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FEQ Carbon

Next stop, the Twilight Zone.

Imagine listening to Charlie Parker at Birdland, then walk into Carnegie Hall and getting seated in the best seats in the house. This is possible when you add Atmosphere to your listening room. No other technology allows you to tailor the size and scale of your soundstage with stunning realism, to portray the music and venue you are experiencing accurately. The Synergistic Research FEQ Carbon is a third-generation, two-channel acoustic field generator.  New to the FEQ Carbon is a wholly redesigned PCB with dual RF generators. The first function of the redesign was to provide the ability to create different wave shapes, and the second was the addition of a 2nd, independently controlled ULF generator channel.  This is similar to what has been used in the SR Atmosphere Infinity but is the first FEQ to have this ability, which meant 100’s of hours in the listening room finding the perfect combination of options and settings.  Next was the new carbon fiber chassis.  Not only cosmetically beautiful, but the carbon fibre chassis also improves the broadcast of ULF frequencies through its conductive weave. As a result, layering, three-dimensionality, and holographic realism are much improved over all single frequency FEQ’s of the past decade.  In some aspects, the FEQ Carbon even outperforms the much larger and more complex Synergistic Research Atmosphere Infinity as we have isolated two different frequency combinations that represent a near-perfect yin and yang with focus and clarity on acoustic recordings and a more holographic soundstage on recordings mastered to convey a large and enveloping sound field. 

Two frequency bias, one perfect sound. 

Blue Frequency: voiced for acoustic instruments, vocals, and smaller-scale performances.  Note: FEQ Carbons manufactured before 12-5-2022 had this setting as red

Red Frequency: convincingly portrays large-scale performances and electronic music.  Note: FEQ Carbons manufactured before 12-5-2022 had this setting as purple

$1695.00 110v
$1895.00 230v

Learn more about Acoustic Field Generators

Atmosphere and FEQ began when our lead designer Ted Denney contemplated why systems seem to sound better late at night and worse mid-day. As a pioneering designer of the first high-performance power cord, the original AC Master Coupler of 1994, and his later work in 2007 to develop the world’s first patented non-current limiting AC filter found in our PowerCell AC line conditioners, he knew there must be more to the mystery of what we hear late at night vs. mid-day than just the state of AC coming out of the wall. After all, if it were only AC than power conditioning and high-performance power cords would have solved this problem long ago.

So we began researching variables that could contribute to the mystery of midnight vs. mid-day system performance and came to the conclusion that man-made and solar RF must play a significant role. This led us to research of factors that contribute to fluctuations in the Earth’s ambient RF environment. Ted reasoned that if differences in RF can degrade the sound, then RF can be modeled and shaped to improve the sound.


“OK folks - we all know that when a newer, updated version of a familiar product is released, often it’s met with a bit of skepticism and possibly doubt.  So when during a recent email exchange with Andy Wiederspahn (i.e., SR’s right-hand person), followed quickly by a phone call, he mentioned that the former FEQ X4 unit had been recently updated and he’d like to know if I’d be interested in checking it out.  Also, being aware of the positive effects of the now discontinued unit, my response was — absolutely. Anyway - what I wasn’t prepared to experience is something that totally caught me off guard. Without question, once installed in my reference system and per instruction - left turned on for an initial period for the unit to settle in and acclimate to my listening environment - the newer FEQ Carbon unit immediately let me know it’s ability by providing a noticeable improvement over the older unit.

First and foremost, the FEQ Carbon device simply helped to more completely saturate the entire sound field and by enhancing the sensation of openness and dimensionality including width, height and depth. Additionally, my listening room took on the proverbial sensation of the walls simply falling away.  Beyond this - the sound simply poured forth more effortlessly and natural than before.  Interestingly, in addition to the immediately noticeable enhanced organic texture to both voice and instruments, the bass became a bit more robust, not in a negative, forward-sounding way, but with enhanced impact and umph. Throughout the midrange - there was a greater sense of presence and with a wonderful sense of fullness.  Bottomline - the new FEQ Carbon literally impacted (and enhanced) the entire frequency spectrum and in a most enjoyably musical manner.” - Review forthcoming

Bill Wells - Stereotimes - November 2021

Full Review

ATM Carbon

FEQ Carbon Tuning Module

The new ATM Carbon was explicitly voiced for the new FEQ Carbon with its breakthrough ULF frequency combinations. Still, it is also a significant improvement over RED and GREEN ATMs when used with Atmosphere Acoustic Field Generators. When you place ATM Carbon atop FEQ Carbon, you create a more natural holographic scale with a lower perceived noise floor for effortless sound where vocals and instruments take on lifelike timbre. In addition, frequency extension improves from bottom to top, where high frequencies seem to decay into a much larger space, and bass notes are better controlled and more impactful. Think of ATM Carbon as a turbo charger for the new FEQ Carbon. Available with a no-risk 30-day money-back guarantee so you can confirm performance before making a final decision.

