Talk:Cutoff frequency

This article is rated C-class on Wikipedia's content assessment scale. It is of interest to the following WikiProjects:

Telecommunications Mid‑importance This article is within the scope of WikiProject Telecommunications, a collaborative effort to improve the coverage of Telecommunications on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.TelecommunicationsWikipedia:WikiProject TelecommunicationsTemplate:WikiProject TelecommunicationsTelecommunications Mid This article has been rated as Mid-importance on the project's importance scale. Professional sound production Mid‑importance This article is within the scope of WikiProject Professional sound production, a collaborative effort to improve the coverage of sound recording and reproduction on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.Professional sound productionWikipedia:WikiProject Professional sound productionTemplate:WikiProject Professional sound productionProfessional sound production Mid This article has been rated as Mid-importance on the project's importance scale. Electronics Mid‑importance This article is part of WikiProject Electronics, an attempt to provide a standard approach to writing articles about electronics on Wikipedia. If you would like to participate, you can choose to edit the article attached to this page, or visit the project page, where you can join the project and see a list of open tasks. Leave messages at the project talk pageElectronicsWikipedia:WikiProject ElectronicsTemplate:WikiProject Electronicselectronic Mid This article has been rated as Mid-importance on the project's importance scale.

Hi, sorry for any confusion - I originally proposed a deletion of the cutoff wavelength article because there isn't any point in having an article about cutoff frequency and cutoff wavelength. Then I read this article, and it is somewhat incomplete - it doesn't include anything specifically about waveguides such as the optical waveguides mentioned in the other article. I'll start adding to this article soon, and hopefully incorporate the info in the cutoff wavelength stub. Thanks --Bmk 05:41, 13 July 2006 (UTC)Reply

The lowest TM cutoff frequency for for a rectangular waveguide should be n=1,m=1 not (0,1). If either n or m is 0 then the electric field will equal 0, since Ez (x,y) = E0 sin (n*Pi*x/a) sin (m*Pi*y/b).

--Pozarnik (talk) 07:09, 19 November 2007 (UTC)Reply

I don't understand this article at all. It doesn’t seem very clearly explained in everyday terms, and relies on knowledge of other terms and concpets which I don’t think most people would understand.

I would suggest that a more dumbed-down explanation is used in the introduction, before getting more technical later on. I’d write a clearer explanation myself, but unfortunately I don’t have a clue what “cutoff” means. (Well, actually, I thought I did know what cutoff meant before I read this article, but this article doesn’t seem to support my definition of cutoff. Or maybe it does and I just can’t understand it?)

Grand Dizzy (talk) 18:46, 4 October 2008 (UTC)Reply

I agree the lead was a mess; see if my attempt to clarify helps. Bring more suggestions if this doesn't do it. Dicklyon (talk) 20:11, 4 October 2008 (UTC)Reply

Tagged for technical detail. Also would like to merge/supersede Half power point with this article. ChrstphrChvz (talk • contribs) 06:04, 13 November 2014 (UTC)Reply

This seems to be mentioning alot about electronics, but nothing about the use if cutoff, bandpass, highpass, or lowpass, as in synthesizers for music. I think this article needs to list more things that use said filters, instead of just the very broad "electronics". G man yo (talk) 09:19, 29 October 2008 (UTC)Reply

Good suggestion. Why not write a text that refers to articles such as high frequency limit, subtractive synthesis, voltage-controlled filter VCF (which i.m.o. should be extended to also cover Digitally Controlled Filters DCF), Parametric equalization, Wah-wah (music), Audio crossovers for loudspeakers, etc. Or put it in the low-pass filter and band-pass filter articles. Mange01 (talk) 00:18, 30 October 2008 (UTC)Reply

I could try, but I dont know what half of that stuff means, I just thought it might be a good idea :P. I could research in some of my spare time, though.G man yo (talk) 09:47, 3 November 2008 (UTC)Reply

In Single-pole transfer function example, where article reads: "...and i is the imaginary unit", don't you mean "...and j is the imaginary unit", since the equations are using j not i? 71.139.173.203 (talk) 06:37, 29 September 2013 (UTC)Reply

crossover frequency redirects here, this is very wrong and confusing82.168.65.130 (talk) 17:41, 29 October 2013 (UTC)Reply

Agreed, this article is not a very good target for crossover frequency. I have retargeted it to audio crossover. SpinningSpark 19:10, 30 October 2013 (UTC)Reply

Neither of the two diagrams at the top of the page clearly demonstrate cutoff frequency in general terms - both refer specifically to filters, and are not ambiguous enough to show the cutoff for an amplifier, for example, where cutoff is defined as the point where the graph intersects with unity gain. — Preceding unsigned comment added by 89.101.14.248 (talk) 02:19, 4 January 2015 (UTC)Reply

Do you have a diagram you would like to offer? I think the existing diagrams are fine as examples of cutoff frequency. A specific example often makes a concept easier to grasp. As for amplifier cutoff being defined as unity gain, the article does not even discuss this so having a diagram would be a bit odd. Besides, I don't believe that it is an engineeringly useful concept, it is more of a device used by manufaturer's spec sheet writers that enable them to quote a larger bandwidth than they otherwise could. SpinningSpark 10:07, 4 January 2015 (UTC)Reply

Example transfer function does not align with https://en.wikipedia.org/wiki/Low-pass_filter#Laplace_notation, e.g. the frequencies are reciprocals of each other, the DC gain is different. The one in the low-pass filter page seems correct. 158.184.198.4 (talk) 01:14, 22 January 2025 (UTC)Reply

There seems to be a formatting error at the end of the Electronics section where backend webcode is uncompiled. I don't know enough to fix this error, but I wanted to bring it to the attention of those who do. 2607:FEA8:1E40:E000:A1C7:C885:E7A7:C6A9 (talk) 01:31, 17 February 2025 (UTC)Reply

I do not see an error, but different servers are used for different places. This may be a math error as mentioned at VPT here. I just edited the whole article without changing anything, and clicked Publish. That might cause the page to be redrawn and make the error go away (or it might make it worse). Johnuniq (talk) 01:58, 17 February 2025 (UTC)Reply

On my screen, the last sentence of "Electronics" reads

For a [[Low-pass filter#:~:text=information: Electronic filter-,First-order passive,-[edit]|first-order]] network, the roll-off is −20 dB per decade (approximately −6 dB per octave.)

I checked on another device and it also sees this bugged text as above. 2607:FEA8:1E40:E000:A1C7:C885:E7A7:C6A9 (talk) 02:46, 17 February 2025 (UTC)Reply

Yes, I see that. It was added recently (diff). I was looking for the kind of error that I mentioned—they are much more prominent. I restored the original text to fix the problem. Johnuniq (talk) 05:02, 17 February 2025 (UTC)Reply

In the "Electronics" paragraph, the voltage ratio is given as sqrt(1/2), which is incorrect. The correct expression is 1/sqrt(2), which agrees with the stated value of approximately 0.707. I would perform an edit, buy frankly I don't know how. 😊 ~2026-44478-41 (talk) 01:01, 13 August 2026 (UTC)Reply

What difference do you perceive between sqrt(1/2) and 1/sqrt(2)? Dondervogel 2 (talk) 08:56, 13 August 2026 (UTC)Reply