Synergistic Research HFT's

I acquired a ten-pack of SR's HFT room treatments and installed them according to directions just prior to last night's listening session. Easy to install using the blue-tack type of material that was included in the package.

The listening room already sported two pairs of Shataki  Holograms ... one pair in the front corners of the room and a second pair in the rear corners of the room. In addition to the Holograms, there are tube traps along the rear of the listening position. I thought I had my room problems solved with the existing treatments and I was satisfied with those results.

Enter the SR HFT's ...

I had my friend Robert over last night to help evaluate the changes, if any. I was looking forward to maybe a small improvement at best. I mean, what can one expect from little metal devises that stick to your walls ... little devises so small that one wouldn't even notice them unless they were called attention to?

Long story short ... we were hit over the head with astounding disbelief at the ... I don't want to use the word "improvement," because that would be an understatement. I'll use the word trans-formative instead.  Because, that's exactly what this tweak has done; its transformed my listening environment, and consequently my entire system, into an unbelievable music machine. 

The first CD I played was a private recording of Rachmaninoff's third piano concerto, with the L.A. Philharmonic orchestra during a Rachmaninoff piano competition. The disc features the winner of the contest on piano.  This has always been one of the favorite recordings in my collection. It transports the listener into the venue in a very natural way. This CD was burned right from the master tape with no artificial reverb or compression.   A good test for any changes to the system. 

Uhhh .... what I thought was a great recording transported us into the live event. Astounding to say the least.  How can such a simple tweak as ten little dots spread around the room have such a huge effect?  My theory is ... the sound energy coming from the speakers causes certain resonances at certain frequencies, and those resonances  excite certain areas of the room and smears the sound. The HFT's take those resonances out of the equation. That's my  theory, anyway. 

Here's the noted improvements:

1. A much more solid presentation at higher volume levels. Everything just seems to hang together better. 

2. Bass control: The best bass from my system yet. Very defined. The lower registers of the piano are a delight. 

3. Size of the presentation:  What I thought was a big sound stage before has been expanded in a very focused way.

4. Transparency: I can "see" much further into the presentation now. The audience noises,coughs & sneezes, the orchestra tuning up, the members turning the pages of the music, the conductor walking on the platform ... all there where a lot of it wasn't before. 

5.  Musicality: The correct tones of the instruments, which I've paid particular attention to in the system, were much improved. Strings, timpani's and the presence of the piano were all dead-nutz on. Amazing. 

6. 3-D:  A much more holographic presentation.  Good Lord, how much better can this get? So much more "air" around the performers. It really adds to the suspension of disbelief in a big way.

I could go on and on with our positive impressions last night, but I will echo what Robert said:  "This is your greatest tweak ever!"  "It sounds like you've improved your entire system." 

After playing a number of CD's featuring piano, we switched to the analog rig and played a whole variety of music ... from straight ahead jazz to Hawaiian music.  The expansion of the sound space, and the realism from analog and tubes with the new room treatment? Unbelievable. 

The ten pack of HFT's gets you to "level two" ... one more pack of five would get it to "level three."  Based upon last  nights results, there is another five pack in my near future. 

Are any of you other A'goners using SR HFT's in your room?  If so, please post your results here. I'd like to know if your experiences with these devises are similar to mine. 

Happy listening, guys. 
Have you also tried their little thing that goes on the pickup arm headshell?
^^^ Nope, but that's definitely on the agenda.  That the PHT's, pronounced "POT."   They come in a two-pack. I'm going to try one on the cartridge and one on the turntable's junction box where the RCA connectors are. 

In the meantime ... the HFT room treatments are fantastic!
Glad to hear of the excellent results you're getting with the HFT's. I will be exploring them myself here shortly as I picked up a package deal from the Newport show which consists of an Atmosphere mini, a 5 pack of the original HFT's, a 5 pack of the HFT 2.0's and a 5 pack of the new HFT X.

As a side note, I just moved my FEQ into the HT system to make room for the Atmoshere mini in the main rig and am very pleased with the results, especially the visual acuity on my plasma monitor. Who would have thought the FEQ would improve that?!  

