HFT&FEQ

6 moons.com 06/2014

Steve Marsh

Publisher’s foreword.

Just a few years ago, the subject of ‘acoustic resonators’ was not only new but highly controversial, with commentators who’d never experienced them quick to denounce them as voodoo tweaks which couldn’t possibly work. It wasn’t long though until the first outright clones of the original Acoustic System Intl. devices appeared like the Dutch Zilplex. Now forward a few years. With the effectiveness of such devices no longer in doubt, a number of manufacturers inspired by Franck Tchang’s resonators and sugar cubes have entered the market with their own take on related acoustic treatment devices. This review discusses two of them to add user data on the general subject.

I was first introduced to the Synergistic Research high-frequency transducer (HFT) and frequency-equalizer technology (FEQ) acoustic devices at the 2013 Rocky Mountain Audio Fest. In my show report I describe the demo of these products as possibly "the single most impressive demo I heard at this show (and possibly any show)."

After this demo I chatted with Peter Hansen of Synergistic Research about exploring these products further. I assumed that he had a lot of interested reviewers but a month or so later Peter squeezed in a visit to my home on a multi-stop trip to promote Synergistic products to reviewers and potential dealers. I invited two dealer friends to my home to help maximize the potential benefits of Peter’s cross-country trip.

Peter had me remove my Stein Music harmonizers and magic stones from my listening room before beginning to place the HFT and FEQ devices, claiming that the two technologies were incompatible. Peter began the demo with the HFT devices. The below excerpt from the Synergistic Research website explains how the HFT devices work to improve the sound of your system: "HFTs are tiny high frequency transducers that clean up high frequency harmonics in your listening room. You see, harmonics are interconnected. When you affect harmonics—even those beyond the limits of human hearing—you also affect the lower frequency harmonics you can hear. HFTs literally cancel harmonic noise on any surface they are placed. And as you follow our easy placement guidelines, 5 HFTs at a time, you systematically overcome your room’s tendency to fight with your system. HFTs replace random out-of-tune resonance with sympathetic resonance that complements the music."

* Publisher's comment:

As was the case for the ASI Intl. products, the various explanations given for the precise workings of this group of devices often seem vague, the associated language unscientific. In fact the language usually just describes the effects, not really *how* they're achieved. This would indicate a lack of understanding. That of course doesn't deny their effectiveness. It's simply that scientific-minded people tend to shy away from products whose workings hide behind quasi-magical descriptions. That's why reports like Steve's who spent considerable time to experiment with them helps to legitimize such products until such time that more properly scientific explanations as to their actual operation become available.

Peter began by placing the first pack of five HFT on the front wall behind the speakers just as outlined on the Synergistic Research website. The HFT devices are attached to the wall or other surfaces with the supplied Bostic Blu-Tack or equivalent. The most prominent and readily discernible effect was an expansion of the soundstage laterally and behind the speakers. Concomitant with this was a sense of more air within the soundstage. Peter proceeded to add two more five packs as described in the above link for Level II and III. The soundstage expanded out toward my listening seat and to the sides of the room, following the direction of the HFT placement. At this point Peter got out the Synergistic Research FEQ and placed it behind my system rack on top of three Synergistic Research MiG mechanical interface grounding component footers, and plugged it into a nearby AC outlet. One must be sure to plug in the adaptor with its cord exiting the adaptor toward the ground connector in the outlet (i.e. toward the floor in most homes I would imagine). A separate ‘ground plane’ wire has a three-prong plug on the end that is inserted into a separate nearby AC outlet (not into your power conditioner if you have one).

Synergistic Research’s website explains the function of the FEQ as follows: "Enter the active FEQ, an ultra-low frequency RF pulse generator that acts as low frequency dither to overpower the ambient RFI and EMI fields in your listening room. Simply plug the FEQ and its internal ground plane into two separate wall sockets in your listening room. Then place the FEQ behind and between your two main speakers and turn it on for an immediate and unmistakable improvement in sound. In fact one FEQ will improve an average listening room all by itself even when no HFTs are present. But the real magic begins when you place an active FEQ with passive HFTs in the same room. Now all HFTs in your listening room are excited by the ULF pulse generated by the FEQ which acts as an amplifier for the HFTs. Subjective benefits of the FEQ are heard as an expansion of the soundstage, a lowering of the noise floor and a noticeable improvement in low frequency extension and control."

While the music was playing, Peter turned on the FEQ by flipping its switch on the back. There was an immediate sense of greater liquidity to the sound and a billowing out of the soundstage into the room (most noticeable between the speakers). The bass also gained some heft and firmness. In my opinion I would not use the HFT devices without also purchasing an FEQ. They seem to work in a complementary fashion.