(Sold separately)

FEQ Carbon - Acoustic Field Generator

A/B recodings

We recommend listening with your high-end headphones or download the hi-rez audio files to listen through your audio system.  In-home auditions are available from your Synergistic Research dealer.

The Sun and RF Propagation on Earth

There are three major disturbances on the Sun that affect radio propagation here on Earth. Solar Flares, Coronal Holes, and Sudden Disappearing Filament (SDF). Each disturbance causes both electromagnetic radiation and ejection of material from the Sun that alters RF on Earth. What we looked at was how each of these disturbances affects our RF environment during the day vs. late at night with the intention to mimic late-night conditions to improve sound mid-day.

Learn more

Solar Flares

Solar flares release huge amounts of energy, including sustained, high-energy bursts of radiation from VLF to X-ray frequencies and vast amounts of solar material. Most solar flares occur around the peak of the 11-year solar cycle. The first earthly indication of a huge flare is often a visible brightness near a sunspot group, along with increases in UV and X-ray radiation and VHF radio noise.

The sudden increase in X-ray energy from a large flare can immediately increase RF absorption in the Earth’s lowest ionospheric layers, sometimes causing a phenomenon known as a Sudden Ionospheric Disturbance (SID). An SID affects all HF communication on the sunlit side of the Earth and signals in the 2 to the 30-MHz range may disappear entirely. Even background noise may cease in extreme cases. When you experience a big SID, your first inclination may be to look outside to see if your antenna fell down! SIDs may last up to an hour before ionospheric conditions temporarily return to normal.

Typically, several hours after a flare erupts at the Sun, particles begin to arrive at the Earth in the form of a plasma, a highly ionized gas made up of electrons, protons and neutral particles, traveling at speeds up to 300 miles per second. Really high-energy protons may even disable satellites orbiting high above the atmosphere and seem to have a negative effect on the way our audio systems sound.

Coronal Hole

A second major solar disturbance is a so-called “coronal hole”. Matter ejected through this “hole” becomes part of the solar wind and can affect the Earth’s magnetic field.

Statistically, coronal holes tend to occur most often during the declining phase of the 11-year solar cycle and they can last for a number of solar rotations. This means that a coronal hole can be a “recurring coronal hole,” disrupting communications and degrading the subjective performance of our audio systems for several days.

Sudden Disappearing Filament

The Sudden Disappearing Filament (SDF) is the third major category of solar disturbance that can affect RF propagation on Earth. SDFs take their names from the manner in which they suddenly arch upward from the Sun’s surface, spewing huge amounts of matter as plasma out into space in the solar wind.

When the conditions are right, a flare, coronal hole or an SDF can launch a plasma cloud into the solar wind, resulting in an Ionospheric Storm here on Earth. Unlike a hurricane or a Nor’easter in New England, an ionospheric storm is not something we can see with our eyes or feel on our skin. However, we can see the indirect effects of an ionospheric storm on magnetic instruments located on the Earth’s surface because disturbances in the ionosphere are intimately related to disturbances in the Earth’s magnetic field.

During a geomagnetic storm (“geo” means Earth, in Greek), we may experience extraordinary radio noise and interference, especially at HF. You may hear solar radio emissions as increases of noise at VHF. A geomagnetic storm generally adds noise and weakens or disrupts ionospheric propagation for several days.

Solar Flares, Coronal Holes, The Sudden Disappearing Filament, and Wi-Fi—Oh my.

In a nutshell, we discovered that during the day ambient RF is stronger while the Earth’s Schumann Resonance is weaker in relation to overpowering solar and man-made radio frequencies. Typically speaking the ambient RF environment is at a higher frequency and is more complex during the day, and at a lower frequency and somewhat less complex late at night as our planet turns away from the sun. While charting Solar Flare, Coronal Hole and SDF activity we learned that the prevailing RF environment is affected by solar activity much more during the day, and less at night and this led to the discovery of specific RF environments conducive to what we perceive as good sound.

Synergistic Research Ground Block and Tranquility UEF LPS

Take it to the next level.


greater or less spaciousness, greater focus, more or less detail, depending on the option chosen


As good as everything sounds, it only got better with the Atmosphere XL4. Amazingly, what you read in the scene descriptions is exactly what you get. As mentioned, we were very fond of the “Ethereal” + “Air & Grounded” settings. The improvement in resolution, contrast, and control almost sounded like a source upgrade. I wish I were exaggerating. 

- Siao Jer - June 2018


The HFT/FEQ combination serves to make your listening room canvas more pristine so that when your audio system paints the music on it, the end result is a lot more true to life. Needless to say, the Synergistic Research HFT/FEQ combination I used in this review is not going anywhere. They are now an integral part of my reference audio system.

