Retaining audio levels when encoding to 5.1 AC3/DTS

[Seraphic-]

Hi,

The audio levels from my raw six channel multi-channel WAV is just what I'm looking for.
However, encoding to 5.1 DTS lowers the audio levels a fair amount and encoding to 5.1 AC3 lowers the audio levels even more then DTS did.
How can you retain the correct audio levels from the raw WAV when encoding to AC3/DTS? :confused:

Raw 6 Channel Multi-Channel WAV (http://www.temp.seraphicgate.com/testwav.rar)
Test DTS 5.1 Encode (http://www.temp.seraphicgate.com/testdts.rar)
Test AC3 5.1 Encode (http://www.temp.seraphicgate.com/testac3.rar)

Thanks

[tebasuna51]

The audio levels from my raw six channel multi-channel WAV is just what I'm looking for.
However, encoding to 5.1 DTS lowers the audio levels a fair amount and encoding to 5.1 AC3 lowers the audio levels even more then DTS did.
How can you retain the correct audio levels from the raw WAV when encoding to AC3/DTS?

You need adjust your player system.

Your ac3/dts can't be more loud:
Statistics: dts ac3
-------------- -------------------- --------------------
RMS power ch0: 18.20% (-14.80 dB) 19.00% (-14.42 dB)
RMS power ch1: 20.66% (-13.70 dB) 21.53% (-13.34 dB)
RMS power ch2: 13.12% (-17.64 dB) 13.70% (-17.27 dB)
RMS power ch3: 4.89% (-26.21 dB) 6.20% (-24.15 dB)
RMS power ch4: 20.97% (-13.57 dB) 29.60% (-10.57 dB)
RMS power ch5: 21.58% (-13.32 dB) 30.51% (-10.31 dB)
-------------- -------------------- --------------------
Max value ch0: 100.00% (-0.00 dB) 100.00% ( 0.00 dB)
Max value ch1: 100.00% (-0.00 dB) 100.00% ( 0.00 dB)
Max value ch2: 99.97% (-0.00 dB) 100.00% ( 0.00 dB)
Max value ch3: 66.67% (-3.52 dB) 63.76% (-3.91 dB)
Max value ch4: 90.48% (-0.87 dB) 100.00% ( 0.00 dB)
Max value ch5: 88.03% (-1.11 dB) 100.00% ( 0.00 dB)

You can see the ac3: all channels reach 100%
There are many clip sounds (to much gain) but i think is already in wav source (not downloaded), your upmix process seems very agressive.

[Seraphic-]

You need adjust your player system.

Your ac3/dts can't be more loud:
Statistics: dts ac3
-------------- -------------------- --------------------
RMS power ch0: 18.20% (-14.80 dB) 19.00% (-14.42 dB)
RMS power ch1: 20.66% (-13.70 dB) 21.53% (-13.34 dB)
RMS power ch2: 13.12% (-17.64 dB) 13.70% (-17.27 dB)
RMS power ch3: 4.89% (-26.21 dB) 6.20% (-24.15 dB)
RMS power ch4: 20.97% (-13.57 dB) 29.60% (-10.57 dB)
RMS power ch5: 21.58% (-13.32 dB) 30.51% (-10.31 dB)
-------------- -------------------- --------------------
Max value ch0: 100.00% (-0.00 dB) 100.00% ( 0.00 dB)
Max value ch1: 100.00% (-0.00 dB) 100.00% ( 0.00 dB)
Max value ch2: 99.97% (-0.00 dB) 100.00% ( 0.00 dB)
Max value ch3: 66.67% (-3.52 dB) 63.76% (-3.91 dB)
Max value ch4: 90.48% (-0.87 dB) 100.00% ( 0.00 dB)
Max value ch5: 88.03% (-1.11 dB) 100.00% ( 0.00 dB)

You can see the ac3: all channels reach 100%
There are many clip sounds (to much gain) but i think is already in wav source (not downloaded), your upmix process seems very agressive.

Thanks for the reply. Yeah, it might just be my playback setup. However, what I was trying to get across was that the DTS/AC3 sounded much lower/less in volume then the original WAV track.

Interesting readout, what did you use to get those statistics? Also, when you say they reach 100%, do you mean the levels are peaking out at max?

This stereo to 5.1 upmix was done with hardware using my soundcard. I'm still trying to fine tune the volume levels, but overall, it comes out well. Sounds better then what I tried with software upmix.

If I enable just "Front L/F, Back L/F, Front C/Sub", all the channels are duplicated. Meaning, front left, center, and left surround and front right, LEF, and right surround are exactly the same. Only if I enable "Back C/Top and Side L/R" as well is each stream different. But thinking to myself, isn't that then more then 5.1 channels? It still record records 5.1 when using them all, but that is ten channels when only six should be used.

