Sony Vegas limits the sound level of ac3 5.1 encoded file to -6 dB

[MicoMaco]

Hello there!

I use this method to produce surround ac3 files: First I create 6 mono wave channels out of original stereo With Adobe Audition 3 and import them into Sony Vegas 8 pro. Than I render those files with AC-3 ACM 4 Aud-X Codec. Now the problem.
If I import this newly created ac3 5.1 file back into Adobe Audition I notice the distinct -6dB barrier that is not crossed by any of the channels (center channel being the loudest = closest to that barrier).
Is there any way that the sound levels of the channels contained within 5.1 ac3 file would remain the same as the 6 source mono wave channels?
How do I achieve that?
Any idea why Sony Vegas creates 5.1 ac3 files being quieter for 6 dB than original 6 mono wave files imported into Sony Vegas?
:stupid: ... maybe not

Thx for your time and trouble!

[madshi]

Have you checked whether the AC3 files have dialnorm activated? If so, that may explain the volume difference. You can try disabling dialnorm ("dialog normalization") when creating the AC3 file. Not sure, though, if that's an available option. If not you can run the AC3 file through eac3to to remove the dialnorm feature.

[setarip_old]

@MicoMaco

Hi!First I create 6 mono wave channels out of original stereo With Adobe Audition 3 and import them into Sony Vegas 8 pro.Have you checked the volume levels of these 6 files BEFORE converting to .AC3?

[MicoMaco]

Have you checked whether the AC3 files have dialnorm activated?

I've never seen this function in Sony Vegas before. Also browsing through Sony Vegas Help didn't yield any results regarding this term.

[MicoMaco]

@MicoMaco

Hi!Have you checked the volume levels of these 6 files BEFORE converting to .AC3?

That's the funny thing. When I import these 6 mono wave files into Sony Vegas they have the same levels as they had in Adobe Audition. In my case the Center channel being the loudest one and peaking just below 0 dB barrier (the peaks of the Center channel are approximately around -1 dB level) and this wave image is the same in Sony Vegas and in Adobe Audition. Apparently something happens (or is somehow set, not that I know how or where) during the panning process and sets the dB barrier to -6 dB so none of the resulting channels within the new ac3 5.1 file exceeds -6 dB level even though the Center channel was just below 0 dB level originally. WTH is going on...:confused:

Would be nice if someone using the same method (stereo -> adobe audition -> 6 mono wave -> sony vegas -> 5.1 ac3) could enlighten me.

Thx

[madshi]

I've never seen this function in Sony Vegas before. Also browsing through Sony Vegas Help didn't yield any results regarding this term.
As I already said, in that case you can use eac3to to check if dialnorm is activated (do "eac3to your.ac3") - and if so eac3to can also remove it ("eac3to source.ac3 dest.ac3"). I don't know if dialnorm is the problem here, maybe yes, maybe no.

[setarip_old]

@MicoMacoI've never seen this function in Sony Vegas before. Also browsing through Sony Vegas Help didn't yield any results regarding this term.Although the following information indicates how to ADD normalization, you should be able to use it to determine whether your setup inadvertently includes "normalizing" - and, if so, you should be able to turn it off...

http://www.vasst.com/training/vegasfaq.htm

How do I normalize audio in Vegas?
Simply right click the audio event and check the "normalize" checkbox. Vegas will normalize the event. If you have several events to normalize, copy the first one after normalizing, then select all other audio, right click, and use "Paste Event Attributes" to normalize all other audio. There is also a script on the VASST scripting pages to accomplish this.

[G_M_C]

[...]
Would be nice if someone using the same method (stereo -> adobe audition -> 6 mono wave -> sony vegas -> 5.1 ac3) could enlighten me.

Thx

Isn't that a long detour to get AC3 ? AFAIK audition can make AC3's (through plugin) or doesn't Vegas accept ac3 as input ?

If Vegas DOES accept AC3 as input, you can allways try Aften to make you AC3's, Aften is very versatile and can be tweaked to suit most needs.

[FlimsyFeet]

Make sure that every WAV is inserted at the 0dB level, and panned hard into the relevant channel. (While I've never actually tried Vegas, I did once have a play with a trial of Sony Acid Pro, so this advice might be relevant.)

[MicoMaco]

As I already said, in that case you can use eac3to to check if dialnorm is activated (do "eac3to your.ac3") - and if so eac3to can also remove it ("eac3to source.ac3 dest.ac3"). I don't know if dialnorm is the problem here, maybe yes, maybe no.

I'd try your suggestion but in the meanwhile I enabled Sony's ac3 pro & studio encoder and this time it seems that encoded ac3 files preserve the dB level information from 6 source wave files. Maybe the codec I used till now (Aud-X AC3 freeware) couldn't do it. Thx anyway.

[MicoMaco]

@MicoMacoAlthough the following information indicates how to ADD normalization, you should be able to use it to determine whether your setup inadvertently includes "normalizing" - and, if so, you should be able to turn it off...

http://www.vasst.com/training/vegasfaq.htm



The problem here isn't the normalization process/function. In fact if I'd use the normalization that would severely distort my ac3 5.1 output cause I don't want front L&R channels to have the same loudness level as front center or surround channels. I wanna keep their relative ratios as they are cause I already created them in adobe audition to be as they are imported in sony vegas (hope this makes sense).

[tebasuna51]

...
Maybe the codec I used till now (Aud-X AC3 freeware) couldn't do it. Thx anyway.

Is well know than old free ac3 encoders (ac3enc.dll and equivalents) lose 6 dB from source volume.

Aften and ffmpeg are the only free ac3 encoders recommended.

[MicoMaco]

Isn't that a long detour to get AC3 ? AFAIK audition can make AC3's (through plugin) or doesn't Vegas accept ac3 as input ?

If Vegas DOES accept AC3 as input, you can allways try Aften to make you AC3's, Aften is very versatile and can be tweaked to suit most needs.

As far as I know audition can't create 5.1 ac3 files or I don't have the plugin... or money to get one:rolleyes:
Vegas does not accept ac3 files, it can't even see them even tho it has the ac3 plugin. On the other hand it can render mono files into single surround ac3 file.
Aften... yes... maybe After:) I try all the other ideas/options. Thx 4 the suggestion!

[MicoMaco]

Is well know than old free ac3 encoders (ac3enc.dll and equivalents) lose 6 dB from source volume.

Aften and ffmpeg are the only free ac3 encoders recommended.

Thx for enlightenment!

[MicoMaco]

Make sure that every WAV is inserted at the 0dB level, and panned hard into the relevant channel. (While I've never actually tried Vegas, I did once have a play with a trial of Sony Acid Pro, so this advice might be relevant.)

That was also my idea, to pann the "listening position" straight into the speaker so the dB level drops from -6 dB (default) value to 0 dB. But this resulted only in distorting the resulting waveform of specific channels within the resulting ac3 file : the waveforms become much more flat and unfortunately still limited with -6 dB barrier. Thx 4 the suggestion anyway.

[setarip_old]

@MicoMaco

Please re-read what I said:

...to determine whether your setup inadvertently includes "normalizing" - and, if so, you should be able to turn it off...

[MicoMaco]

@MicoMaco

Please re-read what I said:



Was turned off all and every time.