You MUST remove the studs from the driver.
The pockets in the mounting face of the horn are only deep enough to accept the head of a bolt, NOT a stud and nut.
It's 14 degrees F here this morning, when it warms up a bit, i'll dig thru storage and post a pic of the factory setup where the plate...
Assuming you mean QSC amplifiers, those models have no business going below 8 ohms when bridged, you'll let the magic smoke out.
Most versions of 802 have an impedance curve that dips to ~3 ohms across a portion of the bass range. Very few amplifiers will be happy with that load in bridged mode.
I guess i dropped the ball on the "B" part of your question.
The answer in a word is compression.
Many of the same benefits and attributes that are characteristic of high frequency compression drivers are also true across at least a portion of the BW of a suitable low frequency transducer...
In Altec circles it's called a constrained throat.
JBL fanboys will call it a Perkins spec in honor of Cal Perkins, the designer of the 4550 and 4560.
https://fohonline.com/featured/in-memoriam-cal-perkins-1942-2022/
Comes from a series of very heavy duty, low noise gear. See page 10 here: https://www.preservationsound.com/wp-content/uploads/2011/02/AltecFullLine1968.pdf
902 has a response that's shifted an octave upward from the 800 series drivers it replaced. Don't cross it below 1200hz.
The model N-1201 network would be an excellent choice giving you precisely a circa 1980 A7X load.
Altec part number 034633 was the woofer used in model 8 series II, model 14, 9842 monitor, and the LF-2 subwoofer. 033785 was the woofer used in model 9 II, model 15 II, and Santana II.
Once upon a time, Electori, a Japanese importer was receiving a supply of salesman model VOTTs that were loaded with 405's, no HF element.
Whether they were actually made by Altec or not remains a mystery.
https://www.audioheritage.org/vbulletin/showthread.php?10185-mini-Altec-Voice-of-the-Theater
Totally agree.
The metal lightning bolt logo came on gear.
RCA would have applied it front AND CENTER.
An accessory box would have used a water slide or decal.
Series I and II, and model 800 industrial used 8 ohm, cloth surround drivers made by CTS, wired 3 x 3 series/parallel.
Same 8 ohm drivers were used in several small pro monitors back in the day, CGM, Bullfrog, Galaxy Hot spot, etc..