I Have some material archived that "might" be encoded.
If anyone of the pros can give me some tips on how to tell using
the various tools, if a source is encoded.
Great topic.
My first thought is to contact the parties involved. Listening through a decoder or viewing on a scope can be deceiving due to the mixing methods used at the time quad was popular. And just because it does not sound good does not mean it was not encoded, could be poor mastering or engineering.
I always could tell an SQ encoded recording by and increase in the 250hz to 2k region. Do not know why, but when you compare to the stereo mix, that is where i heard a frequency difference.
QS also had a similar "muddy" sound to me when not decoded and compared to the stereo release.
Ambisonic UHJ does not have the same effect on me other than a wider image but stereo only counterparts are usually not available to compare too.
I am currently trying to figure out if the Spectrum 73 Who show is still SQ encoded. I have other incomplete sources of this show that are suposed to be from the KBPH reel to reels. Other than using the scripts on both versions and listening, is there anyway to tell? The original tapes of these shows were supposed to have been destroyed in a fire. Most modern CDs are remixes from the masters that weren't destroyed, so no SQ encoding. But the back label of this spectrum show does mention soundboard recording so?