As a side note, I just moved my FEQ into the HT system to make room for the Atmoshere mini in the main rig and am very pleased with the results, especially the visual acuity on my plasma monitor. Who would have thought the FEQ would improve that?!  
As it happens the Atmosphere does not replace the FEQ, you can and should use both. See the discussion here on how to set up (scroll down and ignore the haters)

I drink the HFT kool-aid too. I have 18 of the regular ones festooning my walls and speakers (3 on each--not necessarily located where SR suggests) and 3 HFT 2.0s. I "energize" them if that is the term, with an Atmosphere and an FEQ. I seem to get best results with the Atmosphere set to "Expansive" on most material. This is not to say that you need the boxes to get the benefit of the HFTs--they are amazing on their own.
The speaker - room interaction is one key to obtaining that special listening experience that I sought for many years. The HFT family (HFT, HFT 2.0, and HFT-X) have allowed me to dial in my room to a degree of music satisfaction that I never accomplished using the older technology of absorption and diffraction.

The addition of an Atmosphere Unit and FEQ Unit then further augments the beneficial effects of the HFT's. Visually the HFT's are not obtrusive which is vital in my house. Also in today's world where we are moving more often and renting more often, this system can taken down and then applied successfully to any number of future rooms. 

The Synergistic Research pictures on their web site and the suggested placement pictures included with the HFT's make installation straight forward.

David Pritchard
Oops. I don't count good. 20 HFTs on my walls, four on each speaker and a few on various USB cables...
Put the tonearm HFT's on my Rega tonearm with Ortofon Bronze cartridge. Nothing. No audible change in sound. Had the Shatki holograms in my room for a year. Took them out of the room and the sound improved. Also played around with a RR-777. Worthless. You will get bigger changes in your room by moving your speakers around. I have setb up for myself and friends about a dozen rooms and gotten great sound for everyone without ever using any room correction. Buy better speakers. That will help the most

Alan ...

I've done a demo for friends many times with the Shatki Holograms by taking them out of the room, then putting them back into the system.  The improvement is dramatic every time ... with the Shatki Holograms in the system. So dramatic, as a matter of fact, that I cannot imagine anyone improving the sound by taking them out of the system. 

How will "better speakers" solve room problems? 


I was amazed by the demo at Axpona2016. Bought the Atmosphere, Black Box, HFT, HFT-X and HFT2.0 

The first test I did in my room is the Black Box. Bass is tighter with it. Then I added the HFT-X on the speakers and center of front wall between speakers. The detail of the music opened up. Then I added the Atmosphere. Imaging was so amazing. It made my room sound so much bigger. Then I added the rest of the dots. I'm blown away on how such small passive thing can change how our room sound. 
Its worth every penny IMO


Congratulations on improving your room's acoustics. Thank you for taking the time to display the photos of your room and system. By seeing the room one can really understand the improvements you have obtained.

David Pritchard

s1nn3r ...

I second what David just said. You have a beautiful system and room. Love your floors too. :-)

I've gotten the same results as you, in that, the room just seems to get larger with each SR tweak I install.  Larger, but way more focused. The SR HFT's really opened things up for me. 

SR's demo at the  Newport show really showed what all of their products can do when combined together. Like I said, it was like a huge 3-D I-max theater picture of sound with the products in the system, and then it all collapsed and went away when the products were either disconnected and/or removed entirely from the room.

I can just imagine what the effects would be in a large home theater environment set up properly with a huge screen and projection TV with state of the art electronics and an ultra high-end speaker system.  

My business takes me into many very expensive homes that have custom theater rooms. These people need to know about the SR products for sure. 

How anyone cannot hear the improvements made by these products is beyond me. Maybe it has to do with the resolving ability of the system in the first place. I mean, one can put lipstick on a pig ... but its still a pig, right? And then there's that old sow's ear and silk purse thing. :-)

Thank you Davidpritchard and Oregonpapa. I agree, those who couldn't hear the difference might either be the system doesn't have the resolving ability or maybe just too old for their ears to do so. The same could be said for those who think cables doesn't make the difference.
" As it happens the Atmosphere does not replace the FEQ, you can and should use both. See the discussion here on how to set up (scroll down and ignore the haters)"

Thanks for the link. When I first installed the FEQ in the main rig, I heard  a definite improvement in my HT system which is two rooms away from the main rig so it seems the FEQ reach is quite a distance. Who knows, maybe the Atmosphere mini will affect my HT as well, we'll see but the FEQ is staying put in the HT system as the results are just too impressive.

