Titanic (1997): Cinema DTS sound mix-Prepping for the Print…One Hopes.

[alexp120]

As a special project for myself, I wanted take the Cinema DTS sound mix and sync it to the Blu Ray release. Through the good graces of Jetrell Fo, I’ve obtained the film’s Cinema DTS CD-ROMs from his collection.  I was able to extract the discs and gain access to each of the reel’s audio files---each reel contains 6 mono wave files representing the film’s surround soundtrack (Front Left Channel, Front Right Channel, Center Channel, Lower Frequency Effects Channel, Surround Left Channel, and Surround Right Channel).  

I’ve selected a reel to work-on—one that has a well-rounded mix of normal speaking dialogue and aggressive sound effects, but not involving the film’s climatic sequences.  It's the one where the ship hits the iceberg.  The software I’ve used were the free Audacity and a high-end one, not free, I’ve been using for over a decade, Steinberg’s WaveLab 4.0.

After making my syncs of the 6 mono waves to the clip from the Blu Ray and lowering the sound level of the surround channel by 3 decibels, the real work was in the center channel.  In it, there were passages where the sound level was very soft, like the dialogue; and others where the sound level was very high, like the sound effects.  As is, the viewer would have to turn the volume up and down every 5 seconds, especially when the film’s climatic part comes in.  By applying a limiter and raising the gain, I was able to get the center channel to an acceptable level…

…however, that is my perception.  This is where you all come in.  I need another pair of hears to check-out my work before I work on the remaining 9 reels.

So, here it: a sample of one reel—an MKV video that contains a rip from the Blu Ray with 2 audio options that feature the following mixes:

1. A 16bit/48k, 5.1 channel LPCM of the Cinema DTS sound mix
   
2. A 24bit/48k, 5.1 channel DTS-HDMA of the Blu Ray release, for comparison
   

https://mega.nz/#!7sFmRKzR!1qdybyFeaqpO2...h5R8TsGLvE

Thank you, all, for your time and help.

[Jetrell Fo]

I thought it sounded pretty darn good. I hope others can give better technical advice than I can.

[jerryshadoe]

For this to be a truly honest comparison, can you please include the unaltered Cinema DTS track, as well?

Because the Cinema DTS audio tracks that I have listened to so far (and there has been a decent amount of them) usually sound fantastic just the way they are. The fact that the altered DTS sounds better than the BD can easily be argued in the sample you provided, BUT does it sound better that the original, unaltered Cinema DTS track??

NOT trying to be a d**k, just trying to give a fair assessment

[Stamper]

Awesome! Not sure you should alter the center channel on your own.

If the dialogue is too low, you only need to adjust the center channel I think to reference level. In the DTS-HD master suite, you have an option to do that. You either need to calculate the center channel volume using an app like audio leak, and then add the correction in db, or just let the suite do it.

[alexp120]

Thanks for your responses. I will try and address your concerns as best as I can.

Even if I didn’t do any sound level changes, each of the mono channels had to be altered from the original audio files anyway. The original unprocessed DTS sound files at the sampling rate of 41K, 16bit from the CD-ROM discs were formatted to be played to a media—motion picture film--that is 24 frames per second. I am formatting these files to be played to a media—Blu Ray--that is 23.97 fps, so that it can be played with a set of full-range speakers. It is recommended that the audio should be formatted to Blu Ray specifications of, at least, 16bit/48K. If I were to mux the unprocessed audio to the Blu Ray video, they would be out of sync to each other—the audio would be ahead of the video by the end of the video program. And I would image that the print, if it ever gets worked on, would be formatted to that Blu Ray spec of 23.97fps.

In working with the audio files, not only did I had to change the sampling rate from 41K to 48K, but I had to decrease the duration of the audio, but keeping the pitch the same, to fit the length of the video in getting a good sync. So what I am doing is not going to sound exactly like the original because of the media that I’m comforting to. The question one should ask themselves is this, "Does what this guy has done with the files sound good to me?"

Nonetheless...

