized frequencies or weak areas. You get a very pleasant, listenable, coherent, enjoyable sound from the HERO interconnect. If your system is a little shy on dynamics/punch, this is not the cable for you though. You might be happier with a more aggressive cable. If you have dynamics and punch but find the sound not smooth and balanced top to bottom, HERO can rescue you from lesser cables which can muck with things to a great extent. I liked HERO a lot. It is going to be one of my "cost effective cable" recommendations for quite a while, I think.

I’m sure some of you are wondering how HERO stands up to the new KC-AG. Let’s just say in this case you get what you pay for. HERO is a good performer at $110, but it is not Jack-the-Giant killer. KC-AG with the new premium WBT 144s would definitely be my choice if money were not a consideration. The new WBT-improved KC-AG becomes very nicely balanced and stretches the envelope a little when it comes to detail, openness and transparency.

Besides the 2 meter HERO, Kimber provided a 30 foot pair of HERO interconnects for the surround amp. I’ve said this here before and I’m saying it again… in the home theater world, do not underestimate the importance of good cables, electronics, and speakers in the surround channels. HERO works really well in this 30’ run. I get less hum than usual, a possible consequence of being able to tighten the locking collar on the WBT RCAs to get much better ground/shield contact at both ends of this long cable run. Surround sound has never been quite so natural and ‘open’ or detached from the speakers or whatever you want to call it. Suffice it to say that the surround field is bigger, less obvious and holds more fine detail than with any of the other 30’ interconnects I’ve been able to try. When you need a long run like this, you have to watch the wire cost. HERO seems to be one way to get really good, well balanced surround performance. It won’t be dirt cheap, but it is at least in the ‘do-able’ range for many audiophiles and home theater enthusiasts.

Lately I’ve been exploring power line conditioners. After examining the performance of several brands, the standout has been Mike VansEvers’ "clean line" Power Line Conditioners (PLC). I’m going to save some details for later. But I can tell you that these PLCs are performing very well here. I can also tell you that Mike VansEvers is a very observant and clever guy. Coming from a pro-audio background, MVE used to think audiophiles were nut cases. Then one day in the mid-70s he heard something that changed his life forever. He heard what audiophiles were talking about. He heard it for himself and he demonstrated it to other non-believing pro-audio buddies and they heard it too. Now MVE is a card carrying audiophile. He’s taken his interests in high-end audio, pro-audio, mechanical resonance tuning and how AC power becomes an audio signal inside audio components and turned them into, first, the "clean line" Power Line conditioners and what will surely end up being an impressive array system tuning products and techniques.

I never really gave too much thought to what happens in a preamp or amp or other component outside of the circuits and mechanical components needed to make it. But every one of those components makes a brand new audio signal. The raw material for that brand new audio signal is the power coming from the wall outlet the component is plugged in to. For example, the amplifier makes a brand new audio signal. The signal from the preamp is only used as a template for making the new signal in the amplifier. The raw material for that new amplifier output signal is the AC power from the wall outlet. The preamp signal is discarded once it has been used as a template for the new bigger signal. Same thing happens in the preamp, same thing happens in CD players/DACs. The only component different in this regard is the turntable/phono cartridge which generates its own signal internally. So if you think PLCs are less important than other components in your system, I’m going to have to "buzz" you. I’ve been there and now know the error in that thinking. However, PLCs are fickle. Any old PLC is not going to get the job done. Some are worse than having nothing. When you have one that is really working correctly in your system, you’ll know it immediately. But it might take experimenting with tuning and setup of the PLC to get all the magic.

The real reason I want to tell you about these PLCs is because Mike VansEvers taught me something I have never seen in print anywhere before… tuning the PLC changes the sound of a high-end system as much as changing any component! I initially did not like the sound of "The Unlimiter" ($549, 4 outlets, 1800 watts total), MVE’s PLC for amplifiers. After a few questions, MVE learned I had put it on its face with the outlets pointing up for easy access and that "The Unlimiter" was sitting on the carpet. He told me I needed to support it properly which sent me off to experiment with AudioPoints, Navcom feet, sandbags, inner tubes, Whatchamacallits, mdf boards, etc. In the end, I found a small amplifier platform with an inner tube plus heavy MDF board on top of the inner tube and AudioPoints isolated from touching the aluminum chassis sounded better than any other combination I had available. The change/improvement was impressive. Tuning let me control how much bass there was, how prominent or recessed the midrange was, how much decay there was on cymbals, how sharp Keb’ Mo’s slapping of the body of his guitar was… I could go on and on. All I was doing was changing how I was supporting and tuning the PLC.

