The E field is always there around a battery, if theres voltage theres E field, there the same thing, (which also applies to any conductor connected to the battery.) Flipping the switch causes a step voltage which is basically AC till the circuit reaches steady state than well have DC.
Indeed. I was replying to Markw4's post where he asked:
So for a DC source before closing the switch the ultra sensitive bulb would not light as there's no change in the field, even if present.
In a beam steered array the magnitude and phase of every loudspeaker in the array is controlled individually to create the desired coverage pattern. This can be done dynamically, for example in a parliament house where the person speaking could be anywhere in the chamber and yet must still be heard by everyone else in the chamber, the coverage pattern of each public address loudspeaker is adjusted as microphones in different positions are turned on.
I recommend using an appropriate cable for the application in hand. There is no one single 'correct' cable.
Electrical parameters are an important consideration, but often so are aesthetics and other mechanical properties such as flexibility.
I generally use cables from one of the internationally highly regarded professional audio cable manufacturers, e.g. Canare (Japan), Klotz (Germany), Belden (US), Eurocable (Italy) etc.
I prefer Canare (pronounced 'canary' like the bird) star-quad configurations for a number of reasons including electrical parameters, flexibility and aesthetics, the most common I use are 4S8 (13AWG) and 4S11 (11AWG). If I need more copper than 4S11 for low series R, I generally use Eurocable 04N40 (8AWG). Unfortunately Eurocable use PVC insulation which is ionic and has a small deleterious effect compare to the non-ionic PE insulation used by Canare. This is relevant in very high end systems and verified in double blind tests, not likely to be relevant to any DIYer on this forum.
I use Eurocable 02N25C coaxial (13AWG) sometimes because it is very flexible and the smallest diameter cable I know of with 2.5mm2 of copper per conductor and will fit into the 2-pin DIN plug which some European audio manufacturers use e.g. Bang & Olufsen.
Inside high performance loudspeaker cabinets I sometimes use Canare, although the four conductors make terminations difficult, or coaxial cable like the Eurocable above or Canare GS6 (18AWG). Cables inside cabinets are usually very short so the series R and other lumped parameters are not particularly important, however star-quad and coaxial cables will mitigate cross-coupling of signals between the output sections of the crossover.
Some might argue that cable effects are inaudible, from decades of experience I cannot agree, but even if true that main cost of cable is the copper content, not the packaging, so one may as well use a configuration that is as "perfect" as is practicable when there is no cost penalty.
Loudspeaker cables also act as RF antennae and feed interference back into the amplifier's feedback circuits. In some amplifier designs this causes an increase in nonlinear distortion which impacts the sound quality. Star-quad and coaxial configurations greatly mitigate this problem. Of course any system's susceptibility will vary depending on the actual components and its location, so there are no blanket generalisations possible. However as above there is no real cost penalty for doing cabling 'properly'.
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Unless you are steering a null to the microphone that doesn't make sense as the listeners are not moving so why should the coverage pattern?
If you read my posts you know that I do not endorse fancy voodoo cables or expensive cables either, so I am not sure what your point is.
The article you cited does contain as much electrical, electromechanical and electroacoustic engineering mis-truth as it does truth. As an attempt to assert a non-scientific precept it is no different from the cable pseudoscience it purports to debunk. Nothing in Roger Russel's article refutes any science I know of and so doesn't change my understanding of speaker cables. It does not address the performance parameters that I discussed or give any reason to abandon the application of proper electroacoustical engineering. 🙂
Because the position of the person speaking is changing. There may be well over 100 positions for microphones in the chamber.
The operator of the system has a large touch panel plan of the layout of the chamber. Microphones are given precedence by selecting the position of the person who 'has the floor' (i.e. is entitled to speak) on the plan, and the system is automatically configured achieve the desired performance (gain stability and effective acoustic distance to listeners in the chamber) as the position of the active microphones changes.
If you are interested in the complexities there is an article describing the challenges here:
https://www.acousticdirections.com/wp-content/uploads/pro_audio_asia_march-april_2012_clear_debate_feature.pdf
That article says nothing about changing the speakers beam patterns on the fly with microphone switching. In fact the beam steering is entirely for the gallery.
I offered that link as an example of a system; as such it is not the be-all and end-all of the application of steered array systems, and not specifically the example I was talking about. Nor is any media release article obliged to state every aspect of a system's operation; absence of something being mentioned does not insinuate absence of its existence.
The speakers for the chamber were downward firing and unsteered! Did you actually read the article before linking it?
I think that setup is overly complicated, but to each his own. Simple is best for most reasonable applications.
Zip cord style wire works best. I did notice your preference for the more in-fad wire types. Star quad doesn't actually help anything but the dealer selling wire to be honest.
RF pickup is low using zip cord style wire. The conductors are very close, and a twist will greatly ease any problems that may exist. Just like 300 ohm twin lead with TV signals. Star quad is a gimmick.
-Chris
Zip cord style wire works best. I did notice your preference for the more in-fad wire types. Star quad doesn't actually help anything but the dealer selling wire to be honest.
RF pickup is low using zip cord style wire. The conductors are very close, and a twist will greatly ease any problems that may exist. Just like 300 ohm twin lead with TV signals. Star quad is a gimmick.
-Chris
Star quad cables will always have a much higher (up to 50%) capacitance per unit length compared to an equivalent zip cord. For speaker cables, that's the worst you can do, without any real benefit, since the magnetic immunity is simply not an issue.
Not true. The star-quad configuration was originally patented well over 100 years ago, so it's hardly a fad. The same amount of copper in a four conductor cable is roughly the same price as a two conductor cable. 🙂