Now we were ready to ascend to Level IV. After placing the four HFT devices on each of the speaker cabinets, Peter placed the last two HFTs on the sidewalls about five feet above the HFTs previously placed there. This was because I have recently been listening exclusively to vinyl so placing them on my digital components as recommended made no sense. The effects of Level IV were more difficult to discern. At this point I began to suspect diminishing returns with each level. Or I was beginning to suffer from listener fatigue. I decided to revisit this later. My plan was to repeat the level additions, take more careful notes on what I heard and try to determine how many levels were the best bang for the buck. First I left all devices in place and did a lot of listening to establish a feel for the sound. Playing the title cut from Ella Fitzgerald Ella at Duke’s Place [Verve VG-4070], I decided to remove the HFTs in reverse order and see what I heard.  In contrast to my prior suspicion, I had to admit that I did hear a reduction in the amount of ambient energy in the room from removing the Level IV HFTs, with the soundstage becoming a bit more localized in the speakers.

Removing Level III came next using the same Ella Fitzgerald cut. While there was a noticeable drop in excitement level, there was also a perceptible drop in high-frequency air and energy. The bloom into the room receded. It also seemed that the more noticeable portion of the effects were in the high frequencies. Removing Level II reduced resolution and information. There was an unmistakable lessening of the sound coming from outside of the speakers as well as out in front of the speakers. Removing Level I caused markedly less height to the soundstage but Ella’s voice had a more sonorous tonality without the HFTs. As I later discovered, sometimes the extension and increased clarity in the high frequencies from the HFT devices can accentuate the upper registers of a female voice in a not always welcome way.

I now decided to compare my results to Synergistic Research’s claims for the HFT and FEQ devices which are listed on their website as follows:

1. Tunes acoustics, chassis and speaker cabinet resonance
2. Expands soundstage height, width and depth
3. Extends and clarifies high frequencies
4. Dramatically improves low frequency extension/bass control
5. Lowers noise floor for improved inner detail and micro-dynamics
6. Significantly improves all aspects of system performance

I would definitely agree with claims number 2 and 3. However, further explanation is in order. The soundstage does expand but it is not so much the instruments on the stage being perceived as moving further left, right, forward or back. Some of this does occur but what I predominantly heard was an increased sense of hall ambience and reverberation emanating from more of the room when the HFT devices were in place. Essentially this ambience expanded in the room in direct proportion to the number of levels of HFT devices installed. Regarding claim number 4, I did not hear an improvement in low-frequency extension and control with the HFT devices. However I did hear an improvement in the bass with the addition of the FEQ. Rather than ‘dramatic’ I would call it significant. Of course one man’s significant may be another man’s dramatic. The bass improvement from the FEQ was only half of its magic though. I spent a good deal of time switching it on and off while playing music.

For some unknown reason I got stuck on playing the 1976 Thin Lizzy album Jailbreak [Mercury SRM-1-1081]. This album is hard rock. While not the best recording, it was a good tool for hearing what the FEQ did. On the hit cut "The Boys Are Back In Town", turning on and off the FEQ showed that in addition to the bass improvement, the center of the soundstage got more dimensional and focused. Also the lead vocal popped out more in front of the stage. I liked everything the FEQ did and felt that the bass and soundstage dimensionality improvements wrought by it were significant enough to recommend it for any high-end system.

In a phone conversation I had with Peter Hansen, I dug deeper into his initial warning that the HFT/FEQ system was incompatible with my Stein Harmonizers/Magic Stones. Peter clarified that it was the FEQ (not HFT devices) which was incompatible with the Stein Harmonizers. He said that if the Steins are used in the room with the FEQ, they will "fight each other" and you won’t hear the full potential of the FEQ. He went on to state that the effect of the FEQ is actually more powerful than the Steins, claiming that one FEQ is more powerful than four Stein Harmonizers. They are now experimenting with placing more than one FEQ in a room too. They have placed a second one on a sidewall up high and it purportedly added even more sense of space from the front to the back of the room. A reader emailed me when he saw this review announced in the upcoming review section. He asked whether the FEQ produces a Schumann resonance like the Acoustic Revive RR-77. Peter said that the FEQ has nothing to do with the Schumann resonance. However he also warned that the Acoustic Revive RR-77 was not compatible with the FEQ.