I'll report out on the results once I get the Atmosphere mini hooked up in the main rig.
Inspired by this thread I spent an hour or so relocating my Atmosphere and 2 FEQs this morning. In my wide but not deep room I ended up with best results (most openeness and air) with
a) The Atmosphere on the ground center front, it had been raised on a Grand Prix Audio Monaco amplifier stand which actually did not help - maybe that the issue was it blocked direct sight to my ART resonator but in any case floor works best
b) Both FEQs mid way along the side walls, while this meant not having the FEQs connected into my dedicated power lines the location mattered more than the power
c) Both FEQs placed on the floor isolated by Les Davis’ thin constrained layer damping pads (these are very useful accessories)

The differences were pretty subtle but at no cost other than my time well worth getting it tuned in

Fascinating stuff!

Did you have an atmosphere or FEQ in the room when you got these results?
nyame ...

Nope, no atmosphere or FEQ in the system. Just the SR HFT's and the room treatments I alluded to earlier.  For what they are, just ten little devises that you stick around the room, they are NOT subtle at all. A major advancement forward in my system for sure. Like my friend Robert said ... the best tweak I've tried yet. The improvement in the bass response is amazing ... and of course, everything else up the line is improved along with it. 
Hey OP, how did you deal with the racks of albums, windows, doors, and rack when placing your buttons? Did you feel you compromised the placement because of those or would you say location is not super critical +- some inches?
I have the Atmosphere mini hooked up and the unit has been on for 24 hrs and I have to report that the results are pretty impressive to say the least and I haven't even installed the HFT's yet!!  

I have my system setup as a semi nearfield listening configuration with extensive ASC tube traps and room resonance control and it has quite pronounced imaging, soundstaging and bass agility without the mini but with the mini it is a much more engulfing experience. The most vivid attribute is the liquidity which still has me shaking my head as I have taken great care in my AC supply with that being high current balanced power, Oyaide outlets along with judicious grounding of components.

In my 35 years of being an audiophile, this is possibly the most profound upgrade I've implemented although I think a system/room that has been assembled with thought and research certainly will be beneficial to the Atmosphere's attributes, there is no doubt that any system will benefit from implementing one of the Atmosphere units to the point of being a major upgrade. 

Off to listen to more music...
bugredmachine ...

Yes, I did have to compromise a bit. 

First, let me say that I have no wife to deal with, so nothing in the sound system has to pass "the wife test."  *lol*

There is a window covered with vertical blinds about 8 feet behind the speakers, right where one of the HFT's is supposed to go. (you can see the blinds if you go to my system page). So, I keep the blinds shut and have one HFT stuck to one of the blinds. Its the same with the HFT on the left center ... its stuck to the closed blinds. All of the other HFT's were placed according to the directions. Actually, they are all in the proper locations, I just have to keep the vertical blinds shut. I always shut the blinds for listening sessions anyway, because I've found that the reflections off of the large windows negatively affect the sound. 

It is a trial and error thing though. Yesterday morning, I warmed up the system and it didn't sound quite as good as before. I checked around and found that the HFT on the ceiling had come loose  over night and fell on the floor. I got some Blue Tack and put it back into place and walla ... all was good again. Imagine that ... one little HFT made that much difference. Not really drastic, but I could tell the difference. 
So as a first time user & considering your experiences would you suggest beginning with 5 or 10 of the original HFT? 

Infection ...

Considering the results I'm getting with the 10-pack, If I had to do it over again, I'd go with 15 of these suckers right off the bat. That would take the HFT's to level 3. 

