Yes, the Soul Box CD is SQ encoded. I also have Soul Box on a 2 SQ LP set, which is labeled as Quad, and a 2 Q8 set.
CTI/Kudu did several other Quad titles:
GEORGE BENSON - I have an SQ labeled LP of this.
Body Talk. CTI CT-6033 [previously CTSQ-6033] (SQ), CTRQ-6033
(QR), CTQ8-6033 (Q8)
{Originally released in separate Quad and Stereo versions, Later
released in Quad only. The same number appears on the early stereo
version and on the later Quad-only version, which are distinguishable
by the SQ logo on the back side of the Quad-only album jacket.}
HANK CRAWFORD - I have an SQ labeled LP & Q8 of this.
Wildflower. Kuda KU-15 [previously KSQX-15] (SQ), KQRX-15 (QR),
KQ8X-15 (Q8)
{this title when originally released in quad and stereo had only the
words quadraphonic on the front cover and had a grey border around the
front cover. the spine also has the words quadraphonic.
{Originally released in separate Quad and Stereo versions, Later
released in Quad only. The same number appears on the early stereo
version and on the later Quad-only version, which are distinguishable
by the SQ logo on the back side of the Quad-only album jacket.}
EUMIR DEODATO - I have a SQ labeled LP, Q8 and SQ CD of Prelude and a Q8 and SQ CD of Deodato 2. I've heard the recently remastered CD's are NOT SQ encoded!
Deodato 2. CTI CT-6029 [previously CTSQ-6029] (SQ), CTRQ-6029
(QR), CTQ8-6029 (Q8), 4D-6 (CD4) [Japan]
Prelude. CTI CT-6021 [previously CTSQ-6029] (SQ), CTRQ-6029
(QR), CTQ8-6029 (Q8)
{Originally released in separate Quad and Stereo versions, Later
released in Quad only. The same number appears on the early stereo
version and on the later Quad-only version, which are distinguishable
by the SQ logo on the back side of the Quad-only album jacket.}
EUMIR DEODATO & AIRTO MOREIRA - I have a Q8 and a Japan SQ CD of this. THEY DON'T PLAY TOGETHER, it's a half and half live album.
Deodato / Airto in Concert. CTI CT-6041 [previously CTSQ-6041]
(SQ), CTRQ-6041 (QR), CTQ8-6041 (Q8), SR-3357 (SQ) [Japan]
{Originally released in separate Quad and Stereo versions, Later
released in Quad only. The same number appears on the early stereo
version and on the later Quad-only version, which are distinguishable
by the SQ logo on the back side of the Quad-only album jacket.}
{The only indication of quad on the Japanese version is SQ etched in run
out groove}
JOE FARRELL - I have an SQ LP of this. I've never seen a copy of this with an SQ labeled jacket.
* Penny Arcade. CTI 6034 (SQ)
{No indication of quad except "SQ"' prefix written in the run-out area on
both sides, other copies have the "Q" scratched out. Possible that not all
songs were mixed for SQ so company did not want to release as a quad record}
AIRTO MOREIRA [see also EUMIR DEODATO] - I have this on a Q8 and and SQ Japan CD. I also studied percussion with Airto, thanks to the kindness of Slingerland Drum folks.
Fingers. CTI CT-6028 [previously CTSQ-6028] (SQ), CTQR-6028 (QR),
CTQ8-6028 (Q8), King 4D-19 (CD4) [Japan]
{Originally released in separate Quad and Stereo versions, Later
released in Quad only. The same number appears on the early stereo
version and on the later Quad-only version, which are distinguishable
by the SQ logo on the back side of the Quad-only album jacket.}
{The title above was released only in quad, no stereo version known}
DON SEBESKY - I have a SQ labeled 2 LP issue of this.
Giant Box. CTI [2 LP] CTX-6031/32 [previously CTSQX-6031/32]
(SQ), CTRQX-6031/32 (QR), CTQ8X-6031/32 (Q8)
{Originally released in separate Quad and Stereo versions, Later
released in Quad only. The same number appears on the early stereo
version and on the later Quad-only version, which are distinguishable
by the SQ logo on the back side of the Quad-only album jacket.}
STANLEY TURRENTINE - I have a Q8 and SQ labeled LP of this.
Don't Mess with Mr. T. CTI CT-6030 [previously CTSQ-6030] (SQ),
CTRQ-6030 (QR), CT8Q-6030 (Q8)
{Originally released in separate Quad and Stereo versions, Later
released in Quad only. The same number appears on the early stereo
version and on the later Quad-only version, which are distinguishable
by the SQ logo on the back side of the Quad-only album jacket.}
To my recollection, these are the only CTI/Kudu Quads. IMHO, they're ALL GOOD. The George Benson is the one I like the least, even though I'm a Benson fan. Airto's Fingers and Deodato's Prelude are the best, at least musically.
Listings taken from Mark Anderson's Quad Discography.
AH...! That explains it! I have no clue about CTI or Kudu-chrome..
Did they do a lot of Quad records?
Yes Mistress..!
It feels like being back at school..!
Ps. Is your CD of Grover W. Jr.'s Soul Box SQ Quad encoded?