River Cable FLEXYGY 6-conductor Flat Speaker Cable
SRP: $255 4M pair; $270 5M pair (contact River Cable for custom lengths)
River Cable Technologies
350 Power Avenue
Hudson, NY 12534
6 x 16 gauge fine-stranded copper flat speaker wire; .6” wide by .18” thick; available in a dark blue jacket with gold pins, spades, or banana plug ends; 30 day in-home trial; cable “birth certificate” that certifies the cable meets or exceeds certain technical requirements: capacitance <43 pF/ft, DC resistance <.003 ohms/ft, velocity factor > .87; LIFETIME warranty.
B&W 703 loudspeakers, Musical Fidelity A308 Integrated Amplifier, Musical Fidelity A308 CD player (used as transport), Musical Fidelity TriVista 21 DAC, Audioquest Jaguar interconnect, Audioquest Optilink III Optical cable, DeCorp 12DePWR speaker wire and Audioquest Type 4 and CV-6 for comparison.
The River Cable speaker wire was connected and played for a couple of days on the system; right away the impressions were positive. For the comparison tests, cables were plugged and unplugged utilizing the multiple connections on the back of the Musical Fidelity A308 integrated amplifier. I requested the FLEXYGY cables with spades on both ends. The spades fit sideways into the amplifier, but did not fit around the posts on the speakers. I used some Phoenix Gold A405 banana adapters to make plugging and unplugging more convenient with the speakers. To be fair I used them on the other cables as well. I contacted River Cable and they told me that the spades are also available in 8mm and 9mm sizes that probably would have fit.
These cables are available only in a full-range option, so bi-wiring can only be accomplished with a second set of cables, in other words, double bi-wiring. For the tests, I left the jumpers in place on the B&W speakers. Replacing these might have improved sound further, but at least I maintained a level playing field with the cables in the test.
Technology, History, and Cable Design
Even though the River Cable brand is fairly new, their parent company, HAVE Inc., has been designing and building cable systems for the broadcast television and professional audio industry for over twenty-five years. In 1993, they produced the Digiflex Gold audio line that was well reviewed in Stereophile magazine.
Included in the press packet (and available for viewing on the River Cable website) is a narrative account of the history behind the design of the FLEXYGY cable. To summarize very briefly: The ultimate goal is to provide a cable that has almost no resistance and near zero inter-conductor capacitance. The paper distinguishes between the differing cable design choices for vacuum tube amplifiers (or unstable designs) and (high quality) solid-state amplifiers. For properly designed amplifiers (low-output impedance and stable designs) the engineering goals are low capacitance and low resistance. It is claimed that a flat cable is typically the best topology/geometry to achieve this goal. Unlike many other companies that use exotic materials, solid core construction, filters, etc., Don, the author of the paper, emphasizes the use of multiple ultra-fine-drawn, high-purity copper in a flat configuration to provide the best possible performance.
Note: No mention is made of inductance.
The Birth Certificate
One of the things that make River Cable products unique is the inclusion of the “Birth Certificate”—a paper indicating the cable has met or exceeded certain preset specifications. With the speaker cables, I received a certificate for each channel. Each cable goes through a physical inspection and a basic continuity/short test. DC resistance is noted (mine measured .06 ohms each), capacitance (mine came out to .79 nF each), and there is a graph to guarantee no excessive overshoot/undershoot with a 5KHz square wave when a 4 ohm load is used.
Listening Part I – River Cable vs. DeCorp cable
I must admit that I was a bit uncertain how to proceed with the comparison. The reason? I thought I would have a hard time hearing the difference between these two flat cables. When I finally made the first switch, I thought I had done something wrong. There was an immediate difference in sound—much more than I ever expected. I called a friend over to determine if I was crazy, and he too, was surprised at the difference after the switch.
I began the critical listening with track 1, “100 Lovers,” from Carla Lother’s CD 100 Lovers. The sound with the DeCorp cable was brighter and had more air, while the River Cable made the music sound richer and warmer. I went back and forth a couple of times and even within 20 seconds of listening the difference was quite obvious. The choice as to which one was better was up to debate. With this recording and this set of equipment, I liked the extra bit of high frequency with the DeCorp. Just for fun, I threw in a 10’ pair of Audioquest Type 4 (not really expecting it to be as good), and sure enough, it wasn’t. This cable is less expensive, but definitely sounded inferior. The sound was constricted and edgy–not at all like the DeCorp or the River Cable. I don’t have any measurement to back up this statement, but this is how three people who listened best described the cable.