Tonight's listening session lasted until 1:45 in the morning.  Even my room mate, who is no audiophile by any  means, came out and listened for a couple of hours. We ended up with some of Bach's orchestral music ... with the final cut being Bach's Air on a G string.  Let me tell you ... I've listened to that recording at least a hundred times, and never have the strings been so defined, lovely and tonally correct. They just washed over us like pure ocean water. Heaven! 

So, yeah ... I have the 10 pack placed right where they need to be ... but if five more would enhance what we experienced tonight, bring 'em on.  :-)



I am glad the HRT"s are making a significant difference. The HFT- 2.0 placed on the speakers and front wall further improved what the original HFT's did for my system. They are tuned to a different frequency. By using a combination of the original HFT, HFT-2, and the HRT - X one is tuning the room at three frequency points and thereby having a speaker - room interaction that is harmonically richer and more complex that using a single type of HFT.

My room having a lot of glass windows did not benefit from HFT-X, but really improved with the HFT + HFT-2.0 combination. The Synergistic Research installation pictures at their web site are a good starting point of where to place these room tuning devices. One then needs to be ready to deviate from the pictures by listening to the effect in their own room.

After living with the final HFT combination for a while I used a glue gun to more firmly affix the HFTs to the ceiling, walls, and speakers. They can still be removed if needed after being glue gunned.

David Pritchard

^^^ Thanks for the suggestions, David. I'll check into the 2.0's.  

I wish you could have heard that Air on a G String last night. the power must have been extra pure at that early hour (1am) ... it was glorious. 

I am sure Bach was a special event . In addition to the quality of the power often being better late at night, the decrease in solar disturbance of the electro-magnetic fields helps the sound. Listen to your system improve during the time interval of one half hour before and after sunset.

I bet you can hear as the sun sets the system's sound improves.

David Pritchard  


When you are ready, treat yourself to a set of
HFT-Xs and place as suggested.  Listen as your speakers
are transformed!

The variety offered by the different HFT versions is special.
Welcome to the party.
Thanks, sgordon1 ...

Each step I've taken with the SR tweaks has revealed so much more from my recordings. Quite unbelievable, actually. 

What was your experiences with the HFT-X's? 
Great detail and focus.
A great compliment to the other versions.

Have you placed any HFTs in your car interior?
^^^ No, not yet in the car. 

I drive a low mileage Lexus LS 430 with the Mark Levinson sound system. It sounds really good and its a pleasure to listen to on trips.  I like to burn record albums to cassette tape for use in the car. All analog, ya know. :-)

I was wondering what the car  would do with an SR Black fuse for the radio ... but I hadn't considered the HFT's.  Have you tried them in your car?
My system has benefitted tremendously with the HFT's and the HFT-2.0. However the HFT- X (high frequency resonator) did not add to my sonic enjoyment. And that is the beauty of this HFT "system". There are resonators that respond to three different frequency bands. By careful placement of a mixture, you can really optimize the listening room - speaker- listener interface. It is fabulous that these products come with a thirty day trial to allow you to tune the room and return what is not needed.

I drive a Honda Minivan. High frequency speakers on the front dash in each corner and low frequency drivers in the front doors. After adding HFT-2.0's to my room, I had too many original type HFT's on the walls and removed some.

I now have 9 original HFT's on the front windshield. I also have three mounted on the ceiling about two feet behind the front seats. The Tone controls are set to Left 3, Front 3, Trebble 4, Bass minus 1. I am the only one in the car 95% of the time. With the HFT and tone adjustment, I now have a fabulous soundstage with good instrument positioning, and nice decay of notes. I now often listen to solo piano and chamber music while driving to work! This music would have not have conveyed any emotion in my untreated car.

The HFT's were glued into place with windshield glass glue bought at Home Depot after final position was obtained. The HFT will fall off the windshield on a hot day when Blue Tack is used to afix the HFT to the car glass.

To reduce electronic glare- noise etc., I added seven ECT (Electronic Circuit Transducers) to the CD player. As a bonus I now know how to remove a CD + radio from a Honda!

To complete the sound system transformation , I installed an Acoustic Revive 777 unit to the ceiling about three feet benind the front seats. This gives better focus and less fatigue.

This was a very fun and rewarding project.
David Pritchard

David ...

