PC Based SQ DECODING - ALMOST DONE!

[JonUrban]

Once I get this down, I can make a web page here at QQ with all of the steps and screen shots!

 

[imploder]

Once I get this down, I can make a web page here at QQ with all of the steps and screen shots!

OK. Sounds good!
I discovered a new topic regarding my scanned "princip":

Before mixing the org. SQ file with the "helper file" both must be decreased to 70% of their volume (with the normalizing function), then the rear channels will have the accurate volume!
For the later removing of the rear parts, the 100% summary file must be used, of course.

 

[QUADradial]

I just reduced the level of each track by -3db in the mixdown...

 

[ArmyOfQuad]

Right. So, where is this phase change thingie in adobe audition?

 

[Bob Romano]

My question is... what will this do to a normal recording that is not SQ encoded?

Will it be similar to running it through DPLII?

 

[QUADradial]

No, this is a very specific process. DPLII is really an odd bird. I have just purchased the Minnetonka DPLII encoder and I'm running a few quad reels thru it to encode them into DPLII...because NOBODY has released any decent test material!!! There is a lot of voodoo that you have to perform to get the mix to sound right, both in stereo and in surround.

Tab

 

[imploder]

Do not compare the above decoding process with running a plain stereo source trough an analog SQ (or whatever) decoder!
The decoder will not work in logic mode then and only phase shift and mix the signals, that may produce a quite interesting result, but not more.

Our method here is especially focused on the SQ matrix process and only reverses what is done while encoding. We try to get out the original discrete four channels as far as possible.

I would use some kind of Vario-Matrix or Vari-Martix (I use that one) system for producing Pseudo-Quad while playback, because there is the possibility to adjust the matrix while listening and not while decoding. For the SQ decoding process a fixed system can be used, for blowing up stereo to Pseudo-Quad a variable system must be used.

Last thought: Was SQ intended to be separated completely while playback as we do now? Or was the crosstalk calculated? Hmmm...perhaps nobody at CBS thought of that...

 

[imploder]

Right. So, where is this phase change thingie in adobe audition?

It is called "Graphical Phase Shifter" and can be found in the "Filters" section at the plugins.

 

[imploder]

I just reduced the level of each track by -3db in the mixdown...

Cause my source was normalized, the mix was distorted (more than 0db peaks). That's why I did the 70% thing.

Crazy thing: Even if I think the filters are set too high, in summary it always sounds correct!

 

[winopener]

Cause my source was normalized, the mix was distorted (more than 0db peaks). That's why I did the 70% thing.

Crazy thing: Even if I think the filters are set too high, in summary it always sounds correct!

Personally i suggest a 32-bit conversion and after that a -6dB normalize; during the sum-difference process with only -3dB i went offscale frequently, even if the final result was perfectly into the -3dB range.

 

[QUADradial]

Well, we will have to name this process something. I'm all for naming it the Bergbauer decoding method...after the guy that figured it all out!

 

[kempfand]

Does anybody know a simular plugin of annother program to remove signals at a specified phase? It may even work better!

There is the mgPhaseShifter VST, but if I understand things correctly, it doesn't do what is needed here. I.e. With the mgaudio one, the phase of the entire signal is shifted, but each frequency is shifted with a different amount.

If you shift your signal by 10ms, for example, you will have a 90° phase shift at a certain low frequency, but this will be a bigger shift for higher frequencies, like 720°, for example.

A really decent phase shifter is Voxengo's PHA-979 VST, where the phase of all the frequencies is shifted of the same amount, like 90 degrees for example.

I just wonder how Audition does it ...

Andreas

 

[ress4278]

Now, for those of us with little or no technical background, does this mean that it is possible to SQ/QS encode stereo discs for future DTS or DVD release?

If not, please help me understand how this translates into more quad recordings available for trade and listening?
Thanks

 

[QUADradial]

It will decode SQ for conversion to dts or DVD...

 

[CWBudde]

Hello,

i've received an offer to create a dedicated vst plugin for SQ En/Decoding. Currently i have done a really simple pack, which does the matrix multiplication, which was mentioned by Andreas (i gues it was a scan or something like that).
You might want to grap the pack here. But at least, it doesn't contain any logic. That's the next upcoming step.
Unfortunatly the center channel extractor of audition is somehow complex and not so easy to program, but i already got some ideas about that.
If you have any suggestions, feel free to contact me.

Regards,

Christian

P.S.:Since the development is a custom development i'm not sure about a possible resale. Maybe there will be a free light version.

 

[imploder]

Thanks for the credits, guys!
I was not sure if I am on the right way...until I decoded today Mike Oldfield's Omadawn from the boxed quad mix...unbelievable, how clear everything stands in the room (OK, I listened very, very loud...).
So...decode everything you like and know very good to compare...and enjoy like I did just right now. I have only the problem that my wife gets a little disappointed, I have to slow down a little bit. But I am not sure if she has a chance now, the results are too amazing.
The credits belong to the authors of Cool Edit (now Adobe Audition), I think. Without the filters there this simple decoding process would not be possible until somebody has managed to program a simple VST plugin.
Yeah, just continiuing decoding, wife is in bed....

 

[imploder]

By the way: "Bergbauer" means "MountainFarmer". Hmmm. Cool name for a SQ decoding method invented in a cottage in the bavarian mountains...with DSL connection and Quad equipment... just joking about the picture somebody can get about me...

 

[kempfand]

I just tried this method on "Theme from shaft" by Isaac Hayes (using TP's settings in the 1st post), and it gives very good results indeed !

Congrats guys !

 

[imploder]

just found this:

http://www.mtsu.edu/~dsmitche/rim456/Quad/Quad_Formats.html

It means, that we decode SQ better than it ever was intended to be...
Nobody thought of a complete reversion of the channel mixdown.

My next step will be to decode QS. Only have to find fitting "Software", I mean recordings.

 

[QUADradial]

So it's the Mountain Farmer's SQ decoding method then!

Tab