If you have a PLC or 2 in your system and you just plopped them on the floor, you could be in for a huge treat when you experiment with supports and tuning and find out how much better your system sounds when the PLC has a good setup. In my system, the Navcom feet (no AudioPoints and no sandbag) were a close second place which surprised me. I don’t like the Navcom feet on any other component in my system. But on the PLCs they are pretty darn good sounding. So when you experiment, try all the old cones and pucks, and balls you have laying around. Even if they didn’t work best on other components, they might be perfect for the PLC. To get the best sound (so far) in my system I ended up with an inner tube isolation platform made from Michael Green Justarack equipment platform and a "loose" shelf on top of the inner tube. Supporting "The Unlimiter" I have AudioPoints but they have to be isolated from the chassis with something to avoid an upper midrange emphasis. When listening to speakers that are actually too bright, "The Unlimiter" tames things down nicely if I put 2 small sand bags on top of it. For a system with neutral balance, nothing on top of "The Unlimiter" sounds the best. The Model 85 is an 8 outlet PLC with analog, digital and amplifier filters. It is also isolated with an inner tube, but space and tipsy balance problems required a different tuning strategy so it wouldn’t keep falling over. I had to stand it on it’s side for clearance and access reasons. That makes it tall and top heavy. In this case, Navcom feet under the small side add a bit of stability and sound almost as good as the isolated AudioPoints.

If you don’t have a PLC, it’s time to think real hard about getting one. I had 6 dedicated AC power lines installed in my listening room, 4 at 20 amps and 2 at 30 amps. I live in an area that is reasonably "clean" power-wise compared to larger metropolitan areas. Presently MVE’s "The Unlimiter" is plugged in to one of the 30 amp lines and MVE’s "Model 85" ($639, 2 switched digital/video outlets, 2 unswitched digital/video, 2 switched analog, 2 switched amplifier, 1800 watts total) plugged in to one of the 20 amp outlets. The sound quality is significantly better than no PLCs and all 6 dedicated lines in use. If you are thinking about dedicated lines… great, do it. But don’t bother over-doing it. After what I’ve heard here, I can’t imagine more than 2 or at the very most 3 dedicated lines being needed unless the system has some extraordinary current/voltage demands.

Mike VansEvers believes that current is the key to good sounding and effective PLCs. We only seem to read and talk about voltage. But current is equally important. Current draw is not continuous during operation of a component. Current is drawn in pulses. The magnitude and frequency of the pulses depend on the musical content and the volume the music is being played at. Further, the component can only draw current from the AC line when the instantaneous AC line voltage exceeds the voltage in the power supply rails. {Intentionally simplified, no space to discuss how 200+ volt rails in tube equipment still pull current.} This means there are fairly long periods of time during an AC cycle where components are not able to draw current. When the component can draw current, it needs a lot of current, fast. MVE studied the current pulse demands of various components and built his PLCs so that all of those current pulses can be delivered, without limiting, to the connected devices. Designing PLCs for current pulse peaks that are far in excess of averaged current measurements is one of MVE’s trade secrets… oops. MVE felt he had to do this without transformers because transformers seriously limit current pulse capability unless they are huge which also means very expensive.

MVE is enough of a realist that he won’t tell you his PLCs are the best. He knows better. He’s had too many experiences where some other PLC at some different location just plain works better than his. But he’s also found a lot of situations like mine where people thought some other PLC was sounding better or that the VansEvers PLC did not improve the sound enough because they had failed to setup the VansEvers PLC properly.

With that said, I feel duty bound to tell you that I have another brand of PLC here right now and they are not beneficial to the sound of the system no matter what I do with them. The prices of these are similar to VansEvers prices. The sound is dulled significantly. Dynamics are reduced. Transparency is several steps worse. In effect, the music becomes boring when these other PLCs are used. The next test will be to see if the other PLCs sound better than no PLC at all. Certainly the performance of the VansEvers PLCs are very clearly much better in my location/system. Your PLC-age may vary, of course.

Nordost kindly loaned a box full of their SPM Reference speaker cable and interconnect. The attractive semi-transparent lavender wide and flat cables have had quite an impact on me. These are excellent cables that deliver performance in the top category. The bad news is that these are the top of Nordost’s cable line. They are quite expensive. $1,100/meter for the interconnects and $3,350 for a stereo or bi-wire stereo speaker cable set 8 feet long. Nordost sent 2 single-wire stereo sets, $6,700 retail, so that they could be used for vertical bi-amping.

Why the high cost? Nordost says that there are a number of factors. The copper used is pure to 8 decimal points and is plated with high purity silver. The conductors are very small and rectangular. The extrusion process they have to use to make the tiny 32 gauge rectangular conductors with the designed surface finish is exceptionally slow. Adding the Teflon insulation to each tiny wire and keeping 16 (interconnect) or 32 (speaker cable) tiny conductors perfectly parallel while the Teflon external ribbon/jacket is extruded over them is very time consuming. A high percentage of what is made, either individual wires or finished cable, has to be scrapped for either electrical or cosmetic reasons. The slow extrusion process ties up very expensive extrusion machinery for long periods of time when it could be making hundreds or thousands of feet of more conventional wire. Nordost has been in the commercial wire business for many years. This is not a company that is buying off-the-shelf wire and putting their name on it. They spend time studying what they think is important in audio wire performance and how other manufacturers’ products measure up. The R&D involved in making a high performance audio cable from scratch is not an insignificant cost.