I have to say, you are one fully dedicated audiophile for sure. Geeze, now I'm looking forward to upgrading the car with the SR products. Have you tried any ECT's on the battery terminals? How about putting an ECT on, or inside the fuse box. Or ... even upgrading the stock fuse that runs your car's audio system with an SR Black fuse? I mean ... ya never know, right? :-)
I wish it was always easy making sonic improvements in a system but usually it takes a fair bit of time, fiddling, and hopefully products with a good return policy as not all will work. 
I have tried an ECT at the Honda's fuse box -sitting on top of the music system's 10 amp fuse. No improvement. The ECT's I put on the bottom of the radio-CD player in a star pattern as it was too tricky to further open the unit. I put one ECT where the bundle of wires enters and exits the unit.

I talked at the Newport Beach Audio Show with Rick Reus (of very high end car audio installation systems).  He did not get a benefit in sound putting HFT's on the front windshield of one of his cars. But he did get an improvement putting an FEQ unit in the car (they are 12 volt DC powered). The exact placement of the FEQ was not critical for improvement. 

Car fuses use a special blade type fuse so a Black fuses will not fit. Also remember the car system is all DC powered and not AC powered like most home systems.

I do try to approach the subject in a planned stepwise manner. Then if I get positive results, I report them. 

David Pritchard

I just ordered a 10 pack of HFT and I'm wondering if I should order a FEQ also since both are on a 30 day trial basis. I've read the reviews and it seems both work well together. Has anyone tried both together and then removed either the FEQ or the HFT for a comparison?

They work beautifully together. Plus I believe it will help you to optimize the HFT's locations with an FEQ in the system. 

David Pritchard

Thanks for your response. How much did you change the original locations of the HFTs and what kind of sound difference did it make.

Well I received both the 10 pack of HFTs and the FEQ and did some serious listening with various genre.

First I removed the acoustic panels from the front and side reflection points and listened so there wouldn’t be any interference. I then installed the first 5 HFTs and couldn’t hear any or little difference. I proceeded by adding the next 5 and again nothing. Maybe my 59 year old ears are going but I did hear a big difference when I replaced the after market fuses on my tube amp, dac and music server. (I actually preferred AH fuses over the SR fuses)

Next I added the FEQ and now the sound improved. The music was more detailed with less smearing. The sibilance was reduced especially on vocals plus both front and backing vocals became clearer. The soundstage became a little larger.

I then removed the HFTs and kept the FEQ in the system. It sounded the same as when both were in the system. I experimented again and again with various genre with the same conclusion. The HFTs did nothing to improve the sound of my system. I added back my original acoustic panels and along with the FEQ I couldn’t be happier.

As we all know, not every tweak works with every system. As with the after market fuses, I would suggest trying any of these tweaks since they all come with 30 trial period.

Ron ...

That's very interesting. I couldn't be happier with my HFTs in the room.  Its not subtle at all. It was a major improvement. Unlike you, I left all of the previous room treatments in the room when I added the HFTs' 

I have cobbled together my own DIY version of HFTs -- a total of 70 of them in the system, so far. The sound improvement is spectacular. I have left all the other room treatments as is, including ART.
^^^  Hi, sabai ...

Could you be more specific?  How about posting a picture of your DIY project? 

I use copper beading cones inserted in copper caps. No pics available at the moment. Crystals coming soon.
Hmm ... copper beading cones inserted in copper caps?  Thanks for clearing that up. :-)
I replaced HFTs with AudioMagic Bells.   They have a crystal inside the bell and found them more effective in my room.
I ordered 10 sets of each as well from a random site. Did you put a nail through the cone into the cup into the wall?
The original creator of the home built HFTs (Ozzy) said he glued the cones into the caps and mounted the finished product with Blue Tack.
i'll be buying the parts this week in trying to make a few of my own.

Post removed 
toolbox ...

If they work for you, please post info on the parts supplier and specifically what you bought. Thanks ...

Will do.  I'm trying to not re-invent the wheel here so hopefully I'll get a little direction.  Oh, I also have to get back home from Mexico.  

For you people that are experimenting with crystals, what kind of crystal would you buy?