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Re: [regsaudioforum] Re: Sigtech and the rest

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  • Ken Holder
    ... It s a brand name, not a brand name. In other words, that s what Mr. Sbragion calls it, it s not registered or trade-marked or anything like that. Ken
    Message 1 of 48 , Oct 6, 2011
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      At 09:36 AM 10/3/2011, Robert wrote:
      >
      >
      >This is surely not true! The initials DRC were in common
      >use long before Denis came on the scene!


      It's a "brand" name, not a brand name. In other words,
      that's what Mr. Sbragion calls it, it's not registered
      or trade-marked or anything like that.

      Ken Holder
    • Robert
      This is not exactly clearly expressed I think. The advantage comes at the measurement end. One can do an anechoic measurement of the speaker(above 300 Hz say)
      Message 48 of 48 , Oct 7, 2011
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        This is not exactly clearly expressed I think.
        The advantage comes at the measurement end.
        One can do an anechoic measurement of the
        speaker(above 300 Hz say) with extremely high
        frequency-domain resolution. If one tried
        to do this with in room measurements, one would
        have either a lot of room sound or such a short
        time window that the resolution of frequencies
        would be lower.

        Once one has decided what to do it really does not
        matter if you do it in one step on not. But what DOES matter
        is how you measured.

        The point is that by using learning and a complex kind of spatial averaging, the ear/brain learns to hear the speaker
        separately in a way that microphone measurements do not do.
        This is why a system where recording the acoustic event at the listening position sounds almost the same as the input event does not necessarily produce the correct result.

        In Tony's case, I think it gets close because he has a special room
        where he has minimized early reflections. In an RFZ room,
        the two ideas get much closer. But in more ordinary rooms,
        there is a significant difference.

        "Microphones are not ears" is a mantra of recording engineers,
        and it is often used to justify nonsense. But it also has
        its elements of truth. As Gunther Theile pointed out,
        it seldom happens that the speaker is not "heard out" at some level as a sound source. One can see this locationally: the ear/brain at some level knows where the speakers are. Otherwise the front to back position of the image would have nothing to do with how far away the speakers were. (The width of the image is allowed to depend on speaker position in theoretical stereo because the angles count. But the distance is not supposed to count!)

        This is also true on the tonal level. The ear/brain hears out things that are hard to see from measurement at the listening position.
        Try a narrow band not large peak introduced around 4k with
        pink noise. Switching it in and out one hears the difference easily(0.2 dB is plenty for this). A little whistle comes and goes.
        And once you have heard the whistle it is easily observed in an absolute sense. No in and out necessary.

        But if you look at an inroom response measurement, this can be really hard to see in absolute terms, that the peak is there, because room reflections will generate lots of ups and downs. But the room reflection ups and downs will not prevent you from hearing the peak! (Relatively, in a comparison you will be able to see it on measurements in room but not if you do not have the comparison, you
        would be hard put to know it was there.)

        This is how things work. I have tried this many times.
        S have lots of other people. This is why the Holm unit is the
        way it is--it is the best way to do it.

