[blownrx7]

I have a pair of ACI Saturn subwoofers that I purchased/assembled in 1990. I initially used them with a pair of Dahlquist DQ-10's and a Audio Control Richter Scale Series III crossover/equalizer. Each sub has 2-12" drivers arranged in a push-pull arrangement at the bottom of a tall (~4 ft) column . They were great for music but recently got a little out of sorts when I pressed them into service for the HT stuff. Lo and behold I discovered that the woofer surrounds were laying at the bottom - disintegrated.    
Right now, I am going the cheapest route possible and refoaming the surrounds. But, longer term, I was wondering if I could reuse the cabinets and replace the drivers or even make them active subs....
The cabinets are 13.5x14.5x 35" tall! They are extremely well-built so I feel "re-using" them is a viable option.
I was hoping some of you knowledgeable types might make a suggestion for my next step?
Stay with the refoamed woofers?
Put in new drivers? What are the popular/desired/best for low freq etc?
Stay with the push/pull configuration or go with std single driver?
Go active? Of course that opens up a whole buch of options.
My budget? Hmmm. I guess about $1000 to redo both units.
Thanks in advance for your help!

[Mike Dzurko]

Those are nice looking cabinets, oak? Let me give this one a bit of thought . . . thanks!

[blownrx7]

Yes, that's right - Oak.
Thanks! I eagerly await input.

[Rossd]

I did some checking for you. You have about 4 cu.ft. of internal volume
to play with. One possibility would be to install the guts of our
current Titan subs. We don't usually sell them without cabs, but if
you're interested, contact me through email and I'll do some
checking on availability/price. If you go that route, your cabinets will
be about twice as large as they should be. You'd have to fill up about
50% of the volume with Styrofoam or something similar. A pair of Titans
would be a major upgrade from what you have had.
If you want to research DIY, that large volume should give you some
flexibility with some of the newer 12" DIY drivers available. Probably
the best places to ask questions about those are the Lab Section on this
site, and the DIY area at Home Theater Forum.

[blownrx7]

Ross,
Thanks for the reply, you have email.

I did, in fact post my question on the HT DIY forum.
One interesting response I got suggested an Adire DPL12 driver:
http://www.adireaudio.com/TextPages/DPL12PageFrameText.htm

This is where my ignorance shows... The datasheet says it requires a Vas of 149liters (appx 5.2 cu ft) and talks a lot about dipole application and also mentions dual voice-coils.  
What are they talking about when they mention dipole? Are they referring to a driver at either end of the cabinet pointed in opposite directions (oppositie of the push-pull arrangement where the drivers actually face each other). And what do I do with dual voice-coils?  
Also, since my cabinets have appx 2.7 cuft of internal volume, will it work, or do I have to vent it?  If so, I would also need to know how big the vent tube would need to be... How do I determine that?

[Rossd]

A dipolar sub is an open sub without enclosure. As far as the Adire and
other raw sub units, you'd want to consult with the manufacturer and or
some of the expert DIY folks at sites like HT forum. They can help you
with specific applications, venting issues etc.

P.S. I will get back to you on the email.