Next I asked Peter more about how the HFT devices work. He confirmed that the 8mm diameter horn-shaped opening is critical to their function. In fact the HFTs operate as an acoustical driver and somehow cancel harmonic noise at ultrasonic frequencies. The HFT effect on these ultrasonic harmonics has a positive effect on the harmonics in the audible range since harmonics from even ultrasonic frequencies extend into and affect those in the audible range. The HFTs are "creating sympathy between harmonics." He added that the HFTs "create a uniform energy field in the room." Since some of what we hear from our speakers is delayed and reflected sound, it's helpful to address the nature of this reflected sound. Placing an HFT on a wall (or any surface in the room) creates a harmonic structure in this reflected sound that is more in sympathy with the direct sound from the speakers.

For some unknown reason I got stuck on playing the 1976 Thin Lizzy album Jailbreak [Mercury SRM-1-1081]. This album is hard rock. While not the best recording, it was a good tool for hearing what the FEQ did. On the hit cut "The Boys Are Back In Town", turning on and off the FEQ showed that in addition to the bass improvement, the center of the soundstage got more dimensional and focused. Also the lead vocal popped out more in front of the stage. I liked everything the FEQ did and felt that the bass and soundstage dimensionality improvements wrought by it were significant enough to recommend it for any high-end system.

In a phone conversation I had with Peter Hansen, I dug deeper into his initial warning that the HFT/FEQ system was incompatible with my Stein Harmonizers/Magic Stones. Peter clarified that it was the FEQ (not HFT devices) which was incompatible with the Stein Harmonizers. He said that if the Steins are used in the room with the FEQ, they will "fight each other" and you won’t hear the full potential of the FEQ. He went on to state that the effect of the FEQ is actually more powerful than the Steins, claiming that one FEQ is more powerful than four Stein Harmonizers. They are now experimenting with placing more than one FEQ in a room too. They have placed a second one on a sidewall up high and it purportedly added even more sense of space from the front to the back of the room. A reader emailed me when he saw this review announced in the upcoming review section. He asked whether the FEQ produces a Schumann resonance like the Acoustic Revive RR-77. Peter said that the FEQ has nothing to do with the Schumann resonance. However he also warned that the Acoustic Revive RR-77 was not compatible with the FEQ.

 

 

 

 

Next I asked Peter more about how the HFT devices work. He confirmed that the 8mm diameter horn-shaped opening is critical to their function. In fact the HFTs operate as an acoustical driver and somehow cancel harmonic noise at ultrasonic frequencies. The HFT effect on these ultrasonic harmonics has a positive effect on the harmonics in the audible range since harmonics from even ultrasonic frequencies extend into and affect those in the audible range. The HFTs are "creating sympathy between harmonics." He added that the HFTs "create a uniform energy field in the room." Since some of what we hear from our speakers is delayed and reflected sound, it's helpful to address the nature of this reflected sound. Placing an HFT on a wall (or any surface in the room) creates a harmonic structure in this reflected sound that is more in sympathy with the direct sound from the speakers.

Getting back at Synergistic’s list of sonic benefits, I must say that I am somewhat hesitant about claims number 5 and 6. While I heard these benefits relatively speaking, I hear much more lowering of the noise floor from a good power conditioner like the Nordost QRT power purification products (QX4 and QBase) which I use. In other words, the HFT/FEQ system will not substitute for a good power conditioner nor is it intended to do so. Since I normally use a set of 4 Stein Harmonizers and their accompanying 10 Magic Stones as acoustic treatment devices, I decided to remove all of the Synergistic products and go back to the Steins as a point of reference. This was not a fair comparison on a cost basis since my Stein system retails for $3’999 while the price for the five packs of HFT devices and the FEQ was $2’245.

After the requisite 15-min. warm up for the Stein Harmonizers, I listened to the same musical selections as before. Bass had a bit more heft with the Steins than HFT/FEQ. Also the Steins produced a warmer sonic signature, fleshing out the midrange without any accentuation of the high frequencies. The Steins give a similar sense of soundstage expansion but the effects are not as completely enveloping as the full-blown HFT/FEQ combination. The ambience does not extend out in front of the speakers as far. Nor does ambience seem to be coming from the sides and behind the listening seat. For me a major attraction of the Stein Harmonizers is that they improve dynamics. I do not hear this effect to the same degree with the HFT/FEQ system. With the Steins, instrument solos just soar into the room and become completely detached from the speakers. Despite being advised against it by Peter Hansen, I decided to try the FEQ with my Stein Harmonizers/Magic Stones. While I may not have been experiencing the full effect of the FEQ, I could clearly hear the benefits in the bass and soundstage imaging I heard before. For me this combination worked to my satisfaction.

