I know that this thread is a bit dated, but I would suggest that "spkrdtr" is incorrect. I own four AR-6 speakers, all purchased from the original owner - who was quite specific in telling me that he made no modifications to them - and each of which has a zobel circuit glued to the woofer.
Further, there are several threads on the Classic Speaker Pages site referencing this design, which also includes a three-position switch on the tweeter circuit. This version of the AR-6 uses a woofer with a ceramic magnet, and has a 10uf cap in the tweeter circuit (along with two 3 ohm resistors in the switch portion of the circuit), and a 880mH coil, plus the 10 ohm resistor/24uf cap zobel, in the woofer circuit.
This is one of the so-called European versions of the AR-6. Some of the AR experts on CSP suggest that bypassing all elements of the crossover except for the tweeter cap, and replacing it with a 6uf cap, produces a much better sounding speaker. In this scenario, I assume that you could choose to leave the switch circuit in place to allow fine-tuning of the tweeter's response.
From what I have read, a later production version of the AR-6 used precisely this crossover (that is, a simple 6uf cap), but with a two position switch.
