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3ll3d00d

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Posts posted by 3ll3d00d

  1. X-curve compensation re-EQ

    in Bass Content

    Posted

    I wouldn't watch the whole film again, don't mind trying some specific scenes though.

    >> Did you implement the JRiver coefficients that you posted here (what I'm calling "v1")?  Or did you calculate new JRiver coefficients, based the updated "v2" config I posted afterwards?

    the v1 ones

    >> What playback level (approximately) did you use to evaluate?

    -7

    >> How are your speakers calibrated?  Do you use Acourate?  And if so, what kind of target curve do you use for the high frequencies?  Or did you use outdoor / anechoic polar response measurements?

    current target rises ~5dB from 125Hz down to 25Hz and is basically flat above that, the correction switches at about 900Hz to an anechoic only correction (based on measurements taken outdoor from 0-60 degrees). The speaker itself is maybe 1dB down from 1-16kHz on axis, graphs in http://www.avsforum.com/forum/155-diy-speakers-subs/2188265-attempting-3way-seos10.html#post54724444

     

  2. X-curve compensation re-EQ

    in Bass Content

    Posted

    I gave the correction a try on a few scenes, bit of a mixed bag tbh. Effects noticed included;

    Voices in some scenes were more natural  (less full/warm) though were also less obviously the focus of the scene.

    Some scenes took on a certain hollowness/metallic tang which was similar to a sound ISTR from one particular EQ which went wrong and was doing something excessive around 1kHz. 

    Some scenes, which involved more ambient noise, were less engaging as if the track had receded into the distance.

    I tried ~4-5 scenes (a couple from the island stage, a couple from the later ww1 bit) and a few had fairly inconsequential differences, the 2 that stood out more were the scene in the castle when he tries to chat to the chemist (ambient voices as he walks up to her were receded, their voices were less pronounced but more natural) and the scene when the young diana is asking her mum to let her train and her mum is going on about moulding her out of clay (metallic tang).

    I'm afraid I couldn't trial this over a prolonged slice of film because I thought the film itself was borderline terrible which was a surprise given the reviews. I thought it had a bizarrely disjointed storyline that felt like they mashed 3 different films together and was at least 30mins too long. The love story angle was pretty sad too given the main character & the seriousness with which they played the film given the storyline was rather odd. 

  5. X-curve compensation re-EQ

    in Bass Content

    Posted

     

    Wonder Woman (2017, BD / Atmos) - JRiver equivalent filters

    NB: I refer to it as S below to differentiate from the original post, jriver calls this Q though.

    measurement to verify shape -> https://imgur.com/a/05Ixe

    UHF / distance (relative to flat response; see note*): 

    High Shelf: f0 = 13900.0; S = 0.442082; gain = -3.501

    HF slope (see note **): 

    High Shelf: f0 = 3140; S = 0.9997; gain = -2.0
High Shelf: f0 = 7750; S = 0.552885; gain = -2.0
EQ Peak: f0 = 1950; Q = 1.75; gain = +0.33

    MF shelf: 

    Low Shelf: f0 = 1000; S = 0.720521; gain = -1.25

    LF shelf: 

    Low Shelf: f0 = 265; S = 0.785708; gain = -4.0

  11. The Bass EQ for Movies Thread

    in Bass Content

    Posted

    On 08/11/2017 at 9:15 PM, SME said:

    I am also thinking a bit about automation here.  I think the tricky thing about using something like MSO to find filters is that we want to only make coarse shape adjustments.  The finer peaks and dips in the peak and/or average graphs should be retained because they arise from specific effects that are meant to have characteristic sounds.

    That still may not be the most time consuming part though.  That might be the headroom check.  

    The reason I suggested using MSO is because you have complete control over the parameter range for each filter and also complete control over how many filters, and what type, it can use. Combine this with smoothing of the response if necessary and I would have thought you'd end up with a smooth filter shape.

    re headroom, is it the summed result that is the concern? 

    On 09/11/2017 at 4:13 AM, maxmercy said:

    Anywhere from 4-12 hours per film, with about 1/2 that time just waiting for processing to happen as I think about how to do the next trial solution. 

    that seems a long time to wait for processing, what are you using for that?

  13. The Bass EQ for Movies Thread

    in Bass Content

    Posted

    If the approach is based on a target curve which is based on other known good bass films then t seems like this should be amenable to automation, at least as a first cut anyway.

    For example, create a minimum phase representation of the actual response and a target curve, load into MSO and create a configuration that has a load of adjustable Q shelf filters & some PEQ available to it then give it some time to work out what combination of filters produces the target response. 

     

  14. The Bass EQ for Movies Thread

    in Bass Content

    Posted

    FWIW I used jriver convert format to generate the input wav file and then these are run through my app in a way that is equivalent to the approach used around here in speclab (which decimates it to 1000Hz and then runs it through the fft with a nuttall window of either 0.5Hz or 1Hz resolution, I forget which). I used a 0.5Hz resolution in my case, this is pretty much all done by scipy (for the fft bits) and librosa (for the resampling)

    I thought I'd double check so used eac3to to generate the wavs instead (though they both use the same underlying dts decoder anyway - https://github.com/foo86/dcadec), same result. 

    If you get a different result then it would be interesting to know how you're performing that extraction and conversion.

  19. The Low Frequency Content Thread (films, games, music, etc)

    in Bass Content

    Posted

    I tried another one and got similar results, hacked together a multichannel wav with a sine wave at a different frequency for each channel and ran that through jriver then analysed it, result is a mono wav with a missing channel 4, i.e. no LFE channel in the output. I'm quite sure this used to work so will report over at jriver forum to see what is going on.

     

    edit: see https://yabb.jriver.com/interact/index.php/topic,111023.0.html  appears to be some random defect in this particular installation of jriver :|

     

    edit2: turns it out it is a bug in jriver - https://yabb.jriver.com/interact/index.php/topic,111023.msg767472.html#msg767472

  21. The Low Frequency Content Thread (films, games, music, etc)

    in Bass Content

    Posted

    Any idea why your PvA looks so different from what JSS posted above?

     

    Yours appear to be higher resolution (longer window?) but looks smoother, so I don't think it's a resolution issue.  Indeed, the curve shape and levels both look quite a bit different.  Could the difference have to do with how the down-mixing is being done before analysis?

    dunno, I downmix using jriver as per http://www.avsforum.com/forum/113-subwoofers-bass-transducers/1333462-new-master-list-bass-movies-frequency-charts.html#post23468771

     

    I just doublechecked the settings, recreated the mono wav and ran it through speclab and my app. I get the same result each time.

  22. The Low Frequency Content Thread (films, games, music, etc)

    in Bass Content

    Posted

    1. Level - This is measured by digitally bass-managing the 5.1 or 7.1 signal.  The Level is a composite number, and is calculated by the average of the [1] highest peak in dB (maximum 126dB for 5.1, 128dB for 7.1), [2] the average/RMS dB level of the track (125ms integration time) and [3] the RMS peak level (loudest single 1/8th of a second of the film) in dB.  Full modulation of the waveform is considered to be 0dBFS.  The ratings are as follows:

     

    5 Stars - >112.5dB composite

    4 Stars - >110dB composite

    3 Stars - >107.5dB composite

    2 Stars - >105dB composite

    1 Star - <105dB composite

     

     

    @maxmercy how do you calculate [2]? I don't understand how the integration time relates to a single dB level for the entire track. The time window sounds like it relates to the length of each slice in the spectrogram but then how do you turn that into a single number?

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