While I was finishing up my experimentation with the HFT/FEQ devices, a dealer friend of mine asked Jerry Ramsey, proprietor of Audio Magic, to send me his own acoustic devices that adhere to the wall in the same way as the Synergistic HFT devices. I certainly had no intention of stealing any thunder from the Synergistic products featured in this review but it seemed like a good opportunity to compare another approach to treatment of room acoustics - especially one that was similar to the HFT devices in implementation.

15 Audio Magic room correction bells ($600 for the set) arrived in a blue plastic case along with a one-page instructional diagram on where to place the bells on the walls. No explanation of how they work was supplied so I contacted Jerry Ramsey to inquire. The following is my summary of the conversation: "The bells are custom made of OFC copper and tuned for high frequencies. They are cryogenically treated and ‘nano-streamed’ (an in-house proprietary treatment). The bell’s thickest point is at the back and it gets thinner toward the edge. Inside the bell, one or two Himalayan quartz crystals are epoxied at the bottom. This crystal type was chosen after auditioning many different types like amethyst, smoky quartz, rose quartz etc. Each crystal type sounded different but the Himalayan crystals were the most tonally balanced. There also needs to be a certain quantity of crystals in the bell to provide for the correct amplification.

"The bells work by absorbing high frequencies in the crystals. They amplify what they absorb and broadcast it back out in a broader dispersion pattern. As such they operate as a room diffractor and high-frequency energy dispersion device. They also operate a little lower in frequency and are broader band than the Synergistic Research HFTs. If you look at the normal high-frequency dispersion pattern in a room, the highs are bouncing off walls and the sound can be confusing. The bells broadcast the high frequencies in a more uniform pattern. The sonic benefits are better tonal balance which is especially noticeable in the midrange. You have to play with them quite a bit to maximize what they do. Each room varies in the number of bells that is optimal." Jerry uses about 22 in his room.

I left my Stein Harmonizers in the room and the Synergistic Research FEQ on for auditioning the Audio Magic bells since Jerry did not warn against using the bells with other acoustic treatments. I started out with all fifteen bells in place. The most noticeable sonic effect was that midrange instruments and vocals sounded fuller and had better tonal purity and body. However the full complement of fifteen bells actually flattened the soundstage. After talking with a friend who was also experimenting with them, he said that he got his best results with just ten bells. I followed suit and did indeed find that I was able to get the increased midrange body with little or no flattening of the soundstage. Playing the Thin Lizzy "The Boys Are Back In Town" cut again, I also found that the Audio Magic bells made the vocals more coherent and intelligible. The bells did not seem to expand the soundstage or add ambience as much as the Synergistic Research HFTs or Steins. In fact as I found out, too many bells will have adverse effects on soundstage depth.

I then heard through the grapevine that Jerry Ramsey had just finished another room correction bell design. This version was of larger diameter and designed to work just like the high-frequency bells but targets the midrange frequencies instead. Only three midrange bells are supplied and to be placed on the front wall as directed in the included diagram, replacing three of the high-frequency bells. Much like the high-frequency bells benefited the midrange, I found the sonic benefits of these new midrange bells to be in the lower midrange and upper bass. The record that showed this well was Count Basie’s Evergreens [GM 2201].

With the power of Count Basie’s big band, the sonic benefits were not difficult to discern. The midrange bells added both weight and punch to the lower midrange and upper bass. However, upon extended listening and an email exchange with Jerry Ramsey, I found that I preferred leaving all of the high-frequency bells in place and positioning the midrange bells immediately below the three. Removing the three high-frequency bells diminished some of their benefits and the midrange got less full-bodied and smooth. Also I sometimes preferred the sound without the midrange bells. On the Earl Hines/Budd Johnson Linger Awhile [Classic Jazz 129], the extended standup bass solo in the cut "The Dirty Old Men" was made a bit too prominent in the mix for my taste.

While I found the effects of the Synergistic Research HFT and FEQ devices to be more powerful  or overall easier to hear than the Audio Magic devices, they both had distinct merits. The Synergistic HFT devices had dramatic spatial effects while the Audio Magic devices were more about improving (purifying, clarifying, increasing impact for) distinct frequency ranges. I have no idea if they can be used together and did not try to do so. Primarily I was averse to the idea of having so many devices attached to my walls. Reflecting back on Synergistic Research’s demo of their HFT/FEQ devices at Rocky Mountain Audio Fest 2013, I think they were clever to demo with a Bose Wave Radio.