For this to be a truly honest comparison, can you please include the unaltered Cinema DTS track, as well?

Here is the link to the unaltered 41K, 16bit audio of that reel for sound quality comparison.

https://mega.nz/#!GsEi1DIA!fQIfp1553W9t5...yDg1HQ94Ko

Please be advised that there is 2 seconds of extra audio on the head and tail ends of the audio file in each of the mono channels. However, even if you removed those 4 seconds from the audio file, it will still not fit the Blu Ray clip because of what I've mentioned earlier.

[alexp120]

Awesome! Not sure you should alter the center channel on your own.

If the dialogue is too low, you only need to adjust the center channel I think to reference level. In the DTS-HD master suite, you have an option to do that. You either need to calculate the center channel volume using an app like audio leak, and then add the correction in db, or just let the suite do it.

Unfortunately, I do not own DTS Master Suite (I hear that thing is priced pretty high).  

However, I do have a set of the sync'd center and surround channels where the sound levels are unaltered, so, if I have an opportunity, I'll always have those files handy without redoing the sync'ing.  

[alexp120]

Here is another sample waiting for your input:

https://mega.nz/#!Os1XUC5S!EnRfKWYAUxgws...OV-SonifN4

This is reel 2. It's the one where the ship casts-off and gets its legs "stretched", and Leo does his "king-of-the-world" bit.

[spoRv]

I think here we are all aware that the Cinema DTS audio is 44.1KHz (and NOT 41KHz) 24fps, and should be first converted to wav, then upsampled to 48KHz (with eventual related pitch/tempo fix, and 23.976fps conversion, the latter accordingly to the video source frame rate) to be BD/DVD compliant; +3db "hot" surround tracks happened only in the first two or three years of the format (IIRC) so not all titles should be fixed for that; at the end, the usual sync to video track; these tasks could be accomplished, in several ways, by many of us; you are welcome to do that for a given project, because it will save a lot of time and work for the project maker!

So, if your purpose is to have an home version of the DTS cinema audio track, that can be muxed along a BD (HD-DVD, D-theater, HDTV, DVD etc) video track, to be watched in an hardware player, you should not touch anything else; if you start touching the center (or other) channel without a reference is a bit like making a new sound mix... this isn't wrong per se, but you should be clear you are altering the track (apart the previous needed changes, of course); at the end, it will be your own version of the mix.

Still an entertaining exercise, though! For example, I added the Cinema DTS .1 subwoofer track to the HD-DVD foreign tracks of Waterworld, because they lacked it; a creative use, IMHO.

Last thing: if someone would just sinc it with a video track and watch it in a computer, there is no need to convert to 48KHz and/or 23.976fps, as software players (and some hardware ones, too) have no problems to play correctly a 44.1KHz audio track; also, remux a 23.976fps video track to 24fps is lossless, at the contrary of audio conversion.

[alexp120]

I was not aware that DTS started attenuating decibels in the surround channels for later titles.

As I mentioned in a previous post, I have a set of sync’d center and surround channel wave files in 16bit/48K where the sound levels are unaltered, so, when the time comes I can easily swap those out.

Last thing: if someone would just sinc it with a video track and watch it in a computer, there is no need to convert to 48KHz and/or 23.976fps, as software players (and some hardware ones, too) have no problems to play correctly a 44.1KHz audio track; also, remux a 23.976fps video track to 24fps is lossless, at the contrary of audio conversion.

I was taken into consideration that there may be people that want to burn the movie with the CinemaDTS audio to a disc, hence, my audio files being formatted for BD complianance.

Based on your advise, I guess I'll continue prepping the audio by sync'ing and leaving its sound levels alone.

[Jetrell Fo]

alex, there is a whitepaper on cinema DTS and it's properties. I probably have it somewhere but you can also use google to dig it up. It would probably be informational to you. Also, hairy_hen over at OT has done some great work explaining audio stuff like this.

Maybe Doombot will chime in here as he has done some great work with the cinema DTS audio I've shared for syncing.