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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.