Best viewed in "landscape" mode.
The "Large" Advent Speaker
The so-called "Large" Advent speaker, with its various acronyms, was originally simply "The Advent Speaker", when it was the only product made by the company.
There are essentially three generations of it: the "original", or "OLA", the "New Large Advent", or "NLA", which I have seen marked on the rear as the "A3", and the 5002/5012.
All three used ten-inch woofers that were similar in function, although different in appearance. The original uses a Masonite ring to mount the cone in a twelve-inch basket, and had an "inverted" surround to clear the grill. The "New" version has a custom-stamped basket that fits a 12" hole but supports the 10" cone/surround with metal. This woofer was continued in use for the 5002.
The first two used similar tweeters, often refered to as the "fried egg tweeter", with the first showing a raised mounting panel and the "NLA" version flush-mounted on a metal plate. The latter used Ferrofluid, and uses a different crossover. The 5002 has a plastic dome tweeter.
Here are some crossover diagrams. The first four are for the OLA - one shows the full "stock" configuration, with the switch and all parts, the other three show the circuit in reduced form for each switch position. The bottom two are the "New Large Advent" on the left, and the 5002/5012 on the right. They are all linked to more readable sized versions.
Key to Crossover Symbols and Component Values (in a new window)
When I make new crossovers for these speakers, I omit the switch and hard-wire the circuit in one configuration, usually the "normal" one. I don't mind building them in the "extended" or "decrease" setup, if asked to do so.
This shows one such assembly installed in a Large Advent. The parts are all mounted on my non-resonant board, with five-way gold-plated binding posts for the speaker wires. Note that I have retained the "off board" mounting of the woofer choke (to the left).
7 Kelsey Road, Lee, New Hampshire 03861