Synergistic Research HFT, XOT and Purple Fuses
REFERENCE AUDIO – WITHAM ESSEX
BOB’s Review Series - No 54 – Synergistic Research Purple Fuses, HFTs and XOT Carbon Crossover Transducers
Introduction – My last review looked at the Synergistic Research (SR) Black Box that has now gone back to the showroom. It was designed by SR to enhance bass performance in listening rooms whereas this review looks at 4 types of their High Frequency Treatment (HFT) devices which ale essentially small pea sized metal dots that are fixed to your speakers, walls and ceilings to help treat high frequency room acoustics. In conjunction with the HFTs I also tried out a pair of their XOT Carbon Crossover Transducers that fit to the speaker terminals to reduce EM interference. I also installed several their 13amp Purple Mains Fuses.
Before listening to the HFT and XOT devices I installed the 13amp Purple Fuses in all my mains leads, seven in total and listened for a couple of weeks. There is no doubt that these fuses do improve sound quality in a system by seemingly reducing background noise and bringing a sense of calmness yet increased dynamics to all types of music. Like all things audio don’t expect immediate gratification, they do seem to get better after a couple of days in place and they also get better the more you add to your wiring loom. I haven’t tried any of their internal fuses, but my colleague Neil has been using them and reported even more benefits. They are not cheap at £190 per fuse but do give value for money in terms of a more enjoyable listening experience. They probably won’t be your first tweak, but they are definitely worth considering when funds and the need to scratch another audio upgrade itch come about.
Moving on to the HFT devices it’s probably better to let SR describe what they do rather than me trying to clumsily explain it.
‘About the size of a shirt button, yet powerful enough to transform the way you experience music, HFT’s improve nearly all aspects of system and room performance. With HFT’s your speakers and room disappear leaving you with nothing but a live holographic musical event in your listening room or living room. HFTs oscillate at high frequencies creating an energy field in your room that overpowers room vibrational distortions to correct phase and frequency interactions for harmonic balance in your treated room. You hear an increase in depth and width, with clearer more extended highs, and tighter bass. Everything sounds more live, clearer, and more natural than you could ever imagine’.
Although small these little devices are precision engineered and not inexpensive. The HFT and HFT 2.0 are £350 for packs of five and the HFT-X are the same price for packs of three. But they can be purchase in mixed bundles of 7 to treat a single speaker at around £450. The HFT Wide Angle also come in pack of 3 at around £450. The XOT are £449 for a pair.
I ended up with a mixture of all 4 types of HFT devices with 24 used in total plus the pairs of XOTs. The total cost for all these devices is around £2,300 (excluding the fuses).
Technology – These HFT devices come in a variety of design solutions that all look and feel pretty much the same but are in fact intended for different uses and placement around your listening room. They are fixed to speakers, walls and ceilings with white-tack which is strong enough to keep them in place without leaving any permanent marks should you want to remove or reposition them.
I used a combination of their standard HFT, HFT-X and HFT 2.0 and even tried their HFT Wide Angle devices. During this review I also connected a pair of their XOT Carbon Crossover Transducers to my speaker terminals. Other companies make similar speaker terminal devises that I guess attempt to do a similar thing. This is how SR describe them ‘XOT Carbons are high-frequency filters specifically designed for your speaker’s crossovers. They scrub the nasty EM fields that adversely affect your music. The powerful XOTs clean up high-frequency noise that otherwise distorts harmonic structures within the music signal’. They are available with either spade or banana plugs to suit your speaker terminals and existing speaker cables.
System Components used in this Review:
Pre-Amp: Gryphon Essence with DAC Module Fitted
Power Amp: Gryphon Essence
Streamer: Innuos Statement
CD Player: Gryphon Scorpio S
SUB: REL Carbon Limited
Cables: Jorma Cables Throughout
Equipment Stands: Gryphon StandArt
Performance – Do they make a difference? If so was it an enhancement? And are they worth the investment? Three questions I’ll try to answer but before I do here is how I used them in my listening room. Firstly, it’s knowing when to stop applying them, I had 24 HFTs set up but I could easily have added more but location and spacing is also room dependant, so some experimentation is required and of course the cost of adding more needs to be considered. They can of course be installed in stages as funds allow. The only constraint is that the use of only three HFT Wide Angle devices is recommended by SR.
Setting up is relatively straightforward because SR give helpful diagrams on their website which explains how and where each type of HFT is to be used. Placement on speakers depends on whether you have front, rear of no port speakers and whether they are floor standing of stand mounts. My Marten speakers are ported out of the base so I used the SR guidance for non-ported floor standers and located one standard HFT on the ceiling directly above each speaker, one standard HFT on the front below the bass unit and one centrally on the rear. I used one HFT 2.0 on each side of each speaker placed centrally and one HFT-X on top of the speaker and another one on the front between the tweeter and midrange drivers. The remaining devices were applied to walls and the ceiling in accordance with SR guidance. All relatively straightforward but open to interpretation and experimentation.
Did they make a difference? – yes, they do and mostly for the better. The fuses make the biggest improvements followed by the XOTs which bring clarity and relaxation but without compromising detail or enjoyment. The HFTs are I believe more room dependant and some rooms will benefit more than others.
Was it an Enhancement? – For the most part yes, see above, but for me any enhancements brought about by installing HFTs are very subjective. They did change the sound in my system, but I wasn’t convinced it was better, just different. But you may find otherwise.
Are they worth the investment? – The fuses are definitely an improvement, buy as many as you can afford. The XOTs yes but they need a few days to settle in. The HFTs are much more room dependant and in some spaces they will work better than in others. They did give a good central image, but my system wasn’t exactly lacking in that department beforehand. I wasn’t bowled over by them.
What were the benefits with all the HFT devices in place? – a slight increase in soundstage and openness but I’d counter this with perhaps a slight decrease in stage depth with everything seeming just that bit flatter across the gap between the speakers. Very detailed and if they were more domestically acceptable, I would probably buy them.
What happened when I removed the HFTs? – I first removed the 9 HFTs mounted on the walls and ceiling and noticed a slight reduction in soundstage but it was very slight and could have just been my imagination. But if you are of a highly critical disposition, you could either take the stance that every perceived reduction in sound quality is to be avoided or you might just think so what I just saved £700, the choice is yours and is probably also very room and system dependant. I then removed the 3 HFT Wide Angles and I can’t say I really noticed any difference. That just left the 6 various HFTs attached to each speaker and after I had removed them I couldn’t really hear any difference. Perhaps younger ears than mine could find these HFT devices more of a benefit in their room and system but for me perhaps a slight loss of high frequency hearing made these High Frequency Transducers of little benefit. Still for those with highly revealing systems, difficult rooms and/or better high frequency hearing they may prove to be just what you have been looking for.
I would have like to try them with a Black Box in the room to cater for low frequency enhancement and then perhaps they would all have then worked together in a more cohesive way.
Conclusion – The fuses are certainly worth the investment bringing clear benefits to the way your system reproduces music. I also liked the XOT devices for adding yet more detail without compromising quality and by helping with a relaxed and yet dynamic sound. The fuses and XOTs are of course not an issue with regards to visibility in your listening room whereas sticking lots of little dots to your speakers, walls and ceilings is controversial, especially when your significant other first notices them and comments with a “what the **** are those”. Believe me I couldn’t have kept them whatever their impact on perceived sound quality. But if you live alone or have a dedicated listening room, they may just be the icing on the cake. I suspect they will behave differently in different rooms and I did notice a greater improvement in our demo room than I did at home. The HFTs do change the sound but only you can decide if that’s for the better.
Bob – Team Reference Audio – December 2022