FAQ - Frequently asked Questions...

WHY ARE SOMMER CABLE EMPLOYEES ALWAYS IN A GOOD MOOD?

We have often asked ourselves that same question. It probably is because we have a modern company structure. We have many very nice customers and collegues who are all easy to get on with and to work with. Our boss pays us well and on time. In short: We love our job!




CAN A CABLE REALLY SOUND?

Not really. A cable is a passive element and should transmit the signal as true to the original and free of losses as possible. A good cable will not alter the signal, but echo the music on your sound medium, not as opera music (how should it anyway? It did not even attend...). A neutral cable will not be able to improve the sound of a trumpet if it was not mixed very well on the compact disc.
So it would be a big mistake to expect that a cable can reproduce features not even present on the compact disc. But you can "tune" the HiFi system using a cable. If you know what the cable is capable of achieving electrically and in the way of sound (e.g. increase heights) then go ahead and experiment. Your dealer will be glad to advise you about the correct use of SOMMER CABLEs.



WHAT IS A "SKIN EFFECT"?

If an alternating current runs through a conductor the current will constantly change direction and strength, creating a changing magnetic field. These changes in the magnetic field induce eddy currents into the copper conductor, counter-acting the current inside the conductor, while they maintain the same direction on the surface as the current inside the conductor. Thus the current density exponentially decreases toward the center. The suppression of the current increased with the frequency of the alternating current and the diameter of the conductor, i.e. the conductor resistance increases due to the suppression within the respective frequency range. Some users say that in some cases this effect can be heard on audio cables with a large diameter, for smaller diameters however it is rather unlikely.
On AES/EBU-cables this phemomenon should be avoided, because too high a skin effect can cause data loss.



WHAT IS THE DIFFERENCE BETWEEN A CAT5, 6, AND CAT7 CABLE?

The simple CAT5 standard was designed for 100 Mbps LANs and has been available since the beginning of the nineties. This standard - as is common in the fast world of computer technology - soon reached its limits and was replaced by the CAT5e standard, which supports the operation of Full-Duplex Fats Ethernet and Gigabit Ethernet. The CAT5 is a 100 MHz standard, just like big brother CAT5e.
In June of 2002 the CAT6 standard was retified by TIA/EIA, which delivers as significantly higher performance than the CAT5e standard, with a transmission capacity of 200 MHz. Of course, all CAT6 components are downward compatible to CAT5e components.
The CAT7 cable is designed for data transmission of up to 600 MHz. It is favored for use in building installation, because the wire pairs are individually shielded, with very low cross-talk.



WHAT IS THE DIFFERENCE BETWEEN AN UNBALANCED AND A BALANCED CABLE?

The unbalanced cable is mostly used to connect guitar and amplifier, HiFi-components, or as a simple control cable. It consists of a signal wire and shielding.
The balanced cable has two signal wires with the phase twisted by 180 °C (+/-). The opposite phase releases interference signals, which is why this type of cable is preferred for long transmission distances or sensitive, interference-prone components such as microphones, mixing boards, etc.



HOW IMPORTANT IS THE QUALITY OF THE SOLDER?

The quality of the solder and especially the quality of workmanship on the soldered spots should not be underestimated for the transmission of audio signals. Bad tin or a soiled solder bath can cause transmission resistances to increase. This is not only physically detectable, but in rare cases can also be heard.
So use high quality tin to work with (partially with silver), make sure to provide a clean working environment, and do not touch the wire insulation with the solder tip.



ARE ALL SHINY THINGS MADE OF GOLD?

Or: How important is the gold-plated contact on a plug connector really? But first: Pins made of genuine gold would not only be too expensive, but would not make any real technical sense. Gold is a heavy metal and would break without an alloy treatment after only a few plug cycles.
Mostly nickel-plated pins or alloys are used in connection with silver or copper to affect the hardness and surface properties.
Most plug connectors only have thin gold-plating and reasonably priced, sometimes only painted, cinch connectors, i.e. a real cheap plug connector cannot be gold-plated.
The good conductive values of gold can only be utilized if both socket and plug are gold-plated. If this is not the case, the harder alloy would simply scrape off the soft gold and oxides would build up. Contrary to public opinion the layperson cannot recognize the quality of the gold by the color, because very often more complex alloys are used on the plug connectors, depending on applications and plug cycles.




WHAT IS THE MAXIMUM TRANSMISSION LENGTH FOR CABLES IN AN SDI- AND HDTV- FORMAT?

That is hard to say, because it very much depends on the peripherals used and the quality of the interface installed. The question is comparable to one you would ask the filling station attendant: If I fill 10 liters of gasoline into my car, how far can I drive? The answer to the question would depend on the type of vehicle, and the same it true for HDTV-cables. Here too the hardware data has to be considered and used to calculate the transmission length.
An SDI-cable should be able to transmit 270 Mbit/sec. and the HDTV-cable is designed to transmit within a range of 1.5 Gbit, ensuring the resolution required for the PAL 625-line format.
The range of the HD-SDI depends on the bitrate used (compressed or not compressed). At 1.485 Gb/s (not compressed) the damping value is drawn on at half the bit rate (720 MHz) and the cable length possible at a damping value of 20 dB or 30 dB is considered relevant parameter.




There is no doubt that the length of the guitar cable has an effect on the sound. But is the optimum cable length and the sound only determined by value of the cable?

It is not easy to answer this question, because not only a low capacity is important for the sound of a guitar cable, but the entire cable construction must be considered.
A guitar cable can have an extremely low capacitive value and still sound "faint" or flat.
This often is the case if the individual litz is stranded parallel instead of concentrically (as is the case e.g. at SOMMER CABLE).

Parallel stranded litz does not only have too small a conductive surface, but it also breaks real fast. Too small a conductive surface is even noticeable on a bass cable: It transmits the typical deep sounds, but it will be missing the all important "attack" and the dynamics.

The insulation material on guitar cables with almost unbelievably low capactive values is often very highly foamed. But highly foamed insulation material is very sensitive to pressure and already looses stability after having been wound a few times (i.e. after each gig), thus again increasing the capacity. To avoid this effect SOMMER CABLE uses an especially robust and lacquered insulation material to finish off porous surfaces.

Cable manufacture has to find a compromise between good electrical values and a certain continuous stability for insulators and jacket.
If merely the capacity was considered the cable would have to be 30 cm long, and that would not be very practical. The solution: Testing the sound or sound characteristics of different cables and selecting the shortest practical, available cable length for the selected version (mostly 3.0 m or 4.5 m) - just to be on the safe side.



Pascal Miguet