-Malcolm Gomes - June 2018 - Issue 97


“Need more space and ambiance? More there thereness… then this is final frontier in atmospheric realness-ness…”


“The combination of the Atmosphere and ATM delivers on its promised performance and showed itself as an essential upgrade to my reference system. Now with the Atmosphere and ATM in my system to stay, critical music listening is possible day or night. Highly recommended”


“By now we are ready for Synergistic Research’s ‘WTF’ moment”


“The combination of the FEQ and HFTs has made the biggest improvement in my system’s performance since I been reviewing high end audio components over the last 11 years.”

User Review

“Thank goodness I am not a HiFi journalist who has to put into words what Atmosphere Infinity plus Satellite are doing to the sound of my system!? Is “incredible” an adequate term? I do not know. But I do know that everybody who has ears and a decent system to listen to should test these “Towers“ and let his ears decide.”

Full Review

Thank goodness I am not a HiFi journalist who has to put into words what Atmosphere Infinity plus Satellite are doing to the sound of my system!? Is “incredible” an adequate term? I do not know. But I do know that everybody who has ears and a decent system to listen to should test these “Towers“ and let his ears decide. If he (or she) does not hear a significant improvement concerning the sound quality of his/her system he (or she) should look for a different hobby!!! In my system, they just do magic – nothing more, nothing less!
Due to the “circumstances“, I can also say that the improvement created by the Satellite is beyond my expectations.  I’m fully aware of the fact that everything I say is subjective and as adjectives describing the sound quality of a system may be interpreted differently by different people, I spare me and you any “HiFi journalist prose” but rather try to explain in a hopefully understandable way what the sound does to me whenever I sit in front of my system for concentrated listening.  To give you an idea of what happened in my living room I want to go back a bit:
It is generally acknowledged that Class A Amps need at least an hour or longer to reach their full performance. To my surprise, this “warm-up period” seemed to have gone. However, I quickly learned that it had not gone at all, but the sound of the cold amps now is at least as good as the sound was at operating temperature without the Atmospheres. I think this comparison is one way of showing what the Towers do because I don’t think there is any serious way of expressing a percentage concerning the improvement as nobody knows what 100 percent is.

So what does the music do to me when the system has reached the correct temperature?  Music means highly personal emotions to me and these can manifest themselves in different ways when listening to certain passages: e.g. a comforting shiver is sent down my spine, my feet can’t stop tapping, and – as the headbanging days are over – I gently move my head to the rhythm, or I just close my eyes and the music makes me forget anything around me including my speakers. The sound fills the room and makes me very happy and lets me relax. So I often extend the listening sessions deep into the night.
What it boils down to maybe described like this: If only everything was as easy as installing about 40 HFT’s of all kinds, 3 ATM’s and Atmosphere Infinity plus Satellite to achieve such an improvement concerning the sound quality of one’s system.
Just like the doubting Thomas who only wanted to believe what he could see with his own eyes, I only believe what I can hear with my own ears. Therefore I tend to be skeptical when I read or am told that there is something absolutely new and has never been there before and is better than all the rest etc. etc. …..
In this case, I can only support your description of what the Atmospheres do and advise everybody who is taking this fantastic product into consideration - test it!!! IMHO you won’t be able to listen to your system without these SR tools any longer.

With most musical regards



“Even though parts of the Atmosphere/ATM/UEF/HFT system may sound voodooish, these things work, making smaller rooms sound like larger ones and making big multiway speakers disappear in them like two-way mini-monitors. ”  - JV

Atmosphere Infinity

with Satellite Capability

110V - $3495.00 (Includes Red ATM - $495 Value)
230V - $3995.00 (Includes Red ATM - $495 Value)

(Available in White/Chrome or Black/Black)

Learn more

The NEW Atmosphere Infinity benefits from a more powerful signal generator and is now infinitely scalable with the addition of optional plug and play Satellite Atmosphere Towers for increased room saturation with more even RF dispersion than is possible with a single quad antenna Atmosphere tower. And because you can add one or more Atmosphere Satellite antennas controlled by a single Atmosphere Infinity you’ll have improved placement options perfect for difficult rooms that preclude a single Atmosphere Tower between your two main speakers; merely place one Atmosphere Infinity and additional Atmosphere Satellites in your listening room for added performance and added flexibility for your placement options. With Atmosphere Infinity and Atmosphere Satellites you experience Atmosphere’s seven acoustic scenes so convincingly you’ll swear you’ve been transported to a live event. Simply install the downloadable Atmosphere Control App to your iPad and select from a gallery of scenes that compliment different genres of music and acoustic spaces. To tune your acoustics and system with Synergistic Research UEF Technology to your favorite musical tracks, select a scene that corresponds to the type of music you’re listening to, and your iPad sends a Bluetooth command to your Atmosphere Infinity and optional Atmosphere Satellites altering their broadcast to optimize your room and system to match your favorite music. Atmosphere is engineered to work in conjunction with HFT’s, UEF Acoustic Panels and DOTs, as well as the Black Box low-frequency resonator array, SR cables equipped with UEF Shielding, and Tranquility Base UEF platforms for the ultimate integration of every aspect of a system and acoustic performance.

