Eurorack Quad Setup and Shakmat Aeolus Demo (Quadraphonic Quark Encoded)

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I also wanted to thank you for this and the quark decode how-to that you posted. I coincidentally started the year wanting to try more quad in my Eurorack, and you've provided a good focus for some of those efforts.

And congrats on the new album release, Franck!
Many thanks most appreciated. Please share what you do in quad, we can learn from each others.
 
Interesting! I have a small 84HP Eurorack rig (2 VCOs, 2 VCAs, 2 EGs, 1 LP VCF and a single LFO) and have been hand-encoding things to EV-4 using Audacity (simplest matrix to work with). I'll have to look into your work and QUARK some more!

I always felt that there should have been at least one consumer encoding standard for home/semi-pro musicians back in the day. It wouldn't have taken much for a company like Electro-Voice to take a few op amps and make a home EV-4 encoder (well actually you could have done it in the mixing console if you were clever enough).
 
Interesting! I have a small 84HP Eurorack rig (2 VCOs, 2 VCAs, 2 EGs, 1 LP VCF and a single LFO) and have been hand-encoding things to EV-4 using Audacity (simplest matrix to work with). I'll have to look into your work and QUARK some more!

I always felt that there should have been at least one consumer encoding standard for home/semi-pro musicians back in the day. It wouldn't have taken much for a company like Electro-Voice to take a few op amps and make a home EV-4 encoder (well actually you could have done it in the mixing console if you were clever enough).
There are a few demo videos on where you can get quark: Download - QUARK

It is not overly complicated, you do a quadraphonic project (in Logic Pro) and on your master track you get quark to encode it to 2 channels.

Glad you get into music in space.

Some encoders have more issues than others, not sure which ones, but some common positions for a sound would cancel it once encoded.
 
Interesting! I have a small 84HP Eurorack rig (2 VCOs, 2 VCAs, 2 EGs, 1 LP VCF and a single LFO) and have been hand-encoding things to EV-4 using Audacity (simplest matrix to work with). I'll have to look into your work and QUARK some more!

I always felt that there should have been at least one consumer encoding standard for home/semi-pro musicians back in the day. It wouldn't have taken much for a company like Electro-Voice to take a few op amps and make a home EV-4 encoder (well actually you could have done it in the mixing console if you were clever enough).
Involve Audio have the Evaluation Encoder module, which encodes in QS. It's inexpensive, very easy to use, and and does a terrific job of encoding. It's perfect for the hone experimenter.
 
I've been toying with the idea of getting a 90 HP Eurorack to supplement my bank of semimodulers; this definitely adds to my interest! I'll check this out. The Basimilus Iteritas line (and of course the must-have Maths) make it so attractive, and now this. . . .

If only the surround hobby wasn't so expensive already, sigh.
 
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shakmat aeolus seeds.jpg

I got mine!
 
Involve Audio have the Evaluation Encoder module, which encodes in QS. It's inexpensive, very easy to use, and and does a terrific job of encoding. It's perfect for the hone experimenter.
A little pricey for what it is though. I have Stefan Hotto's encoder Java applet somewhere on an external HD I use from time to time. I don't see why inexpensive software can't be used in this application compared to hardware. After all, Involve Audio's encoder and decoders are just glorified low powered computers running custom software anyway.

Encoding EV-4 in Audacity is not that hard to do. Yeah yeah I know it's not everyone's beloved QS but for me it's quick, simple, and can be decoded using anything from a passive decoder box to QS with good enough results. I'm more of an ambient quad guy rather than a 'I demand four perfect discrete signals in m'speakers, dammit!' person so I don't mind the lack of channel separation. ;)

Code:
Split the front and rear final tracks to mono
Duplicate those four mono tracks (four will be used for LT, the other four for RT)
Rename all eight mono tracks using their proper speaker position (LF, RF, LB, RB)
Following the encoding parameters given by Leonard Feldman in 'Four Channel Sound':
    For LT
        Keep LF the same
        Reduce RF by about 10.5dB ((log(0.3) * 20))
        Keep LB the same
        Reduce RB by about 6dB ((log(0.5) * 20) and invert it
        Mix these four tracks down to LT
    For RT
        Keep RF the same
        Reduce LF by about 10.5dB ((log(0.3) * 20))
        Keep RB the same
        Reduce LB by about 6dB ((log(0.5) * 20) and invert it
        Mix these four tracks down to RT
Rejoin to stereo
 
I'm about $500 into this Eurorack setup...but I'm still 4 cables short of testing the Shakmat Aoleus Seeds out. This weekend hopefully I get amazing results.
 
I'm about $500 into this Eurorack setup...but I'm still 4 cables short of testing the Shakmat Aoleus Seeds out. This weekend hopefully I get amazing results.
Like everything it takes a bit of time to get to Magical, but I welcome you in the quadraphonic space and looking forward to hear what you make.
 
https://www.quadraphonicquad.com/fo...12-e-w-mag-scheiber-matrix-quad-system.30082/
The Scheiber matrix is QS matrix like, but without 90 degree phase shifts, it should be easier to implement in software (or with a mixing board and some phase reversals) than QS.

I haven't worked thru the math of Scheiber encode/QS decode, but it seems like it would be almost indistinguishable from QS encode/decode.

As with QS, the Scheiber matrix could also be decoded with Dolby Pro-Logic decoder(s) and the simple DynaQuad speaker matrix.


Kirk Bayne
 
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