Glossary of technical terms used in hi-fi and home cinema cabling
 
  Attack: The leading edge of a musical note. Every type of musical instrument has a distinctive shape to the notes played on it. The attack is the time taken for a note to rise to its full loudness. Poor quality cables can have a seriously detrimental effect on what is critical part of music. The initial rise on a note can be lost beneath a high noise floor or altered by interference or mechanically induced noise. [ top ]
 
 

Timing: Another favourite of the hi-fi industry. Used to describe a systems ability to deliver sound in a coherent manner [ top ]
 

  Coherence: Used by Hi-Fi magazines and manufactures alike to describe the ability of a hi-fi or home cinema system to present music as a coherent whole. The way in which interconnects or speaker cables affect the coherence of a system can be dramatic, badly designed and built cables can almost completely destroy a systems ability to produce a coherent sound. Crucial to a systems coherence will be a cables ability to move dynamic and timbrel information accurately across a given bandwidth. [ top ]
 
 

Bandwidth: In this case the frequency range of a system. If used to describe the characteristics of a cable, bandwidth would be used to describe the ability of the cable to transmit very high and low frequency information. As cable design gets more exotic so its ability to transmit this information accurately increases. [ top ]
 
  Decibel: (db) The unit of measurement used to describe the loudness of a sound, the higher the louder.
motorhead are reputed to have played concerts at volumes in excess of 130 decibels! [ top ]
 
  Dynamics: The dynamic range is the difference between the quietest and loudest sound. The human ear has a dynamic range of around 120 decibels (dB). Almost every hi-fi and home cinema component will list its dynamic range. No Cable can increase the dynamic range of a system, but a badly designed cable can significantly reduce it. [ top ]
 
  Envelope: The shape of a musical note. A musical note can be split into three parts, the attack, sustain and decay. The envelope of a note played on a piano is completely different to the envelope of a note played on banjo. Please visit http://www.clubi.ie/amhiggins/adsr.html for an introduction to this wonderful and complex world. [ top ]
 
  Frequency: The system used to measure the pitch of a note. A440 Hz is the frequency of the A note in the middle of a piano keyboard. Most commonly used in hi-fi to describe the frequency range of a speaker. We might use it to describe a cables ability to accurately transmit signals over a particular frequency range (see bandwidth) [ top ]
 
  Interference: A really big deal, interference is simply anything that interferes with the signal travelling along the cable. This can be electrical or mechanical and is something cable designers spend a great deal of effort in attempting to protect the signal from. Anything that interferes with a signal will affect that signal. Interference will increase the noise floor of a system, corrupt the picture from a DVD player and will in severe cases seriously affect the performance of a hi-fi or home cinema setup.. [ top ]
 
  Mechanical: The way in which a cable is designed and built will affect its susceptibility to either transmitted or airborne vibrations. We found that cables built to a tight mechanical tolerance sounded better than those with a lower build tolerance. So we chose to build cables this way simply because they sounded better. As well as insisting on a high build tolerance we use particular materials, which through experimentation we have established are effective at dealing with this problem. There are other companies doing some really interesting work in this area [ top ]
 
  Micro dynamics: Human hearing is incredibly sensitive and able to detect tiny differences in loudness. This ability is critical to the way we respond to music. A really good illustration of the way these tiny dynamic shifts are vital to a piece of music would be a piece of music played on an acoustic guitar. Most music is built around repeating rhythmic patterns, so a sequence of notes will have a regularly occurring start point. The guitar player will emphasise the start of the sequence by hitting the first note very slightly harder than the following notes. Likewise other notes in the sequence will be played slightly harder or softer to emphasise the rhythmic or melodic structure. Read more [ top ]
 
 

Noise floor: In almost any system there will be present, when the system is switched on, a degree of noise (sometimes audible as hiss). This can be caused by electrical noise generated by the components within the system or by interference picked up along the length of the cabling connecting the system together. By way of illustration, assume that the noise generated by the system and/or cables is measured at 35 decibels, so any recorded sound on the music you are playing that is below that level will be masked by the noise. (more info) A properly designed cable with high levels of wide frequency interference rejection fitted in place of a cable without these characteristics can significantly lower the noise floor of a system.

