Talk:Impulse response

message: (i) The mathematical discussion seems to be based on discrete-time signals. Why? The same discussion could be written using time-continuous functions, resulting in a more general description (in mathematical terms). Or, to put it another way: I get the impression that the article relates to digital signal processing. While the impulse response certainly is important in digital signal processing, it surely is not limited to this discrete-time application. I therefore suggest to rewrite the formulae for the more general case of time-continuous functions. What dou you think?
(ii) Why not use round brackets?
:The square brackets are presumably related to the first point you note: the apparent focus on discrete time.  It is a bit odd in that context that only the Dirac and never the Kronecker delta function is mentioned.  I personally think the huge string of equations is a bit hard to follow and the rest seems disorganized.  I'll try to make some edits to the structure of the article in the next few days. Aluvus 08:10, 26 May 2006 (UTC)
replies: text: I have no idea what the long string of equations is trying to show, in fact it seems the whole content is contained in the last few lines: T[x] = folding(x, L[delta]).  E.g. the part about \sum_k x[k] \delta[n-k] lying in the domain of T is redundant, as this sum is identical to the original x[n] by definition. 84.150.103.113 20:00, 4 February 2007 (UTC)

text: The article says this: "While this is impossible in any real system, it is a useful concept as an idealization."  For an analog system, yes, there is no such thing as an ideal impulse response.  However, isn't it possible to have an impulse response from a digital system with discrete samples?  (I'm not an expert so I could be wrong about this.) Steveha 04:02, 7 June 2006 (UTC)
replies: text: Yes, the impulse used is not a Dirac Delta in this case, for the simple reason that you can't go to infinitely short times when discretely sampling.  The signal corresponding to the Delta function is the 1 for the zeroth sample, and 0 otherwise. 84.150.103.113 20:00, 4 February 2007 (UTC)
replies: text: OTOH discrete sampling can be reasonably elegantly analysed in terms of a fixed spaced sequence of dirac delta's, so there is an impulse response when the impulse coincides with one of the sequence.WolfKeeper 20:13, 4 February 2007 (UTC)
thread_title: questions

message: This page needs to be split up into sections so its easier to read. Fresheneesz 05:09, 19 April 2006 (UTC)
thread_title: headers

message: This needs some pictures. —Ben FrantzDale 20:24, 16 May 2006 (UTC)
thread_title: Diagram

message: The voice of the article isn't quite encyclopedic. —Ben FrantzDale 04:09, 28 May 2006 (UTC)
thread_title: Cleanup

message: I think the section on loudspeakers a little bit to specific for a general article on the impulse response. It appears to claim that the impulse method is a 'silver bullet' which solved problems that other methods (like swept sine or white noise injection) cannot measure. I am not really an expert on acoustics, but for someone with a background in control theory I find this (implied) claim a little bit strange. The loudspeaker could be used as an example, but all the other claims should be removed, unless a proper citation is given.--193.205.74.131 (talk) 12:20, 30 September 2008 (UTC)
thread_title: Weird section on loudspeakers

message: The broadband/DSL example cited in the text is misleading. Adaptive equalisation *does* play a role in the DSL technologies in compensating for line conditions, and this does lead to a *partial* improvement in throughput. However, a far more significant factor is that in the pre-DSL era filters were installed on individual phone lines or at the exchange limiting the available bandwidth on a copper line to approx 3kHz (see Loading coil). This is sufficient for a POTS speech service, but the shannon limit for a line with 3kHz bandwidth is approximately 36kbit/sec (see Modem). It wasn't until these filters were removed that sufficient bandwidth was made available for DSL services allowing Mbit levels of service to become available.
I have kept the reference to line equalisation in, but I have reworded this comment so it is less misleading.  —Preceding unsigned comment added by Stephenellwood99 (talk • contribs) 23:08, 17 March 2009 (UTC)
thread_title: Misleading Example - Electronic Processing / Adaptive Equalisation

message: According to Dirac_delta_function, it is the Fourier transform which is 1. As far as the Laplace transform goes it is stated that
:"By analytic continuation of the Fourier transform, the Laplace transform of the delta function is found to be \int_{0}^{\infty}\delta (t-a)e^{-st} \, dt=e^{-sa}."
24.85.131.247 (talk) 09:21, 22 October 2012 (UTC)
thread_title:  Laplace transform of Dirac delta is 1?