I'm about to mount a JVC RS57 w a Peerless PRG-UNV attached to a Peerless ACC 840 vibration dampening ceiling plate. I'm a little unsure about exactly how far I am going to drop it down and I seem to probably fall right into a gap in the Peerless extension column line (I've only seen a 6-9" adjustable and a 12-18" adjustable... I'll probably need about 10").
I've seen a few people advocate just buying threaded nipple tube at Home Depot and using that. Today I purchased a few varying lengths so I have some flexibility - 8", 10" and 12".
I noticed when looking at the installation manual for the ACC 840 that the Peerless extension columns have a slot cut into the tube threaded area so the locking screw can insert. On the PRG-UNV the screw simply jams against the threads.
Has anyone experienced any issues with not having the slot for the screw on the ceiling plate? My initial thought is that the slot is only there to guarantee it won't be unscrewed, which I view as very unlikely to happen.