15 Audio Magic room correction bells ($600 for the set) arrived in a blue plastic case along with a one-page instructional diagram on where to place the bells on the walls. No explanation of how they work was supplied so I contacted Jerry Ramsey to inquire. The following is my summary of the conversation: "The bells are custom made of OFC copper and tuned for high frequencies. They are cryogenically treated and ‘nano-streamed’ (an in-house proprietary treatment). The bell’s thickest point is at the back and it gets thinner toward the edge. Inside the bell, one or two Himalayan quartz crystals are epoxied at the bottom. This crystal type was chosen after auditioning many different types like amethyst, smoky quartz, rose quartz etc. Each crystal type sounded different but the Himalayan crystals were the most tonally balanced. There also needs to be a certain quantity of crystals in the bell to provide for the correct amplification.

"The bells work by absorbing high frequencies in the crystals. They amplify what they absorb and broadcast it back out in a broader dispersion pattern. As such they operate as a room diffractor and high-frequency energy dispersion device. They also operate a little lower in frequency and are broader band than the Synergistic Research HFTs. If you look at the normal high-frequency dispersion pattern in a room, the highs are bouncing off walls and the sound can be confusing. The bells broadcast the high frequencies in a more uniform pattern. The sonic benefits are better tonal balance which is especially noticeable in the midrange. You have to play with them quite a bit to maximize what they do. Each room varies in the number of bells that is optimal." Jerry uses about 22 in his room.

I left my Stein Harmonizers in the room and the Synergistic Research FEQ on for auditioning the Audio Magic bells since Jerry did not warn against using the bells with other acoustic treatments. I started out with all fifteen bells in place. The most noticeable sonic effect was that midrange instruments and vocals sounded fuller and had better tonal purity and body. However the full complement of fifteen bells actually flattened the soundstage. After talking with a friend who was also experimenting with them, he said that he got his best results with just ten bells. I followed suit and did indeed find that I was able to get the increased midrange body with little or no flattening of the soundstage. Playing the Thin Lizzy "The Boys Are Back In Town" cut again, I also found that the Audio Magic bells made the vocals more coherent and intelligible. The bells did not seem to expand the soundstage or add ambience as much as the Synergistic Research HFTs or Steins. In fact as I found out, too many bells will have adverse effects on soundstage depth.

I then heard through the grapevine that Jerry Ramsey had just finished another room correction bell design. This version was of larger diameter and designed to work just like the high-frequency bells but targets the midrange frequencies instead. Only three midrange bells are supplied and to be placed on the front wall as directed in the included diagram, replacing three of the high-frequency bells. Much like the high-frequency bells benefited the midrange, I found the sonic benefits of these new midrange bells to be in the lower midrange and upper bass. The record that showed this well was Count Basie’s Evergreens [GM 2201].

With the power of Count Basie’s big band, the sonic benefits were not difficult to discern. The midrange bells added both weight and punch to the lower midrange and upper bass. However, upon extended listening and an email exchange with Jerry Ramsey, I found that I preferred leaving all of the high-frequency bells in place and positioning the midrange bells immediately below the three. Removing the three high-frequency bells diminished some of their benefits and the midrange got less full-bodied and smooth. Also I sometimes preferred the sound without the midrange bells. On the Earl Hines/Budd Johnson Linger Awhile [Classic Jazz 129], the extended standup bass solo in the cut "The Dirty Old Men" was made a bit too prominent in the mix for my taste.

While I found the effects of the Synergistic Research HFT and FEQ devices to be more powerful or overall easier to hear than the Audio Magic devices, they both had distinct merits. The Synergistic HFT devices had dramatic spatial effects while the Audio Magic devices were more about improving (purifying, clarifying, increasing impact for) distinct frequency ranges. I have no idea if they can be used together and did not try to do so. Primarily I was averse to the idea of having so many devices attached to my walls. Reflecting back on Synergistic Research’s demo of their HFT/FEQ devices at Rocky Mountain Audio Fest 2013, I think they were clever to demo with a Bose Wave Radio.

In my estimation the soundstage expansion effects of their devices would be more noticeable when the music starts out coming from a smaller source than the typical two-speaker stereo system on demo. I’m not implying any trickery or deception. The HFT/FEQ system has very real and audible benefits that, in my experience, are both powerful and cost effective when you compare them to many other acoustic devices and room treatments on the market. My only caveat would be regarding the effect of the HFT devices on the high frequencies. Your own reaction to "extending and clarifying the high frequencies" will depend on your speakers, room acoustics and your own taste of course. From what I have heard in talking to others who own or have tried them, most have been very pleased to downright ecstatic. Synergistic Research offers a 30-day home trial so you have nothing to lose by trying them.