One of the things Nordost found out is that many audiophile cables propagate signals at only 60% - 70% the speed of light. SPM Reference propagates all audio frequencies at 95% the speed of light. At Nordost, they believe that this speed is one of the factors that makes SPM Reference sound better than many similarly priced cables. SPM Reference is very low in capacitance and inductance, among the lowest available. But impedance… 110 ohms for the interconnect and 90 ohms for the speaker cable is different. That’s very atypical for high-end cables which usually approach zero ohms. This impedance is not causing me any problems, but you do need to know it is there and that there could be some systems which may not appreciate the added impedance. This is a pretty small amount of added impedance. There is not discernable loss in playback volume, for example, when using SPM Reference. Measurements with a digital volt meter and oscilloscope show miniscule signal losses in typical applications.

The RCAs used on the SPM Reference are excellent. The outer shield has a spring loaded outer barrel that contacts the female RCA first. Push the RCA onto the female connector and the barrel retracts allowing full insertion of the center conductor and tight connection of the smaller diameter inner portion of the shield. This "ground first" connection means that even if you unintentionally plug or unplug one of these cables with the system powered, you’ll hear nothing more than the slightest ‘fzt’ as the connection is made or broken. Nothing remotely like the noise you get when connecting/disconnecting typical RCA connections. You should be turning your equipment off to connect/disconnect anyway, but you know that!

The sound of these cables is in the top echelon of audio cables. Every other cable here, except Magnan Signature, sounds muffled and squeezed together in comparison. After listening to these two cable brands, I have a whole new appreciation for role cables play in a system. Why can’t all wire sound more like this? The difference between "typical" sounding cables and these top rank cables is not subtle. Cost is not the only determining factor for top level performance. There are comparably priced cables which sound like "typical" cables complete with the compression and muffled sound. Cables that I was quite happy with suddenly become big disappointments. These 2 top performers seem to float a whole level above other cables I’ve experienced.

I wish I could tell you that you can get this level of cable performance for $500 or that the improvement is only small increments after the $500 mark. I was even beginning to think that was true… until I heard the SPM Reference and Magnan Signature. SPM Reference was the first to give me a whole new perspective on just how big a jump sound quality can take because of a cable change. Magnan Signature was the second. Let’s put this in perspective… I was feeling kind of up against a brick wall, cable-wise. I was hearing differences in expensive cables, but the magnitude of the differences was not startling. The differences were enough to worry over picking the best sounding cable, but there was no ‘revolutionary’ change to the sound of the system. I was also getting frustrated in trying to find one cable that did everything "the best." SPM Reference and Magnan Signature have produced the breakthrough I figured must be out there somewhere. The system is not totally different sounding, yet the improvement is significant. The system still sounds like ‘the system’ – but it is a much more interesting and pleasurable version of ‘the system’ with the SPM Reference, and Magnan Signature (which I’m going to stop referencing now, see full review next issue).

Nordost’s SPM Reference interconnect and speaker cable gave me a new perspective on what is really possible in the way of audio cable sonic performance. I have a whole new outlook on cables and their role in good system sound. This review of the SPM Reference cable is a rave because they are among the few that show the way to a new level of cable/system performance. Many other cables are left in the dust. Within this top performing group of cables there is still room for differences in sound quality. However, at the top level, the differences are like selecting the perfect wine from a cellar where every bottle is among the best of its kind. You will have preferences, but even if you had to live with your last choice from this group your system would still benefit significantly. SPM Reference is a solid citizen in the top echelon. Audition it if you get the chance.

Last issue we failed to notice that we had not included contact information for Dave Belles and his excellent $1,195 100 watt per channel solid state amplifier. This amp continues to set a very high standard for price-performance and is highly recommended. Very musical, very dynamic, very involving. You’ll find the contact information at the end of this article.

Michael Green Designs / Room Tunes
888-ROOMTUNE
888-766-6886
Hotline for product information and consulting on room tuning options
lanc@cynet.com

Nordost Cables
SPM Reference Interconnect $1100/meter
SPM Reference Speaker Cable $3350/8 feet pair

Nordost
420 Franklin Street
Framingham, MA 01702
508-879-1242 (voice); 508-879-8197 FAX
http://www.nordost.com
info@nordost.com

Dave Belles
Belles 150A stereo amplifier - $1,195
Belles 150A 3 channel amplifier - $1,495

Power Modules, Inc.
479 East Street
Pittsford, NY 14534
716-586-0740 (voice); 716-586-4203 (FAX)
http://www.powermodules.com
selleb@aol.com

clean line by VansEvers
Model 85 Power Line Conditioner, 8 outlets - $639
The Unlimiter for power amplifiers, 4 outlets - $549

The VansEvers Co., Inc.
1250 East Hillsborough Ave.
Tampa, FL 33604
813-239-0700 (voice); 813-239-0805 (FAX)
http://www2.VansEvers.com
vans@tampa.mindspring.com

Kimber Kables
HERO Interconnect w/WBT 144 RCAs - $110/meter
KC-AG with WBT 108 RCAs - $425/meter

Kimber
2752 South 1900 West
Ogden, UT 84404
801-621-5530 (voice); 801-627-6980 (FAX)
http://www.kimber.com
sean@kimber.com

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