Who it’s for: The music lover with a full complement of Synergistic Research Acoustic Tech including HFT’s and or UEF Acoustic Panels and DOT’s and Black Box bass resonators looking for the ultimate in system room integration. They want the ability to actively control their acoustic environment to mirror different recordings and acoustic venues without the distortion of DSP processors that operate in-the-signal-path.

Dimensions - 52″ tall  (Base 9″ wide x 8.25″ deep)

110V - $3495.00 (Includes Red ATM - $495 Value)
230V - $3995.00 (Includes Red ATM - $495 Value)

Atmosphere Satellites

Available in XL and Mini sizes

Satellite XL  –  110V $1995.00
Satellite XL  –  220V $2495.00

Satellite Mini  - 110V $1195.00
Satellite Mini  - 230V $1395.00

(Available in White/Chrome or Black/Black)
(Shown with optional ATM- sold separately)

Learn more

The NEW Atmosphere Satellite is an outboard broadcast antenna that connects to Atmosphere Infinity with an included ethernet cable for increased signal strength as well as improved dispersion of Atmosphere’s signal throughout a listening room. This is of particular benefit for larger rooms, rooms that preclude the use of a single Atmosphere placed in the one location where a single Atmosphere is most effective, directly between your two main speakers, and for users seeking maximum effect in small, medium and larger rooms. And when you are daisy-chaining one or more Satellites to a single Atmosphere Infinity, you dramatically upscale performance to realize each of Atmosphere’s different scene settings with greater clarity and character.

Who it’s for: People with difficult rooms that would otherwise compromise Atmosphere’s performance because of less than optimal placement options including rooms that preclude the use of a single Atmosphere between the two main speakers or anyone who wants to experience the ultimate from Atmosphere’s scenes as selected on the iPad control app.

Dimensions XL - 52″ tall (Base 9″ wide x 8.25″ deep) 

Dimensions  Mini  -  14″ tall  (Base 4.1″ wide x 4.1″ deep)

Satallite XL  -  $1995.00
Satallite Mini  - $1195.00

NEW FEQ Carbon

110V - $1695.00
230V - $1895.00


Learn more

The new FEQ X4 dramatically improves upon the original single antenna FEQ with 4-large broadcast antennas for a full 360-degree immersive experience. This is our ultimate set it and forget it acoustic field generator and is perfect for people who want increased performance from their audio systems and SR products with UEF Technology but without the complexity of the iPad controlled Atmosphere. Moreover, while the FEQ X4 is larger than the original single antenna FEQ it’s still small enough to hide in furniture, behind drapes and sofas, or in bookcases for the ultimate in invisible acoustic control. FEQ X4 is a single channel ULF (Ultra Low Frequency) RF pulse generator that acts as a low-frequency dither to overpower the ambient RFI and EMI fields in your listening room broadcasting over (4) separate channels for a more immersive experience than was possible from the original single and smaller antenna FEQ. In addition to acoustic benefits, it also improves the performance of all SR products with UEF Technology. UEF Tech responds to specific ultra-low frequencies so your Core UEF, Atmosphere X, and Galileo SX cables perform better, along with your HFT’s and UEF Acoustic Panels. Even Tranquility Base UEF component platforms and Black Box low-frequency resonator arrays perform with noticeably increased levels of performance when excited by the strategic ULF signal generated in a 360-degree wave pattern from the new FEQ XL4. Dimensionally the chassis and antennas were extended from 7″ to 14″ giving the FEQ X4 approximately 8x the broadcast strength of the previous generation FEQ with a 360-degree radiation pattern to the original’s 180-degree pattern so placement is less critical while overall performance is increased. To use, plug the FEQ X4 and its internal Ground-Plane into two separate wall sockets in your listening room and place behind and between your two main speakers or where ever you find space. Then turn it on for an immediate and unmistakable improvement in sound. One FEQ X4 will improve an average size listening room with a greater sense of clarity, a lower noise floor, and more natural harmonics.

Who it’s for: Anyone who wants to improve the acoustic response of their listening room without the complexity of iPad control, simply turn it on, set it, and forget it.

Dimensions - 14″ tall  (Base 4.1″ wide x 4.1″ deep)

Global MSRP - $995.00 

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