Product Review -
Nordost Flatline Cables - January, 1995 (Updated September, 1995)
By John E. Johnson, Jr.
2 Flat, Flatline, Magic 1, Blue Angel, Blue Heaven, Red Dawn.
Speaker cables and interconnects. Copper and copper/silver extruded in Teflon dielectric.
Nordost Corporation, 58 Pearl Street, Framingham, Massachusetts 01701, (508) 879-1242.
Speaker cables and interconnects represent one of the most controversial subjects in audio/video. Do they make a difference in the quality of the signal being passed from one component to another? Are they worth the price? You will find audiophiles of all degrees of experience and expertise answering these two questions with yes's and no's. Why the controversy? At least part of the answer lies in what we have been told, rather than what we have heard for ourselves. Secondly, it is difficult to define precisely what to listen for when comparing cables, and third, any particular cable may sound quite different with one set of equipment than with another.
During the last year, we began researching some of these questions for ourselves, believing at the outset that cables probably did not make any truly noticeable improvement in sound quality. We were wrong in our assumption, and how!
Cables do make a difference, and in order to see why, it is first necessary to understand the characteristics that affect their ability to transmit a signal.
The "personality" of a cable is determined by three basic electrical properties: resistance, capacitance, and inductance. Resistance is probably the smallest factor, because cables use good conductors (copper and silver). The real culprits in cable transmission are capacitance, measured in picofarads or pF (trillionths of a farad) per foot, and inductance, measured in microhenrys (millionths of a henry) per foot.
Any time conductors are surrounded by an insulator (dielectric), capacitance occurs. You want this to happen with capacitors inside the amplifier, but not in the cables. Depending on the insulator, some of the electrical signal passing through the cable is transferred to the insulator, stored as energy (electrons), then released back into the cable where it causes a degradation in the sound quality. The type of insulator has a direct effect on the capacitance. Various insulators are used in high fidelity cables, and, in increasing quality, they are PVC, followed by polyethylene, polypropylene, and finally, Teflon, which is the best. Usually, Teflon insulated cables are the most expensive, partially because it is a difficult material to work with. Typical values of capacitance with high quality audio cables vary from 6pF to 50pF per foot. Inductance is the property of the signal in one conductor inducing current in another nearby conductor, and inhibiting current flow in the opposite direction. This is desirable in transformers, but not in cables. Since cables usually have two leads, each conducting in the opposite direction to complete the circuit, high inductance can cause the flow of current in one lead to interfere with the flow in the other lead. Inductance values for audio cables vary from about 0.1 microhenrys to 0.6 microhenrys per foot.
Some amplifiers are more sensitive than others to the load that the speaker cable places upon them. The higher the output impedance, the more likely capacitance and inductance of the cable will affect the sound quality. Tube amplifiers are probably most sensitive, since they tend to have higher output impedances (e.g., 1 Ohm) than solid state amplifiers (e.g., 0.01 Ohm). In any case, however, capacitance and inductance values are important in determining how the cables will perform in any sound system.
The Nordost cables have the lowest capacitance and inductance of any cables we have worked with (6 - 7.8pF/ft and 0.09 - 0.11 microhenrys/ft, respectively). There are four types of cable design available, all flat for easy placement under carpets for Home Theater use, and all insulated with Teflon as the dielectric: 1. Flatline Speaker Cable has eight very thin and very flat copper conductors side-by-side, all insulated from one another by the dielectric. Four conductors are used for one signal path (positive) and four as the other (negative). The two sets of four conductors are attached, so that the cable appears as eight conductors across. They are split at the ends for termination with banana plugs or spade connectors. Magic 1, which is a new interconnect cable for 1995, is the same cable, but there are two conductors assigned to each of the signal paths, with RCA connectors as terminals. The cable appears as a strip with four conductors across. 2. Flatline Blue Angel is a very different design. Each conductor has seven silver plated copper wires twisted together, and there are ten conductors in each strip, all separated by the dielectric. Thus, for the interconnect, there are five conductors each for the positive and negative signal paths, with RCA connectors as terminations Blue Angel is not available as a speaker cable. 3. Flatline Blue Heaven uses thirty six conductors each for the positive and negative signal paths, for both the speaker cable and interconnect versions. Each conductor is a solid core copper wire, with silver plating, and is round, rather than flat. The cables are supplied with banana plugs or spade terminals for the speaker cables and RCA connectors for the interconnects. (a total of seventy two conductors across in a single cable for both types). 4. Flatline Red Dawn (new for 1995) has seven # 26 conductors and twelve # 28 conductors for each signal path. Instead of silver electroplating, the silver is extruded onto the copper during the formation of the cable. It is available in both interconnects and speaker cable configurations.
