Synergistic Research Atmosphere High Definition Ground Cables




Giradi2.jpgThis is a follow-up review to the Synergistic Research (SR) Grounding Block review I wrote back in July (here).  For those not familiar with the SR Grounding Block (GB), it’s a device that applies the Uniform Energy Field (UEF), internally allowing for 18 ground connections to complete a star-grounding scheme for one’s system. Typical application for star-grounding each component involves connecting the GB to an unused RCA connector. In computer based digital systems, USB and CAT5 cable connections between the GB and computer are also an option.  In the referenced review, I tested the GB with the standard cables supplied with the GB on my SR Tranquility Base and SR Atmosphere and was blown away by how natural my system sounded. Following the review, I learned that SR developed a High Definition Ground (HDG) cable as an upgrade to the standard supplied wires that come with the Tranquilly Base and Atmosphere.  This review will compare the performance of both cables and will convey how my system was transformed when fully grounded using the HDG cables on each component in my reviewing system. 


High Definition Ground Cables

In comparison to the standard supplied wires that are a non-shielded single Copper core wire, the hand built HDG cables are constructed with UEF field shielding and Synergistic Research’s Silver Air String geometries originally developed for the flagship Galileo System cables. The HDG cables are clearly more refined in design and implementation.  In addition to the component connection options listed above, there is an upgraded Main Ground plug cable that mates directly with the GB which uses a G07 wall plug found in the SR’s higher end power cables. HDG cables are not offered for the Atmosphere Series cables given their inherent construction based on the implementation of the UEF technology.  Typically a system component’s unused RCA jack which provides a direct printed circuit board grounding scheme is mated to the GB. In my reviewing system, I tested HDG cables connected through the RCA jacks on my Ayon Audio Triton integrated amplifier, LT Memory Player and REL R-528 SE subwoofer.  Other applications of the HDG cable tested included my SR Tranquility Base and SR Atmosphere acoustic enhancement device. One should note that HDG cables are offered in standard 4ft lengths and 8ft extensions.

No Filter LOL rev 2

Fourplay.jpgFourplay [Warner Brothers Records], is the 1991 debut album from the contemporary jazz quartet of the same name; composed of legendary keyboardist Bob James, guitarist Lee Ritenour, bassist Nathan East and drummer Harvey Mason. It has had a significant amount of play time as of late. The style is a soulful blend of jazz, R&B, and pop with an emphasis on original compositions by each band member. The reviewing process started with playing various cuts with the non-shielded single Copper core wire (standard) installed on the SR Tranquility Base and Atmosphere.  For this recording, I preferred the “Ethereal” setting with “Stratosphere” on the Atmosphere. On the sixth cut, “After the Dance,” El DeBarge lends his seductive vocals to the Marvin Gaye classic to round out this musical masterpiece.

Swapping in the HDG cables on these two components removed an edginess in the music that I didn’t realize was there.  The perceived lower noise floor was clearly heard in the more natural vocals of El DeBarge while the instruments were more fleshed out within the soundfield.  I particularly enjoyed how the grand piano was more focused on the third cut, “Foreplay” and eleventh cut, “Rainforest” and the natural liquidity of the electric and classical guitars on the fourth cut, “Moonjogger” and seventh cut, “Quadrille.”  On various cuts of this recording, the HDG cable differentiated itself as not just a tweak but an integral part of one’s high end system. Although the HGD cables can be a little pricey, they clearly out classed the standard supplied cable.


In the next part of the review, I began connecting a HGD cable to each system component starting with my REL R-528 SE subwoofer.  It was much easier to follow the opening bass line on the eight cut, “Midnight Stroll,” following connection of the HDG cable to my REL subwoofer.  Connection of the HDG cables to my upstream digital source, the Laufer Teknik Memory Player and my Ayon Audio Triton integrated amplifier also resulted in a significant overall improvement.  With my system fully grounded by the HDG cables into the SR GB, the bass was much tighter and faster and gone was all traces bass frequency overhang.  The bass improvement really stood out for me in how fast and tight it now was.  When one of my local audiophile who was quite familiar with my system buddies came over for a listen, his first thing he noticed was how much ricer the tone of the high and midrange frequencies were and how dense the soundfield became out the extreme edges.  This system upgrade was clearly an example of when all of your system components is operating at their best all other aspects of the music fall into place. 

Olu.jpgAnother album that’s been getting some major playtime in my system has been Neighborhoods by Olu Dara [Atlantic Records].  In this recording, Dara delivers more of his cross-genre African American autobiographical soundscapes. I found this to be another recording that showcased the additive effect of the HDG cables and GB.  On the second cut, “Neighborhoods, Ola Dara’s vocals sounded more real and less digitally constructed, the bass guitar was extremely rich in overtones and the sound of the sax and trumpet was so holographic, I thought I could reach out and touch it.   I also appreciated this recording for how each instrument was localized within the soundscape and how Dara’s vocals appeared in the background while having a distinctive separation.  Overall, the music was projected further into room while enveloping the listener when the HDG cables were installed.  After you read this review, I recommend you procure the needed HDG cables for your system, a Ground Block and this album.  You’ll be in for a trick or treat.


I wouldn’t hesitate to recommend the High Definition Grounding cables.  The expense is justified by that delivered performance. The addition of the SR GB and HDG cables exceed my expectations and was similar to the level of improvement the SR Powercell 10 SE MKII I reviewed back in 2013 brought to my system.  The more I listened to my system with the HDG cables and Grounding Block, the more I was convinced that the addition of these products are on the critical path in assembling a truly high performance audio system. 


Mike Girardi   




High Definition Grounding Cable (RCA, XLR, USB, Ethernet), 4ft, $395

High Definition Grounding Cable Wall Plug, 10ft, $495  

High Definition Ground Cable (Banana for TB, FEQ, and Atmosphere), 4ft, $395.00
High Definition Ground Cable (Spade for Chassis Grounds), $395.00


Phone numbers: (800) 578-6489 within US and (949) 476-0000 outside the US



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