        REG



        --- In regsaudioforum@yahoogroups.com, "tonycdk" <tcdk@...> wrote:
        >
        > The key to this is that you can process a linearization of the speaker in a different way from the room correction. If one uses the same processing for both the speaker linearization and the room correction there is no advantage.
        >
        >
        > Tony
        >
        >
        > --- In regsaudioforum@yahoogroups.com, Uli Brueggemann <uli.brueggemann@> wrote:
        > >
        > > There is also a technical reason to think about a speaker correction
        > > independent of a room correction.
        > > So if you like to completely correct the behaviour of the passive crossovers
        > > you need to apply an excessphase correction. Therefore you need a certain
        > > window size (not just a single window of fix size but a certain size of
        > > frequency dependent windows).
        > > In case of a pure speaker measurement (without room influences) you can
        > > apply big windows and the overall behaviour is keeping stable.
        > > In case of a room measurement in many cases the window sizes are restricted,
        > > otherwise you get pre-ringing with the correction. So a pre-correction of
        > > the speaker itself helps to optimize the direct speaker sound. The
        > > excessphase room correction has only to correct room infuences as the
        > > speaker itself is already optimized.
        > >
        > > Uli
        > >
        > > On Thu, Oct 6, 2011 at 6:43 PM, Robert <regonaudio@> wrote:
        > >
        > > > **
        > > >
        > > >
        > > >
        > > > Why not)measure the room/speaker combination at listening distance only)
        > > >
        > > > Reason: This is not how the ear/brain hears things. Above around 300 Hz,
        > > > the ear/brain(according to one line of thought anyway)
        > > > forms an impression of what the speaker is actually doing.
        > > > (cf Gunther Theile, 1989). This is done by spatial averaging
        > > > of a kind that is not easily modeled.
        > > >
        > > > Also, the inroom measurement,unless it is spatially averaged in a
        > > > correct way(which is not easy to do), contains a lot of noise from room
        > > > reflectins--unless one uses a very short time window which
        > > > inevitably reduces resolution in the frequency domain.
        > > >
        > > > If you do anechoic speaker correction from 300 Hz on up and then in room
        > > > correction of 300 Hz down(with some sort of smnooth transition)
        > > > you get a much better representation of what the ear/brain actually
        > > > hears, or interprets what it is hearing.
        > > >
        > > > In practice, this may not maka a huge difference. But it is the right way
        > > > to do it. I think almost everyone who has studied the psychoacoustics of
        > > > this carefully agrees on this general outline.
        > > > Not to do this is to ask the correction system to incorporate a model
        > > > of how the ear/brain interprets upper frequency sounds--not an easy thing
        > > > to do, and one unlikely to be done correctly, and if one did do
        > > > it correctly, what one would end up with would be the same essentially
        > > > as the speaker separately and the room below.
        > > >
        > > > REG
        > > >
        > > > PS Because I tend to listen fairly close up in quite dry rooms,
        > > > it took me a while to understand the importance of this point,
        > > > theoretically clear though it has always been. It really is the right way to
        > > > do it, I believe.
        > > >
        > > >
        > > > --- In regsaudioforum@yahoogroups.com, Ken Holder <ken_holder@> wrote:
        > > > >
        > > > > At 01:09 PM 10/3/2011, laurie483000 wrote:
        > > > >
        > > > > >I can think of all sorts of further questions I could go on to ask,
        > > > > >including more about Foobar and for example something that was
        > > > > >discussed here before on equalising the speaker before going on to
        > > > > >doing the room - but you've been more than helpful already.
        > > > >
        > > > >
        > > > > Oh, yes, I also make a filter based on having the microphone
        > > > > about a meter (or a "yard", 3-feet) on-axis, etc. But it
        > > > > seems silly to run the measurement signal through that
        > > > > and then generate a "room" filter. I mean, just a one-
        > > > > shot should include both fixing the speaker and fixing
        > > > > the room interaction, right? If not, why not?
        > > > >
        > > > >
        > > > > >I note your comment about having all music in the one 196KHz format
        > > > > >- I seem to remember someone else telling me that it's necessary to
        > > > > >reboot the program, if not the computer when changing bit rates etc.
        > > > >
        > > > >
        > > > > That's something to do with the business of using a Linux
        > > > > machine running Brute FIR as a black box. The SoX resampler
        > > > > for Foobar is smart enough to notice if you are playing
        > > > > a file with a different sample rate and adjust accordingly.
        > > > > In fact, I find the problems people have with the Linux-black-
        > > > > box system rather confusing and strange since Foobar2000 on
        > > > > Windows doesn't have all those problems and seems like a much
        > > > > more straightforward way of doing things. (Actually, you can
        > > > > run Foobar under WINE on Linux if you want to -- don't know
        > > > > much about that except I did it once and it indeed runs.)
        > > > >
        > > > > Ken Holder
        > > > >
        > > >
        > > >
        > > >
        > >
        >
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