In testing the Nordost line of cables, we used two reference systems. One is completely solid state, with 600 watts per channel to the front, and 400 watts per channel to the rear. The second reference system has a solid state preamplifier and a Pure Class A single ended triode tube amplifier driving mini-monitors, with self- powered (solid state) subwoofers to handle frequencies from 16 Hz to 100 Hz. The single ended triode is very revealing, with any artifacts produced by other components in the system becoming easily apparent.
The sound quality of all four Nordost designs is exceptional, and going from the entry level Magic 1 to the Blue Angel and then to the Blue Heaven, there is a progressive smoothing of the high end of the audio spectrum, and a reduction in harshness that is prevalent in so many digital recordings. With Red Dawn, the brightness of the Magic 1 was there, but it was more refined. There was no difficulty in any of the cables' ability to handle high power, (400 - 600 watts per channel). The Nordost products were quite neutral, thus requiring no boost in either the treble or bass to provide listening satisfaction. We also noticed that we could listen to music for much longer periods of time, without fatigue.
We used the cables with movie sounds (Jurassic Park) as well as with classical and popular recordings. Piano and human voices are particularly good test materials, since they are difficult to render with precision. All four cables were splendid in this regard. Also, we noticed a marvelous ability to reproduce very soft, delicate sounds, for example a single violin or triangle in the background. These sounds were not masked by any artifacts, such as smearing, that might have otherwise been produced if the cables were not so electronically transparent.
It is difficult to determine the nature of the reduced harshness (high end refinement, "sweetness") with the more advanced Nordost cable since they have several variables: the number of conductors, presence of silver plating, and flat vs stranded vs solid core (their capacitance and inductance values vary slightly). There was a slight tendency for the Magic 1 to be more sensitive to hum, but as long as the cables are carefully placed, the sound quality is excellent. Using the Magic 1 in a balanced configuration eliminated the hum, so this could be a best buy (we had them custom made for us in order to test this inexpensive cable in balanced mode). Flatline Blue Angel, Blue Heaven, and Red Dawn interconnects in the balanced versions also performed well, with reduced noise levels (their sonic personalities were not changed). The Magic 1s are designed as an entry level product, and could be used for applications in the numerous package systems that come with a CD player, tuner, cassette deck, equalizer, and amplifier, all in a cabinet, with speakers. These systems sell for about $1,000 or less.
The Blue Angel, Blue Heaven, and Red Dawn cables are ideal for "High Definition" (we prefer this term over "High End Audio"), including Home Theater applications. Our final choices for our two reference systems were as follows: for the all solid state system, we decided on Blue Angel or Red Dawn interconnects, and Blue Heaven speaker cables to the front speakers, while Flatline was chosen for the rear speakers (a Home Theater configuration). In this manner, harshness from CD music and movie sound tracks played at high volume was reduced. For the second reference system, we chose Blue Heaven interconnects from the CD player to the solid state preamplifier and subwoofer line inputs, Blue Heaven or Red Dawn interconnects from the preamplifier to the tube power amplifier, and Flatline or Red Dawn speaker cables. Since the tube amplifier is very smooth and without harshness at all, the Blue Heaven speaker cables made the sound a bit too smooth, so we preferred the crispness of the Flatline and Red Dawn.
In summary, the Nordost cable products are among the best we have ever used, and we highly recommend them for all high definition audio applications.
UPDATE - September, 1995. Nordost has just released their newest speaker cable product, called 2 Flat. It consists of two 1/8" wide flat copper conductors, arranged side-by-side, with Teflon dielectric (insulation). The cable is 3/8" wide and white in appearance (see photo). Like all their cables, the 2 Flat is . . . well, flat (0.02" thick). This is an entry level product, so we compared it with zip cord in a surround sound system with 100 - 135 watts per channel. The difference was most noticeable in the high frequencies, with a reduction in harshness using 2 Flat. It is rated at 30 amperes/conductor, 6.5 picofarads/foot capacitance, 0.11 microhenrys/foot inductance, and 0.0064 Ohms/foot resistance. For home theater applications, this is a great product because it is relatively inexpensive, and it would be ideal for connections to the rear surround speakers. Since the copper conductors are flat strips, the cable can be creased if it is stepped on or sucked into the vacuum cleaner, so tuck it against the wall or place it under the rug when installing it. The cable can be purchased in rolls of several lengths. Pin, banana, and spade connectors are available.
John E. Johnson, Jr.
© Copyright 1995, 1996, 1997 Secrets of Home Theater & High Fidelity
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