To further investigate the differences in high frequency extension, I chose “Spanish Harlem” by Rebecca Pidgeon from The Ultimate Demonstration Disc by Chesky Records. The FLEXYGY cable seemed to produce more low bass (“dummmmm” I wrote in my notes) than the DeCorp. Voice appeared to be richer with more of an “ahhh” sound quality to it. As with the previous recording, the DeCorp had more high frequency output. This had the effect of making Pidgeon’s voice seem to have more range and extension. Low bass was lighter in balance and images were more spread out.
With track 3, “Deacon Blues,” from the Mobile Fidelity Ultradisc version of Steely Dan’s Aja, my preference changed to the River Cable. The DeCorp cable had more sheen on cymbals although voice still seemed clearer. Where earlier the top end seemed more extended, on this recording that extra bit of high frequency made the recording sound overly bright—it was just a bit too much. The River Cable sounded smoother on top and slightly richer from top to bottom. The quality of cymbals was tonally different. There was clearly a trade-off between slightly sizzly sound and slight lack of air and resolution. To my ears, the extra high-frequency energy imparted by the DeCorp prevented complete enjoyment on this recording, while the FLEXYGY was much more listenable.
Track 5, “Fragile,” a remake of the Sting tune by Cassandra Wilson from the Oct/Nov 2003 One Way Sampler shed more light on the differences between the two cables. The DeCorp added some extra sizzle to the percussion, but the voice was so palpable it was as if you could reach out and touch Wilson. The sound was more spatial and offered a larger acoustic space. The River Cable made the voice richer and the highs were detailed and clear, though the sound was not quite as elevated in the high frequencies. The sound was mellow and just flowed from the speakers. This lack of irritation and edge that still manages to reveal inner details yet sounds smooth is highly appealing.
Listening Part II – River Cable vs. Audioquest CV-6
I’m a big fan of Audioquest and the CV-6 cable has gotten a lot of good press. Imagine my surprise when (in the test system) the River Cable clearly sounded better! Track 10, Beethoven’s Cello Sonata op. 102 No. 2 (the 1st Movt: Allegro con Brio) from a Deutsche Grammophon Sampler started things off. The FLEXYGY made the music sound as if it had more range. The cello had more bite, and in the opening of the track, the piano attack was clearer. The transient sounds were more noticeable and it was almost like there were improved dynamics in comparison to the CV-6. The Audioquest came off as sweeter with a warmer middle, softer, relaxed, and more laid back. With this system it just seemed to lean too much in that direction.
I tried another track (#7), Seal’s “Waiting For You,” from the same One Way Sampler used earlier. The sound with the River Cable was brilliant, and you could discern the layers of sound even in the somewhat over-produced mix. The voice was a bit sibilant and hard. The Audioquest cable seemed to remove this, but a little at the expense of the music. Bass with the River Cable was pounding and distinct. At 1:40 into the track, the soundstage opens up wide and the presentation was big and bold. The CV-6 smoothed the voice, and the bass was not as powerful. There was less high frequency content on the voice and the sound was slightly restrained, although not necessarily in a bad way, just different. With the earlier comparison it was the River Cable that sounded more subdued while the DeCorp tended to be brighter, although in this comparison the opposite was the case.
Lastly, I listened to track 14, “Cavali di frisia” by Gianmaria Testa from Extramuros off the Triangle Acoustics sampler CD. The guitar sound with the River Cable was excellent. It sounded completely different in comparison with the CV-6—more natural and with more resolution. The voice floated nicely between the speakers. The sound was more detailed and had better dynamics than with the Audioquest cable. The CV-6 was mellower, richer, and warm. The voice was very intimate, and there was not as much edge when the track got louder at 1:15.
The River Cable FLEXYGY offers outstanding performance and flexibility in terms of placement. It acquitted itself very well in the tests with other high performance cables, and ultimately system matching and personal preference will weigh in as to which cable best suits the individual user. The DeCorp cable is designed for on-wall installation and although it performs well, will not be an acceptable solution in most listeners’ homes due to its appearance. With River Cable offering the optional size spades, the issues I had with connection should be eliminated, and custom lengths allow virtually any speaker/amplifier placement option. A friend was so impressed with the sound he immediately borrowed my set after I had finished my review. With a 30-day in-home trial how can you go wrong?
— Brian Bloom