[tebasuna51]

Interesting readout, what did you use to get those statistics?
Wavosaur (free and simple wav editor)
Also, when you say they reach 100%, do you mean the levels are peaking out at max?
Yep, I see many cuts in wave form. You need decrease the volume when you record.

[Seraphic-]

Yep, I see many cuts in wave form. You need decrease the volume when you record.

Yeah, I've seen them as well. But lowering the recording volume much more and the overall volume of the recording will be too low.

[Southstorm]

Would the Dialog Normalization have anything to do with the lower volume output?

Cause I used to have a similar problem, but since then have scanned my audio track to find average RMS, and inputed that figure for Dialog Norm and been quite happy with the results.

[tebasuna51]

The DTS is encoded without DialNorn, but the ac3 is encoded with DialNorm = -27 dB.

If the decoder is not instructed to ignore DialNorm this can cause -4 dB

BTW i can't understand for what is encoded with -27 dB. Always use DialNorm= -31 dB for this kind of audio.

[Mtz]

On my standalone (DivX) Players always the MP3 is louder than DTS, which is louder than AC3.

enjoy,
Mtz

[tebasuna51]

On my standalone (DivX) Players always the MP3 is louder than DTS, which is louder than AC3.

Try with the samples from Seraphic. If still is low sound maybe you need reconfigure your players.:)

[EuropeanMan]

A relevant question here regarding encoding levels. When encoding DTS from .wavs, if we feel the DTS audio levels are a bit too low, what would be the correct way to 'boost' (i guess?) the volume? Sorry, this is the first time I'm doing this...would like to get ideal parametres...thanks. Also, I'm still a n00b as far as touching audio from movies. In the future, would want to rip the AC3 from a movie, clean up the .wavs and encode them back to the AC3 to mux back...as for DTS, just wanted to try it for kicks to see what I would get. Thanks in advance for all help.

[tebasuna51]

A relevant question here regarding encoding levels. When encoding DTS from .wavs, if we feel the DTS audio levels are a bit too low, what would be the correct way to 'boost' (i guess?) the volume?
You don't need boost nothing, the volume is the same than the input wavs. If you listen more low then you must adjust your player.

[unskinnyboy]

A relevant question here regarding encoding levels. When encoding DTS from .wavs, if we feel the DTS audio levels are a bit too low, what would be the correct way to 'boost' (i guess?) the volume?Outside of what tebasuna51 said, you could however apply a boost when creating the WAVs, using the -boost() parameter of BeSweet (if that's how you are creating the WAVs).

Also, I'm still a n00b as far as touching audio from movies. In the future, would want to rip the AC3 from a movie, clean up the .wavs and encode them back to the AC3 to mux back...Touching the audio? What is that you are trying to fix in your AC3 track?

[Seraphic-]

So if I lower the audio levels so there are no cuts in the wave during recording, the volume of the overall wave will be much too lower. What is a recommended way to boost the volume if it's too low? However, won't boosting the volume produce cuts in the wave?

[tebasuna51]

So if I lower the audio levels so there are no cuts in the wave during recording, the volume of the overall wave will be much too lower. What is a recommended way to boost the volume if it's too low? However, won't boosting the volume produce cuts in the wave?

The boost procedures are enemy of quality and good Dynamic Range. Only for poor audio equipment/headphones is recommended apply Dynamic Range Compress and/or boost methods.

If you want more volume turn up the volume button of your amplifier.

[EuropeanMan]

Outside of what tebasuna51 said, you could however apply a boost when creating the WAVs, using the -boost() parameter of BeSweet (if that's how you are creating the WAVs).

Touching the audio? What is that you are trying to fix in your AC3 track?

the problem with many Hindi movies, is that they incorrectly master a 5.1 AC3 track...if I could learn how to separate the audio and try my level best at making it actually SOUND like 5.1 sound, then i'd love to do that...as it is, most of these AC3 5.1 tracks really are horrible...and if those same DVD9s come with 2-CH ac3 tracks, they sound infinitely better...i'm just trying to learn how to encode the audio side as well for personal knowledge and satisfaction i guess...

[unskinnyboy]

the problem with many Hindi movies, is that they incorrectly master a 5.1 AC3 track...if I could learn how to separate the audio and try my level best at making it actually SOUND like 5.1 sound, then i'd love to do that...as it is, most of these AC3 5.1 tracks really are horrible...and if those same DVD9s come with 2-CH ac3 tracks, they sound infinitely better...i'm just trying to learn how to encode the audio side as well for personal knowledge and satisfaction i guess...Technically, what do you mean when you say they are incorrectly mastered? Incorrect channel mapping? Or something else?

[Seraphic-]

Could the reason why my AC3/DTS audio files sound and playback with a much lower volume then the raw wave be because of AC3Filter?

[tebasuna51]

Could the reason why my AC3/DTS audio files sound and playback with a much lower volume then the raw wave be because of AC3Filter?

If you use Ac3Filter to play ac3/dts and sound much lower than wav source files, of course you have AC3Filter bad configured.