Klipsch KPT-8000-M Manuel D'installation page 11

SURROUND SPEAKER MOUNTING
1.125" length screws allow for a maximum bracket thickness
of 0.75" (19.05 mm).
If using bracket other than Soundfold SB-6 or SB-7 then exceeding max
bracket thickness requires screw substitution. The length of the screw
must accommodate a minimum 0.3125" (7.94 mm) and a maxmimum 1"
(25.4 mm) thread engagement between screw and surround speaker.
All manuals and user guides at all-guides.com
Must use!
1.125" (2.86 cm)
1/4-20 x 1.125 UNC 2A
Speaker Bracket Thickness
0.75" length screws allow for a maximum bracket thickness
of 0.375" (9.53 mm).
If using bracket other than Soundfold SB-6 or SB-7 then exceeding max
bracket thickness requires screw substitution. The length of the screw
must accommodate a minimum 0.3125" (7.94 mm) and a maxmimum
19/32" (15.08 mm) thread engagement between screw and Angled Insert.
Must use!
.75" (1.9 cm)
1/4-20 x 0.75 UNC 2A
Speaker Bracket Thickness