Not to be confused with this fascinating site: http://www.noisefloor.org/ [ top ]

 
 

Timbre: In "This Is Your Brain On Music" written by Daniel Levitin can be found the Acoustical Society of Americas definition of timbre, which is that "Timbre is everything about a sound that is not loudness or pitch". The only way this helps is by illustrating just how complex timbre is. Timbre is the information that lets us define what a musical note is played on. The timbre of a note played on a guitar is completely different to the same note played on a piano. Two otherwise identical guitars can have very different sounds because the body of one is rosewood (brighter tone, better defined bass) and the other mahogany (softer, less attack to notes). This barely scratches the surface of what is a vast and complex subject, but it is one of the areas where properly designed cables can have a profound effect.

One of the biggest challenges for anyone involved in hi-fi design are bowed instruments. The tonal complexity of a string quartet is extraordinary and it was the desire to transfer as much of that complexity as we could that led to the use of the advanced shielding systems we use in many of our cables. Timbre also plays a vital role in the way music communicates emotions and our emotional response to music is critical to our love of music. [ top ]
 
 

Stereo image: "Stereo imaging is the audio jargon term used for that aspect of sound recording and reproduction concerning spatial locations of the performers, both laterally and in depth. An image is 'good' if the performers can be effortlessly located; 'bad' if there is no hope of doing so. A well-made stereo recording, properly reproduced, can provide good imaging within the front quadrant; a well-made Ambisonic recording, properly reproduced, can offer good imaging all around the listener and even including height information" - read the rest of this piece at Wikipedia [ top ]
 

  Tone: Ideally, a system should have an even tonal balance; in other words it should not emphasise one particular tonal frequency over another. If a system or component does emphasise a particular tonal frequency range it is often described as coloured. Cables can and do influence the tonal qualities of a system and research into this has shown that there is an important relationship between the type of conductor and the material used to insulate it. Get this right and it is possible to produce a neutral balance right across the frequency range [ see fitting new speaker cables ] [ top ]
 
  Technical
 
 

Conductors: In the case of cables, conductors are the wires used to carry the signal. These can be either multi-stranded or solid-core.

A multi-stranded conductor will be made up from a number of strands; there is a considerable variance in the number and diameter of strands used and the way in which they are configured.

A solid core cable has a single strand conductor and as with multi-stranded conductors there can be a great deal of variation in the diameter of the single strand. [ read more ] [ top ]
 
 

Oxygen free copper: Oxygen free copper is the most commonly used conductor material for hi-fi and home cinema interconnects as well as speaker cables. Often referred to as four nines copper (99.99% pure), oxygen free copper contains around 50 parts per million oxygen, compared with around 750 parts per million found in the copper used for household appliances. The higher levels of oxygen will cause oxidisation and this will increase resistance.
In terms of sound quality, cables that use oxygen free copper transfer more information than normal copper and the lower levels of oxidisation means that oxygen-free copper cables maintain their performance for a longer period. [ top ]
 
 

Ultra cast copper:

Ultra-cast copper: A variation on oxygen free copper. Ultra -cast copper is cast then recast to further eliminate impurities. In theory this should make Ultra-cast copper the conductor of choice in all Chords' products, but despite much experimentation we have yet to successfully produce an analogue cable using Ultra-cast copper. The area where we have achieved real results with this material is digital signal transmission, both the Prodac Pro-Digital and the Signature Digital interconnects use Ultra-cast copper conductors. Despite the fact that a digital cable carries a digital signal, the Ultra cast copper conductors in direct comparison to more conventional oxygen free copper conductors produced a marked more detailed and natural sound. Although the tonal characteristics of both cables cannot be attributed solely to the choice of conductor material, Ultra-cast copper obviously has a marked influence. [ top ]
 
  Silver: A lot of the cables in the Chord range employ silver-plated conductors. Silver has a marginally lower resistance than copper but our primary reason for using silver is its ability to accurately carry both small and high level signals across a wide frequency range. However, the insulating material used influences the tonal characteristics of silver. We use Teflon extensively; this ensures an extremely neutral tonal quality across the frequency range. Other insulation materials can introduce unwanted colourations to parts of the frequency range. [ top ]
 
  Silver plating: So far we have chosen to use silver-plating rather than use solid silver wire. We have experimented with this and feel that the extra price of silver wire does not justify itsself in terms of performance. [ top ]
 
