Talk:Nominal impedance

message: Loudspeakers
Matching of loudspeaker impedance to the output of an amplifier is far more critical than matching of signal level impedance.
In the days of valves, most loudspeakers had a nominal impedance of 16 Ω. Valve outputs require an output transformer to match the very high output impedance and voltage of the output valves to this lower impedance. These transformers were commonly tapped to allow matching of the output to a multiple loudspeaker setup. For example, two 16 Ω loudspeakers in parallel will give an impedance of 8 Ω. It is possible to use several taps at once but the calculations can get quite involved, so as to balance the power between the loudspeakers, match the impedance of the output, and avoid overloading any part of the output transformer secondary winding.
Since the advent of solid-state transformerless outputs, these multiple-impedance outputs have become rare, and lower impedance loudspeakers more common. The most common impedance for a single loudspeaker is now 8 Ω. Most solid-state amplifiers are designed to work with loudspeaker combinations of anything from 4 Ω to 8 Ω, and many will go down to 2 Ω or up to 16 Ω.
Now moved back to article page to see if it fits--Light current 21:41, 7 November 2005 (UTC)
replies: text: Do we talk about nominal impedances in guitars and guitar amplification? Im not sure. I dont! It just high or low isnt it? and you get what you get out of the amp. You cant change impedances without using a preamp between guitar and main amp.(unless yuo use a transformer which will lower the o/p)--Light current 21:56, 7 November 2005 (UTC)
thread_title:  Temporary home for stuff to be moved 

message: Any electronic source device (electric guitar, microphone, amplifier output, battery, generator, turbine, etc.) can be simplified to two imaginary electronics components.  This simplified model is only valid under certain conditions, but it is valid nonetheless.  These two components are a source (Vsource) and a source impedance (Zsource).  These are usually connected to a load (loudspeaker, amplifier input, motor, space heater, etc.) which can be simplified to only one component, the load impedance (Zload).  This diagram shows the three components:
These three components form a voltage divider, one of the basic electric circuit configurations.  The voltage across the load will be proportional to the ratio of the two impedances.
For instance, an electric guitar can be modeled as a voltage source (Vsource) in series with a general impedance (Zsource).  The impedance will probably be mostly resistive and inductive, because the pickups of the guitar are a coil, which is an inductor. All of these properties are lumped together into one value.  The value of this impedance and of the voltage source depend on the properties of the coil, tone circuitry, the position of the knobs, etc.
:Do we talk about nominal impedances in guitars and guitar amplification? Im not sure. I dont! It just high or low isnt it? and you get what you get out of the amp. You cant change impedances without using a preamp between guitar and main amp.(unless yuo use a transformer which will lower the o/p)--Light current 21:56, 7 November 2005 (UTC)
thread_title:  Source Impedances 

message: "Most equipment is designed to operate with the internal impedance of a signal source roughly equal to the impedance of the input to which it is connected. This provides the most efficient coupling, and is best in most but not all situations"
:Um.  most audio equipment uses impedance bridging, where maximum voltage transfer is the ideal, not power transfer, not impedance matching.  some old equipment needs to be impedance matched, because it was designed for transformers and tubes.
"Matching of loudspeaker impedance to the output of an amplifier is far more critical than matching of signal level impedance."
:Um.  loudspeakers should also be bridged, not matched.  see damping factor.  maybe this paragraph doesn't mean they should be matched, but it sounds like it does.  this article is confusing. - Omegatron
Generally speaking, interfaces for low frequency analog circuits should have a low source impedance and a relatively high load impedance. As stated above, maximum voltage transfer is the ideal. Source, load, and transmission-line impedance matching becomes important in RF interfaces that are subject to reflections when unmatched impedances come into play. 76.211.225.16 01:54, 14 August 2007 (UTC)
thread_title: i think this is wrong

message: which definition of the word nominal does this article mean? - Omegatron 21:21, May 23, 2005 (UTC)
nom·i·nal (nŏm'ə-nəl) pronunciation
adj.
:1.
::1. Of, resembling, relating to, or consisting of a name or names.
::2. Assigned to or bearing a person's name: nominal shares.
:2. Existing in name only.
:3. Philosophy. Of or relating to nominalism.
:4. Insignificantly small; trifling: a nominal sum.
:5. Business.
::1. Of, relating to, or being the amount or face value of a sum of money or a stock certificate, for example, and not the purchasing power or market value.
::2. Of, relating to, or being the rate of interest or return without adjustment for compounding or inflation.
:6. Grammar. Of or relating to a noun or word group that functions as a noun.
:7. Aerospace & Engineering. According to plan or design: a nominal flight check.
:::Yes, we definitely need to know what nominal means before we attempt to fix this article. I personally have only heard the term used with Loud Speakers (15ohms nominal etc) or maybe some device where the exact impedance does not matter. So what do we maen by 'nominal'??--Light current 22:05, 26 September 2005 (UTC)
replies: text: I suggest cleanig this article by making it a disambiguation page. Each link would then point to the relevant page and thersfore indicate the usage of the term nominal in that specific application.--Light current 15:35, 7 November 2005 (UTC)
replies: text: No, Ive changed my mind. Ive cleaned up much of it and tried to keep as much in as I can whilst still making the content have some meaning with regard to the term Nominal impedance. See what others think!--Light current 22:01, 7 November 2005 (UTC)
thread_title:  "nominal" 

message: I have more or less completely rewritten this article (I kept a couple of existing paragraphs concerning speakers and valve amps).  It is now cleared of all the myths and misconceptions (I hope) and is extensively referenced.  On that basis I am removing the maintenance templates as I think they no longer apply.  Please speak up if you think there is something dubious still in the article. SpinningSpark 19:04, 10 October 2009 (UTC)
thread_title:  Rewrite 

message: Maslin's book was recently removed as a source on the grounds it had nothing ot say on nominal impedance.  I dispute that and have restored it.  The 1987 edition isn't previewable on gbooks but the 2017 edition on page 78 is previewable and includes "This is normally specified in terms of a nominal impedance (assumed to be resistive)..." SpinningSpark 01:15, 5 August 2020 (UTC)
thread_title:  Maslin source