Identifying QS- & SQ-Encoded CDs and Digital Files

[timalin]

Hi.

I have a large collection of CDs and lossless downloads, including many that saw matrix-encoded quad release - sometimes I have multiple masters of the same titles. Some of those are bound to be quad-encoded and I would like to have a go at decoding them for quad playback.

What is the quickest or easiest way to identify correctly whether a release is quad-encoded, given that I'm new to the subject and may be susceptible to false positives?

Is it possible to decode on the fly for the purposes of identification, using a PC, or will I have to go down the Adobe Audition route as a first resort?

Thanks.

 

[Franklin]

That's a good question. A possible problem is that some stereo mixes seem to give interesting results in quad... If you are trying to differentiate between different masters of the same track, there should be some mix differences when played in stereo. SQ will probably sound a bit wierd and phasey. You could just rip a single track and process that. I tried that recently with McCartney's Ram and came to the conclusion it was not a "secret quad" as it did not decode particularly well in either QS or SQ, in my humble opinion of course.

 

[timalin]

Thanks for the response. What do you mean by "secret quad"? I would have presumed that referred to an album that did decode well in QS or SQ, or one of the other matrix systems.

I know that there are secret quad albums like a number of the Beach Boys Brother Records albums, where the regular stereo mixes were encoded (albeit in DY).

I had planned to go through all the QS- and SQ-encoded LPs on Discogs that I have in digital format, and to run through them as quickly as possible, ideally on the fly, to check for quad. It sounds from what you're saying that it's something that would take a long time and would be best cross-referenced with a non-encoded edition (what if both versions I have are encoded?)

I just wondered how the experts knew what to look for and how to avoid false positives. I'm sure I've got some hidden quad waiting to be discovered.

 

[Franklin]

What do you mean by "secret quad"?

Pretty much as you understand it, which is an album released in quad, but with no indication on the sleeve or label, etc. Some have suggested Ram was a QS encoding but not announced as EMI went with SQ, but I don't think that's the case. (I actually thought it decoded better in SQ just using the first track.) There is a thread here somewhere about CDs with matrix encoding: Mike Oldfield's Boxed is one.

 

[quadsearcher]

That's a good question. A possible problem is that some stereo mixes seem to give interesting results in quad... If you are trying to differentiate between different masters of the same track, there should be some mix differences when played in stereo. SQ will probably sound a bit wierd and phasey. You could just rip a single track and process that. I tried that recently with McCartney's Ram and came to the conclusion it was a "secret quad" as it did not decode particularly well in either QS or SQ, in my humble opinion of course.

Do you mean you concluded it was NOT a "secret quad"?

 

[Franklin]

Oops - that's exactly what I meant! Will correct if I can!