  Co-axial cable: The best example of a co-axial cable is the cable that connects an aerial to a television. An insulator and shield surround the central conductor. The signal travels along the central conductor and the shield screens the signal from interference and provides a return path to complete the circuit.
Co-axial cables are used extensively to produce both analogue and digital interconnects. We use high quality co-axial cables to produce digital interconnects but feel that analogue signals can be better carried via a pseudo-balanced configuration cable. [ top ]
 
  Pseudo-balanced cable: This is a term used to describe a cable that has two or more sets of identical conductors. This type of cable design is also referred to as balanced or semi-balanced. However this does not mean that a pseudo-balanced cable carries a balanced signal. The term is used to describe a cable where both the signal and the return are carried by identical sets of conductors. This type of cable geometry is used throughout our range of analogue interconnects; pseudo-balanced cables have a lower noise floor and transmit dynamic and timbrel information more accurately than co-axial designs. [ top ]
 
  Balanced connections: Not to be confused with pseudo-balanced. A signal can be carried from one component to another in two ways, single ended and balanced. A single ended output will usually use an RCA/phono or Din connection (and on the odd occasion and somewhat confusingly an XLR connection). Most modern hi-fi and home cinema components are fitted with RCA/phono sockets. Most professional audio and some domestic equipment however, offer the option of a balanced connection via three pin XLR connectors.
In theory the balanced connection system offers some serious advantages[ read more ] [ top ]
 
  Dielectric: The dielectric (or insulator) is the material used to insulate conductors, either from each other or from a surrounding shield. The most commonly used dielectrics are all plastics and each type has a different set of electrical properties. Teflon is widely acknowledged as being the best dielectric material to use, but polyethylene can also be made to measure and perform extremely well. Bottom of the list in performance terms is PVC. (read more) We use either Polyethylene or Teflon in the construction of all Chord Company interconnects and speaker cables, we do however make use of PVC as material for outer jackets. [ top ]
 
 

Shields: We believe that effective shielding of both audio and visual signals is one of the most critical areas of cable design. The average house is full of potential sources of mains and airborne electronic interference, both of which can have a seriously detrimental effect on sound and picture quality. A shield does exactly what it says and protects an audio or visual signal from interference.

Methods of shielding signals vary enormously and the types we use are listed below:

 
  Foil: The simplest method of shielding. A ribbon of conductive foil is wrapped around the conductor(s); economical and reasonably effective, foil shields can be extremely useful when used in combination with other types of shield. [ top ]
 
  Lapped shield: A lapped shield is made up of multiple strands of copper or other conductive materials wound around a central conductor in an overlapping spiral. Lapped shields are extremely flexible and when used in cables with multiple sets of separately insulated conductors, make for an extremely versatile cable that can be terminated with a wide variety of plugs. [ top ]
 
  Braided shield: A braided shield also uses multiple strands of copper but rather than being wrapped around they are interwoven around the conductor(s). The density of the weave will have an effect on the efficiency of the shield. [ top ]
 
  Floating shield: There are many ways of configuring a shield or shielding system. The simplest method is to connect the shield to the plugs at each end of the cable. However many manufactures of interconnect cables for use with hi-fi equipment (including Chord Co) adopt a pseudo-balanced configuration. This means that the shield can be connected at one end only and is not part of the circuit, or not connected at all and left fully floating. [ top ]
   
  Flat braid shield: A variation on the more commonly found braided shield. A flat braid shield uses flat ribbon copper and a very dense weave to produce a shield that is extremely effective at protecting signals from interference across a very wide range of frequencies. [ top ]
 
 

Combination shielding: All of the above shields can be used in combination with each other to produce still higher levels of shield effectiveness. The Chord Indigo interconnect uses a foil, braided and flat braided shield to protect the signal from extremely high frequency interference. [ read more ] [ top ]
 
 

Outer jacket: The outer jacket of a speaker cable or interconnect can influence the sound or picture quality to a surprising degree. The most obvious purpose of an outer jacket is to protect the conductors and the shields. However, the ability of the material chosen to control and reduce external and internal vibrations (see mechanically induced noise) can influence the performance characteristic of the cable. We use several materials including Silicone and PVC. [ read more ] [ top ]
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