OK, but on a truly discrete presentation, like the DVD-A and the track on 'The Collection', it doesn't end up sounding at all like a mono 'quad center'. My seat is in the 'quad center' (equal real or virtual distance from the four quad speakers, whicha re level matched). THe opening of 'For the Love of Money' sounds like....bass zigzagging diagonally. Highly directional.
'For The Love Of Money' doesn't feature any diagonally panned phantom center placements. The bass zigzagging diagonally actually makes logical sense, because each time the riff plays, it alternates between being bathed in reverb and being completely dry - so it goes front left (reverby) -> front right (dry) -> rear left (reverby) -> rear right (dry, where it stays for the remainder of the song). The net result is that the reverbed bass is confined to the left side of the room and the dry bass to the the right side.
Most of the other tracks on Ship Ahoy feature some diagonally derived 'quad center' placement:
1 Put Your Hands Together (bass guitar FL & SR)
2 Ship Ahoy (bass guitar FL & SR)
3 This Air I Breathe (backing vocals FL & SR during outro)
4 You Got Your Hooks In Me (low backing vocalist FL & SR)
5 For The Love Of Money (nothing 'quad center' as mentioned)
6 Now That We Found Love (bass drum & backing vocals FL & SR)
7 Don't Call Me Brother (low backing vocalist FL & SR)
8 People Keep Tellin' Me (backing vocals FL & SR)
If you don't have this disc, the Isley Bros. 'That Lady' track on the AF Collection disc is a good example of diagonally panned 'quad center' placement, the lead guitar is panned like that on the song, in the front left and rear right channels.
Regarding the SQ and 4-channel master tapes, both were created simultaneously from the same mixing session. They ran two tape decks - a 15ips 4-track for the discrete 4-channel master, and at the same time, the 4 channel outputs from the board were fed to an SQ encoder which was routed in to a 15ips 2-track tape deck for the SQ encoded master. When mixes were completed, safety copies of both the quad and SQ masters were made and stored in Sigma's vault, while the original masters went to the label. So presumably now Sony should have two copies of all the discrete masters of all the PIR quad releases, as their tape vault was cleaned out and safety masters were returned to parent labels (along with 6,000 unclaimed tapes going to Drexel University's audio archive) when the studio went out of business a decade or so ago.
The reason they didn't just make a 4-channel discrete master and then use it to create the SQ master (ie 4 channel deck -> SQ encoder -> 2 channel deck) was that CBS felt that the less number of tape generations and other things in the signal chain, the less chance there would be of anything interfering with the phase information that was inherent in the SQ encoding. To that end, the PIR LP's were mastered and cut flat, with little or no EQ and no compression at the behest of CBS - I guess you'd presume all the CBS subsidiary labels (Columbia, Epic, Blue Sky, etc.) were probably done this way if they were advising PIR to do that.
Sigma Sound did have the facility to monitor in real-time what their mixes sounded like decoded SQ (ie the routing would take the 4 channel discrete output, encode and decode it) but Arthur told me that they abandoned referring to it very quickly, because in his words, decoded SQ 'sounded weird' no matter how they mixed. So their working practice was basically to adhere to the rules CBS had set down for SQ (nothing placed rear center, and reverbs could only emanate from the same location as what was creating them, ie if you had reverb on drums, and drums were in the front, the drum reverb could only be in the front too) but they treated the discrete 4-channel master as the definitive mix. They didn't go back and listen to the SQ decode and then change the discrete mix to try and eke more out of the SQ decode - they understood SQ was a flawed system and treated the SQ master as sort of an "it is what it is" proposition.
Would very much welcome a fix if anyone knows how to balance it out?
