maxmercy

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

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I can't speak for anybody else but I rip the movies to my computer and then use SpecLab to directly read the digital audio file.  I had a lot of issues when I tried to run things through my sound card as well so I quit doing it.

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 SpecLab to directly read the digital audio file.

 

Hi, is it possible for you to tell me how you were able to configured SpecLab to do this?

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in the 'file' menu there's an entry for 'audio file and stream analysis'.  In that menu select 'analyze audio file (without DSP)'.  That'll take you to a menu where you can select the audio file and set the FFT lengths.

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I can't seem to add the are file, what program to you use to convert it into a wav file. Sorry I should of asked this from the beginning.

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in the 'file' menu there's an entry for 'audio file and stream analysis'. In that menu select 'analyze audio file (without DSP)'. That'll take you to a menu where you can select the audio file and set the FFT lengths.

I can't seem to add the dts file, what program do you use to convert it into a wav file? Sorry I should of asked this from the beginning.

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I can't seem to add the dts file, what program do you use to convert it into a wav file? Sorry I should of asked this from the beginning.

 

I use eac3to.  It'll convert Dolby and DTS files to multiple WAV files (one for each channel).  Then those files are mixed down to a mono WAV in Audacity.

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mixed down to a mono WAV in Audacity.

 

That's interesting, i would of thought that down mixing especially to mono would pretty much ruin the audio file and not give an accurate result. why would it not do that?

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That's interesting, i would of thought that down mixing especially to mono would pretty much ruin the audio file and not give an accurate result. why would it not do that?

A receiver does pretty much the same thing, redirects all (5 or 7 channels) the low frequencies to the lfe (mono).

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That's interesting, i would of thought that down mixing especially to mono would pretty much ruin the audio file and not give an accurate result. why would it not do that?

 

Mixing WAV's together doesn't do anything to the quality of the audio (unless you change bit rates or sampling frequencies).  We have to do that mixing in order to create the PvA graphs and level numbers when we graph movies.  You can run individual channels through SpecLab if you want to see what's going on in them but in order to capture the overall bass in a track you need to mix them down to a single file.

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Mixing WAV's together doesn't do anything to the quality of the audio (unless you change bit rates or sampling frequencies). We have to do that mixing in order to create the PvA graphs and level numbers when we graph movies. You can run individual channels through SpecLab if you want to see what's going on in them but in order to capture the overall bass in a track you need to mix them down to a single file.

Ok perfect explanation . I've made graphs with wav files that contained multiple channels would that make the results any diffrent or less accurate?

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To the best of my knowledge SpecLab can't process multichannel WAVs, it can only do mono.  That's why we do the mixdowns

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To the best of my knowledge SpecLab can't process multichannel WAVs, it can only do mono.  That's why we do the mixdowns

That's interesting I wonder why it tells me it's multi channel and the amount of channel when I import wav file. I'll have to test both mono and multi to see if it comes up different and check the manual. also i wonder if it auto down mix it mono, this it how it looks for me when i import. edit, OK i am testing now, the file size is extremely small compared to the 6-7GB wav i was getting on the longer multi channel films, now lets see if the results are the same.

 

specc.png

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the first one is done by adding the multi channel wav to Speclab

 

the second one was done by extracting all channels then adding them to Audacity and exporting as mono wav in the same 24bit as the original movie files.

 

 

leon_single_wave.png

 

 

leon_single_wave.png

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the second one was done by extracting all channels then adding them to Audacity and exporting as mono wav in the same 24bit as the original movie files.

 

You have to respect the differing digital signal levels in the lfe channel vs the other channels. Just summing them doesn't deal with this.

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You have to respect the differing digital signal levels in the lfe channel vs the other channels. Just summing them doesn't deal with this.

 

How is this done? is there a guide that was written?

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Unfortunately i don't have any fo those programs. Mrkazador method pretty much does the same am i right?

 

  • Load all the wavs into Audacity. Lower the gain by -20.2db for all channels EXCEPT LFE. After that is done, lower the LFE channel by -10.2db.

 

  • Select all tracks and go to Tracks-> Mix and Render. This will merge all the individual wavs to a mono file.

 

  • You want to add about 1min of silence to the beginning and end of the track by selecting Generate-> Silence. SpecLab for some reason doesn't render the end of the file so add a bit of silence to fix that problem.

 

  • Export your mono wav as a wav.

 

http://www.avsforum.com/forum/113-subwoofers-bass-transducers/1333462-new-master-list-bass-movies-frequency-charts-366.html#post23817564

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looks like the same yes

 

Perfect! Thanks allot for helping me :) I'll be doing over all my graphs so if you are interested I'll be MrGrey in the bass forum on AVS   :).

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In the Heart of the Sea screen caps:


 

MobyDick4.jpg

 

MobyDickAtSeaWhale1.jpg

 

MobyDickAtSeaWhale2.jpg

 

Very bass heavy:

MobyDickLandSighting.jpg

 

Very very bass heavy:

MobyDickSecondWhaleHit2.jpg

 

Small boats storm scene. Lots of proper bass:

MobyDickStormSceneSmallShips.jpg

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As a note of interest, mixing all the channels down to mono does potentially discard content, even though bass management does exactly the same.  If the bass is out of phase between one or more channels, then there will be some cancellation on the mix-down or after bass management.  OTOH, if you are running full-range mains (or a low XO like 40 Hz), that bass will still get played by the speakers.  The direct sound arrival for that bass may cancel at the listening position, but it will be returned to the listening position in later reflections.  This is an interesting dilemma because it means that amount of bass reproduced from a track depends to some extent on the mains XOs used.  The "reference" for bass managed systems is somewhat ambiguously defined.

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The direct sound arrival for that bass may cancel at the listening position, but it will be returned to the listening position in later reflections.

What do you mean by that exactly? The difference between the transient leading edge of a signal vs steady state or something else?

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