That crossover sheet was drawn up some years back by another member of the group and reflects owner input on what they observed in their crossovers. The capacitor values represent early-mid, late and Regnar values roughly in that order. R3 shows the different resistances observed from early-mid and late, but reverse of that. (5.6ohms was s/n 6000-8000, iirc, with 5.5ohms being the standard). Early crossovers were wired up fairly different and had the odd variation here and there as parts supply influenced some choices (such as a short run where two 40uF caps were used in lieu of a single 80uF and the like).
This is Dahlquist's final crossover schematic that came out sometime in the 1980s (the move from Freeport to Hauppauge occurred in 1980) and matches those seen in units on through to and above s/n 50000:
Caps should be replaced. Resistors are worth checking to make sure they're still good (they can get a bit toasty in these or fall apart over the years). The inductors don't need touching unless they're showing signs of being overheated and melting some (seen some examples like that). Upsizing the gauge to 'better' inductors can upset the balance of the series crossover by reducing the DCR too low. It's not so much an issue in parallel crossovers, but can be with a series setup like this.
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Aging issues with the Philips AD5060/W8 are certainly a concern. Rubber surrounds, much like caps, do not last forever (no matter what the Cliff Clavins on some forums maintain). They stiffen with age and that is not a reversible process. The very hokey attempts at fixing them you'll find in various online fora such as ArmorAll or even brake fluid (a solvent to rubber) only alter the compliance in unpredictable ways and nothing like to the original parameters. Manually manipulating them only induces cracks that again alters the compliance to something other than original. As Philips quit making them ~1985, there are no NOS options that aren't suffering from age as well. The AD5062/W8 is a drop-in replacement and, in fact, was what Dahlquist used the last couple of years of DQ-10 production after supplies of the AD5060 ran out and will be newer, but it isn't the most readily available and will be aging as well. Simply Speakers, however, does sell a refoam kit for the driver that should work:??It's not rubber, but that shouldn't impact much for the bandpass it's used in with the DQ-10. (The main differences between the two materials are more of an issue at higher frequencies where the different acoustic impedance matches and damping they present the cone impacts resonant and break-up behavior and so are chosen accordingly for the desired results. Foam is usually better at this than the rubber-esque options anyways and why it was and still is used in so many drivers.)
